Epicardial and intra-thoracic adipose tissue and cardiovascular calcifications in type 1 diabetes (T1D) in epidemiology of diabetes Interventions and Complications (EDIC): A pilot study.

Objective: Coronary artery, aortic valve, and descending aorta calcification (CAC, AVC, DAC) are manifestations of atherosclerosis, and cardiac epicardial adipose tissue (EAT) indicates heart adiposity. This study explored the association between cardiac adipose tissue and cardiovascular calcification in participants with long-standing T1D. Methods: EAT and intra-thoracic adipose tissue (IAT) were measured in 100 T1D subjects with cardiac computed tomography (CT) scans in the EDIC study. Volume analysis software was used to measure fat volumes. Spearman correlations were calculated between CAC, AVC, DAC with EAT, and IAT. Associations were evaluated using multiple linear and logistic regression models. Results: Participants ranged in age from 32 to 57. Mean EAT, and IAT were 38.5 and 50.8 mm3, respectively, and the prevalence of CAC, AVC, and DAC was 43.6 %, 4.7 %, and 26.8 %, respectively. CAC was positively correlated with age (p-value = 0.0001) and EAT (p-value = 0.0149) but not with AVC and DAC; IAT was not associated with calcified lesions. In models adjusted for age and sex, higher levels of EAT and IAT were associated with higher CAC (p-value < 0.0001 for both) and higher AVC (p-values of 0.0111 and 0.0053, respectively), but not with DAC. The associations with CAC remained significant (p-value < 0.0001) after further adjustment for smoking, systolic blood pressure, BMI, and LDL, while the associations with AVC did not remain significant. Conclusion: In participants with T1D, higher EAT and IAT levels are correlated with higher CAC scores. EAT and IAT were not independently correlated with DAC or AVC.

Evidence for C-Peptide as a Validated Surrogate to Predict Clinical Benefits in Trials of Disease-Modifying Therapies for Type 1 Diabetes.

Type 1 diabetes is a chronic autoimmune disease in which destruction of pancreatic ß-cells causes life-threatening metabolic dysregulation. Numerous approaches are envisioned for new therapies, but limitations of current clinical outcome measures are significant disincentives to development efforts. C-peptide, a direct byproduct of proinsulin processing, is a quantitative biomarker of ß-cell function that is not cleared by the liver and can be measured in the peripheral blood. Studies of quantitative measures of ß-cell function have established a predictive relationship between stimulated C-peptide as a measure of ß-cell function and clinical benefits. C-peptide levels at diagnosis are often high enough to afford glycemic control benefits associated with protection from end-organ complications of diabetes, and even lower levels offer protection from severe hypoglycemia in type 1 diabetes, as observed in large prospective cohort studies and interventional trials of islet transplantation. These observations support consideration of C-peptide not just as a biomarker of ß-cell function but also as a specific, sensitive, feasible, and clinically meaningful outcome defining ß-cell preservation or restoration for clinical trials of disease-modifying therapies. Regulatory acceptance of C-peptide as a validated surrogate for demonstration of efficacy would greatly facilitate development of disease-modifying therapies for type 1 diabetes.

Neuropathic Pain With and Without Diabetic Peripheral Neuropathy in Type 1 Diabetes.

OBJECTIVE: Diabetic peripheral neuropathy (DPN) is common; however, the features and burden of neuropathic pain (NP) in type 1 diabetes (T1D) are poorly understood. We evaluated the incidence of first occurrence, annual prevalence, remission, and risk factors for NP during long-term follow-up of participants with T1D. RESEARCH DESIGN AND METHODS: The Michigan Neuropathy Screening Instrument (MNSI) was administered annually (1994-2020) for 1,324 participants in the Epidemiology of Diabetes Interventions and Complications (EDIC) study. NP with clinical signs of DPN (NP DPN+) was defined according to self-reported NP plus an examination score >2, while NP without clinical signs of DPN (NP DPN-) was defined according to self-reported NP and an examination score ≤2. RESULTS: At EDIC year 1, median age for participants was 36 years (interquartile range 30, 41), diabetes duration 13 years (10, 18), and HbA1c 7.9% (7.2, 8.9). At year 26 (median diabetes duration 39 years), cumulative incidence of NP was 57%, regardless of concomitant clinical signs of DPN (36% NP DPN+ vs. 46% NP DPN-). NP prevalence was 20% at 26 years (11% NP DPN+ and 9% NP DPN-), suggesting frequent remission. Annualized remission rates were similar regardless of pain medication use. In addition to HbA1c, female sex was associated with NP DPN-. CONCLUSIONS: NP incidence in T1D was high and frequently occurred in the absence of clinical signs of neuropathy, as assessed with the MNSI. Pain remission was not explained by pain medication use. Effective clinical strategies for identification and management are needed.

