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Background:\ud \ud Systemic inflammation has been linked with mood disorder and cognitive impairment. The extent of this relationship remains uncertain, with the effects of serum inflammatory biomarkers compared to genetic predisposition toward inflammation yet to be clearly established.\ud \ud Methods:\ud \ud We investigated the magnitude of associations between C-reactive protein (CRP) measures, lifetime history of bipolar disorder or major depression, and cognitive function (reaction time and visuospatial memory) in 84,268 UK Biobank participants. CRP was measured in serum and a polygenic risk score for CRP was calculated, based on a published genome-wide association study. Multiple regression models adjusted for sociodemographic and clinical confounders.\ud \ud Results:\ud \ud Increased serum CRP was significantly associated with mood disorder history (Kruskal–Wallis H = 196.06, p < 0.001, η2 = 0.002) but increased polygenic risk for CRP was not (F = 0.668, p = 0.648, η2 < 0.001). Compared to the lowest quintile, the highest serum CRP quintile was significantly associated with both negative and positive differences in cognitive performance (fully adjusted models: reaction time B = −0.030, 95% CI = −0.052, −0.008; visuospatial memory B = 0.066, 95% CI = 0.042, 0.089). More severe mood disorder categories were significantly associated with worse cognitive performance and this was not moderated by serum or genetic CRP level.\ud \ud Conclusions:\ud \ud In this large cohort study, we found that measured inflammation was associated with mood disorder history, but genetic predisposition to inflammation was not. The association between mood disorder and worse cognitive performance was very small and did not vary by CRP level. The inconsistent relationship between CRP measures and cognitive performance warrants further study.

Background: Alzheimer’s disease (AD) is a neurodegenerative condition where the underlying etiology is still unclear. Investigating the potential influence of apolipoprotein E (APOE), a major genetic risk factor, on common blood biomarkers could provide a greater understanding of the mechanisms of AD and dementia risk. \ud \ud Objective: Our objective was to conduct the largest (to date) single-protocol investigation of blood biomarkers in the context of APOE genotype, in UK Biobank. Methods:After quality control and exclusions, data on 395,769 participants of White European ancestry were available for analysis. Linear regressions were used to test potential associations between APOE genotypes and biomarkers. \ud \ud Results: Several biomarkers significantly associated with APOE ɛ4 ‘risk’ and ɛ2 ‘protective’ genotypes (versus neutral ɛ3/ɛ3). Most associations supported previous data: for example, ɛ4 genotype was associated with elevated low-density lipoprotein cholesterol (LDL) (standardized beta [b] = 0.150 standard deviations [SDs] per allele, p

Depression is more frequent among individuals exposed to traumatic events. Both trauma exposure and depression are heritable. However, the relationship between these traits, including the role of genetic risk factors, is complex and poorly understood. When modelling trauma exposure as an environmental influence on depression, both gene-environment correlations and gene-environment interactions have been observed. The UK Biobank concurrently assessed Major Depressive Disorder (MDD) and self-reported lifetime exposure to traumatic events in 126,522 genotyped individuals of European ancestry. We contrasted genetic influences on MDD stratified by reported trauma exposure (final sample size range: 24,094–92,957). The SNP-based heritability of MDD with reported trauma exposure (24%) was greater than MDD without reported trauma exposure (12%). Simulations showed that this is not confounded by the strong, positive genetic correlation observed between MDD and reported trauma exposure. We also observed that the genetic correlation between MDD and waist circumference was only significant in individuals reporting trauma exposure (rg = 0.24, p = 1.8 × 10−7 versus rg = −0.05, p = 0.39 in individuals not reporting trauma exposure, difference p = 2.3 × 10−4). Our results suggest that the genetic contribution to MDD is greater when reported trauma is present, and that a complex relationship exists between reported trauma exposure, body composition, and MDD.

Additional file 1: Table S1. Characteristics of the population according to their COVID-19 test and the frailty index. Table S2. Associations between the frailty phenotype and severe COVID-19 infection (sensitivity analysis).

