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Objective: To describe the prevalence and clinical correlates of functional limitations in middle-aged and older adults with long-standing type 1 diabetes.Research Design and Methods: Functional limitations were assessed for 1,094 participants in the Epidemiology of Diabetes Interventions and Complications (EDIC) study, a multicenter, longitudinal, observational follow-up of participants with type 1 diabetes randomly assigned to intensive or conventional diabetes therapy during the Diabetes Control and Complications Trial (DCCT). The primary outcome measure was a score <10 on the Short Physical Performance Battery (SPPB). The secondary outcome, self-reported functional limitation, was assessed by written questionnaire. Logistic regression models were used to assess associations of both outcomes with demographic and clinical factors (glycemic and nonglycemic factors, micro- and macrovascular complications, DCCT cohort, and treatment assignment).Results: Participants were 53% male, with mean ± SD age 59.5 ± 6.8 years and diabetes duration 37.9 ± 4.9 years. The prevalence of SPPB score <10 was 21%. The prevalence of self-reported functional limitations was 48%. While DCCT treatment assignment was not associated with physical function outcomes measured ∼25 years after the end of the DCCT, the time-weighted mean DCCT/EDIC HbA1c was associated with both outcomes. Other clinical factors associated with both outcomes in multivariable analyses were BMI, general psychological distress, and cardiac autonomic neuropathy.Conclusions: Almost half of the middle-aged and older adults with long-standing type 1 diabetes reported functional limitations, which were associated with higher HbA1c and BMI, general psychological distress, and cardiac autonomic neuropathy. Future research is needed to determine whether these findings are generalizable. [ABSTRACT FROM AUTHOR]

We determined the relationship between plasma kallikrein and cardiovascular disease (CVD) outcomes as well as major adverse cardiovascular events (MACE) in the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) cohort of type 1 diabetes (T1D). Plasma kallikrein levels were measured longitudinally in 693 subjects at DCCT baseline (1983-1989), midpoint (1988-1991), and end (1993) and at EDIC years 4-6 (1997-1999), 8-10 (2001-2003), and 11-13 (2004-2006). Cox proportional hazards regression models assessed the association between plasma kallikrein levels and the risk of CVD. In unadjusted models, higher plasma kallikrein levels were associated with higher risk of any CVD during DCCT/EDIC (hazard ratio [HR] = 1.16 per 20 nmol/L higher levels of plasma kallikrein; P = 0.0177) as well as over the EDIC-only period (HR = 1.22; P = 0.0024). The association between plasma kallikrein levels and the risk of any CVD remained significant during the EDIC follow-up after adjustment for age and mean HbA1c (HR = 1.20; P = 0.0082) and in the fully adjusted model for other CVD risk factors (HR = 1.17; P = 0.0330). For MACE, higher plasma kallikrein levels were associated with higher risk in the unadjusted (HR = 1.25; P = 0.0145), minimally adjusted (HR = 1.23; P = 0.0417, and fully adjusted (HR = 1.27; P = 0.0328) models for EDIC only. These novel findings indicate that plasma kallikrein level associates with the risk of any CVD and MACE in T1D individuals. [ABSTRACT FROM AUTHOR]

Most replicated genetic determinants for type 1 diabetes are common (minor allele frequency [MAF] >5%). We aimed to identify novel rare or low-frequency (MAF <5%) single nucleotide polymorphisms with large effects on risk of type 1 diabetes. We undertook deep imputation of genotyped data followed by genome-wide association testing and meta-analysis of 9,358 type 1 diabetes case and 15,705 control subjects from 12 European cohorts. Candidate variants were replicated in a separate cohort of 4,329 case and 9,543 control subjects. Our meta-analysis identified 27 independent variants outside the MHC, among which 3 were novel and had MAF <5%. Three of these variants replicated with Preplication < 0.05 and Pcombined < Pdiscovery In silico analysis prioritized a rare variant at 2q24.3 (rs60587303 [C], MAF 0.5%) within the first intron of STK39, with an effect size comparable with those of common variants in the INS and PTPN22 loci (combined [from the discovery and replication cohorts] estimate of odds ratio [ORcombined] 1.97, 95% CI 1.58-2.47, Pcombined = 2.9 × 10-9). Pharmacological inhibition of Stk39 activity in primary murine T cells augmented effector responses through enhancement of interleukin 2 signaling. These findings provide insight into the genetic architecture of type 1 diabetes and have identified rare variants having a large effect on disease risk. [ABSTRACT FROM AUTHOR]