Association of Baseline Factors With Glycemic Outcomes in GRADE: A Comparative Effectiveness Randomized Clinical Trial.

OBJECTIVE: To describe the individual and joint associations of baseline factors with glycemia, and also with differential effectiveness of medications added to metformin. RESEARCH DESIGN AND METHODS: Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE) participants (with type 2 diabetes diagnosed for <10 years, on metformin, and with HbA1c 6.8-8.5%; N = 5,047) were randomly assigned to a basal insulin (glargine), sulfonylurea (glimepiride), glucagon-like peptide 1 agonist (liraglutide), or dipeptidyl peptidase 4 inhibitor (sitagliptin). The glycemic outcome was HbA1c ≥7.0%, subsequently confirmed. Univariate and multivariate regression and classification and regression tree (CART) analyses were used to assess the association of baseline factors with the glycemic outcome at years 1 and 4. RESULTS: In univariate analyses at baseline, younger age (<58 years), Hispanic ethnicity, higher HbA1c, fasting glucose, and triglyceride levels, lower insulin secretion, and relatively greater insulin resistance were associated with the glycemic outcome at years 1 and/or 4. No factors were associated with differential effectiveness of the medications by year 4. In multivariate analyses, treatment group, younger age, and higher baseline HbA1c and fasting glucose were jointly associated with the glycemic outcome by year 4. The superiority of glargine and liraglutide at year 4 persisted after multiple baseline factors were controlled for. CART analyses indicated that failure to maintain HbA1c <7% by year 4 was more likely for younger participants and those with baseline HbA1c ≥7.4%. CONCLUSIONS: Several baseline factors were associated with the glycemic outcome but not with differential effectiveness of the four medications. Failure to maintain HbA1c <7% was largely driven by younger age and higher HbA1c at baseline. Factors that predict earlier glycemic deterioration could help in targeting patients for more aggressive management.

Diabetes Risk Factors and Bone Microarchitecture as Assessed by High-Resolution Peripheral Quantitative Computed Tomography in Adults With Long-Standing Type 1 Diabetes.

OBJECTIVE: To determine whether type 1 diabetes and its complications are associated with bone geometry and microarchitecture. RESEARCH DESIGN AND METHODS: This cross-sectional study was embedded in a long-term observational study. High-resolution peripheral quantitative computed tomography (HR-pQCT) scans of the distal radius and distal and diaphyseal tibia were performed in a subset of 183 participants with type 1 diabetes from the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study and 94 control participants without diabetes. HbA1c, skin advanced glycation end products (AGEs), and diabetes-related complications were assessed in EDIC participants with >30 years of follow-up. RESULTS: Compared with control participants (aged 60 ± 8 years, 65% female), EDIC participants (aged 60 ± 7 years, diabetes duration 38 ± 5 years, 51% female) had lower total bone mineral density (BMD) at the distal radius (-7.9% [95% CI -15.2%, -0.6%]; P = 0.030) and distal tibia (-11.3% [95% CI -18.5%, -4.2%]; P = 0.001); larger total area at all sites (distal radius 4.7% [95% CI 0.5%, 8.8%; P = 0.030]; distal tibia 5.9% [95% CI 2.1%, 9.8%; P = 0.003]; diaphyseal tibia 3.4% [95% CI 0.8%, 6.1%; P = 0.011]); and poorer radius trabecular and cortical microarchitecture. Estimated failure load was similar between the two groups. Among EDIC participants, higher HbA1c, AGE levels, and macroalbuminuria were associated with lower total BMD. Macroalbuminuria was associated with larger total area and lower cortical thickness at the distal radius. Higher HbA1c and AGE levels and lower glomerular filtration rate, peripheral neuropathy, and retinopathy were associated with deficits in trabecular microarchitecture. CONCLUSIONS: Type 1 diabetes is associated with lower BMD, larger bone area, and poorer trabecular microarchitecture. Among participants with type 1 diabetes, suboptimal glycemic control, AGE accumulation, and microvascular complications are associated with deficits in bone microarchitecture and lower BMD.