Supplemental material, APOE-CamCAN-BNA-Stage2_SupMat for Effect of apolipoprotein E polymorphism on cognition and brain in the Cambridge Centre for Ageing and Neuroscience cohort by Richard N. Henson, Sana Suri, Ethan Knights, James B. Rowe, Rogier A. Kievit, Donald M. Lyall, Dennis Chan, Else Eising and Simon E. Fisher in Brain and Neuroscience Advances

Objectives: \ud To determine the independent association of central adiposity, assessed by waist circumference, with odds of psoriasis, PsA and RA prevalence after controlling for general adiposity (BMI).\ud \ud Methods: \ud A cross-sectional study of UK Biobank participants aged 40–70 years was performed. Logistic regression was used to calculate the odds of psoriasis, PsA and RA occurrence compared with controls without these conditions by waist circumference, adjusting for covariates: age, sex, smoking status, socioeconomic deprivation and self-reported physical activity (Model 1), followed additionally by BMI (Model 2).\ud \ud Results: \ud A total of 502 417 participants were included; 5074 with psoriasis (1.02%), 905 with PsA (0.18%), 5532 with RA (1.11%) and 490 906 controls without these conditions. Adjusted odds ratios (ORs) (Model 1) for psoriasis, PsA and RA, per S.D. (13.5 cm) higher waist circumference were 1.20 (95% CI 1.16, 1.23), 1.30 (95% CI 1.21, 1.39) and 1.21 (95% CI 1.17, 1.24), respectively (all P < 0.001). These ORs remained significant after further adjustment for BMI (Model 2) in psoriasis [OR 1.19 (95% CI 1.12, 1.27), P < 0.001] and RA [OR 1.19 (95% CI 1.12, 1.26), P < 0.001], but not in PsA [OR 1.11 (95% CI 0.95, 1.29), P = 0.127].\ud \ud Conclusion: \ud Central adiposity as measured by waist circumference is associated with greater odds of psoriasis and RA prevalence after adjustment for confounders and for BMI. Our findings add support for central adiposity as a long-term clinically relevant component of these conditions.

Objective:\ud To investigate the association of cardiorespiratory fitness with all-cause mortality, and cardiovascular, respiratory, COPD and cancer mortality and incidence.\ud \ud Design:\ud Prospective population based study.\ud \ud Setting: \ud UK Biobank.\ud \ud Participants:\ud Of the 502,628 (5.5% response rate) participants recruited by UK Biobank, we included 73,259 (14.6%) participants with available data in this analysis. Of these, 1,374 participants died and 4,210 developed circulatory diseases, 1,293 respiratory diseases and 4,281 cancer, over a median of 5.0 years [IQR 4.3–5.7] follow-up.\ud Main outcome measures - All-cause mortality and circulatory disease, respiratory disease, chronic obstructive e pulmonary disease (COPD) and cancer (any-type, colorectal, lung, breast and prostate) mortality/incidence. Fitness was estimated with a submaximal cycle ergometer test.\ud \ud Results:\ud The hazard ratio for all-cause mortality for each MET higher fitness was 0.96 ([95% CI 0.93–0.98]). Similar results were observed for incident circulatory (HR 0.96 [0.95–0.97]), respiratory disease (HR 0.96 [0.94–0.98]), COPD (HR 0.90 [0.86–0.95]), and colorectal cancer (HR 0.96 [0.92–1.00]). Nonlinear analysis revealed that a high level of fitness (>10 METs) was associated with a greater incidence of atrial fibrillation (HR 1.24 [1.07–1.44]) and prostate cancer (HR 1.16 [1.02–1.32]) compared with average fitness. All results were adjusted for sociodemographic, lifestyle, and dietary factors, body composition, and morbidity at baseline and excluded events in the first 2 years of follow up.\ud \ud Conclusions:\ud Higher cardiorespiratory fitness was associated with lower risk of premature mortality and incidence of cardiovascular, respiratory disease and colorectal cancer.

Objective:\ud \ud To investigate the associations of objectively measured cardiorespiratory fitness (CRF) and grip strength (GS) with incident heart failure (HF), a clinical syndrome that results in substantial social and economic burden, using UK Biobank data.\ud Patients and Methods:\ud \ud Of the 502,628 participants recruited into the UK Biobank between April 1, 2007, and December 31, 2010, a total of 374,493 were included in our GS analysis and 57,053 were included in CRF analysis. Associations between CRF and GS and incident HF were investigated using Cox proportional hazard models, with adjustment for known measured confounders.\ud Results:\ud \ud During a mean of 4.1 (range, 2.4-7.1) years, 631 HF events occurred in those with GS data, and 66 HF events occurred in those with CRF data. Higher CRF was associated with 18% lower risk for HF (hazard ratio [HR], 0.82; 95% CI, 0.76-0.88) per 1–metabolic equivalent increment increase and GS was associated with 19% lower incidence of HF risk (HR, 0.81; 95% CI, 0.77-0.86) per 5-kg increment increase. When CRF and GS were standardized, the HR for CRF was 0.50 per 1-SD increment (95% CI, 0.38-0.65), and for GS was 0.65 per 1-SD increment (95% CI, 0.58-0.72).\ud Conclusion:\ud \ud Our data indicate that objective measurements of physical function (GS and CRF) are strongly and independently associated with lower HF incidence. Future studies targeting improving CRF and muscle strength should include HF as an outcome to assess whether these results are causal.