Objective: The Diabetes Control and Complications Trial (DCCT) and its observational follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) demonstrated the dominant role of glycemia, second only to age, as a risk factor for a first cardiovascular event in type 1 diabetes (T1D). We now investigate the association between established risk factors and the total cardiovascular disease (CVD) burden, including subsequent (i.e., recurrent) events.Research Design and Methods: CVD events in the 1,441 DCCT/EDIC participants were analyzed separately by type (CVD death, acute myocardial infarction [MI], stroke, silent MI, angina, percutaneous transluminal coronary angioplasty/coronary artery bypass graft [PTCA/CABG], and congestive heart failure [CHF]) or as composite outcomes (CVD or major adverse cardiovascular events [MACE]). Proportional rate models and conditional models assessed associations between risk factors and CVD outcomes.Results: Over a median follow-up of 29 years, 239 participants had 421 CVD events, and 120 individuals had 149 MACE. Age was the strongest risk factor for acute MI, silent MI, stroke, and PTCA/CABG, while glycemia was the strongest risk factor for CVD death, CHF, and angina, second strongest for acute MI and PTCA/CABG, third strongest for stroke, and not associated with silent MI. HbA1c was the strongest modifiable risk factor for a first CVD event (CVD: HR 1.38 [95% CI 1.21, 1.56] per 1% higher HbA1c; MACE: HR 1.54 [1.30, 1.82]) and also for subsequent CVD events (CVD: incidence ratio [IR] 1.28 [95% CI 1.09, 1.51]; MACE: IR 1.89 [1.36, 2.61]).Conclusions: Intensive glycemic management is recommended to lower the risk of initial CVD events in T1D. After a first event, optimal glycemic control may reduce the risk of recurrent CVD events and should be maintained. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the prevalence of hearing impairment in participants with type 1 diabetes enrolled in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study and compare with that of a spousal control group without diabetes. Among participants with type 1 diabetes, to evaluate the association of hearing impairment with prior DCCT therapy and overall glycemia.Research Design and Methods: DCCT/EDIC participants (n = 1,150) and 288 spouses without diabetes were recruited for the DCCT/EDIC Hearing Study. All subjects completed a self-administered questionnaire, medical history, and physical measurements. Audiometry was performed by study-certified personnel; audiograms were assessed centrally. Speech-frequency (pure-tone average [PTA] thresholds at 500, 1,000, 2,000, and 4,000 Hz) and high-frequency impairment (PTA thresholds at 3,000, 4,000, 6,000, and 8,000 Hz) were defined as PTA >25 dB hearing loss. Logistic regression models were adjusted for age and sex.Results: DCCT/EDIC participants and spousal control subjects were similar in age, race, education, smoking, and systolic blood pressure. There were no statistically significant differences between groups in the prevalence or adjusted odds of speech- or high-frequency impairment in either ear. Among participants with type 1 diabetes, for every 10% increase in the time-weighted mean HbA1c, there was a 32% (95% CI 1.15-1.50) and 19% (95% CI 1.07-1.33) increase in speech- and high-frequency hearing impairment, respectively.Conclusions: We found no significant difference in the prevalence of hearing impairment between the group with type 1 diabetes and the spousal control group. Among those with type 1 diabetes, higher mean HbA1c over time was associated with hearing impairment. [ABSTRACT FROM AUTHOR]

Objective: Intensive treatment (INT) of type 1 diabetes reduces the incidence of cardiovascular disease (CVD) events compared with conventional treatment (CONV), but it also results in more weight gain. Our objective was to examine whether excessive weight gain from INT of type 1 diabetes is independently associated with subsequent CVD events.Research Design and Methods: Quartiles (Q) of weight gain in 1,213 participants aged 18 years and older at enrollment in the Diabetes Control and Complications Trial (DCCT) were determined within randomized treatment groups (INT vs. CONV) using change in BMI from baseline to the closeout DCCT visits. Effects of this weight gain on CVD risk factors and outcomes during an additional 20 years of observational follow-up were then determined.Results: The Q4 INT group experienced greater proportional weight gain (median change in BMI, 6.08 kg/m2), increases in CVD risk factors, and need for medications for hypertension and lipids compared with the Q1-3 INT and comparable CONV groups. Over a mean of 26 years of follow-up, the numbers of major and total CVD events were not statistically different in Q4 compared with Q1-3 of either the INT or CONV group. By year 14, however, the incident CVD event curve became significantly higher in the Q4 INT group than in the Q1-3 INT groups (P = 0.024) and was similar to that for the CONV group.Conclusions: For the first 13 years after DCCT, INT for type 1 diabetes reduced macrovascular events compared with CONV, even when excessive weight gain occurred. After this, total CVD events significantly increased in the Q4 INT group, becoming equivalent to those in the CONV group. Longer follow-up is needed to determine whether this trend continues and results in more major CVD events. [ABSTRACT FROM AUTHOR]

