54 results on '"Samani, NJ"'
Search Results
2. Polygenic risk score adds to a clinical risk score in the prediction of cardiovascular disease in a clinical setting.
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Samani NJ, Beeston E, Greengrass C, Riveros-McKay F, Debiec R, Lawday D, Wang Q, Budgeon CA, Braund PS, Bramley R, Kharodia S, Newton M, Marshall A, Krzeminski A, Zafar A, Chahal A, Heer A, Khunti K, Joshi N, Lakhani M, Farooqi A, Plagnol V, Donnelly P, Weale ME, and Nelson CP
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- Humans, Middle Aged, Female, Male, Risk Assessment methods, Aged, Adult, Case-Control Studies, Risk Factors, Heart Disease Risk Factors, Multifactorial Inheritance genetics, Genetic Risk Score, Cardiovascular Diseases genetics, Cardiovascular Diseases epidemiology
- Abstract
Background and Aims: A cardiovascular disease polygenic risk score (CVD-PRS) can stratify individuals into different categories of cardiovascular risk, but whether the addition of a CVD-PRS to clinical risk scores improves the identification of individuals at increased risk in a real-world clinical setting is unknown., Methods: The Genetics and the Vascular Health Check Study (GENVASC) was embedded within the UK National Health Service Health Check (NHSHC) programme which invites individuals between 40-74 years of age without known CVD to attend an assessment in a UK general practice where CVD risk factors are measured and a CVD risk score (QRISK2) is calculated. Between 2012-2020, 44,141 individuals (55.7% females, 15.8% non-white) who attended an NHSHC in 147 participating practices across two counties in England were recruited and followed. When 195 individuals (cases) had suffered a major CVD event (CVD death, myocardial infarction or acute coronary syndrome, coronary revascularisation, stroke), 396 propensity-matched controls with a similar risk profile were identified, and a nested case-control genetic study undertaken to see if the addition of a CVD-PRS to QRISK2 in the form of an integrated risk tool (IRT) combined with QRISK2 would have identified more individuals at the time of their NHSHC as at high risk (QRISK2 10-year CVD risk of ≥10%), compared with QRISK2 alone., Results: The distribution of the standardised CVD-PRS was significantly different in cases compared with controls (cases mean score .32; controls, -.18, P = 8.28×10-9). QRISK2 identified 61.5% (95% confidence interval [CI]: 54.3%-68.4%) of individuals who subsequently developed a major CVD event as being at high risk at their NHSHC, while the combination of QRISK2 and IRT identified 68.7% (95% CI: 61.7%-75.2%), a relative increase of 11.7% (P = 1×10-4). The odds ratio (OR) of being up-classified was 2.41 (95% CI: 1.03-5.64, P = .031) for cases compared with controls. In individuals aged 40-54 years, QRISK2 identified 26.0% (95% CI: 16.5%-37.6%) of those who developed a major CVD event, while the combination of QRISK2 and IRT identified 38.4% (95% CI: 27.2%-50.5%), indicating a stronger relative increase of 47.7% in the younger age group (P = .001). The combination of QRISK2 and IRT increased the proportion of additional cases identified similarly in women as in men, and in non-white ethnicities compared with white ethnicity. The findings were similar when the CVD-PRS was added to the atherosclerotic cardiovascular disease pooled cohort equations (ASCVD-PCE) or SCORE2 clinical scores., Conclusions: In a clinical setting, the addition of genetic information to clinical risk assessment significantly improved the identification of individuals who went on to have a major CVD event as being at high risk, especially among younger individuals. The findings provide important real-world evidence of the potential value of implementing a CVD-PRS into health systems., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)
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- 2024
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3. Genetic analyses identify brain structures related to cognitive impairment associated with elevated blood pressure.
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Siedlinski M, Carnevale L, Xu X, Carnevale D, Evangelou E, Caulfield MJ, Maffia P, Wardlaw J, Samani NJ, Tomaszewski M, Lembo G, Holmes MV, and Guzik TJ
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- Humans, Blood Pressure, Brain, Mendelian Randomization Analysis methods, Genome-Wide Association Study, Polymorphism, Single Nucleotide genetics, Hypertension complications, Hypertension genetics, Cognitive Dysfunction genetics
- Abstract
Background and Aims: Observational studies have linked elevated blood pressure (BP) to impaired cognitive function. However, the functional and structural changes in the brain that mediate the relationship between BP elevation and cognitive impairment remain unknown. Using observational and genetic data from large consortia, this study aimed to identify brain structures potentially associated with BP values and cognitive function., Methods and Results: Data on BP were integrated with 3935 brain magnetic resonance imaging-derived phenotypes (IDPs) and cognitive function defined by fluid intelligence score. Observational analyses were performed in the UK Biobank and a prospective validation cohort. Mendelian randomisation (MR) analyses used genetic data derived from the UK Biobank, International Consortium for Blood Pressure, and COGENT consortium. Mendelian randomisation analysis identified a potentially adverse causal effect of higher systolic BP on cognitive function [-0.044 standard deviation (SD); 95% confidence interval (CI) -0.066, -0.021] with the MR estimate strengthening (-0.087 SD; 95% CI -0.132, -0.042), when further adjusted for diastolic BP. Mendelian randomisation analysis found 242, 168, and 68 IDPs showing significant (false discovery rate P < 0.05) association with systolic BP, diastolic BP, and pulse pressure, respectively. Most of these IDPs were inversely associated with cognitive function in observational analysis in the UK Biobank and showed concordant effects in the validation cohort. Mendelian randomisation analysis identified relationships between cognitive function and the nine of the systolic BP-associated IDPs, including the anterior thalamic radiation, anterior corona radiata, or external capsule., Conclusion: Complementary MR and observational analyses identify brain structures associated with BP, which may be responsible for the adverse effects of hypertension on cognitive performance., Competing Interests: Conflict of interest The authors have declared the following conflict of interest: institutional support from the Italian Ministry of Health (G.L.); institutional support from the UK Dementia Research Institute which is funded by MRC, Alzheimer’s Society and Alzheimer’s Research UK, Stroke Association, BBSRC, Fondation Leducq, EU Horizon 2020, Alzheimer’s Research UK, and Alzheimer’s Society (J.W.); European Stroke Organisation Chair of Guideline on Cerebral Small Vessel Disease and European Stroke Organisation Chair of Annual Conference 2021 and 2022 (J.W.); British Heart Foundation (J.W., TJG, P.M., and M.V.H.); and Boehringer Ingelheim (consulting fees) and 23andMe (stock) (M.V.H.). Other authors have declared that no conflict of interest exists., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)
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- 2023
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4. Albuminuria as a marker of systemic congestion in patients with heart failure.
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Boorsma EM, Ter Maaten JM, Damman K, van Essen BJ, Zannad F, van Veldhuisen DJ, Samani NJ, Dickstein K, Metra M, Filippatos G, Lang CC, Ng L, Anker SD, Cleland JG, Pellicori P, Gansevoort RT, Heerspink HJL, Voors AA, and Emmens JE
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- Humans, Prognosis, Biomarkers urine, Natriuretic Peptide, Brain, Hospitalization, Peptide Fragments, Stroke Volume physiology, Albuminuria diagnosis, Albuminuria urine, Heart Failure
- Abstract
Aims: Albuminuria is common in patients with heart failure and associated with worse outcomes. The underlying pathophysiological mechanism of albuminuria in heart failure is still incompletely understood. The association of clinical characteristics and biomarker profile with albuminuria in patients with heart failure with both reduced and preserved ejection fractions were evaluated., Methods and Results: Two thousand three hundred and fifteen patients included in the index cohort of BIOSTAT-CHF were evaluated and findings were validated in the independent BIOSTAT-CHF validation cohort (1431 patients). Micro-albuminuria and macro-albuminuria were defined as urinary albumincreatinine ratio (UACR) 30 mg/gCr and 300 mg/gCr in spot urines, respectively. The prevalence of micro- and macro-albuminuria was 35.4 and 10.0, respectively. Patients with albuminuria had more severe heart failure, as indicated by inclusion during admission, higher New York Heart Association functional class, more clinical signs and symptoms of congestion, and higher concentrations of biomarkers related to congestion, such as biologically active adrenomedullin, cancer antigen 125, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) (all P 0.001). The presence of albuminuria was associated with increased risk of mortality and heart failure (re)hospitalization in both cohorts. The strongest independent association with log UACR was found for log NT-proBNP (standardized regression coefficient 0.438, 95 confidence interval 0.350.53, P 0.001). Hierarchical clustering analysis demonstrated that UACR clusters with markers of congestion and less with indices of renal function. The validation cohort yielded similar findings., Conclusion: In patients with new-onset or worsening heart failure, albuminuria is consistently associated with clinical, echocardiographic, and circulating biomarkers of congestion., Competing Interests: Conflict of interest: K.D.: Consultancy fees Abbott, Boehringer Ingelheim, AstraZeneca; F.Z.: for Actelion, Amgen, Applied Theraputics, AstraZeneca, Bayer, Boehringer, Boston Scientific, Cardior, Cellprothera, Cereno, CEVA, CVRx, G3Pharmaceutical, Merck, Novartis, NovoNordisk, Vifor-Fresenius. Founder of CardioRenal and CVCT; M.M.: personal fees of minimal amounts in the last 3 years: from Actelion as member of Data Monitoring Committeee of sponsored clinical trials; from Amgen, Livanova, Servier, and Vifor pharma as member of Executive Committees of sponsored clinical trials; from AstraZeneca, Abbott vascular, Bayer, Boheringer Ingelhelm, and Edwards Therapeutics for participation to advisory boards and/or speeches at sponsored meetings; S.D.A.: fees from Abbott, Actimed, Bayer, Boehringer Ingelheim, Cardiac Dimension, Cordio, Impulse Dynamics, Novartis, Occlutech, Servier, and Vifor Pharma, and grant support from Abbott and Vifor Pharma., (The Author(s) 2022. Published by Oxford University Press on behalf of European Society of Cardiology.)
- Published
- 2023
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5. Professor Anthony H. Gershlick.
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McCann GP, Curzen NP, Ray SG, and Samani NJ
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- 2021
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6. Hypertension and renin-angiotensin system blockers are not associated with expression of angiotensin-converting enzyme 2 (ACE2) in the kidney.
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Jiang X, Eales JM, Scannali D, Nazgiewicz A, Prestes P, Maier M, Denniff M, Xu X, Saluja S, Cano-Gamez E, Wystrychowski W, Szulinska M, Antczak A, Byars S, Skrypnik D, Glyda M, Król R, Zywiec J, Zukowska-Szczechowska E, Burrell LM, Woolf AS, Greenstein A, Bogdanski P, Keavney B, Morris AP, Heagerty A, Williams B, Harrap SB, Trynka G, Samani NJ, Guzik TJ, Charchar FJ, and Tomaszewski M
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- Adrenergic beta-Antagonists pharmacology, Adult, Age Factors, Aged, Angiotensin Receptor Antagonists pharmacology, Angiotensin-Converting Enzyme Inhibitors pharmacology, Animals, COVID-19 complications, Diuretics pharmacology, Female, Gene Expression Profiling, Glomerular Filtration Rate, Humans, Kidney Tubules physiopathology, Male, Middle Aged, Rats, Rats, Inbred SHR, SARS-CoV-2, Sequence Analysis, RNA, Sex Factors, Transcriptome drug effects, Angiotensin-Converting Enzyme 2 genetics, Angiotensin-Converting Enzyme 2 metabolism, Antihypertensive Agents pharmacology, Hypertension drug therapy, Hypertension genetics, Kidney Tubules metabolism, Lung metabolism, Renin-Angiotensin System drug effects
- Abstract
Aims: Angiotensin-converting enzyme 2 (ACE2) is the cellular entry point for severe acute respiratory syndrome coronavirus (SARS-CoV-2)-the cause of coronavirus disease 2019 (COVID-19). However, the effect of renin-angiotensin system (RAS)-inhibition on ACE2 expression in human tissues of key relevance to blood pressure regulation and COVID-19 infection has not previously been reported., Methods and Results: We examined how hypertension, its major metabolic co-phenotypes, and antihypertensive medications relate to ACE2 renal expression using information from up to 436 patients whose kidney transcriptomes were characterized by RNA-sequencing. We further validated some of the key observations in other human tissues and/or a controlled experimental model. Our data reveal increasing expression of ACE2 with age in both human lungs and the kidney. We show no association between renal expression of ACE2 and either hypertension or common types of RAS inhibiting drugs. We demonstrate that renal abundance of ACE2 is positively associated with a biochemical index of kidney function and show a strong enrichment for genes responsible for kidney health and disease in ACE2 co-expression analysis., Conclusion: Our results indicate that neither hypertension nor antihypertensive treatment is likely to alter the expression of the key entry receptor for SARS-CoV-2 in the human kidney. Our data further suggest that in the absence of SARS-CoV-2 infection, kidney ACE2 is most likely nephro-protective but the age-related increase in its expression within lungs and kidneys may be relevant to the risk of SARS-CoV-2 infection., (© The Author(s) 2020. Published by Oxford University Press on behalf of the European Society of Cardiology.)
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- 2020
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7. Chronic infarct size after spontaneous coronary artery dissection: implications for pathophysiology and clinical management.