Relationships Between the Cumulative Incidences of Long-term Complications in Type 1 Diabetes: The DCCT/EDIC Study.

OBJECTIVE: To describe the relationships between the cumulative incidences of long-term complications in individuals with type 1 diabetes (T1D) and assess whether observed associations are independent of age, duration of diabetes, and glycemic levels. METHODS: Proliferative diabetic retinopathy (PDR), clinically significant macular edema (CSME), reduced estimated glomerular filtration rate (eGFR), amputations, cardiovascular disease (CVD), and mortality were assessed in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Study over ∼30 years. RESEARCH DESIGN AND RESULTS: The cumulative incidence of complications ranged from 3% (amputations) to 37% (CSME). There were large differences in the cumulative incidence of PDR between participants with versus without prior CSME (66% vs. 15%), reduced eGFR (59% vs. 29%), and amputation (68% vs. 32%); reduced eGFR with or without prior PDR (25% vs. 9%), amputation (48% vs. 13%), and CVD (30% vs. 11%); CVD with or without prior reduced eGFR (37% vs. 14%) and amputation (50% vs. 16%); and mortality with or without prior reduced eGFR (22% vs. 9%), amputation (35% vs. 8%), and CVD (25% vs. 8%). Adjusted for age, duration of T1D, and mean updated HbA1c, the complications and associations with higher risk included PDR with CSME (hazard ratio [HR] 1.88; 95% CI 1.42, 2.50), reduced eGFR (HR 1.41; 95% CI 1.01, 1.97), and CVD (HR 1.43; 95% CI 1.06, 1.92); CSME with higher risk of PDR (HR 3.94; 95% CI 3.18 4.89), reduced eGFR (HR 1.49; 95% CI 1.10, 2.01), and CVD (HR 1.35; 95% CI 1.03, 1.78); reduced eGFR with higher risk of CVD (HR 2.09; 95% CI 1.44, 3.03), and death (HR 3.40; 95% CI 2.35, 4.92); amputation(s) with death (HR 2.97; 95% CI 1.70, 2.90); and CVD with reduced eGFR (HR 1.59; 95% CI 1.08, 2.34) and death (HR 1.95; 95% CI 1.32, 2.90). CONCLUSIONS: Long-term micro- and macrovascular complications and mortality are highly correlated. Age, diabetes duration, and glycemic levels do not completely explain these associations.

Optimal Frequency of Urinary Albumin Screening in Type 1 Diabetes.

OBJECTIVE: Kidney disease screening recommendations include annual urine testing for albuminuria after 5 years' duration of type 1 diabetes. We aimed to determine a simple, risk factor-based screening schedule that optimizes early detection and testing frequency. RESEARCH DESIGN AND METHODS: Urinary albumin excretion measurements from 1,343 participants in the Diabetes Control and Complications Trial and its long-term follow-up were used to create piecewise-exponential incidence models assuming 6-month constant hazards. Likelihood of the onset of moderately or severely elevated albuminuria (confirmed albumin excretion rate AER ≥30 or ≥300 mg/24 h, respectively) and its risk factors were used to identify individualized screening schedules. Time with undetected albuminuria and number of tests were compared with annual screening. RESULTS: The 3-year cumulative incidence of elevated albuminuria following normoalbuminuria at any time during the study was 3.2%, which was strongly associated with higher glycated hemoglobin (HbA1c) and AER. Personalized screening in 2 years for those with current AER ≤10 mg/24 h and HbA1c ≤8% (low risk [0.6% three-year cumulative incidence]), in 6 months for those with AER 21-30 mg/24 h or HbA1c ≥9% (high risk [8.9% three-year cumulative incidence]), and in 1 year for all others (average risk [2.4% three-year cumulative incidence]) was associated with 34.9% reduction in time with undetected albuminuria and 20.4% reduction in testing frequency as compared with annual screening. Stratification by categories of HbA1c or AER alone was associated with reductions of lesser magnitude. CONCLUSIONS: A personalized alternative to annual screening in type 1 diabetes can substantially reduce both the time with undetected kidney disease and the frequency of urine testing. ARTICLE HIGHLIGHTS: Kidney disease screening recommendations include annual urine testing for albuminuria after 5 years' duration of type 1 diabetes. We investigated simple screening schedules that optimize early detection and testing frequency. Personalized screening in 2 years for those with current AER ≤10 mg/24 h and HbA1c ≤8%, in 6 months for those with AER 21-30 mg/24 h or HbA1c ≥9%, and in 1 year for all others yielded 34.9% reduction in time with undetected albuminuria and 20.4% fewer evaluations compared with annual screening. A personalized alternative to annual screening in type 1 diabetes can substantially reduce both the time with undetected kidney disease and the frequency of urine testing.