Aims: \ud Cardiometabolic diseases (hypertension, coronary artery disease [CAD] and diabetes are known to associate with poorer cognitive ability but there are limited data on whether having more than one of these conditions is associated with additive effects. We aimed to quantify the magnitude of their associations with non-demented cognitive abilities and determine the extent to which these associations were additive.\ud Methods and results: \ud We examined cognitive test scores in domains of reasoning, information processing speed and memory, included as part of the baseline UK Biobank cohort assessment (N = 474 129 with relevant data), adjusting for a range of potentially confounding variables. The presence of hypertension, CAD and diabetes generally associated with poorer cognitive scores on all tests, compared with a control group that reported none of these diseases. There was evidence of an additive deleterious dose effect of an increasing number of cardiometabolic diseases, for reasoning scores (unstandardized additive dose beta per disease = −0.052 score points out of 13, 95% CI [confidence intervals] −0.063 to − 0.041, P

Background:\ud higher grip strength is associated with better health outcomes. The optimal way to report grip strength (i.e. absolute vs. relative) for prediction, however, remains to be established.\ud \ud Methods:\ud in participants (aged 37–73 at baseline) from the UK Biobank, we examined the associations of grip strength, expressed in absolute terms (kilograms) and relative to anthropometric variables, with mortality and disease incidence, after exclusion of the first 2 years of follow-up, and compared risk predictions scores of handgrip strength when differentially expressed.\ud \ud Results:\ud of the 356 721 participants included in the analysis 6,234 died (1.7%) and 4,523 developed CVD (1.3%) over a mean follow-up of 5.0 years (ranging from 3.3 to 7.8) for mortality and 4.1 years (ranging from 2.4 to 7.0) for disease incidence data. As expected, baseline higher grip strength was associated with lower risk of all-cause and cause specific mortality and incidence. These associations did not meaningfully differ when grip-strength was expressed in absolute terms, vs. relative to height, weight, fat-free mass, BMI, fat-free mass index and fat-free mass, or as z-scores. Similarly the different ways of expressing grip strength had little effect on the ability of grip strength to improve risk prediction, based on C-index change, of an office-based risk score.\ud \ud Conclusions:\ud the ability of grip strength to predict mortality is not altered by changing how it is expressed.

Background: \ud Depression and chronic inflammatory medical conditions have been linked to impaired cognitive ability. However despite frequent comorbidity, their combined association with cognitive ability has rarely been examined.\ud \ud Methods: \ud This study examined associations between self-reported depression and chronic inflammatory diseases and their interaction with cognitive performance in 456,748 participants of the UK Biobank, adjusting for sociodemographic and lifestyle factors. Numbers with available data ranged from 94,899 to 453,208 depending on the cognitive test.\ud \ud Results: \ud Self-reported depression was associated with poorer performance compared to controls in several cognitive tests (fully adjusted models, reaction time: B = 6.08, 95% CI = 5.09, 7.07; pairs matching: incidence rate ratio = 1.02, 95% CI = 1.02, 1.03; Trail Making Test B: B = 1.37, 95% CI = 0.88, 1.87; Digit Symbol Substitution Test (DSST): B = −0.35, 95% CI = −0.44, −0.27). Self-reported chronic inflammatory conditions were associated with slower reaction time (B = 3.79, 95% CI = 2.81, 4.78) and lower DSST scores (B = −0.21, 95% CI = −0.30, −0.13). No interaction effects were observed.\ud \ud Discussion: \ud In this large, population-based study we provide evidence of lower cognitive performance in both depression and a comprehensive category of chronic inflammatory conditions. Results are consistent with additive effects of both types of disorder on cognitive ability. Clinicians should be aware of such effects, particularly as cognitive impairment is linked to poorer disease outcomes and quality of life.