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Al-Hussaini A, Abdelaty AMSEK, Gulsin GS, Arnold JR, Garcia-Guimaraes M, Premawardhana D, Budgeon C, Wood A, Natarajan N, Mangion K, Rakhit R, Hoole SP, Johnson TW, Berry C, Hudson I, Gershlick AH, Ladwiniec A, Kovac J, Squire I, Samani NJ, Plein S, McCann GP, and Adlam D
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- Aged, Case-Control Studies, Contrast Media, Coronary Vessels, Dissection, Female, Gadolinium, Humans, Male, Ventricular Function, Left, Percutaneous Coronary Intervention, ST Elevation Myocardial Infarction diagnostic imaging
- Abstract
Aims: To report the extent and distribution of myocardial injury and its impact on left ventricular systolic function with cardiac magnetic resonance imaging (CMR) following spontaneous coronary artery dissection (SCAD) and to investigate predictors of myocardial injury., Methods and Results: One hundred and fifty-eight angiographically confirmed SCAD-survivors (98% female) were phenotyped by CMR and compared in a case-control study with 59 (97% female) healthy controls (44.5 ± 8.4 vs. 45.0 ± 9.1 years). Spontaneous coronary artery dissection presentation was with non-ST-elevation myocardial infarction in 95 (60.3%), ST-elevation myocardial infarction (STEMI) in 52 (32.7%), and cardiac arrest in 11 (6.9%). Left ventricular function in SCAD-survivors was generally well preserved with small reductions in ejection fraction (57 ± 7.2% vs. 60 ± 4.9%, P < 0.01) and increases in left ventricular dimensions (end-diastolic volume: 85 ± 14 mL/m2 vs. 80 ± 11 mL/m2, P < 0.05; end-systolic volume: 37 ± 11 mL/m2 vs. 32 ± 7 mL/m2, P <0.01) compared to healthy controls. Infarcts were small with few large infarcts (median 4.06%; range 0-30.9%) and 39% having no detectable late gadolinium enhancement (LGE). Female SCAD patients presenting with STEMI had similar sized infarcts to female Type-1 STEMI patients age <75 years. Multivariate modelling demonstrated STEMI at presentation, initial TIMI 0/1 flow, multivessel SCAD, and a Beighton score >4 were associated with larger infarcts [>10% left ventricular (LV) mass]., Conclusion: The majority of patients presenting with SCAD have no or small infarctions and preserved ejection fraction. Patients presenting with STEMI, TIMI 0/1 flow, multivessel SCAD and those with features of connective tissue disorders are more likely to have larger infarcts., (© The Author(s) 2020. Published by Oxford University Press on behalf of the European Society of Cardiology.)
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- 2020
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8. Evidence for Accelerated Biological Aging in Young Adults with Prader-Willi Syndrome.
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Donze SH, Codd V, Damen L, Goedegebuure WJ, Denniff M, Samani NJ, van der Velden JAEM, and Hokken-Koelega ACS
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- Adolescent, Adult, Aging, Premature genetics, Case-Control Studies, Cross-Sectional Studies, Female, Follow-Up Studies, Humans, Incidence, Male, Netherlands epidemiology, Prognosis, Telomere genetics, Young Adult, Aging, Premature epidemiology, Prader-Willi Syndrome physiopathology
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Objective: Adults with Prader-Willi syndrome (PWS) are at increased risk of developing age-associated diseases early in life and, like in premature aging syndromes, aging might be accelerated. We investigated leukocyte telomere length (LTL), a marker of biological age, in young adults with PWS and compared LTL to healthy young adults of similar age. As all young adults with PWS were treated with growth hormone (GH), we also compared LTL in PWS subjects to GH-treated young adults born short for gestational age (SGA)., Design: Cross-sectional study in age-matched young adults; 47 with PWS, 135 healthy, and 75 born SGA., Measurements: LTL measured by quantitative polymerase chain reaction, expressed as telomere/single copy gene ratio., Results: Median (interquartile range) LTL was 2.6 (2.4-2.8) at a median (interquartile range) age of 19.2 (17.7-21.3) years in PWS, 3.1 (2.9-3.5) in healthy young adults and 3.1 (2.8-3.4) in the SGA group. Median LTL in PWS was significantly lower compared to both control groups (P < .01). In PWS, a lower LTL tended to be associated with a lower total IQ (r = 0.35, P = .08). There was no association between LTL and duration of GH treatment, cumulative GH dose, or several risk factors for type 2 diabetes mellitus or cardiovascular disease., Conclusions: Young adults with PWS have significantly shorter median LTL compared to age-matched healthy young adults and GH-treated young adults born SGA. The shorter telomeres might play a role in the premature aging in PWS, independent of GH. Longitudinal research is needed to determine the influence of LTL on aging in PWS., (© Endocrine Society 2019.)
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- 2020
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9. Circulating plasma concentrations of angiotensin-converting enzyme 2 in men and women with heart failure and effects of renin-angiotensin-aldosterone inhibitors.
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Sama IE, Ravera A, Santema BT, van Goor H, Ter Maaten JM, Cleland JGF, Rienstra M, Friedrich AW, Samani NJ, Ng LL, Dickstein K, Lang CC, Filippatos G, Anker SD, Ponikowski P, Metra M, van Veldhuisen DJ, and Voors AA
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- Aged, Angiotensin-Converting Enzyme 2, Betacoronavirus, COVID-19, Coronavirus Infections, Europe, Female, Humans, Male, Middle Aged, Pandemics, Pneumonia, Viral, SARS-CoV-2, Sex Factors, Angiotensin Receptor Antagonists therapeutic use, Angiotensin-Converting Enzyme Inhibitors therapeutic use, Heart Failure blood, Mineralocorticoid Receptor Antagonists therapeutic use, Peptidyl-Dipeptidase A blood, Renin-Angiotensin System drug effects
- Abstract
Aims: The current pandemic coronavirus SARS-CoV-2 infects a wide age group but predominantly elderly individuals, especially men and those with cardiovascular disease. Recent reports suggest an association with use of renin-angiotensin-aldosterone system (RAAS) inhibitors. Angiotensin-converting enzyme 2 (ACE2) is a functional receptor for coronaviruses. Higher ACE2 concentrations might lead to increased vulnerability to SARS-CoV-2 in patients on RAAS inhibitors., Methods and Results: We measured ACE2 concentrations in 1485 men and 537 women with heart failure (index cohort). Results were validated in 1123 men and 575 women (validation cohort).The median age was 69 years for men and 75 years for women. The strongest predictor of elevated concentrations of ACE2 in both cohorts was male sex (estimate = 0.26, P < 0.001; and 0.19, P < 0.001, respectively). In the index cohort, use of ACE inhibitors, angiotensin receptor blockers (ARBs), or mineralocorticoid receptor antagonists (MRAs) was not an independent predictor of plasma ACE2. In the validation cohort, ACE inhibitor (estimate = -0.17, P = 0.002) and ARB use (estimate = -0.15, P = 0.03) were independent predictors of lower plasma ACE2, while use of an MRA (estimate = 0.11, P = 0.04) was an independent predictor of higher plasma ACE2 concentrations., Conclusion: In two independent cohorts of patients with heart failure, plasma concentrations of ACE2 were higher in men than in women, but use of neither an ACE inhibitor nor an ARB was associated with higher plasma ACE2 concentrations. These data might explain the higher incidence and fatality rate of COVID-19 in men, but do not support previous reports suggesting that ACE inhibitors or ARBs increase the vulnerability for COVID-19 through increased plasma ACE2 concentrations., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)
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- 2020
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10. Genetics of educational attainment and coronary risk in Mendelian randomization studies.
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Schunkert H, Erdmann J, Samani NJ, Deloukas P, and Zeng L
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- Heart, Polymorphism, Single Nucleotide, Genome-Wide Association Study, Mendelian Randomization Analysis
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- 2020
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11. Genetically modulated educational attainment and coronary disease risk.
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Zeng L, Ntalla I, Kessler T, Kastrati A, Erdmann J, Danesh J, Watkins H, Samani NJ, Deloukas P, and Schunkert H
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- Coronary Disease etiology, Female, Genetic Predisposition to Disease genetics, Genetic Variation genetics, Genome-Wide Association Study, Humans, Life Style, Male, Mendelian Randomization Analysis, Polymorphism, Single Nucleotide genetics, Risk Factors, Coronary Disease genetics, Educational Status
- Abstract
Aims: Genetic disposition and lifestyle factors are understood as independent components underlying the risk of multiple diseases. In this study, we aim to investigate the interplay between genetics, educational attainment-an important denominator of lifestyle-and coronary artery disease (CAD) risk., Methods and Results: Based on the effect sizes of 74 genetic variants associated with educational attainment, we calculated a 'genetic education score' in 13 080 cases and 14 471 controls and observed an inverse correlation between the score and risk of CAD [P = 1.52 × 10-8; odds ratio (OR) 0.79, 95% confidence interval (CI) 0.73-0.85 for the higher compared with the lowest score quintile]. We replicated in 146 514 individuals from UK Biobank (P = 1.85 × 10-6) and also found strong associations between the 'genetic education score' with 'modifiable' risk factors including smoking (P = 5.36 × 10-23), body mass index (BMI) (P = 1.66 × 10-30), and hypertension (P = 3.86 × 10-8). Interestingly, these associations were only modestly attenuated by adjustment for years spent in school. In contrast, a model adjusting for BMI and smoking abolished the association signal between the 'genetic education score' and CAD risk suggesting an intermediary role of these two risk factors. Mendelian randomization analyses performed with summary statistics from large genome-wide meta-analyses and sensitivity analysis using 1271 variants affecting educational attainment (OR 0.68 for the higher compared with the lowest score quintile; 95% CI 0.63-0.74; P = 3.99 × 10-21) further strengthened these findings., Conclusion: Genetic variants known to affect educational attainment may have implications for a health-conscious lifestyle later in life and subsequently affect the risk of CAD., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2019
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12. Multiancestry Genome-Wide Association Study of Lipid Levels Incorporating Gene-Alcohol Interactions.
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de Vries PS, Brown MR, Bentley AR, Sung YJ, Winkler TW, Ntalla I, Schwander K, Kraja AT, Guo X, Franceschini N, Cheng CY, Sim X, Vojinovic D, Huffman JE, Musani SK, Li C, Feitosa MF, Richard MA, Noordam R, Aschard H, Bartz TM, Bielak LF, Deng X, Dorajoo R, Lohman KK, Manning AK, Rankinen T, Smith AV, Tajuddin SM, Evangelou E, Graff M, Alver M, Boissel M, Chai JF, Chen X, Divers J, Gandin I, Gao C, Goel A, Hagemeijer Y, Harris SE, Hartwig FP, He M, Horimoto ARVR, Hsu FC, Jackson AU, Kasturiratne A, Komulainen P, Kühnel B, Laguzzi F, Lee JH, Luan J, Lyytikäinen LP, Matoba N, Nolte IM, Pietzner M, Riaz M, Said MA, Scott RA, Sofer T, Stančáková A, Takeuchi F, Tayo BO, van der Most PJ, Varga TV, Wang Y, Ware EB, Wen W, Yanek LR, Zhang W, Zhao JH, Afaq S, Amin N, Amini M, Arking DE, Aung T, Ballantyne C, Boerwinkle E, Broeckel U, Campbell A, Canouil M, Charumathi S, Chen YI, Connell JM, de Faire U, de las Fuentes L, de Mutsert R, de Silva HJ, Ding J, Dominiczak AF, Duan Q, Eaton CB, Eppinga RN, Faul JD, Fisher V, Forrester T, Franco OH, Friedlander Y, Ghanbari M, Giulianini F, Grabe HJ, Grove ML, Gu CC, Harris TB, Heikkinen S, Heng CK, Hirata M, Hixson JE, Howard BV, Ikram MA, Jacobs DR, Johnson C, Jonas JB, Kammerer CM, Katsuya T, Khor CC, Kilpeläinen TO, Koh WP, Koistinen HA, Kolcic I, Kooperberg C, Krieger JE, Kritchevsky SB, Kubo M, Kuusisto J, Lakka TA, Langefeld CD, Langenberg C, Launer LJ, Lehne B, Lemaitre RN, Li Y, Liang J, Liu J, Liu K, Loh M, Louie T, Mägi R, Manichaikul AW, McKenzie CA, Meitinger T, Metspalu A, Milaneschi Y, Milani L, Mohlke KL, Mosley TH, Mukamal KJ, Nalls MA, Nauck M, Nelson CP, Sotoodehnia N, O'Connell JR, Palmer ND, Pazoki R, Pedersen NL, Peters A, Peyser PA, Polasek O, Poulter N, Raffel LJ, Raitakari OT, Reiner AP, Rice TK, Rich SS, Robino A, Robinson JG, Rose LM, Rudan I, Schmidt CO, Schreiner PJ, Scott WR, Sever P, Shi Y, Sidney S, Sims M, Smith BH, Smith JA, Snieder H, Starr JM, Strauch K, Tan N, Taylor KD, Teo YY, Tham YC, Uitterlinden AG, van Heemst D, Vuckovic D, Waldenberger M, Wang L, Wang Y, Wang Z, Wei WB, Williams C, Wilson G, Wojczynski MK, Yao J, Yu B, Yu C, Yuan JM, Zhao W, Zonderman AB, Becker DM, Boehnke M, Bowden DW, Chambers JC, Deary IJ, Esko T, Farrall M, Franks PW, Freedman BI, Froguel P, Gasparini P, Gieger C, Horta BL, Kamatani Y, Kato N, Kooner JS, Laakso M, Leander K, Lehtimäki T, Magnusson PKE, Penninx B, Pereira AC, Rauramaa R, Samani NJ, Scott J, Shu XO, van der Harst P, Wagenknecht LE, Wang YX, Wareham NJ, Watkins H, Weir DR, Wickremasinghe AR, Zheng W, Elliott P, North KE, Bouchard C, Evans MK, Gudnason V, Liu CT, Liu Y, Psaty BM, Ridker PM, van Dam RM, Kardia SLR, Zhu X, Rotimi CN, Mook-Kanamori DO, Fornage M, Kelly TN, Fox ER, Hayward C, van Duijn CM, Tai ES, Wong TY, Liu J, Rotter JI, Gauderman WJ, Province MA, Munroe PB, Rice K, Chasman DI, Cupples LA, Rao DC, and Morrison AC
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- Adolescent, Adult, Aged, Cholesterol, HDL blood, Cholesterol, LDL blood, Female, Genome-Wide Association Study, Genotype, Humans, Life Style, Male, Middle Aged, Phenotype, Racial Groups, Triglycerides blood, Vascular Endothelial Growth Factor B, Young Adult, Alcohol Drinking epidemiology, Lipids blood
- Abstract
A person's lipid profile is influenced by genetic variants and alcohol consumption, but the contribution of interactions between these exposures has not been studied. We therefore incorporated gene-alcohol interactions into a multiancestry genome-wide association study of levels of high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. We included 45 studies in stage 1 (genome-wide discovery) and 66 studies in stage 2 (focused follow-up), for a total of 394,584 individuals from 5 ancestry groups. Analyses covered the period July 2014-November 2017. Genetic main effects and interaction effects were jointly assessed by means of a 2-degrees-of-freedom (df) test, and a 1-df test was used to assess the interaction effects alone. Variants at 495 loci were at least suggestively associated (P < 1 × 10-6) with lipid levels in stage 1 and were evaluated in stage 2, followed by combined analyses of stage 1 and stage 2. In the combined analysis of stages 1 and 2, a total of 147 independent loci were associated with lipid levels at P < 5 × 10-8 using 2-df tests, of which 18 were novel. No genome-wide-significant associations were found testing the interaction effect alone. The novel loci included several genes (proprotein convertase subtilisin/kexin type 5 (PCSK5), vascular endothelial growth factor B (VEGFB), and apolipoprotein B mRNA editing enzyme, catalytic polypeptide 1 (APOBEC1) complementation factor (A1CF)) that have a putative role in lipid metabolism on the basis of existing evidence from cellular and experimental models., (Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2019.)