Cardiometabolic Risk Factors and Incident Cardiovascular Disease Events in Women vs Men With Type 1 Diabetes.

Importance: The lower risk of cardiovascular disease (CVD) among women compared with men in the general population may be diminished among those with diabetes. Objective: To evaluate cardiometabolic risk factors and their management in association with CVD events in women vs men with type 1 diabetes enrolled in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study. Design, Setting, and Participants: This cohort study used data obtained during the combined DCCT (randomized clinical trial, conducted 1983-1993) and EDIC (observational study, conducted 1994 to present) studies through April 30, 2018 (mean [SD] follow-up, 28.8 [5.8] years), at 27 clinical centers in the US and Canada. Data analyses were performed between July 2021 and April 2022. Exposure: During the DCCT phase, patients were randomized to intensive vs conventional diabetes therapy. Main Outcomes and Measures: Cardiometabolic risk factors and CVD events were assessed via detailed medical history and focused physical examinations. Blood and urine samples were assayed centrally. CVD events were adjudicated by a review committee. Linear mixed models and Cox proportional hazards models evaluated sex differences in cardiometabolic risk factors and CVD risk over follow-up. Results: A total of 1441 participants with type 1 diabetes (mean [SD] age at DCCT baseline, 26.8 [7.1] years; 761 [52.8%] men; 1390 [96.5%] non-Hispanic White) were included. Over the duration of the study, compared with men, women had significantly lower body mass index (BMI, calculated as weight in kilograms divided by height in meters squared; ß = -0.43 [SE, 0.16]; P = .006), waist circumference (ß = -10.56 cm [SE, 0.52 cm]; P < .001), blood pressure (systolic: ß = -5.77 mm Hg [SE, 0.35 mm Hg]; P < .001; diastolic: ß = -3.23 mm Hg [SE, 0.26 mm Hg]; P < .001), and triglyceride levels (ß = -10.10 mg/dL [SE, 1.98 mg/dL]; P < .001); higher HDL cholesterol levels (ß = 9.36 mg/dL [SE, 0.57 mg/dL]; P < .001); and similar LDL cholesterol levels (ß = -0.76 mg/dL [SE, 1.22 mg/dL]; P = .53). Women, compared with men, achieved recommended targets more frequently for blood pressure (ie, <130/80 mm Hg: 90.0% vs 77.4%; P < .001) and triglycerides (ie, <150 mg/dL: 97.3% vs 90.5%; P < .001). However, sex-specific HDL cholesterol targets (ie, ≥50 mg/dL for women, ≥40 mg/dL for men) were achieved less often (74.3% vs 86.6%; P < .001) and cardioprotective medications were used less frequently in women than men (ie, angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker: 29.6% [95% CI, 25.7%-33.9%] vs 40.0% [95% CI, 36.1%-44.0%]; P = .001; lipid-lowering medication: 25.3% [95% CI, 22.1%-28.7%] vs 39.6% [95% CI, 36.1%-43.2%]; P < .001). Women also had significantly higher pulse rates (mean [SD], 75.2 [6.8] beats per minute vs 71.8 [6.9] beats per minute; P < .001) and hemoglobin A1c levels (mean [SD], 8.3% [1.0%] vs 8.1% [1.0%]; P = .01) and achieved targets for tighter glycemic control less often than men (ie, hemoglobin A1c <7%: 11.2% [95% CI, 9.3%-13.3%] vs 14.0% [95% CI, 12.0%-16.3%]; P = .03). Conclusions and Relevance: These findings suggest that despite a more favorable cardiometabolic risk factor profile, women with type 1 diabetes did not have a significantly lower CVD event burden than men, suggesting a greater clinical impact of cardiometabolic risk factors in women vs men with diabetes. These findings call for conscientious optimization of the control of CVD risk factors in women with type 1 diabetes.

Glycemia Reduction in Type 2 Diabetes - Microvascular and Cardiovascular Outcomes.