Risk factors for cardiovascular disease (CVD) are well-established in type 2 but not type 1 diabetes (T1DM). We assessed risk factors in the long-term (mean 27 years) follow-up of the Diabetes Control and Complications Trial (DCCT) cohort with T1DM. Cox proportional hazards multivariate models assessed the association of traditional and novel risk factors, including HbA1c, with major atherosclerotic cardiovascular events (MACE) (fatal or nonfatal myocardial infarction [MI] or stroke) and any-CVD (MACE plus confirmed angina, silent MI, revascularization, or congestive heart failure). Age and mean HbA1c were strongly associated with any-CVD and with MACE. For each percentage point increase in mean HbA1c, the risk for any-CVD and for MACE increased by 31 and 42%, respectively. CVD and MACE were associated with seven other conventional factors, such as blood pressure, lipids, and lack of ACE inhibitor use, but not with sex. The areas under the receiver operating characteristics curves for the association of age and HbA1c, taken together with any-CVD and for MACE, were 0.70 and 0.77, respectively, and for the final models, including all significant risk factors, were 0.75 and 0.82. Although many conventional CVD risk factors apply in T1DM, hyperglycemia is an important risk factor second only to age. [ABSTRACT FROM AUTHOR]

The hypothesis that plasma prekallikrein (PK) is a risk factor for the development of vascular complications was assessed in a study using the Diabetes Control and Complications Trial (DCCT)/Epidemiology and Diabetes Interventions and Complications (EDIC) cohort of subjects with type 1 diabetes. The circulating levels of plasma PK activity were measured in the plasma of 636 subjects with type 1 diabetes (EDIC years 3-5). Common and internal carotid intima-media thickness (IMT) were measured by B-mode ultrasonography in EDIC years 1 and 6. Plasma PK levels were positively and significantly associated with BMI, hemoglobin A1c, systolic blood pressure, total cholesterol, LDL cholesterol, and triglycerides but not with age, sex, duration of diabetes, or HDL cholesterol. Univariate and multivariable statistical models after controlling for other risk factors consistently demonstrated a positive association between plasma PK and progression of internal carotid IMT. Multivariate analysis using a general linear model showed plasma PK to be significantly associated with progression of both internal and combined IMT (Wilks Λ P value of 0.005). In addition, the mean internal carotid IMT levels were higher in subjects with plasma PK levels in the highest 10th percentile compared with subjects with plasma PK levels in the lower 10th percentile (P = 0.048). These novel findings implicate plasma PK as a risk factor for vascular disease in type 1 diabetes. [ABSTRACT FROM AUTHOR]

Objective: Limited information exists about the influence of urologic complications on health-related quality of life (HRQOL) in patients with type 1 diabetes.Research Design and Methods: We studied 664 men and 580 women from the Diabetes Control and Complications Trial/Epidemiology of Interventions and Complications Study: mean ages were 51.6 ± 6.6 and 50.6 ± 7.2 years and duration of diabetes was 29.5 ± 4.8 and 29.8 ± 5.1 years, respectively. We assessed associations of sexual dysfunction, lower urinary tract symptoms (LUTS), and, in women, urinary incontinence (UI) with general quality of life (SF-36), perceived value of health (EuroQol-5), diabetes-related quality of life (Diabetes Quality of Life Scale [DQOL]), and psychiatric symptoms (Symptom Checklist 90-R).Results: In both men and women, urologic complications adversely affected HRQOL and psychiatric symptoms, even after accounting for history of depression leading to treatment. Multivariable analyses accounting for the presence of diabetic retinopathy, neuropathy, and nephropathy also revealed substantial independent effects. In men, for example, the odds (95% CI) of a low DQOL score (≤25th percentile) were 3.01 (1.90-4.75) times greater with erectile dysfunction and 2.65 (1.68-4.18) times greater with LUTS and in women, 2.04 (1.25-3.35) times greater with sexual dysfunction and 2.71 (1.72-4.27) times greater with UI/LUTS combined compared with men and women without such complications. Similar effects were observed for the other measures.Conclusions: Sexual dysfunction and urinary complications with type 1 diabetes are associated with decreased quality of life and perceived value of health and with higher levels of psychiatric symptoms, even after accounting for other diabetes complications and depression treatment. [ABSTRACT FROM AUTHOR]