- Published
- 2019
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13. Novel endotypes in heart failure: effects on guideline-directed medical therapy.
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Tromp J, Ouwerkerk W, Demissei BG, Anker SD, Cleland JG, Dickstein K, Filippatos G, van der Harst P, Hillege HL, Lang CC, Metra M, Ng LL, Ponikowski P, Samani NJ, van Veldhuisen DJ, Zannad F, Zwinderman AH, Voors AA, and van der Meer P
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- Adrenergic beta-Antagonists therapeutic use, Aged, Aged, 80 and over, Angiotensin-Converting Enzyme Inhibitors therapeutic use, Cluster Analysis, Female, Heart Failure epidemiology, Heart Failure mortality, Heart Failure physiopathology, Hospitalization, Humans, Male, Middle Aged, Natriuretic Peptide, Brain drug effects, Peptide Fragments drug effects, Phenotype, Practice Guidelines as Topic, Treatment Outcome, Biomarkers blood, Heart Failure drug therapy, Natriuretic Peptide, Brain metabolism, Peptide Fragments metabolism, Stroke Volume drug effects
- Abstract
Aims: We sought to determine subtypes of patients with heart failure (HF) with a distinct clinical profile and treatment response, using a wide range of biomarkers from various pathophysiological domains., Methods and Results: We performed unsupervised cluster analysis using 92 established cardiovascular biomarkers to identify mutually exclusive subgroups (endotypes) of 1802 patients with HF and reduced ejection fraction (HFrEF) from the BIOSTAT-CHF project. We validated our findings in an independent cohort of 813 patients. Based on their biomarker profile, six endotypes were identified. Patients with endotype 1 were youngest, less symptomatic, had the lowest N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels and lowest risk for all-cause mortality or hospitalization for HF. Patients with endotype 4 had more severe symptoms and signs of HF, higher NT-proBNP levels and were at highest risk for all-cause mortality or hospitalization for HF [hazard ratio (HR) 1.4; 95% confidence interval (CI) 1.1-1.8]. Patients with endotypes 2, 3, and 5 were better uptitrated to target doses of beta-blockers (P < 0.02 for all). In contrast to other endotypes, patients with endotype 5 derived no potential survival benefit from uptitration of angiotensin-converting enzyme-inhibitor/angiotensin-II receptor blocker and beta-blockers (Pinteraction <0.001). Patients with endotype 2 (HR 1.29; 95% CI 1.10-1.42) experienced possible harm from uptitration of beta-blockers in contrast to patients with endotype 4 and 6 that experienced benefit (Pinteraction for all <0.001). Results were strikingly similar in the independent validation cohort., Conclusion: Using unsupervised cluster analysis, solely based on biomarker profiles, six distinct endotypes were identified with remarkable differences in characteristics, clinical outcome, and response to uptitration of guideline directed medical therapy.
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- 2018
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14. Comparing biomarker profiles of patients with heart failure: atrial fibrillation vs. sinus rhythm and reduced vs. preserved ejection fraction.
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Santema BT, Kloosterman M, Van Gelder IC, Mordi I, Lang CC, Lam CSP, Anker SD, Cleland JG, Dickstein K, Filippatos G, Van der Harst P, Hillege HL, Ter Maaten JM, Metra M, Ng LL, Ponikowski P, Samani NJ, Van Veldhuisen DJ, Zwinderman AH, Zannad F, Damman K, Van der Meer P, Rienstra M, and Voors AA
- Subjects
- Aged, Aged, 80 and over, Biomarkers, Electrocardiography, Female, Humans, Male, Middle Aged, Retrospective Studies, Risk Factors, Atrial Fibrillation complications, Atrial Fibrillation epidemiology, Heart Failure classification, Heart Failure complications, Heart Failure epidemiology, Heart Failure physiopathology, Stroke Volume physiology
- Abstract
Aims: The clinical correlates and consequences of atrial fibrillation (AF) might be different between heart failure with reduced vs. preserved ejection fraction (HFrEF vs. HFpEF). Biomarkers may provide insights into underlying pathophysiological mechanisms of AF in these different heart failure (HF) phenotypes., Methods and Results: We performed a retrospective analysis of the BIOlogy Study to TAilored Treatment in Chronic Heart Failure (BIOSTAT-CHF), which was an observational cohort. We studied 2152 patients with HFrEF [ejection fraction (EF < 40%)], of which 1419 were in sinus rhythm (SR) and 733 had AF. Another 524 patients with HFpEF (EF ≥50%) were studied, of which 286 in SR and 238 with AF. For the comparison of biomarker profiles, 92 cardiovascular risk markers were measured (Proseek® Olink Cardiovascular III panel). The circulating risk marker pattern observed in HFrEF was different than the pattern in HFpEF: in HFrEF, AF was associated with higher levels of 77 of 92 (84%) risk markers compared to SR; whereas in HFpEF, many more markers were higher in SR than in AF. Over a median follow-up of 21 months, AF was associated with increased mortality risk [multivariable hazard ratio (HR) of 1.27; 95% confidence interval (CI) 1.09-1.48, P = 0.002]; there was no significant interaction between heart rhythm and EF group on outcome., Conclusion: In patients with HFrEF, the presence of AF was associated with a homogeneously elevated cardiovascular risk marker profile. In contrast, in patients with HFpEF, the presence of AF was associated with a more scattered risk marker profile, suggesting differences in underlying pathophysiological mechanisms of AF in these HF phenotypes.
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- 2018
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15. Determinants and clinical outcome of uptitration of ACE-inhibitors and beta-blockers in patients with heart failure: a prospective European study.
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Ouwerkerk W, Voors AA, Anker SD, Cleland JG, Dickstein K, Filippatos G, van der Harst P, Hillege HL, Lang CC, Ter Maaten JM, Ng LL, Ponikowski P, Samani NJ, van Veldhuisen DJ, Zannad F, Metra M, and Zwinderman AH
- Subjects
- Aged, Dose-Response Relationship, Drug, Drug Administration Schedule, Europe epidemiology, Female, Heart Failure mortality, Hospitalization statistics & numerical data, Humans, Kaplan-Meier Estimate, Male, Prospective Studies, Treatment Outcome, Adrenergic beta-Antagonists administration & dosage, Angiotensin-Converting Enzyme Inhibitors administration & dosage, Heart Failure drug therapy
- Abstract
Introduction: Despite clear guidelines recommendations, most patients with heart failure and reduced ejection-fraction (HFrEF) do not attain guideline-recommended target doses. We aimed to investigate characteristics and for treatment-indication-bias corrected clinical outcome of patients with HFrEF that did not reach recommended treatment doses of ACE-inhibitors/Angiotensin receptor blockers (ARBs) and/or beta-blockers., Methods and Results: BIOSTAT-CHF was specifically designed to study uptitration of ACE-inhibitors/ARBs and/or beta-blockers in 2516 heart failure patients from 69 centres in 11 European countries who were selected if they were suboptimally treated while initiation or uptitration was anticipated and encouraged. Patients who died during the uptitration period (n = 151) and patients with a LVEF > 40% (n = 242) were excluded. Median follow up was 21 months. We studied 2100 HFrEF patients (76% male; mean age 68 ±12), of which 22% achieved the recommended treatment dose for ACE-inhibitor/ARB and 12% of beta-blocker. There were marked differences between European countries. Reaching <50% of the recommended ACE-inhibitor/ARB and beta-blocker dose was associated with an increased risk of death and/or heart failure hospitalization. Patients reaching 50-99% of the recommended ACE-inhibitor/ARB and/or beta-blocker dose had comparable risk of death and/or heart failure hospitalization to those reaching ≥100%. Patients not reaching recommended dose because of symptoms, side effects and non-cardiac organ dysfunction had the highest mortality rate (for ACE-inhibitor/ARB: HR 1.72; 95% CI 1.43-2.01; for beta-blocker: HR 1.70; 95% CI 1.36-2.05)., Conclusion: Patients with HFrEF who were treated with less than 50% of recommended dose of ACE-inhibitors/ARBs and beta-blockers seemed to have a greater risk of death and/or heart failure hospitalization compared with patients reaching ≥100%., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2017
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16. Comparison of exercise testing and CMR measured myocardial perfusion reserve for predicting outcome in asymptomatic aortic stenosis: the PRognostic Importance of MIcrovascular Dysfunction in Aortic Stenosis (PRIMID AS) Study.
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Singh A, Greenwood JP, Berry C, Dawson DK, Hogrefe K, Kelly DJ, Dhakshinamurthy V, Lang CC, Khoo JP, Sprigings D, Steeds RP, Jerosch-Herold M, Neubauer S, Prendergast B, Williams B, Zhang R, Hudson I, Squire IB, Ford I, Samani NJ, and McCann GP
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Area Under Curve, Exercise Test, Female, Humans, Magnetic Resonance Angiography, Male, Middle Aged, Prognosis, Prospective Studies, Young Adult, Aortic Valve Stenosis physiopathology, Coronary Circulation physiology, Exercise Tolerance physiology
- Abstract
Aims: To assess cardiovascular magnetic resonance (CMR) measured myocardial perfusion reserve (MPR) and exercise testing in asymptomatic patients with moderate-severe AS., Methods and Results: Multi-centre, prospective, observational study, with blinded analysis of CMR data. Patients underwent adenosine stress CMR, symptom-limited exercise testing (ETT) and echocardiography and were followed up for 12-30 months. The primary outcome was a composite of: typical AS symptoms necessitating referral for AVR, cardiovascular death and major adverse cardiovascular events. 174 patients were recruited: mean age 66.2 ± 13.34 years, 76% male, peak velocity 3.86 ± 0.56 m/s and aortic valve area index 0.57 ± 0.14 cm2/m2. A primary outcome occurred in 47 (27%) patients over a median follow-up of 374 (IQR 351-498) days. The mean MPR in those with and without a primary outcome was 2.06 ± 0.65 and 2.34 ± 0.70 (P = 0.022), while the incidence of a symptom-limited ETT was 45.7% and 27.0% (P = 0.020), respectively. MPR showed moderate association with outcome area under curve (AUC) = 0.61 (0.52-0.71, P = 0.020), as did exercise testing (AUC = 0.59 (0.51-0.68, P = 0.027), with no significant difference between the two., Conclusions: MPR was associated with symptom-onset in initially asymptomatic patients with AS, but with moderate accuracy and was not superior to symptom-limited exercise testing. ClinicalTrials.gov (NCT01658345)., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2017
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17. Genetic invalidation of Lp-PLA 2 as a therapeutic target: Large-scale study of five functional Lp-PLA 2 -lowering alleles.