BACKGROUND: Data are lacking on the comparative effectiveness of commonly used glucose-lowering medications, when added to metformin, with respect to microvascular and cardiovascular disease outcomes in persons with type 2 diabetes. METHODS: We assessed the comparative effectiveness of four commonly used glucose-lowering medications, added to metformin, in achieving and maintaining a glycated hemoglobin level of less than 7.0% in participants with type 2 diabetes. The randomly assigned therapies were insulin glargine U-100 (hereafter, glargine), glimepiride, liraglutide, and sitagliptin. Prespecified secondary outcomes with respect to microvascular and cardiovascular disease included hypertension and dyslipidemia, confirmed moderately or severely increased albuminuria or an estimated glomerular filtration rate of less than 60 ml per minute per 1.73 m2 of body-surface area, diabetic peripheral neuropathy assessed with the Michigan Neuropathy Screening Instrument, cardiovascular events (major adverse cardiovascular events [MACE], hospitalization for heart failure, or an aggregate outcome of any cardiovascular event), and death. Hazard ratios are presented with 95% confidence limits that are not adjusted for multiple comparisons. RESULTS: During a mean 5.0 years of follow-up in 5047 participants, there were no material differences among the interventions with respect to the development of hypertension or dyslipidemia or with respect to microvascular outcomes; the mean overall rate (i.e., events per 100 participant-years) of moderately increased albuminuria levels was 2.6, of severely increased albuminuria levels 1.1, of renal impairment 2.9, and of diabetic peripheral neuropathy 16.7. The treatment groups did not differ with respect to MACE (overall rate, 1.0), hospitalization for heart failure (0.4), death from cardiovascular causes (0.3), or all deaths (0.6). There were small differences with respect to rates of any cardiovascular disease, with 1.9, 1.9, 1.4, and 2.0 in the glargine, glimepiride, liraglutide, and sitagliptin groups, respectively. When one treatment was compared with the combined results of the other three treatments, the hazard ratios for any cardiovascular disease were 1.1 (95% confidence interval [CI], 0.9 to 1.3) in the glargine group, 1.1 (95% CI, 0.9 to 1.4) in the glimepiride group, 0.7 (95% CI, 0.6 to 0.9) in the liraglutide group, and 1.2 (95% CI, 1.0 to 1.5) in the sitagliptin group. CONCLUSIONS: In participants with type 2 diabetes, the incidences of microvascular complications and death were not materially different among the four treatment groups. The findings indicated possible differences among the groups in the incidence of any cardiovascular disease. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; GRADE ClinicalTrials.gov number, NCT01794143.).

Glycemia Reduction in Type 2 Diabetes - Glycemic Outcomes.

BACKGROUND: The comparative effectiveness of glucose-lowering medications for use with metformin to maintain target glycated hemoglobin levels in persons with type 2 diabetes is uncertain. METHODS: In this trial involving participants with type 2 diabetes of less than 10 years' duration who were receiving metformin and had glycated hemoglobin levels of 6.8 to 8.5%, we compared the effectiveness of four commonly used glucose-lowering medications. We randomly assigned participants to receive insulin glargine U-100 (hereafter, glargine), the sulfonylurea glimepiride, the glucagon-like peptide-1 receptor agonist liraglutide, or sitagliptin, a dipeptidyl peptidase 4 inhibitor. The primary metabolic outcome was a glycated hemoglobin level, measured quarterly, of 7.0% or higher that was subsequently confirmed, and the secondary metabolic outcome was a confirmed glycated hemoglobin level greater than 7.5%. RESULTS: A total of 5047 participants (19.8% Black and 18.6% Hispanic or Latinx) who had received metformin for type 2 diabetes were followed for a mean of 5.0 years. The cumulative incidence of a glycated hemoglobin level of 7.0% or higher (the primary metabolic outcome) differed significantly among the four groups (P<0.001 for a global test of differences across groups); the rates with glargine (26.5 per 100 participant-years) and liraglutide (26.1) were similar and lower than those with glimepiride (30.4) and sitagliptin (38.1). The differences among the groups with respect to a glycated hemoglobin level greater than 7.5% (the secondary outcome) paralleled those of the primary outcome. There were no material differences with respect to the primary outcome across prespecified subgroups defined according to sex, age, or race or ethnic group; however, among participants with higher baseline glycated hemoglobin levels there appeared to be an even greater benefit with glargine, liraglutide, and glimepiride than with sitagliptin. Severe hypoglycemia was rare but significantly more frequent with glimepiride (in 2.2% of the participants) than with glargine (1.3%), liraglutide (1.0%), or sitagliptin (0.7%). Participants who received liraglutide reported more frequent gastrointestinal side effects and lost more weight than those in the other treatment groups. CONCLUSIONS: All four medications, when added to metformin, decreased glycated hemoglobin levels. However, glargine and liraglutide were significantly, albeit modestly, more effective in achieving and maintaining target glycated hemoglobin levels. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; GRADE ClinicalTrials.gov number, NCT01794143.).