Aims: Several factors are known to increase risk for cerebrovascular disease and dementia, but there is limited evidence on associations between multiple vascular risk factors (VRFs) and detailed aspects of brain macrostructure and microstructure in large community-dwelling populations across middle and older age. Methods and Results: Associations between VRFs (smoking, hypertension, pulse pressure, diabetes, hypercholesterolaemia, body mass index, and waist–hip ratio) and brain structural and diffusion MRI markers were examined in UK Biobank (N = 9722, age range 44–79 years). A larger number of VRFs was associated with greater brain atrophy, lower grey matter volume, and poorer white matter health. Effect sizes were small (brain structural R2 ≤1.8%). Higher aggregate vascular risk was related to multiple regional MRI hallmarks associated with dementia risk: lower frontal and temporal cortical volumes, lower subcortical volumes, higher white matter hyperintensity volumes, and poorer white matter microstructure in association and thalamic pathways. Smoking pack years, hypertension and diabetes showed the most consistent associations across all brain measures. Hypercholesterolaemia was not uniquely associated with any MRI marker.Conclusion: Higher levels of VRFs were associated with poorer brain health across grey and white matter macrostructure and microstructure. Effects are mainly additive, converging upon frontal and temporal cortex, subcortical structures, and specific classes of white matter fibres. Though effect sizes were small, these results emphasize the vulnerability of brain health to vascular factors even in relatively healthy middle and older age, and the potential to partly ameliorate cognitive decline by addressing these malleable risk factors.

Objective:\ud \ud This study aimed to investigate whether the association between a validated genetic profile risk score for BMI (GPRS‐BMI) (based on 93 single‐nucleotide polymorphisms) and phenotypic obesity (BMI) was modified by the combined categories of physical activity (PA) and sedentary behaviors in a large population‐based study.\ud Methods:\ud \ud This study included cross‐sectional baseline data from 338,216 white European adult men and women aged 37 to 73 years. Interaction effects of GPRS‐BMI with the combined categories of PA and sedentary behaviors on BMI were investigated.\ud Results:\ud \ud There was a significant interaction between GPRS‐BMI and the combined categories of objectively measured PA and total sedentary behavior (P[interaction] = 3.5 × 10−6); among physically inactive and highly sedentary individuals, BMI was higher by 0.60 kg/m2 per 1‐SD increase in GPRS‐obesity (P = 8.9 × 10−50), whereas the relevant BMI difference was 38% lower among physically active individuals and those with low sedentary time (β: 0.37 kg/m2; P = 2.3 × 10−51). A similar pattern was observed for the combined categories of objective PA and TV viewing (inactive/high TV viewing β: 0.60 vs. active/low TV viewing β: 0.40 kg/m2; P[interaction] = 2.9 × 10−6).\ud Conclusions:\ud \ud This study provides evidence that combined categories of PA and sedentary behaviors modify the extent to which genetic predisposition to obesity results in higher BMI.

Background:\ud Suicide is a major issue for global public health. Suicidality describes a broad spectrum of thoughts and behaviours, some of which are common in the general population. Although suicide results from a complex interaction of multiple social and psychological factors, predisposition to suicidality is at least partly genetic.\ud \ud Methods:\ud Ordinal genome-wide association study of suicidality in the UK Biobank cohort comparing: ‘no suicidality’ controls (N = 83,557); ‘thoughts that life was not worth living’ (N = 21,063); ‘ever contemplated self-harm’ (N = 13,038); ‘act of deliberate self-harm in the past’ (N = 2498); and ‘previous suicide attempt’ (N = 2666).\ud \ud Outcomes:\ud We identified three novel genome-wide significant loci for suicidality (on chromosomes nine, 11 and 13) and moderate-to-strong genetic correlations between suicidality and a range of psychiatric disorders, most notably depression (rg 0·81).\ud \ud Interpretation:\ud These findings provide new information about genetic variants relating to increased risk of suicidal thoughts and behaviours. Future work should assess the extent to which polygenic risk scores for suicidality, in combination with non-genetic risk factors, may be useful for stratified approaches to suicide prevention at a population level.