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Gregson JM, Freitag DF, Surendran P, Stitziel NO, Chowdhury R, Burgess S, Kaptoge S, Gao P, Staley JR, Willeit P, Nielsen SF, Caslake M, Trompet S, Polfus LM, Kuulasmaa K, Kontto J, Perola M, Blankenberg S, Veronesi G, Gianfagna F, Männistö S, Kimura A, Lin H, Reilly DF, Gorski M, Mijatovic V, Munroe PB, Ehret GB, Thompson A, Uria-Nickelsen M, Malarstig A, Dehghan A, Vogt TF, Sasaoka T, Takeuchi F, Kato N, Yamada Y, Kee F, Müller-Nurasyid M, Ferrières J, Arveiler D, Amouyel P, Salomaa V, Boerwinkle E, Thompson SG, Ford I, Wouter Jukema J, Sattar N, Packard CJ, Shafi Majumder AA, Alam DS, Deloukas P, Schunkert H, Samani NJ, Kathiresan S, Nordestgaard BG, Saleheen D, Howson JM, Di Angelantonio E, Butterworth AS, and Danesh J
- Subjects
- 1-Alkyl-2-acetylglycerophosphocholine Esterase drug effects, 1-Alkyl-2-acetylglycerophosphocholine Esterase genetics, Adult, Aged, Alleles, Case-Control Studies, Coronary Disease diagnosis, Female, Gene Expression Regulation, Genotype, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide, Randomized Controlled Trials as Topic, Reference Values, Reproducibility of Results, Risk Assessment, Treatment Outcome, Benzaldehydes therapeutic use, Coronary Disease drug therapy, Coronary Disease genetics, Molecular Targeted Therapy, Oximes therapeutic use, Phospholipase A2 Inhibitors therapeutic use
- Abstract
Aims Darapladib, a potent inhibitor of lipoprotein-associated phospholipase A
2 (Lp-PLA2 ), has not reduced risk of cardiovascular disease outcomes in recent randomized trials. We aimed to test whether Lp-PLA2 enzyme activity is causally relevant to coronary heart disease. Methods In 72,657 patients with coronary heart disease and 110,218 controls in 23 epidemiological studies, we genotyped five functional variants: four rare loss-of-function mutations (c.109+2T > C (rs142974898), Arg82His (rs144983904), Val279Phe (rs76863441), Gln287Ter (rs140020965)) and one common modest-impact variant (Val379Ala (rs1051931)) in PLA2G7, the gene encoding Lp-PLA2 . We supplemented de-novo genotyping with information on a further 45,823 coronary heart disease patients and 88,680 controls in publicly available databases and other previous studies. We conducted a systematic review of randomized trials to compare effects of darapladib treatment on soluble Lp-PLA2 activity, conventional cardiovascular risk factors, and coronary heart disease risk with corresponding effects of Lp-PLA2 -lowering alleles. Results Lp-PLA2 activity was decreased by 64% ( p = 2.4 × 10-25 ) with carriage of any of the four loss-of-function variants, by 45% ( p < 10-300 ) for every allele inherited at Val279Phe, and by 2.7% ( p = 1.9 × 10-12 ) for every allele inherited at Val379Ala. Darapladib 160 mg once-daily reduced Lp-PLA2 activity by 65% ( p < 10-300 ). Causal risk ratios for coronary heart disease per 65% lower Lp-PLA2 activity were: 0.95 (0.88-1.03) with Val279Phe; 0.92 (0.74-1.16) with carriage of any loss-of-function variant; 1.01 (0.68-1.51) with Val379Ala; and 0.95 (0.89-1.02) with darapladib treatment. Conclusions In a large-scale human genetic study, none of a series of Lp-PLA2 -lowering alleles was related to coronary heart disease risk, suggesting that Lp-PLA2 is unlikely to be a causal risk factor.- Published
- 2017
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18. Genomic prediction of coronary heart disease.
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Abraham G, Havulinna AS, Bhalala OG, Byars SG, De Livera AM, Yetukuri L, Tikkanen E, Perola M, Schunkert H, Sijbrands EJ, Palotie A, Samani NJ, Salomaa V, Ripatti S, and Inouye M
- Subjects
- Female, Genomics, Heart Diseases, Humans, Male, Polymorphism, Single Nucleotide, Risk Assessment, Risk Factors, Coronary Disease
- Abstract
Aims: Genetics plays an important role in coronary heart disease (CHD) but the clinical utility of genomic risk scores (GRSs) relative to clinical risk scores, such as the Framingham Risk Score (FRS), is unclear. Our aim was to construct and externally validate a CHD GRS, in terms of lifetime CHD risk and relative to traditional clinical risk scores., Methods and Results: We generated a GRS of 49 310 SNPs based on a CARDIoGRAMplusC4D Consortium meta-analysis of CHD, then independently tested it using five prospective population cohorts (three FINRISK cohorts, combined n = 12 676, 757 incident CHD events; two Framingham Heart Study cohorts (FHS), combined n = 3406, 587 incident CHD events). The GRS was associated with incident CHD (FINRISK HR = 1.74, 95% confidence interval (CI) 1.61-1.86 per S.D. of GRS; Framingham HR = 1.28, 95% CI 1.18-1.38), and was largely unchanged by adjustment for known risk factors, including family history. Integration of the GRS with the FRS or ACC/AHA13 scores improved the 10 years risk prediction (meta-analysis C-index: +1.5-1.6%, P < 0.001), particularly for individuals ≥60 years old (meta-analysis C-index: +4.6-5.1%, P < 0.001). Importantly, the GRS captured substantially different trajectories of absolute risk, with men in the top 20% of attaining 10% cumulative CHD risk 12-18 y earlier than those in the bottom 20%. High genomic risk was partially compensated for by low systolic blood pressure, low cholesterol level, and non-smoking., Conclusions: A GRS based on a large number of SNPs improves CHD risk prediction and encodes different trajectories of lifetime risk not captured by traditional clinical risk scores., (© The Author 2016. Published by Oxford University Press on behalf of the European Society of Cardiology.)
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- 2016
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19. Improving clinical trials for cardiovascular diseases: a position paper from the Cardiovascular Round Table of the European Society of Cardiology.
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Jackson N, Atar D, Borentain M, Breithardt G, van Eickels M, Endres M, Fraass U, Friede T, Hannachi H, Janmohamed S, Kreuzer J, Landray M, Lautsch D, Le Floch C, Mol P, Naci H, Samani NJ, Svensson A, Thorstensen C, Tijssen J, Vandzhura V, Zalewski A, and Kirchhof P
- Subjects
- Cardiovascular Diseases economics, Clinical Trials as Topic economics, Cost of Illness, Costs and Cost Analysis economics, Data Collection, Drug Approval economics, Drug Approval legislation & jurisprudence, Drug Discovery economics, Drug Industry economics, Europe, Humans, Interprofessional Relations, Precision Medicine economics, Societies, Medical, Technology Assessment, Biomedical economics, Therapies, Investigational economics, Cardiovascular Diseases drug therapy, Clinical Trials as Topic standards
- Abstract
Aims: Cardiovascular disease is the most common cause of mortality and morbidity in the world, but the pharmaceutical industry's willingness to invest in this field has declined because of the many challenges involved with bringing new cardiovascular drugs to market, including late-stage failures, escalating regulatory requirements, bureaucracy of the clinical trial business enterprise, and limited patient access after approval. This contrasts with the remaining burden of cardiovascular disease in Europe and in the world. Thus, clinical cardiovascular research needs to adapt to address the impact of these challenges in order to ensure development of new cardiovascular medicines., Methods and Results: The present paper is the outcome of a two-day workshop held by the Cardiovascular Round Table of the European Society of Cardiology. We propose strategies to improve development of effective new cardiovascular therapies. These can include (i) the use of biomarkers to describe patients who will benefit from new therapies more precisely, achieving better human target validation; (ii) targeted, mechanism-based approaches to drug development for defined populations; (iii) the use of information technology to simplify data collection and follow-up in clinical trials; (iv) streamlining adverse event collection and reducing monitoring; (v) extended patent protection or limited rapid approval of new agents to motivate investment in early phase development; and (vi) collecting data needed for health technology assessment continuously throughout the drug development process (before and after approval) to minimize delays in patient access. Collaboration across industry, academia, regulators, and payers will be necessary to enact change and to unlock the existing potential for cardiovascular clinical drug development., Conclusions: A coordinated effort involving academia, regulators, industry, and payors will help to foster better and more effective conduct of clinical cardiovascular trials, supporting earlier availability of innovative therapies and better management of cardiovascular diseases., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)
- Published
- 2016
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20. Reproducibility of telomere length assessment: an international collaborative study.
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Martin-Ruiz CM, Baird D, Roger L, Boukamp P, Krunic D, Cawthon R, Dokter MM, van der Harst P, Bekaert S, de Meyer T, Roos G, Svenson U, Codd V, Samani NJ, McGlynn L, Shiels PG, Pooley KA, Dunning AM, Cooper R, Wong A, Kingston A, and von Zglinicki T
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- Biomarkers, Blotting, Southern, Humans, International Cooperation, Real-Time Polymerase Chain Reaction, Reproducibility of Results, Aging genetics, DNA genetics, Telomere genetics
- Abstract
Background: Telomere length is a putative biomarker of ageing, morbidity and mortality. Its application is hampered by lack of widely applicable reference ranges and uncertainty regarding the present limits of measurement reproducibility within and between laboratories., Methods: We instigated an international collaborative study of telomere length assessment: 10 different laboratories, employing 3 different techniques [Southern blotting, single telomere length analysis (STELA) and real-time quantitative PCR (qPCR)] performed two rounds of fully blinded measurements on 10 human DNA samples per round to enable unbiased assessment of intra- and inter-batch variation between laboratories and techniques., Results: Absolute results from different laboratories differed widely and could thus not be compared directly, but rankings of relative telomere lengths were highly correlated (correlation coefficients of 0.63-0.99). Intra-technique correlations were similar for Southern blotting and qPCR and were stronger than inter-technique ones. However, inter-laboratory coefficients of variation (CVs) averaged about 10% for Southern blotting and STELA and more than 20% for qPCR. This difference was compensated for by a higher dynamic range for the qPCR method as shown by equal variance after z-scoring. Technical variation per laboratory, measured as median of intra- and inter-batch CVs, ranged from 1.4% to 9.5%, with differences between laboratories only marginally significant (P = 0.06). Gel-based and PCR-based techniques were not different in accuracy., Conclusions: Intra- and inter-laboratory technical variation severely limits the usefulness of data pooling and excludes sharing of reference ranges between laboratories. We propose to establish a common set of physical telomere length standards to improve comparability of telomere length estimates between laboratories., (© The Author 2014. Published by Oxford University Press on behalf of the International Epidemiological Association.)
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- 2015
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21. Is Southern blotting necessary to measure telomere length reproducibly? Authors' Response to: Commentary: The reliability of telomere length measurements.
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Martin-Ruiz CM, Baird D, Roger L, Boukamp P, Krunic D, Cawthon R, Dokter MM, Van Der Harst P, Bekaert S, De Meyer T, Roos G, Svenson U, Codd V, Samani NJ, Mcglynn L, Shiels PG, Pooley KA, Dunning AM, Cooper R, Wong A, Kingston A, and Von Zglinicki T
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- Humans, Reproducibility of Results, Blotting, Southern, Telomere
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- 2015
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22. Reproducibility of telomere length assessment: Authors' Response to Damjan Krstajic and Ljubomir Buturovic.
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Martin-Ruiz CM, Baird D, Roger L, Boukamp P, Krunic D, Cawthon R, Dokter MM, Van Der Harst P, Bekaert S, De Meyer T, Roos G, Svenson U, Codd V, Samani NJ, Mcglynn L, Shiels PG, Pooley KA, Dunning AM, Cooper R, Wong A, Kingston A, and Von Zglinicki T
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- Humans, Reproducibility of Results, Telomere
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- 2015
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23. Adiposity as a cause of cardiovascular disease: a Mendelian randomization study.
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Hägg S, Fall T, Ploner A, Mägi R, Fischer K, Draisma HH, Kals M, de Vries PS, Dehghan A, Willems SM, Sarin AP, Kristiansson K, Nuotio ML, Havulinna AS, de Bruijn RF, Ikram MA, Kuningas M, Stricker BH, Franco OH, Benyamin B, Gieger C, Hall AS, Huikari V, Jula A, Järvelin MR, Kaakinen M, Kaprio J, Kobl M, Mangino M, Nelson CP, Palotie A, Samani NJ, Spector TD, Strachan DP, Tobin MD, Whitfield JB, Uitterlinden AG, Salomaa V, Syvänen AC, Kuulasmaa K, Magnusson PK, Esko T, Hofman A, de Geus EJ, Lind L, Giedraitis V, Perola M, Evans A, Ferrières J, Virtamo J, Kee F, Tregouet DA, Arveiler D, Amouyel P, Gianfagna F, Brambilla P, Ripatti S, van Duijn CM, Metspalu A, Prokopenko I, McCarthy MI, Pedersen NL, and Ingelsson E
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- Body Mass Index, Cross-Sectional Studies, Female, Humans, Male, Mendelian Randomization Analysis, Middle Aged, Prospective Studies, Adiposity genetics, Cardiovascular Diseases genetics, Polymorphism, Single Nucleotide genetics
- Abstract
Background: Adiposity, as indicated by body mass index (BMI), has been associated with risk of cardiovascular diseases in epidemiological studies. We aimed to investigate if these associations are causal, using Mendelian randomization (MR) methods., Methods: The associations of BMI with cardiovascular outcomes [coronary heart disease (CHD), heart failure and ischaemic stroke], and associations of a genetic score (32 BMI single nucleotide polymorphisms) with BMI and cardiovascular outcomes were examined in up to 22,193 individuals with 3062 incident cardiovascular events from nine prospective follow-up studies within the ENGAGE consortium. We used random-effects meta-analysis in an MR framework to provide causal estimates of the effect of adiposity on cardiovascular outcomes., Results: There was a strong association between BMI and incident CHD (HR = 1.20 per SD-increase of BMI, 95% CI, 1.12-1.28, P = 1.9.10(-7)), heart failure (HR = 1.47, 95% CI, 1.35-1.60, P = 9.10(-19)) and ischaemic stroke (HR = 1.15, 95% CI, 1.06-1.24, P = 0.0008) in observational analyses. The genetic score was robustly associated with BMI (β = 0.030 SD-increase of BMI per additional allele, 95% CI, 0.028-0.033, P = 3.10(-107)). Analyses indicated a causal effect of adiposity on development of heart failure (HR = 1.93 per SD-increase of BMI, 95% CI, 1.12-3.30, P = 0.017) and ischaemic stroke (HR = 1.83, 95% CI, 1.05-3.20, P = 0.034). Additional cross-sectional analyses using both ENGAGE and CARDIoGRAMplusC4D data showed a causal effect of adiposity on CHD., Conclusions: Using MR methods, we provide support for the hypothesis that adiposity causes CHD, heart failure and, previously not demonstrated, ischaemic stroke., (© The Author 2015; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.)