Cost-Efficient Multiply Matched Case-Control Study Designs.

In multiply matched case-control studies, a number of cases and controls may be included in each matched set. However, when per-participant costs between cases and controls differ, investigators should be aware of how the numbers of cases and controls per matched set affect the overall total study cost. Traditional statistical approaches to designing case-control studies do not account for study costs. Given an effect size, the power to detect differences is typically a function of the numbers of cases and controls within each matched set. Therefore, the same level of statistical power will be achieved based on various combinations of the numbers of cases and controls. Typical matched case-control studies match a case to a number of controls by levels of 1 or more known factors. Several authors have shown that for study designs with 1 case per matched set, the optimal number of controls within each matched set that minimizes the total study cost is the square root of the ratio of the cost of a case to the cost of a control. Herein, we extend this result to the setting of a multiply matched case-control study design, when 1 or more cases are matched to controls within each matched set. A Shiny web application implementation of the proposed methods is presented.

Association of Estimated Time-in-Range Capillary Glucose Levels Versus HbA1c With Progression of Microvascular Complications in the Diabetes Control and Complications Trial.

OBJECTIVE: Estimated time in range (eTIR) obtained from DCCT glucose profiles (pre- and postprandial and bedtime) was recently reported to be associated with microvascular outcomes and was recommended as a clinical trial outcome, but without consideration of HbA1c. RESEARCH DESIGN AND METHODS: The associations of eTIR with diabetic retinopathy and microalbuminuria were assessed without and with adjustment for HbA1c and baseline covariates. RESULTS: Adjusted for HbA1c and covariates, eTIR was marginally significantly associated with retinopathy in the full cohort (hazard ratio [HR] 1.12 per 10% lower eTIR [95% CI 1.0, 1.26], P = 0.042). Conversely, HbA1c was significantly associated with both outcomes (HR ≥1.19 per 0.5% higher HbA1c, P ≤ 0.0002) in five of six adjusted analyses. CONCLUSIONS: The association of eTIR with complications is largely explained by its correlation with HbA1c. HbA1c, not eTIR or continuous glucose monitoring TIR, remains the preferred outcome in clinical studies of type 1 diabetes complications.

Physical Function in Middle-aged and Older Adults With Type 1 Diabetes: Long-term Follow-up of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Study.

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.

Brain Structure Among Middle-aged and Older Adults With Long-standing Type 1 Diabetes in the DCCT/EDIC Study.

OBJECTIVE: Individuals with type 1 diabetes mellitus (T1DM) are living to ages when neuropathological changes are increasingly evident. We hypothesized that middle-aged and older adults with long-standing T1DM will show abnormal brain structure in comparison with control subjects without diabetes. RESEARCH DESIGN AND METHODS: MRI was used to compare brain structure among 416 T1DM participants in the Epidemiology of Diabetes Interventions and Complications (EDIC) study with that of 99 demographically similar control subjects without diabetes at 26 U.S. and Canadian sites. Assessments included total brain (TBV) (primary outcome), gray matter (GMV), white matter (WMV), ventricle, and white matter hyperintensity (WMH) volumes and total white matter mean fractional anisotropy (FA). Biomedical assessments included HbA1c and lipid levels, blood pressure, and cognitive assessments of memory and psychomotor and mental efficiency (PME). Among EDIC participants, HbA1c, severe hypoglycemia history, and vascular complications were measured longitudinally. RESULTS: Mean age of EDIC participants and control subjects was 60 years. T1DM participants showed significantly smaller TBV (least squares mean ± SE 1,206 ± 1.7 vs. 1,229 ± 3.5 cm3, P < 0.0001), GMV, and WMV and greater ventricle and WMH volumes but no differences in total white matter mean FA versus control subjects. Structural MRI measures in T1DM were equivalent to those of control subjects who were 4-9 years older. Lower PME scores were associated with altered brain structure on all MRI measures in T1DM participants. CONCLUSIONS: Middle-aged and older adults with T1DM showed brain volume loss and increased vascular injury in comparison with control subjects without diabetes, equivalent to 4-9 years of brain aging.