Objective: To examine whether cardiovascular autonomic neuropathy (CAN) is an independent risk factor of cardiovascular disease (CVD) events during DCCT/EDIC.Research Design and Methods: Standardized cardiovascular autonomic reflex tests (R-R response to paced breathing, Valsalva maneuver, postural changes in blood pressure) were performed at DCCT baseline, every 2 years throughout DCCT, and at two time points in EDIC. CVD events were ascertained throughout the study and adjudicated by a review committee. Cox proportional hazards models were used to estimate the effect of CAN at DCCT closeout on subsequent CVD risk.Results: There were 299 adjudicated CVD events in 165 participants following the DCCT closeout assessment: 132 of 1,262 subjects (10%) without CAN at DCCT closeout who experienced 244 CVD events versus 33 of 131 subjects (25%) with CAN at DCCT closeout who experienced 55 events (hazard ratio 2.79, 95% CI 1.91-4.09 for time to first CVD event). The cumulative incidence of the first occurrence of any CVD event during EDIC was significantly higher in participants with CAN at DCCT closeout compared with those without CAN. The association remained marginally significant after adjustment for multiple risk factors, including the EDIC updated mean HbA1c. When analyzed as a continuous variable, R-R variation was significantly lower at DCCT closeout in participants who experienced a CVD event compared with those who did not (P = 0.0012).Conclusions: In the DCCT/EDIC cohort, individuals diagnosed with CAN at DCCT closeout experienced a higher long-term risk of CVD events during follow-up in EDIC. This association was not independent of historic glycemic exposure and its metabolic memory effect, the principal determinant of both long-term CVD risk and CAN in type 1 diabetes. [ABSTRACT FROM AUTHOR]

BACKGROUNDWe investigated residual β cell function in Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study participants with an average 35-year duration of type 1 diabetes mellitus (T1DM).METHODSSerum C-peptide was measured during a 4-hour mixed-meal tolerance test. Associations with metabolic outcomes and complications were explored among nonresponders (all C-peptide values after meal <0.003 nmol/L) and 3 categories of responders, classified by peak C-peptide concentration (nmol/L) as high (>0.2), intermediate (>0.03 to ≤0.2), and low (≥ 0.003 to ≤0.03).RESULTSOf the 944 participants, 117 (12.4%) were classified as responders. Residual C-peptide concentrations were associated with higher DCCT baseline concentrations of stimulated C-peptide (P value for trend = 0.0001). Residual C-peptide secretion was not associated with current or mean HbA1c, HLA high-risk haplotypes for T1DM, or the current presence of T1DM autoantibodies. The proportion of subjects with a history of severe hypoglycemia was lower with high (27%) and intermediate (48%) residual C-peptide concentrations than with low (74%) and no (70%) residual C-peptide concentrations (P value for trend = 0.0001). Responders and nonresponders demonstrated similar rates of advanced microvascular complications.CONCLUSIONβ Cell function can persist in long-duration T1DM. With a peak C-peptide concentration of >0.03 nmol/L, we observed clinically meaningful reductions in the prevalence of severe hypoglycemia.TRIAL REGISTRATIONClinicalTrials.gov NCT00360815 and NCT00360893.FUNDINGDivision of Diabetes Endocrinology and Metabolic Diseases of the National Institute of Diabetes and Digestive and Kidney Diseases (DP3-DK104438, U01 DK094176, and U01 DK094157). [ABSTRACT FROM AUTHOR]