Aims: Several factors are known to increase risk for cerebrovascular disease and dementia, but there is limited evidence on associations between multiple vascular risk factors (VRFs) and detailed aspects of brain macro- and microstructure in large community-dwelling populations across middle- and older age. Methods and Results: Associations between VRFs (smoking, hypertension, pulse pressure, diabetes, hypercholersterolaemia, BMI, and waist-hip ratio) and both global and regional brain structural and diffusion MRI markers were examined in UK Biobank (N = 9722, age range 44-77 years). A larger number of VRFs was associated with greater brain atrophy, lower grey matter volume, and poorer white matter health. Effect sizes were small (brain structural R2 ≤ 1.8%). Higher aggregate vascular risk was related to multiple regional MRI hallmarks associated with dementia risk: lower frontal and temporal cortical volumes, lower subcortical volumes, higher white matter hyperintensity volumes, and poorer white matter microstructure in association and thalamic pathways. Smoking pack years, hypertension and diabetes showed the most consistent associations across all brain measures. Hypercholesterolaemia was not uniquely associated with any MRI marker. Conclusion: Higher levels of VRFs were associated with poorer brain health across grey and white matter macro- and microstructure. Effects are mainly additive, converging upon frontal and temporal cortex, subcortical structures, and specific classes of white matter fibres. Though effect sizes were small, these results emphasise the vulnerability of brain health to vascular factors even in relatively healthy middle and older age, and the potential to partly ameliorate cognitive decline by addressing these malleable risk factors.

Completed STROBE checklist for cross-sectional studies for manuscript 'Social engagement after stroke - is it relevant to cognitive function? A cross-sectional analysis of UK Biobank data"

Background: \ud Circadian rhythms are fundamental to health and are particularly important for mental wellbeing. Disrupted rhythms of rest and activity are recognised as risk factors for major depressive disorder and bipolar disorder.\ud \ud Methods: \ud We conducted a genome-wide association study (GWAS) of low relative amplitude (RA), an objective measure of rest-activity cycles derived from the accelerometer data of 71,500 UK Biobank participants. Polygenic risk scores (PRS) for low RA were used to investigate potential associations with psychiatric phenotypes.\ud \ud Outcomes: \ud Two independent genetic loci were associated with low RA, within genomic regions for Neurofascin (NFASC) and Solute Carrier Family 25 Member 17 (SLC25A17). A secondary GWAS of RA as a continuous measure identified a locus within Meis Homeobox 1 (MEIS1). There were no significant genetic correlations between low RA and any of the psychiatric phenotypes assessed. However, PRS for low RA was significantly associated with mood instability across multiple PRS thresholds (at PRS threshold 0·05: OR = 1·02, 95% CI = 1·01–1·02, p = 9·6 × 10−5), and with major depressive disorder (at PRS threshold 0·1: OR = 1·03, 95% CI = 1·01–1·05, p = 0·025) and neuroticism (at PRS threshold 0·5: Beta = 0·02, 95% CI = 0·007–0·04, p = 0·021).\ud \ud Interpretation: \ud Overall, our findings contribute new knowledge on the complex genetic architecture of circadian rhythmicity and suggest a putative biological link between disrupted circadian function and mood disorder phenotypes, particularly mood instability, but also major depressive disorder and neuroticism.\ud \ud Funding: \ud Medical Research Council (MR/K501335/1).

Aims The data regarding the associations of body mass index (BMI) with cardiovascular (CVD) risk, especially for those at the low categories of BMI, are conflicting. The aim of our study was to examine the associations of body composition (assessed by five different measures) with incident CVD outcomes in healthy individuals. Methods and results A total of 296 535 participants (57.8% women) of white European descent without CVD at baseline from the UK biobank were included. Exposures were five different measures of adiposity. Fatal and non-fatal CVD events were the primary outcome. Low BMI (≤18.5 kg m−2) was associated with higher incidence of CVD and the lowest CVD risk was exhibited at BMI of 22–23 kg m−2 beyond, which the risk of CVD increased. This J-shaped association attenuated substantially in subgroup analyses, when we excluded participants with comorbidities. In contrast, the associations for the remaining adiposity measures were more linear; 1 SD increase in waist circumference was associated with a hazard ratio of 1.16 [95% confidence interval (CI) 1.13–1.19] for women and 1.10 (95% CI 1.08–1.13) for men with similar magnitude of associations for 1 SD increase in waist-to-hip ratio, waist-to-height ratio, and percentage body fat mass. Conclusion Increasing adiposity has a detrimental association with CVD health in middle-aged men and women. The association of BMI with CVD appears more susceptible to confounding due to pre-existing comorbidities when compared with other adiposity measures. Any public misconception of a potential ‘protective’ effect of fat on CVD risk should be challenged. Take home figureThe obesity paradox is mainly due to the effect of confounding on BMI and disappears on other adiposity measures.