Left Ventricular Structure, Tissue Composition, and Aortic Distensibility in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Intervention and Complications.

Alterations in myocardial structure, function, tissue composition (e.g., fibrosis) may be associated with metabolic syndrome (MetS). This study aimed to determine the relation of MetS and its individual components to markers of cardiovascular disease in patients with type 1 Diabetes Mellitus (T1DM). A total of 978 subjects of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications T1DM cohort (age: 49 ± 7 years, 47% female, DM duration 28 ± 5 years) underwent cardiovascular magnetic resonance. In a subset of 200 patients, myocardial tissue composition was measured with cardiovascular magnetic resonance T1 mapping after contrast administration. MetS was defined as T1DM plus 2 other abnormalities based on the American Heart Association/National Cholesterol Education Program criteria. MetS was present in 34.1% of subjects. After adjustment for age, height, scanner, study cohort, gender, smoking, mean glycated hemoglobin levels, history of macroalbuminuria and end-stage renal disease, left ventricle mass was greater by 12.3 g, end-diastolic volume was higher by 5.4 ml, and mass to end-diastolic volume ratio was higher by 5% in patients with MetS versus those without MetS (p <0.001 for all). Myocardial T1 times were lower by 29 ms in patients with MetS than those without (p <0.001). Elevated waist circumference showed the strongest associations with left ventricle mass (+10.1 g), end-diastolic volume (+6.7 ml), and lower myocardial T1 times (+31 ms) in patients with MetS compared with those without (p <0.01). In conclusion, in a large cohort of patients with T1DM, 34.1% of subjects met MetS criteria. MetS was associated with adverse myocardial structural remodeling and change in myocardial tissue composition.

Risk factors for lower bone mineral density in older adults with type 1 diabetes: a cross-sectional study.

BACKGROUND: Type 1 diabetes is associated with lower bone mineral density (BMD) and increased fracture risk, but little is known regarding the effects of diabetes-related factors on BMD. We assessed whether these factors are associated with lower hip BMD among older adults with type 1 diabetes. METHODS: This cross-sectional study was embedded in a long-term observational study, the Epidemiology of Diabetes Interventions and Complications study (EDIC), a cohort of participants with type 1 diabetes, who were originally enrolled in the Diabetes Control and Complications Trial (DCCT), and were followed-up for more than 30 years at 27 sites in the USA and Canada. All active EDIC participants were eligible except if they were pregnant, weighed above the dual-energy x-ray absorptiometry (DXA) scanner limit, had an implanted neurostimulator, or were not willing to participate. The primary study outcome was total hip BMD. Hip, spine, and radius BMD and trabecular bone score (TBS) were measured with DXA at an annual EDIC visit (2017-19). Time-weighted mean HbA1c, kidney disease, and peripheral neuropathy were measured annually during EDIC, and retinopathy was measured every 4 years. Skin intrinsic fluorescence, a measure of advanced glycation end products (AGEs), and cardiac autonomic neuropathy were assessed once (2009-10) during EDIC. FINDINGS: 1147 of the 1441 participants who were enrolled in the DCCT trial remained active EDIC participants at the start of this cross-sectional study. Between Sept 20, 2017, and Sept 19, 2019, 1094 of 1147 participants were screened for the EDIC Skeletal Health study. 1058 participants completed at least one of a set of DXA scans and were included in the analysis. 47·8% were women and 52·2% were men, 96·6% were White and 3·4% were of other race or ethnicity. The mean age of participants was 59·2 years (SD 6·7). Higher mean HbA1c, higher skin intrinsic fluorescence, and kidney disease (but not retinopathy or neuropathy) were independently associated with a lower total hip BMD. Total hip BMD differed by -10·7 mg/cm2 (95% CI -19·6 to -1·7) for each 1% increase in mean HbA1c, -20·5 mg/cm2 (-29·9 to -11·0) for each 5 unit higher skin intrinsic fluorescence, and -51·7 mg/cm2 (-80·6 to -22·7) in the presence of kidney disease. Similar associations were found for femoral neck and ultra-distal radius BMD, but not for lumbar spine BMD or TBS. INTERPRETATION: Poorer glycaemic control, AGE accumulation, and kidney disease are independent risk factors for lower hip BMD in older adults with type 1 diabetes. Maintenance of glycaemic control and prevention of kidney disease might reduce bone loss and ultimately fractures in this population. Osteoporosis screening might be particularly important in people with these risk factors. Further research to identify AGE blockers could benefit skeletal health. FUNDING: National Institute of Diabetes and Digestive and Kidney Disease.