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- 2015
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24. Mendelian randomization of blood lipids for coronary heart disease.
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Holmes MV, Asselbergs FW, Palmer TM, Drenos F, Lanktree MB, Nelson CP, Dale CE, Padmanabhan S, Finan C, Swerdlow DI, Tragante V, van Iperen EP, Sivapalaratnam S, Shah S, Elbers CC, Shah T, Engmann J, Giambartolomei C, White J, Zabaneh D, Sofat R, McLachlan S, Doevendans PA, Balmforth AJ, Hall AS, North KE, Almoguera B, Hoogeveen RC, Cushman M, Fornage M, Patel SR, Redline S, Siscovick DS, Tsai MY, Karczewski KJ, Hofker MH, Verschuren WM, Bots ML, van der Schouw YT, Melander O, Dominiczak AF, Morris R, Ben-Shlomo Y, Price J, Kumari M, Baumert J, Peters A, Thorand B, Koenig W, Gaunt TR, Humphries SE, Clarke R, Watkins H, Farrall M, Wilson JG, Rich SS, de Bakker PI, Lange LA, Davey Smith G, Reiner AP, Talmud PJ, Kivimäki M, Lawlor DA, Dudbridge F, Samani NJ, Keating BJ, Hingorani AD, and Casas JP
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- Case-Control Studies, Female, Gene Frequency, Genotype, Genotyping Techniques, Humans, Male, Mendelian Randomization Analysis, Middle Aged, Risk Assessment, Cholesterol, HDL genetics, Coronary Artery Disease genetics, Polymorphism, Single Nucleotide genetics, Triglycerides genetics
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Aims: To investigate the causal role of high-density lipoprotein cholesterol (HDL-C) and triglycerides in coronary heart disease (CHD) using multiple instrumental variables for Mendelian randomization., Methods and Results: We developed weighted allele scores based on single nucleotide polymorphisms (SNPs) with established associations with HDL-C, triglycerides, and low-density lipoprotein cholesterol (LDL-C). For each trait, we constructed two scores. The first was unrestricted, including all independent SNPs associated with the lipid trait identified from a prior meta-analysis (threshold P < 2 × 10(-6)); and the second a restricted score, filtered to remove any SNPs also associated with either of the other two lipid traits at P ≤ 0.01. Mendelian randomization meta-analyses were conducted in 17 studies including 62,199 participants and 12,099 CHD events. Both the unrestricted and restricted allele scores for LDL-C (42 and 19 SNPs, respectively) associated with CHD. For HDL-C, the unrestricted allele score (48 SNPs) was associated with CHD (OR: 0.53; 95% CI: 0.40, 0.70), per 1 mmol/L higher HDL-C, but neither the restricted allele score (19 SNPs; OR: 0.91; 95% CI: 0.42, 1.98) nor the unrestricted HDL-C allele score adjusted for triglycerides, LDL-C, or statin use (OR: 0.81; 95% CI: 0.44, 1.46) showed a robust association. For triglycerides, the unrestricted allele score (67 SNPs) and the restricted allele score (27 SNPs) were both associated with CHD (OR: 1.62; 95% CI: 1.24, 2.11 and 1.61; 95% CI: 1.00, 2.59, respectively) per 1-log unit increment. However, the unrestricted triglyceride score adjusted for HDL-C, LDL-C, and statin use gave an OR for CHD of 1.01 (95% CI: 0.59, 1.75)., Conclusion: The genetic findings support a causal effect of triglycerides on CHD risk, but a causal role for HDL-C, though possible, remains less certain., (© The Author 2014. Published by Oxford University Press on behalf of the European Society of Cardiology.)
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- 2015
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25. Mendelian randomization studies in coronary artery disease.
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Jansen H, Samani NJ, and Schunkert H
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- C-Reactive Protein genetics, C-Reactive Protein metabolism, Cholesterol Ester Transfer Proteins genetics, Cholesterol Ester Transfer Proteins physiology, Cholesterol, HDL genetics, Cholesterol, HDL physiology, Cholesterol, LDL genetics, Cholesterol, LDL physiology, Diabetes Complications genetics, Fibrinogen physiology, Genetic Markers genetics, Genetic Pleiotropy genetics, Humans, Hypertension complications, Hypertension genetics, Linkage Disequilibrium genetics, Lipoprotein(a) genetics, Lipoprotein(a) physiology, Obesity complications, Obesity genetics, Phospholipases A2 genetics, Phospholipases A2 physiology, Polymorphism, Single Nucleotide genetics, Randomized Controlled Trials as Topic, Receptors, Interleukin-6 genetics, Risk Factors, Serum Amyloid P-Component genetics, Telomere genetics, Triglycerides genetics, Triglycerides physiology, Coronary Artery Disease genetics, Mendelian Randomization Analysis
- Abstract
Epidemiological research over the last 50 years has discovered a plethora of biomarkers (including molecules, traits or other diseases) that associate with coronary artery disease (CAD) risk. Even the strongest association detected in such observational research precludes drawing conclusions about the causality underlying the relationship between biomarker and disease. Mendelian randomization (MR) studies can shed light on the causality of associations, i.e whether, on the one hand, the biomarker contributes to the development of disease or, on the other hand, the observed association is confounded by unrecognized exogenous factors or due to reverse causation, i.e. due to the fact that prevalent disease affects the level of the biomarker. However, conclusions from a MR study are based on a number of important assumptions. A prerequisite for such studies is that the genetic variant employed affects significantly the biomarker under investigation but has no effect on other phenotypes that might confound the association between the biomarker and disease. If this biomarker is a true causal risk factor for CAD, genotypes of the variant should associate with CAD risk in the direction predicted by the association of the biomarker with CAD. Given a random distribution of exogenous factors in individuals carrying respective genotypes, groups represented by the genotypes are highly similar except for the biomarker of interest. Thus, the genetic variant converts into an unconfounded surrogate of the respective biomarker. This scenario is nicely exemplified for LDL cholesterol. Almost every genotype found to increase LDL cholesterol level by a sufficient amount has also been found to increase CAD risk. Pending a number of conditions that needed to be fulfilled by the genetic variant under investigation (e.g. no pleiotropic effects) and the experimental set-up of the study, LDL cholesterol can be assumed to act as the functional component that links genotypes and CAD risk and, more importantly, it can be assumed that any modulation of LDL cholesterol-by whatever mechanism-would have similar effects on disease risk. Therefore, MR analysis has tremendous potential for identifying therapeutic targets that are likely to be causal for CAD. This review article discusses the opportunities and challenges of MR studies for CAD, highlighting several examples that involved multiple biomarkers, including various lipid and inflammation traits as well as hypertension, diabetes mellitus, and obesity., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.)
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- 2014
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26. Leukocyte telomere length associates with prospective mortality independent of immune-related parameters and known genetic markers.
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Deelen J, Beekman M, Codd V, Trompet S, Broer L, Hägg S, Fischer K, Thijssen PE, Suchiman HE, Postmus I, Uitterlinden AG, Hofman A, de Craen AJ, Metspalu A, Pedersen NL, van Duijn CM, Jukema JW, Houwing-Duistermaat JJ, Samani NJ, and Slagboom PE
- Subjects
- Aged, Aged, 80 and over, Biomarkers, Female, Health Status, Humans, Immunoproteins analysis, Inflammation Mediators blood, Male, Middle Aged, Prospective Studies, Aging immunology, Family, Leukocytes immunology, Longevity immunology, Telomere immunology
- Abstract
Background: Human leukocyte telomere length (LTL) decreases with age and shorter LTL has previously been associated with increased prospective mortality. However, it is not clear whether LTL merely marks the health status of an individual by its association with parameters of immune function, for example, or whether telomere shortening also contributes causally to lifespan variation in humans., Methods: We measured LTL in 870 nonagenarian siblings (mean age 93 years), 1580 of their offspring and 725 spouses thereof (mean age 59 years) from the Leiden Longevity Study (LLS)., Results: We found that shorter LTL is associated with increased prospective mortality in middle (30-80 years; hazard ratio (HR)=0.75, P=0.001) and highly advanced age (≥90 years; HR=0.92, P=0.028), and show that this association cannot be explained by the association of LTL with the immune-related markers insulin-like growth factor 1 to insulin-like growth factor binding protein 3 molar ratio, C-reactive protein, interleukin 6, cytomegalovirus serostatus or white blood cell counts. We found no difference in LTL between the middle-aged LLS offspring and their spouses (β=0.006, P=0.932). Neither did we observe an association of LTL-associated genetic variants with mortality in a prospective meta-analysis of multiple cohorts (n=8165)., Conclusions: We confirm LTL to be a marker of prospective mortality in middle and highly advanced age and additionally show that this association could not be explained by the association of LTL with various immune-related markers. Furthermore, the approaches performed here do not further support the hypothesis that LTL variation contributes to the genetic propensity for longevity., (© The Author 2014. Published by Oxford University Press on behalf of the International Epidemiological Association.)
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- 2014
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27. Leukocyte telomere length and marital status among middle-aged adults.
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Mainous AG 3rd, Everett CJ, Diaz VA, Baker R, Mangino M, Codd V, and Samani NJ
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- Adult, Aging ethnology, Biomarkers, Black People ethnology, Cross-Sectional Studies, Female, Health Status, Humans, Leukocytes physiology, Life Style, Longevity physiology, Male, Middle Aged, South Carolina, Telomere physiology, White People ethnology, Black or African American, Aging physiology, Leukocytes ultrastructure, Marital Status, Telomere ultrastructure
- Abstract
Background: being unmarried is associated with worse health and increased mortality risk. Telomere length has emerged as a marker for biological ageing but it is unclear how telomere length relates to marital status., Objective: to examine the relationship between telomere length and marital status in a sample of middle-aged adults., Design and Subjects: cross-sectional analysis among 321 adults aged 40-64 years., Methods: telomere length was measured by PCR (T/S ratio). Participants provided information on healthy lifestyle activities including smoking, alcohol use, diet, exercise, obesity as well as social support., Results: participants married or living with a partner had a mean T/S ratio of 1.70 and those widowed, divorced, separated or never married had a mean T/S ratio of 1.58 in a model adjusted for age, gender and race/ethnicity (P < 0.001). When the analysis was further adjusted for diet, alcohol consumption, exercise, smoking, social support, poverty and obesity, persons married or living with a partner had a higher mean T/S ratio of 1.69 than their unmarried counterparts (1.59) (P = 0.004)., Conclusions: these results indicate that unmarried individuals have shorter telomeres. This relationship between marital status and telomere length is independent of presumed benefits of marriage such as social support and a healthier lifestyle.
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- 2011
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28. Association between left ventricular mass and telomere length in a population study.
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Kuznetsova T, Codd V, Brouilette S, Thijs L, González A, Jin Y, Richart T, van der Harst P, Díez J, Staessen JA, and Samani NJ
- Subjects
- Adult, Aged, Female, Follow-Up Studies, Humans, Hypertension physiopathology, Hypertrophy, Left Ventricular diagnostic imaging, Male, Middle Aged, Predictive Value of Tests, Surveys and Questionnaires, Ultrasonography, Hypertrophy, Left Ventricular physiopathology, Telomere physiology
- Abstract
Experimental studies have implicated telomere dynamics in cardiomyocyte size and replication potential; shorter telomeres mark attenuated proliferation and increased apoptosis. The authors examined whether this translates into an impact of telomere length (TL) on left ventricular (LV) mass in the general population. In 334 randomly selected Flemish participants (mean age = 46.5 years; 52.5% women), they measured TL in circulating leukocytes using quantitative polymerase chain reaction, expressing it as telomere/genomic DNA ratio (T/S). After a median 7.4 years of follow-up (interquartile range, 6.2-8.5) during 1996-2007, they measured LV mass by echocardiography. In multivariable-adjusted analyses accounting for sex, age, body weight and height, systolic blood pressure, and antihypertensive drug use, LV mass and LV mass index significantly increased with mean leukocyte TL in the entire population and in the 198 normotensive subjects. For a 1-standard-deviation increment in T/S ratio, LV mass (mean = 170 g) and LV mass index (mean = 92 g/m(2)) increased by 5.20 g (P = 0.003) and 2.70 g/m(2) (P = 0.004), respectively, in all subjects and by 8.03 g (P = 0.0001) and 3.74 g/m(2) (P = 0.0007) in normotensive subjects. There were corresponding associations with LV wall thicknesses (P < 0.007) but not LV internal diameter (P = 0.26) in normotensive subjects. Longer mean leukocyte TL is associated with increased LV mass, particularly in normotensive subjects. This association could have a biologic basis related to the role of TL in determining cardiomyocyte size and replication potential.