Background: In patients who have had type 1 diabetes for 5 years, current recommendations regarding screening for diabetic retinopathy include annual dilated retinal examinations to detect proliferative retinopathy or clinically significant macular edema, both of which require timely intervention to preserve vision. During 30 years of the Diabetes Control and Complications Trial (DCCT) and its longitudinal follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) study, retinal photography was performed at intervals of 6 months to 4 years.Methods: We used retinal photographs from the DCCT/EDIC study to develop a rational screening frequency for retinopathy. Markov modeling was used to determine the likelihood of progression to proliferative diabetic retinopathy or clinically significant macular edema in patients with various initial retinopathy levels (no retinopathy or mild, moderate, or severe nonproliferative diabetic retinopathy). The models included recognized risk factors for progression of retinopathy.Results: Overall, the probability of progression to proliferative diabetic retinopathy or clinically significant macular edema was limited to approximately 5% between retinal screening examinations at 4 years among patients who had no retinopathy, 3 years among those with mild retinopathy, 6 months among those with moderate retinopathy, and 3 months among those with severe nonproliferative diabetic retinopathy. The risk of progression was also closely related to mean glycated hemoglobin levels. The risk of progression from no retinopathy to proliferative diabetic retinopathy or clinically significant macular edema was 1.0% over 5 years among patients with a glycated hemoglobin level of 6%, as compared with 4.3% over 3 years among patients with a glycated hemoglobin level of 10%. Over a 20-year period, the frequency of eye examinations was 58% lower with our practical, evidence-based schedule than with routine annual examinations, which resulted in substantial cost savings.Conclusions: Our model for establishing an individualized schedule for retinopathy screening on the basis of the patient's current state of retinopathy and glycated hemoglobin level reduced the frequency of eye examinations without delaying the diagnosis of clinically significant disease. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; DCCT/EDIC ClinicalTrials.gov numbers, NCT00360893 and NCT00360815 .). [ABSTRACT FROM AUTHOR]

Aims/hypothesis: Haptoglobin(Hp) 2-2 genotype has been shown to increase coronary artery disease (CAD) risk in numerous type 2 diabetes studies but in only one type 1 diabetes cohort. We assessed the association of Hp2-2 with incident CAD over 26years of follow-up in 1303 Caucasian participants of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study.Methods: DCCT randomized volunteers with type 1 diabetes to intensive versus conventional therapy within two cohorts: 'primary prevention' with 1-5years diabetes duration and 'secondary intervention' with 1-15years diabetes duration and early retinopathy, with or without albuminuria, but no advanced complications. CAD was defined as myocardial infarction (MI) or death judged to be from CAD, silent MI, angina, coronary revascularization, or congestive heart failure due to CAD.Results: In the entire DCCTcohort, Hp2-2 was not significantly associated with incident CAD or MI. However, in pre-specified exploratory subgroup analyses, an increased MI risk was suggested in the secondary cohort for those with Hp2-2.Conclusions/interpretation: The analysis does not statistically confirm an overall association between Hp 2-2 and incident CAD, however, some suggestions of associations were observed in secondary analyses. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To determine the relationships between C-reactive protein (CRP) levels and features of Type 1 diabetes. Research Design and Methods: Serum CRP was measured by nephelometry in a cross-sectional study of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) cohort (n=983) and nondiabetic subjects (n=71). Results: CRP levels [geometric mean (95% CI)] were higher in diabetic than in control subjects, 1.6 (1.5–1.7) vs. 1.2 (1.1–1.5) mg/l, P=.019. CRP was higher in diabetic women (n=438) than in men (n=545) [2.0 (1.8–2.3) vs. 1.3 (1.2–1.5), P<.001]. Diabetic subjects formerly in the DCCT intensive treatment group had higher CRP levels than those who were randomized to the conventional treatment group [1.8 (1.6–1.9), n=479 vs. 1.5 (1.3–1.6), n=456, P=.010], attributable to greater BMI in the prior intensive group. In diabetes, CRP correlated with HbA1c (r=0.13, P<.0001) and with insulin resistance traits: BMI (r=0.34, P<.0001), waist-to-hip ratio (WHR; males: r=0.35, P<.0001; females: r=0.22, P<.0001), diastolic blood pressure (r=0.07, P=.025), triglycerides (r=0.19, P<.0001), apoB (r=0.22, P<.0001), LDL particle concentration (r=0.26, P<.0001), and LDL particle size (r=−0.22, P<.0001). CRP was not associated with complications. Significant independent predictors of CRP in diabetes were gender, BMI, WHR, concurrent HbA1c, and oral contraceptive pill use. Conclusions: CRP was elevated relative to nondiabetic subjects, and in diabetes was higher in females. Elevated CRP in Type 1 diabetes was associated with poor glycemic control, larger body habitus, and other factors that comprise the insulin resistance syndrome. Nevertheless, CRP levels were not associated with complications. Longitudinal studies are warranted. [Copyright &y& Elsevier]