Biochemical Markers of Bone Turnover in Older Adults With Type 1 Diabetes.

CONTEXT: Type 1 diabetes (T1D) is characterized by high fracture risk, yet little is known regarding diabetes-related mechanisms or risk factors. OBJECTIVE: Determine whether glycemic control, advanced glycation end products (AGEs), and microvascular complications are associated with bone turnover markers among older T1D adults. DESIGN: Cross-sectional. SETTING: Epidemiology of Diabetes Interventions and Complications study (6 of 27 clinical centers). PARTICIPANTS: 232 T1D participants followed for >30 years. EXPOSURES: Glycemic control ascertained as concurrent and cumulative hemoglobin A1c (HbA1c); kidney function, by estimated glomerular filtration rates (eGFR); and AGEs, by skin intrinsic fluorescence. MAIN OUTCOME MEASURES: Serum procollagen 1 intact N-terminal propeptide (PINP), bone-specific alkaline phosphatase (bone ALP), serum C-telopeptide (sCTX), tartrate-resistant acid phosphatase 5b (TRACP5b), and sclerostin. RESULTS: Mean age was 59.6 ±â€…6.8 years, and 48% were female. In models with HbA1c, eGFR, and AGEs, adjusted for age and sex, higher concurrent HbA1c was associated with lower PINP [ß -3.4 pg/mL (95% CI -6.1, -0.7), P = 0.015 for each 1% higher HbA1c]. Lower eGFR was associated with higher PINP [6.9 pg/mL (95% CI 3.8, 10.0), P < 0.0001 for each -20 mL/min/1.73 m2 eGFR], bone ALP [1.0 U/L (95% CI 0.2, 1.9), P = 0.011], sCTX [53.6 pg/mL (95% CI 32.6, 74.6), P < 0.0001], and TRACP5b [0.3 U/L (95% CI 0.1, 0.4), P = 0.002]. However, AGEs were not associated with any bone turnover markers in adjusted models. HbA1c, eGFR, and AGEs were not associated with sclerostin levels. CONCLUSIONS: Among older adults with T1D, poor glycemic control is a risk factor for reduced bone formation, while reduced kidney function is a risk factor for increased bone resorption and formation.

Early Trajectory of Estimated Glomerular Filtration Rate and Long-term Advanced Kidney and Cardiovascular Complications in Type 1 Diabetes.

OBJECTIVE: Rapid loss of estimated glomerular filtration rate (eGFR) within its normal range has been proposed as a strong predictor of future kidney disease. We investigated this association of eGFR slope early in the course of type 1 diabetes with long-term incidence of kidney and cardiovascular complications. RESEARCH DESIGN AND METHODS: The annual percentage change in eGFR (slope) was calculated during the Diabetes Control and Complications Trial (DCCT) for each of 1,441 participants over a mean of 6.5 years and dichotomized by the presence or absence of early rapid eGFR loss (slope ≤-3% per year) as the exposure of interest. Outcomes were incident reduced eGFR (eGFR <60 mL/min/1.73 m2), composite cardiovascular events, or major adverse cardiovascular events (MACE) during the subsequent 24 years post-DCCT closeout follow-up. RESULTS: At DCCT closeout (the baseline for this analysis), diabetes duration was 12 ± 4.8 years, most participants (85.9%) had normoalbuminuria, mean eGFR was 117.0 ± 13.4 mL/min/1.73 m2, and 149 (10.4%) had experienced early rapid eGFR loss over the preceding trial phase. Over the 24-year subsequent follow-up, there were 187 reduced eGFR (6.3 per 1,000 person-years) and 113 MACE (3.6 per 1,000 person-years) events. Early rapid eGFR loss was associated with risk of reduced eGFR (hazard ratio [HR] 1.81, 95% CI 1.18-2.79, P = 0.0064), but not after adjustment for baseline eGFR level (HR 0.94, 95% CI 0.53-1.66, P = 0.84). There was no association with composite cardiovascular events or MACE. CONCLUSIONS: In people with type 1 diabetes primarily with normal eGFR and normoalbuminuria, the preceding slope of eGFR confers no additional association with kidney or cardiovascular outcomes beyond knowledge of an individual's current level.