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- 2010
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29. Genetics of myocardial infarction: a progress report.
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Schunkert H, Erdmann J, and Samani NJ
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- Cholesterol, LDL genetics, Gene Frequency, Genome, Human genetics, Humans, Pedigree, Risk Assessment, Coronary Artery Disease genetics, Myocardial Infarction genetics
- Abstract
A small region on chromosome 9p21.3, discovered in parallel by three groups in the year 2007, is typical of the new understanding of the genetic basis of myocardial infarction (MI). The finding emerged from the application of novel high-throughput genome-wide approaches, the risk-associated allele is frequent, acts independently of traditional risk factors, and confers a modest yet highly reproducible hazard. Since then, another 10 chromosomal regions have been identified to affect the risk of MI or coronary artery disease (CAD). Although the number of risk alleles is growing rapidly, several conclusions can already be drawn from the findings to date. First, it appears that multiple hitherto unknown molecular mechanisms--initiated by these chromosomal variants--ultimately precipitate CAD. Secondly, essentially all Caucasians carry a variable number of risk alleles such that disease manifestation is affected to some extent by these inherited factors in basically all individuals. This means that a better understanding of underlying functional genomic mechanisms may offer novel opportunities to neutralize a broadly based genetic susceptibility for CAD in a large proportion of the population. In parallel, the newly discovered genes open novel opportunities for disease prediction. In summary, modern MI genetics carries the promise to identify individuals at high risk and to improve prevention and therapy of this important disease.
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- 2010
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30. Short- and medium-term survival following coronary artery bypass surgery in British Indo-Asian and white Caucasian individuals: impact of diabetes mellitus.
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Hadjinikolaou L, Klimatsidas M, Maria Iacona G, Spyt T, and Samani NJ
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- Aged, Chi-Square Distribution, Coronary Artery Bypass adverse effects, Coronary Artery Disease ethnology, Diabetes Mellitus ethnology, Female, Hospital Mortality, Humans, Incidence, Kaplan-Meier Estimate, Logistic Models, Male, Middle Aged, Prevalence, Proportional Hazards Models, Risk Assessment, Risk Factors, Time Factors, Treatment Outcome, United Kingdom epidemiology, Asian People statistics & numerical data, Coronary Artery Bypass mortality, Coronary Artery Disease mortality, Coronary Artery Disease surgery, Diabetes Mellitus mortality, Life Expectancy ethnology, Survivors statistics & numerical data, White People statistics & numerical data
- Abstract
Previous studies have suggested that South Asian (SA) ethnicity is a predictor of poorer outcome after coronary artery bypass grafting (CABG). Our aim was to identify potential reasons for the higher postoperative mortality in SA patients and investigate all these reasons. All individuals undergoing isolated CABG in a tertiary cardiac centre from April 2002 to September 2007. In total, there were 2897 subjects (2623 white subjects; 274 SA subjects) who were included in an observational study showing the effect of ethnicity on the medium-term survival following CABG. Survival at 30 days and survival up to five years (median 2.7 years) were measured. SA subjects undergoing CABG were younger (62+/-9 vs. 66+/-9 years, P<0.001), less obese [body mass index (BMI) 26+/-4 vs. 28+/-4 kg/m(2), P<0.001] and had a higher prevalence of diabetes mellitus (58% vs. 33%, P<0.001) compared with white subjects. Thirty-day mortality was higher in SA subjects (2.6% vs. 1.0%, P=0.02). Non-diabetic SA had similar 30-day mortality, five-year survival and life expectancy compared to non-diabetic white subjects. In contrast, diabetic SA had a higher 30-day mortality (3.8% vs. 1.4%, P=0.01) and worse life expectancy compared to diabetic white subjects. The higher early postoperative mortality observed in SA patients is related to higher incidence of diabetes among them. SA diabetics have a significantly higher postoperative mortality and worse overall life expectancy. Ethnicity per se is not an independent predictor of short- or medium-term survival after CABG.
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- 2010
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31. Telomere length and psychological well-being in patients with chronic heart failure.
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Huzen J, van der Harst P, de Boer RA, Lesman-Leegte I, Voors AA, van Gilst WH, Samani NJ, Jaarsma T, and van Veldhuisen DJ
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- Aged, Aged, 80 and over, Aging physiology, Aging psychology, Chronic Disease, Cross-Sectional Studies, Female, Geriatric Assessment, Humans, Male, Middle Aged, Polymerase Chain Reaction, Quality of Life, Regression Analysis, Risk Factors, Surveys and Questionnaires, Depression genetics, Depression psychology, Heart Failure complications, Heart Failure genetics, Heart Failure physiopathology, Telomere genetics, Telomere ultrastructure
- Abstract
Background: psychological stress and depressive symptoms have been implicated with accelerated ageing and increased progression of diseases. Shorter telomere length indicates a more advanced biological age. It is unknown whether psychological well-being is associated with telomere length in patients with the somatic condition of chronic heart failure (CHF)., Design: a cross-sectional analysis was used., Setting: patients were admitted to the hospital with signs and symptoms of CHF., Objective: the study aimed to assess the association between telomere length and psychological well-being in patients with CHF., Methods: telomere length was determined by quantitative polymerase chain reaction in 890 patients with New York Heart Association functional class II to IV CHF. We evaluated the perceived mental health by the validated RAND-36 questionnaire. Depressive symptoms were assessed by the Centre for Epidemiologic Studies Depression scale (CES-D), and the presence of type D personality was evaluated by the DS14., Results: a lower perceived mental health on the RAND-36 score was associated with shorter telomere length. Adjustment for age and gender did not change our findings (standardised beta, 0.11; P-value, 0.002). Telomere length was not associated with the CES-D or DS14 score., Conclusion: decreased perceived mental health is associated with shorter leukocyte telomere length in patients with CHF. Future work should determine whether psychological stress accelerates biological ageing.
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- 2010
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32. Inverse associations between androgens and renal function: the Young Men Cardiovascular Association (YMCA) study.
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Tomaszewski M, Charchar FJ, Maric C, Kuzniewicz R, Gola M, Grzeszczak W, Samani NJ, and Zukowska-Szczechowska E
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- Adolescent, Cross-Sectional Studies, Enzyme-Linked Immunosorbent Assay, Humans, Male, Prognosis, Reference Values, Risk Factors, Androgens blood, Creatinine metabolism, Glomerular Filtration Rate physiology, Kidney physiology, Men's Health, Societies, Medical
- Abstract
Background: Men exhibit higher risk of nondiabetic renal diseases than women. This male susceptibility to renal disease may be mediated by gender-specific factors such as sex hormones., Methods: We have undertaken a cross-sectional examination of associations between renal function (creatinine clearance estimated based on Cockcroft-Gault equation) and circulating levels of sex steroids (total testosterone, total estradiol, estrone, androstenedione, dehydroepiandrosterone sulfate (DHEA-S), and dihydrotestosterone) in 928 young (mean age: 18.5 +/- 1.2 years) men., Results: Both androstenedione and DHEA-S showed inverse linear associations with renal function in the crude analysis of lean men (those with body mass index (BMI) less than median). However, only DHEA-S retained its association with renal function in lean subjects after adjustment--assuming no changes in other independent variables 1 s.d. increase in DHEA-S was associated with 13%-s.d. decrease in creatinine clearance (P = 0.004). Testosterone decreased across tertiles of creatinine clearance only in the crude analysis of nonlean (BMI greater than median) subjects (P < 0.001). The adjusted regression analysis that assumed no changes in other independent variables showed that 1 s.d. increase in total testosterone was associated with 11%-s.d. decrease in creatinine clearance of nonlean men (P = 0.006). Factor analysis confirmed an inverse association of renal function with both sex steroids and a different pattern of their loadings on glomerular filtration-related factors in lean (DHEA-S) and nonlean (testosterone) subjects., Conclusions: Our data may suggest that androgens are inversely associated with estimated renal function in apparently healthy men without history of cardiovascular disease.
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- 2009
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33. Gender and effects of a common genetic variant in the NOS1 regulator NOS1AP on cardiac repolarization in 3761 individuals from two independent populations.
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Tobin MD, Kähönen M, Braund P, Nieminen T, Hajat C, Tomaszewski M, Viik J, Lehtinen R, Ng GA, Macfarlane PW, Burton PR, Lehtimäki T, and Samani NJ
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- Adult, Alleles, Electrocardiography, Exercise physiology, Female, Finland, Genotype, Health Surveys, Heart Rate physiology, Humans, Linear Models, Male, Middle Aged, Sex Factors, United Kingdom, Adaptor Proteins, Signal Transducing genetics, Genetic Variation, Heart physiopathology, Long QT Syndrome genetics, Long QT Syndrome physiopathology
- Abstract
Background: A longer heart-rate corrected QT interval (QTc) is associated with increased risk of ventricular arrhythmias. Women have longer resting QTc and are more likely than men to develop drug-induced QT prolongation. Recent studies have shown association between resting QTc and a common variant (rs10494366) of the NOS1 regulator, NOS1AP. We investigated the association between rs10494366 in NOS1AP and QTc, and assessed gender-specific NOS1AP associations with QTc during rest and after exercise., Methods: We investigated the SNP associations with resting QTc in 919 women and 918 men from 504 representative families in the UK GRAPHIC study, and with QTc at rest and at 3 min recovery after exercise in 699 women and 1225 men referred for exercise testing in the Finnish FINCAVAS study., Results: In the GRAPHIC study the minor allele (G) of the NOS1AP SNP rs10494366 prolonged QTc by 4.59 ms (95% CI 2.77-6.40; P = 7.63/10(7)) in women, but only by 1.62 ms (95% CI -0.15 to 3.38; P = 0.073) in men (gender-SNP interaction term P = 0.025). In the FINCAVAS study the G allele significantly prolonged QTc in both women (P = 0.0063) and men (P = 0.0043) at 3 min recovery after exercise, but at rest an association was only seen in women (P = 0.020 excluding outliers)., Conclusions: A common NOS1AP variant prolongs QTc with a difference between genders. Further studies should aim to confirm this finding and to assess whether NOS1AP genotype influences the risk of drug-induced QT prolongation and risk of consequent arrhythmias.
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- 2008
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34. Evidence for genetic regulation of endothelial progenitor cells and their role as biological markers of atherosclerotic susceptibility.
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Whittaker A, Moore JS, Vasa-Nicotera M, Stevens S, and Samani NJ
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- Adult, Atherosclerosis genetics, Biomarkers blood, Case-Control Studies, Cell Count, Cell Movement, Cells, Cultured, Coronary Artery Disease blood, Coronary Artery Disease genetics, Female, Genetic Predisposition to Disease, Humans, Male, Middle Aged, Predictive Value of Tests, Vascular Endothelial Growth Factor A blood, Atherosclerosis blood, Endothelial Cells cytology, Endothelium, Vascular cytology, Hematopoietic Stem Cells
- Abstract
Aims: Endothelial progenitor cells (EPCs) are found in the peripheral circulation and are capable of endothelial repair and neovascularization. EPC number and function are reduced in subjects with cardiovascular risk factors or proven coronary artery disease (CAD). We hypothesized that EPC number and/or function may be genetically regulated and may vary in healthy adult offspring depending on parental history of CAD., Methods and Results: We studied 102 subjects comprising 24 healthy parent-healthy offspring pairs and 27 CAD parent-healthy offspring pairs. We measured the number of circulating CD34(+)VEGFR-2(+) and AC133(+)VEGFR-2(+) EPCs, the number of EPCs grown in culture, and the migration capacity of cultured EPCs towards vascular endothelial growth factor. There was significant correlation in the number of cultured EPCs between healthy parents and their offspring (R = 0.492, P = 0.015) and CAD parents and their offspring (R = 0.751, P < 0.001). Offspring of subjects with CAD had significantly higher numbers of circulating CD34(+)VEGFR-2(+) and AC133(+)VEGFR-2(+) cells (P = 0.018 and P < 0.001, respectively). There was no difference in migration capacity between groups., Conclusion: Our results suggest that EPC number is, at least in part, genetically regulated. Circulating EPCs may represent biological markers of occult vascular damage in offspring with hereditary risk of CAD.
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- 2008
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35. The effect of preoperative atrial fibrillation on survival following mitral valve repair for degenerative mitral regurgitation.
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Alexiou C, Doukas G, Oc M, Oc B, Swanevelder J, Samani NJ, and Spyt TJ
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- Aged, Atrial Fibrillation mortality, Female, Humans, Kaplan-Meier Estimate, Male, Middle Aged, Mitral Valve Insufficiency physiopathology, Mitral Valve Insufficiency surgery, Postoperative Complications, Treatment Outcome, Atrial Fibrillation physiopathology, Mitral Valve surgery, Mitral Valve Insufficiency mortality, Preoperative Care methods
- Abstract
Objective: There is conflicting evidence with regard to the impact of preoperative atrial fibrillation (AF) on the post mitral valve (MV) repair on the early and late outcome., Methods: A total of 349 patients undergoing various MV repair procedures for degenerative mitral regurgitation (MR) between 1997 and 2003 were studied. Preoperatively, 152 (44%) of these patients were in AF and 197 (56%) patients were in sinus rhythm (SR). The clinical features and the outcome in these two cohorts of patients were compared., Results: The patients in the AF group were older than their counterparts in the SR group (66+/-7 vs 62+/-9 years) (p=0.01), had a higher mean NYHA class score (2.4+/-0.6 vs 2.2+/-0.7) (p=0.04) and were more likely to have impaired left ventricular function (60% vs 36%) (p<0.0001). A similar proportion of patients in the AF (38%) and SR (30%) groups had additional cardiac surgical procedures (p=0.12). Operative mortality was 3.9% in AF group versus 0.5% in SR group (p=0.04), and operative morbidity was 27% versus 17%, respectively (p=0.03). At latest follow up, 4% of patients that were in SR preoperatively developed AF; conversely, 2% of the patients in the AF group converted to SR. The rates of recurrent grade II or III MR (4% vs 5%) (p=0.8) and MV re-operation (2.6% vs 2.5%) (p=1.0) were similar in the AF and SR groups. Kaplan-Meier survival at 7 years was 75+/-6% versus 90+/-3% (p=0.005). On Cox proportional hazards regression model, impaired LV function [(p=0.02), hazard ratio 0.25 (95% confidence intervals (C.I.) 0.078-0.84)] and AF [(p=0.03), hazard ratio 2.70 (95% C.I. 1.09-6.68)] were significant adverse predictors of survival., Conclusions: This study shows that in patients undergoing MV repair for degenerative MR, preoperative AF has a major negative impact on the early and late survival.
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- 2007
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36. Plasma matrix metalloproteinase-9 and left ventricular remodelling after acute myocardial infarction in man: a prospective cohort study.
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Kelly D, Cockerill G, Ng LL, Thompson M, Khan S, Samani NJ, and Squire IB
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- Adult, Aged, Aged, 80 and over, Case-Control Studies, Cohort Studies, Enzyme-Linked Immunosorbent Assay, Female, Humans, Male, Matrix Metalloproteinase 2 metabolism, Middle Aged, Myocardial Infarction physiopathology, Prospective Studies, Ventricular Dysfunction, Left blood, Ventricular Dysfunction, Left physiopathology, Matrix Metalloproteinase 9 metabolism, Myocardial Infarction blood, Ventricular Remodeling physiology
- Abstract
Aim: To describe temporal profiles of plasma matrix metalloproteinases (MMP-2 and MMP-9), and their relationship with echocardiographic (Echo) parameters of left ventricular (LV) function and remodelling, after acute myocardial infarction (AMI) in man., Methods and Results: Plasma MMP-2 and MMP-9 were assayed at intervals (0-12, 12-24, 24-48, 48-72, 72-96, and > 96 h) in 91 patients with AMI (ST-elevation/non-ST-elevation 77/24; 73% male; 40% anterior site) and on a single occasion in 172 age- and sex-matched control subjects with stable coronary artery disease. Echo assessment of LV volumes, LV ejection fraction (LVEF), and wall motion index score were assessed before discharge and at follow-up (median 176, range 138-262 days) for patients and on a single occassion in controls. Plasma MMP-2 was similar at all times after AMI, elevated when compared with control (P = 0.005-0.001) and unrelated to LV function or volume during index admission or at follow-up. Maximal MMP-9 was seen at 0-12 h and was elevated when compared with control (P = 0.002) followed by fall to a plateau. Both maximal and plateau MMP-9 concentration correlated with white blood cell (WBC, P = 0.023 to < 0.001) and neutrophil count (P = 0.014 to < 0.001). Maximal MMP-9 had independent predictive value for lower LVEF (P = 0.004) during admission and for greater change in LV end-diastolic volume between admission and follow-up (R = 0.3, P = 0.016). In contrast, higher plateau levels of MMP-9 were associated with relative preservation of LV function (increasing LVEF, P = 0.002; decreasing WMIS, P = 0.009) and less change in end-systolic volume and end-diastolic volumes after discharge (P = 0.001 and 0.024, respectively)., Conclusion: Both MMP-9 and MMP-2 are elevated following AMI. The biphasic profile of plasma MMP-9 is related to LV remodelling and function following AMI in man. Higher early levels of MMP-9 associate with the extent of LV remodelling and circulating WBC levels. In contrast, higher plateau levels later after AMI are associated with relative preservation of LV function. Temporal profile, rather than absolute magnitude, of MMP-9 activity appears to be important for LV remodelling after AMI.
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- 2007
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37. Complementary intron sequence motifs associated with human exon repetition: a role for intragenic, inter-transcript interactions in gene expression.
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Dixon RJ, Eperon IC, and Samani NJ
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- Chromosome Mapping methods, Conserved Sequence, Humans, Sequence Analysis, DNA methods, Sequence Homology, Nucleic Acid, DNA, Complementary genetics, Exons genetics, Gene Expression genetics, Genome, Human genetics, Introns genetics, Repetitive Sequences, Nucleic Acid genetics, Transcription Factors genetics
- Abstract
Motivation: Exon repetition describes the presence of tandemly repeated exons in mRNA in the absence of duplications in the genome. The regulation of this process is not fully understood. We therefore investigated the entire flanking intronic sequences of exons involved in exon repetition for common sequence elements., Results: A computational analysis of 48 human single exon repetition events identified two common sequence motifs. One of these motifs is pyrimidine-rich and is more common in the upstream intron, whilst the other motif is highly enriched in purines and is more common in the downstream intron. As the two motifs are complementary to each other, they support a model by which exon repetition occurs as a result of trans-splicing between separate pre-mRNA transcripts from the same gene that are brought together during transcription by complementary intronic sequences. The majority of the motif instances overlap with the locations of mobile elements such as Alu elements. We explore the potential importance of complementary intron sequences in a rat gene that undertakes natural exon repetition in a strain specific manner. The possibility that distant complementary sequences can stimulate inter-transcript splicing during transcription suggests an unsuspected new role for potential secondary structures in endogenous genes.
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- 2007
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38. A genome-wide survey demonstrates widespread non-linear mRNA in expressed sequences from multiple species.
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Dixon RJ, Eperon IC, Hall L, and Samani NJ
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- Animals, Computational Biology methods, Expressed Sequence Tags chemistry, Genomics methods, Humans, Introns, Mice, Open Reading Frames, Rats, Alternative Splicing, Exons, Genome, RNA, Messenger chemistry
- Abstract
We describe here the results of the first genome-wide survey of candidate exon repetition events in expressed sequences from human, mouse, rat, chicken, zebrafish and fly. Exon repetition is a rare event, reported in <10 genes, in which one or more exons is tandemly duplicated in mRNA but not in the gene. To identify candidates, we analysed database sequences for mRNA transcripts in which the order of the spliced exons does not follow the linear genomic order of the individual gene [events we term rearrangements or repetition in exon order (RREO)]. Using a computational approach, we have identified 245 genes in mammals that produce RREO events. RREO in mRNA occurs predominantly in the coding regions of genes. However, exon 1 is never involved. Analysis of the open reading frames suggests that this process may increase protein diversity and regulate protein expression via nonsense-mediated RNA decay. The sizes of the exons and introns involved around these events suggest a gene model structure that may facilitate non-linear splicing. These findings imply that RREO affects a significant subset of genes within a genome and suggests that non-linear information encoded within the genomes of complex organisms could contribute to phenotypic variation.
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- 2005
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39. Genotypes and haplotypes predisposing to myocardial infarction: a multilocus case-control study.
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Tobin MD, Braund PS, Burton PR, Thompson JR, Steeds R, Channer K, Cheng S, Lindpaintner K, and Samani NJ
- Subjects
- Case-Control Studies, Confounding Factors, Epidemiologic, Coronary Stenosis genetics, Female, Gene Frequency, Genotype, Haplotypes, Humans, Male, Middle Aged, Polymorphism, Genetic genetics, Risk Factors, Genetic Predisposition to Disease genetics, Myocardial Infarction genetics
- Abstract
Aim: To identify polymorphisms and haplotypes in candidate genes that predispose to myocardial infarction (MI) using a multilocus approach., Methods and Results: 1052 subjects, comprising 547 acute MI cases and 505 controls were studied. The association between MI and 58 SNPs in 35 candidate genes (generating 61 016 individual genotypes), and between MI and estimated haplotypes at 14 loci encompassing 16 genes was investigated. Two individual gene variants and haplotypes at two loci showed statistical association with MI. The alpha-adducin 460trp variant (OR 0.73, 95% CI 0.59-0.91, P=0.006) and the cholesteryl ester transfer protein -629A variant (OR 0.82, 95% CI 0.68-0.97, P=0.025) were both associated with a significant protective effect on MI, as was the paraoxonase 1/paraoxonase 2 haplotype comprising met55 and gln192 in paraoxonase 1 and cys311 in paraoxonase 2 (OR 0.52, 95% CI 0.39-0.77, P=0.001). The apolipoprotein C III haplotypes CCTTCG and ATCCCG at positions -641*-482*-455*1100*3175*3206 were associated with an increased risk of MI, odds ratios 1.41 (95% CI 1.06-1.76, P=0.023) and 1.71 (95% CI 1.28-2.14, P=0.038), respectively., Conclusions: We report associations of two polymorphisms and haplotypes at two loci with risk of MI that warrants testing in future studies. Furthermore, we demonstrate the application of a multilocus assay in the setting of a large association study and the additional benefit gained from the study of haplotypes to identify variants influencing risk of coronary heart disease.
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- 2004
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40. Exon repetition: a major pathway for processing mRNA of some genes is allele-specific.
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Rigatti R, Jia JH, Samani NJ, and Eperon IC
- Subjects
- Animals, Coenzyme A Ligases, Heterozygote, Molecular Sequence Data, Proteins genetics, RNA Precursors genetics, RNA Splice Sites genetics, RNA, Messenger genetics, Rats, Rats, Inbred SHR, Rats, Inbred WKY, Regulatory Sequences, Ribonucleic Acid genetics, Reverse Transcriptase Polymerase Chain Reaction, Trans-Splicing genetics, Alleles, Exons genetics, Models, Genetic, RNA Precursors metabolism, RNA Processing, Post-Transcriptional, RNA, Messenger metabolism, Repetitive Sequences, Nucleic Acid genetics
- Abstract
Exon repetition describes the presence of tandemly repeated exons in mRNA in the absence of duplications in the genome. Its existence challenges our understanding of gene expression, because the linear organization of sequences in apparently normal genes must be subverted during RNA synthesis or processing. It is restricted to a small number of genes in some of which over half of the mRNA contains specific patterns of repetition. Although it is sometimes assumed to arise by trans-splicing, there is no evidence of this and the efficiency is very much higher than for examples of bona fide trans-splicing in mammals. Furthermore, a potentially ubiquitous reaction such as trans-splicing is not consistent with a phenomenon that involves such a high proportion of the products of so few genes. Instead, it seems more probable that exon repetition is caused by a specific trans-acting factor. We have tested this and demonstrate for the two best characterized examples that the property is restricted to specific alleles of the affected genes and is determined in cis. It is not determined by exonic splicing signals, as had been suggested previously. In heterozygotes, RNA transcribed from the two alleles of an affected gene can have fundamentally different fates.
- Published
- 2004
- Full Text
- View/download PDF
41. Impact of renin-angiotensin-aldosterone system gene variants on the severity of hypertension in patients with newly diagnosed hypertension.
- Author
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Tiago AD, Badenhorst D, Nkeh B, Candy GP, Brooksbank R, Sareli P, Libhaber E, Samani NJ, Woodiwiss AJ, and Norton GR
- Subjects
- Angiotensinogen genetics, Angiotensinogen physiology, Blood Pressure Monitoring, Ambulatory, Cytochrome P-450 CYP11B2 physiology, Female, Humans, Hypertension ethnology, Hypertension physiopathology, Male, Middle Aged, Outpatients, Peptidyl-Dipeptidase A genetics, Peptidyl-Dipeptidase A physiology, Renin-Angiotensin System physiology, Severity of Illness Index, South Africa, Black People genetics, Cytochrome P-450 CYP11B2 genetics, Hypertension diagnosis, Hypertension genetics, Renin-Angiotensin System genetics
- Abstract
Background: The severity of hypertension has prognostic significance. Previous studies have assessed the relationship between renin-angiotensin-aldosterone system (RAAS) genotype and the severity of hypertension in either treated patients or those who have only recently discontinued treatment., Methods: We assessed the impact of RAAS genotype on ambulatory and office blood pressure (BP) in 231 newly diagnosed hypertensive patients of African ancestry who had never received therapy. Subjects were genotyped for variants of the angiotensin-converting enzyme (insertion/deletion), angiotensinogen (M235T, -20A-->C), and aldosterone synthase (CYP11B2)(-344C-->T) genes., Results: The CYP11B2 gene polymorphism was associated with systolic BP (SBP). In comparison to subjects with at least one copy of the -344C allele (n = 75), patients who were homozygous for the -344T allele (n = 156) had both higher ambulatory SBP (150 +/- 1 v 144 +/- 1 mm Hg, P =.002 before and P =.01 after adjusting for multiple genotyping) and office SBP (163 +/- 2 v 156 +/- 2 mm Hg, P =.01 before and P =.05 after adjusting for multiple genotyping). Neither the angiotensin-converting enzyme insertion/deletion nor the angiotensinogen gene polymorphisms were associated with ambulatory or office SBP or diastolic BP (DBP). The CYP11B2 gene variant also did not affect DBP., Conclusion: A variant within the CYP11B2 locus has a clinically important impact on the severity of SBP changes in individuals with newly diagnosed hypertension who are of African ethnicity.
- Published
- 2003
- Full Text
- View/download PDF
42. A polymorphism of the cholesteryl ester transfer protein gene predicts cardiovascular events in non-smokers in the West of Scotland Coronary Prevention Study.
- Author
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Freeman DJ, Samani NJ, Wilson V, McMahon AD, Braund PS, Cheng S, Caslake MJ, Packard CJ, and Gaffney D
- Subjects
- Aged, Anticholesteremic Agents therapeutic use, Cholesterol Ester Transfer Proteins, Coronary Disease prevention & control, Genotype, Homozygote, Humans, Male, Middle Aged, Multivariate Analysis, Polymorphism, Genetic, Pravastatin therapeutic use, Risk Factors, Scotland, Smoking adverse effects, Cardiovascular Diseases genetics, Carrier Proteins genetics, Glycoproteins
- Abstract
Aim: The association of cholesteryl ester transfer protein (CETP) gene polymorphisms with risk of a cardiovascular event and whether any association was explained by an influence on high-density lipoprotein (HDL) levels or low-density lipoprotein (LDL) size was tested in the West of Scotland Coronary Prevention Study (WOSCOPS). Gene-smoking and gene-treatment interactions were investigated., Methods and Results: Cases (n=498) and controls (n=1108) were typed for TaqIB, C(-631)A, C(-629)A, I405V and D442G CETP polymorphisms. Homozygotes for the TaqIB2 allele (B2B2) had a 30% reduced risk of a cardiovascular event (odds ratio [OR] 0.70, CI(95)0.51-0.96, P=0.03) compared to B1B1 homozygotes. Inclusion of HDL or LDL diameter in multivariate analysis only marginally attenuated the relationships. Non-smokers, but not smokers, showed a dose-dependent association of risk with TaqIB genotype. Treatment benefit was not significantly different in B1B1 (OR 0.71, pravastatin vs placebo), B1B2 (OR 0.68) and B2B2 (OR 0.61) individuals. The other CETP polymorphisms studied had no significant association with cardiovascular risk. Haplotype analysis did not add to the information given by the individual polymorphisms., Conclusion: The association between CETP TaqIB genotype and cardiovascular risk is primarily in non-smokers, is not fully explained by effects on HDL levels or LDL size, and the benefit of pravastatin treatment was not influenced by this polymorphism.
- Published
- 2003
- Full Text
- View/download PDF
43. T594M variant of the epithelial sodium channel beta-subunit gene and hypertension in individuals of African ancestry in South Africa.
- Author
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Nkeh B, Samani NJ, Badenhorst D, Libhaber E, Sareli P, Norton GR, and Woodiwiss AJ
- Subjects
- Blood Pressure, Body Constitution, Case-Control Studies, Epithelial Sodium Channels, Female, Genotype, Humans, Hypertension ethnology, Male, Middle Aged, South Africa, Black People genetics, Hypertension genetics, Point Mutation, Sodium Channels genetics
- Abstract
Background: The T594M variant of the beta-subunit of the sodium epithelial channel (ENaC) gene may contribute to hypertension in individuals of African origin., Methods: A case-control study was performed to assess the role of the ENaC gene variant as an independent risk factor for hypertension in subjects of African ancestry. The effects of the ENaC gene variant on ambulatory blood pressure (BP) in hypertensive individuals and on office BP in hypertensive individuals and control subjects were also assessed. A total of 519 hypertensive patients with 24-h ambulatory BP (ABP) values determined while off medication, and 514 normotensive South African individuals of African ancestry were genotyped for the T594M polymorphism of the ENaC gene., Results: A total of 22 (4.2%) hypertensive participants compared with 23 (4.5%) normotensive participants possessed the T594M variant (odds ratio = 1.06, confidence interval = 0.58 to 1.92, not significant). A similar genotype frequency distribution was noted in subjects representing the two predominant chiefdoms (Nguni and Sotho) in both case and control groups. No differences in frequency distribution of the T594M variant were noted with respect to either body mass index or gender. There were no differences in clinic or ambulatory mean, day, or night BP between hypertensive patients with or without the variant. Similarly, no differences were noted in clinic BP between control subjects with or without the variant. Other phenotypic parameters (including age and hypertension duration and severity) were also similar among hypertensive patients with or without the variant., Conclusion: These results do not support an important role for the T594M variant of the ENaC gene contributing to either the development or severity of hypertension in subjects of African ancestry.
- Published
- 2003
- Full Text
- View/download PDF
44. Genome scans for hypertension and blood pressure regulation.
- Author
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Samani NJ
- Subjects
- Blood Pressure genetics, Humans, Blood Pressure physiology, Genome, Human, Hypertension genetics
- Published
- 2003
- Full Text
- View/download PDF
45. Systemic cholesterol crystal embolisation with pulmonary involvement: a fatal combination after coronary angiography.
- Author
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Walton TJ, Samani NJ, and Andrews R
- Subjects
- Crystallization, Embolism, Cholesterol diagnosis, Fatal Outcome, Humans, Male, Middle Aged, Coronary Angiography adverse effects, Embolism, Cholesterol etiology, Pulmonary Embolism etiology
- Abstract
Cholesterol crystal embolisation (CCE) is a rare but serious complication of invasive arterial procedures associated with a high mortality, and is a condition that medical staff undertaking invasive vascular procedures should be aware of. It is manifest as a multisystem disorder commonly involving the kidneys and peripheries, but rarely affecting the lungs. A case of fatal CCE with pulmonary involvement is reported, and similar published case reports are reviewed. The pathogenesis of lung involvement in CCE is unclear, but the combination is reported to be invariably fatal.
- Published
- 2002
- Full Text
- View/download PDF
46. Alpha-adducin polymorphism in hypertensives of South African ancestry.
- Author
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Barlassina C, Norton GR, Samani NJ, Woodwiss AJ, Candy GC, Radevski I, Citterio L, Bianchi G, and Cusi D
- Subjects
- Adult, Alleles, Blood Pressure, DNA Primers chemistry, Female, Gene Frequency, Genetic Predisposition to Disease, Genotype, Humans, Hypertension epidemiology, Hypertension metabolism, Male, Middle Aged, Point Mutation, Polymerase Chain Reaction, Prevalence, Retrospective Studies, South Africa epidemiology, Tryptophan genetics, Calmodulin-Binding Proteins genetics, Cytoskeletal Proteins genetics, DNA analysis, Hypertension genetics, Polymorphism, Genetic
- Abstract
The alpha-adducin gene contributes significantly to hypertension in MHS rats (rats of the Milan hypertensive strain) and in some white and Japanese populations, causing a low renin, sodium, and diuretic-sensitive hypertension. No data are available from populations of African ancestry who have a high prevalence of low renin, sodium, and diuretic-sensitive hypertension. We studied the relationship between the 460-Trp variant of alpha-adducin gene with hypertension using a case-control study design in black South Africans. Surprisingly we found that the overall frequency of the 460-Trp allele was low (approximately 6%), but in spite of such relatively low frequency, the 460-Trp allele was 2.5-fold more frequent in hypertensives than normotensives (P = .028), with an odds ratio for hypertension associated to the state of carrier of at least one 460-Trp allele of 2.68. The finding of such low frequency of the 460-Trp allele in individuals of African ancestry points to the substantial ethnic variability of the genes that have been found to be associated with hypertension. On the other hand, it suggests an association of the 460-Trp allele with hypertension also in subjects of African origin.
- Published
- 2000
- Full Text
- View/download PDF
47. Analysis of promoter region polymorphism in the aldosterone synthase gene (CYP11B2) as a risk factor for myocardial infarction.
- Author
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Patel S, Steeds R, Channer K, and Samani NJ
- Subjects
- Alleles, DNA Primers chemistry, Female, Gene Frequency, Genetic Markers, Humans, Male, Middle Aged, Myocardial Infarction enzymology, Odds Ratio, Polymerase Chain Reaction, Risk Factors, Cytochrome P-450 CYP11B2 genetics, Myocardial Infarction genetics, Polymorphism, Genetic, Promoter Regions, Genetic genetics
- Abstract
Several polymorphisms in genes of the reninangiotensin-aldosterone system have been found to have pleiotropic effects on cardiovascular disorders. Recently, a polymorphism (-344 C/T) in the promoter region of the aldosterone synthase gene (CYP11B2), which may influence plasma aldosterone levels, has been reported to strongly influence left ventricular diameters and mass in young adults and arterial stiffness in essential hypertensives. We investigated any association with risk of myocardial infarction (MI). CYP11B2 -344 polymorphism genotypes were determined by polymerase chain reaction (PCR) in 542 acute MI cases and 500 control subjects without history of coronary disease. All subjects were white and <75 years old. There was no significant difference in either genotype distributions (cases CC 17%, CT 52%, TT 31%; controls CC 22%, CT 47%, TT 31%, P = .10) or allele frequencies (cases C/T 0.43/0.57, controls C/T 0.46/0.54, P = .39) between cases and controls. The odds ratio (OR) for MI associated with the CC genotype was 0.75 (0.54-1.05), and remained insignificant when analysis was restricted to the 129 (24%) cases and 193 (37%) controls < 55 years of age (OR 0.68 [0.36-1.27], P = .20). In further analyses, there was no interaction of the polymorphism with other cardiovascular risk factors (smoking, hypertension, diabetes, body mass index, or cholesterol level) in determining MI risk, and the polymorphism did not influence the frequency of these risk factors in either cases or controls. In the case cohort, age at MI was not significantly different in subjects with the three genotypes (CC 61.2 +/- 9.8 years, CT 61.8 +/- 9.1 years, TT 62.2 +/- 9.0 years, P = .69). We conclude that the aldosterone synthase -344 promoter region polymorphism does not significantly influence the risk of MI either directly or via interaction with other risk factors.
- Published
- 2000
- Full Text
- View/download PDF
48. Molecular genetics of susceptibility to the development of hypertension.
- Author
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Samani NJ
- Subjects
- Animals, Disease Models, Animal, Disease Susceptibility, Genetic Linkage, Humans, Phenotype, Polymorphism, Genetic, Blood Pressure genetics, Hypertension genetics
- Abstract
Blood pressure is a quantitative multifactorial trait with both environmental and genetic determinants, with essential hypertension simply representing one extreme of the blood pressure distribution. While much is known about environmental factors that predispose to the development of hypertension, the nature of the genetic factors that increase such susceptibility remain virtually unknown. However, with advances in molecular techniques, several loci that influence blood pressure in rodents have been identified and recently in two selected sets of human hypertensives, a molecular variant at the angiotensinogen locus has been linked to the tendency to hypertension. It is likely that in the next few years several genetic determinants of blood pressure variability in humans will be identified. Such information will not only increase our understanding of the pathophysiology of hypertension and identify novel treatments but may permit preventative and therapeutic measures to be targetted more specifically than at present.
- Published
- 1994
- Full Text
- View/download PDF
49. Ventricular aneurysmectomy: indications, operative findings and outcome at a single centre.
- Author
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Samani NJ, Mauric AT, Nair S, Thompson J, and De Bono DP
- Subjects
- Adult, Aged, Angina Pectoris etiology, Angina Pectoris mortality, Angina Pectoris surgery, Female, Heart Aneurysm complications, Heart Aneurysm mortality, Heart Ventricles surgery, Humans, Intraoperative Complications mortality, Male, Middle Aged, Postoperative Complications mortality, Survival Rate, Treatment Outcome, Heart Aneurysm surgery
- Abstract
We assessed all patients (n = 120) who underwent left ventricular aneurysmectomy as part of a cardiac surgical procedure at the Groby Road Hospital subregional cardiothoracic centre (1980-1990). Of these, 71% had had only one prior myocardial infarction and 84% had symptoms generally associated with aneurysms (congestive cardiac failure, ventricular arrythmias or systemic embolism). The indication for surgery was a combination of angina and aneurysm-related symptoms in 43%, one or more aneurysm-related symptoms in 35%, and angina alone in 22%. The majority of patients (57%) underwent aneurysmectomy and coronary artery bypass grafting, although 35% underwent aneurysmectomy alone. Most (61%) aneurysms were > 6 cm in size, and 75% were located at the apex of the left ventricle. Forty per cent had a mural thrombus, and there was no relationship between prior warfarin use and occurrence of mural thrombus. Overall perioperative mortality was 17% (20 patients), although mortality halved between the first and second halves of the study period. The main reason for perioperative was pump failure. Seventeen patients died late during follow-up (mean 52.5 months), the main cause being further myocardial infarction. Nevertheless, 65% were still alive at 5 years, and 81% and 66% of survivors were still better than pre-operatively at 5 and 8 years, respectively. Post-operative improvement was equally as good in patients who underwent aneurysmectomy alone, or those operated on for aneurysm-related symptoms, as in the whole group. In logistic regression analysis, the only predictor of adverse long-term outcome was the number of previous myocardial infarctions.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1994
50. The renin-angiotensin system in cardiovascular physiology and disease: new insights from molecular studies.
- Author
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Samani NJ
- Subjects
- Alleles, Angiotensin-Converting Enzyme Inhibitors metabolism, Humans, Myocardial Infarction genetics, Renin-Angiotensin System physiology, Hypertension genetics, Renin-Angiotensin System genetics
- Published
- 1993
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