Severe Obesity and Selected Risk Factors in a Sixth Grade Multiracial Cohort: The HEALTHY Study

To document the prevalence of severe obesity and associated risk in the HEALTHY cohort

Vitamin D Supplementation and Prevention of Type 2 Diabetes

BACKGROUND Observational studies support an association between a low blood 25-hydroxyvitamin D level and the risk of type 2 diabetes. However, whether vitamin D supplementation lowers the risk of diabetes is unknown. METHODS We randomly assigned adults who met at least two of three glycemic criteria for prediabetes (fasting plasma glucose level, 100 to 125 mg per deciliter; plasma glucose level 2 hours after a 75-g oral glucose load, 140 to 199 mg per deciliter; and glycated hemoglobin level, 5.7 to 6.4%) and no diagnostic criteria for diabetes to receive 4000 IU per day of vitamin D3 or placebo, regardless of the baseline serum 25-hydroxyvitamin D level. The primary outcome in this time-to-event analysis was new-onset diabetes, and the trial design was event-driven, with a target number of diabetes events of 508. RESULTS A total of 2423 participants underwent randomization (1211 to the vitamin D group and 1212 to the placebo group). By month 24, the mean serum 25-hydroxyvitamin D level in the vitamin D group was 54.3 ng per milliliter (from 27.7 ng per milliliter at baseline), as compared with 28.8 ng per milliliter in the placebo group (from 28.2 ng per milliliter at baseline). After a median follow-up of 2.5 years, the primary outcome of diabetes occurred in 293 participants in the vitamin D group and 323 in the placebo group (9.39 and 10.66 events per 100 person-years, respectively). The hazard ratio for vitamin D as compared with placebo was 0.88 (95% confidence interval, 0.75 to 1.04; P = 0.12). The incidence of adverse events did not differ significantly between the two groups. CONCLUSIONS Among persons at high risk for type 2 diabetes not selected for vitamin D insufficiency, vitamin D3 supplementation at a dose of 4000 IU per day did not result in a significantly lower risk of diabetes than placebo. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; D2d ClinicalTrials.gov number, NCT01942694.

Vitamin D Supplementation and Prevention of Type 2 Diabetes

BACKGROUND Observational studies support an association between a low blood 25-hydroxyvitamin D level and the risk of type 2 diabetes. However, whether vitamin D supplementation lowers the risk of diabetes is unknown. METHODS We randomly assigned adults who met at least two of three glycemic criteria for prediabetes (fasting plasma glucose level, 100 to 125 mg per deciliter; plasma glucose level 2 hours after a 75-g oral glucose load, 140 to 199 mg per deciliter; and glycated hemoglobin level, 5.7 to 6.4%) and no diagnostic criteria for diabetes to receive 4000 IU per day of vitamin D3 or placebo, regardless of the baseline serum 25-hydroxyvitamin D level. The primary outcome in this time-to-event analysis was new-onset diabetes, and the trial design was event-driven, with a target number of diabetes events of 508. RESULTS A total of 2423 participants underwent randomization (1211 to the vitamin D group and 1212 to the placebo group). By month 24, the mean serum 25-hydroxyvitamin D level in the vitamin D group was 54.3 ng per milliliter (from 27.7 ng per milliliter at baseline), as compared with 28.8 ng per milliliter in the placebo group (from 28.2 ng per milliliter at baseline). After a median follow-up of 2.5 years, the primary outcome of diabetes occurred in 293 participants in the vitamin D group and 323 in the placebo group (9.39 and 10.66 events per 100 person-years, respectively). The hazard ratio for vitamin D as compared with placebo was 0.88 (95% confidence interval, 0.75 to 1.04; P = 0.12). The incidence of adverse events did not differ significantly between the two groups. CONCLUSIONS Among persons at high risk for type 2 diabetes not selected for vitamin D insufficiency, vitamin D3 supplementation at a dose of 4000 IU per day did not result in a significantly lower risk of diabetes than placebo. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; D2d ClinicalTrials.gov number, NCT01942694.

Financial management of large, multi-center trials in a challenging funding milieu

Abstract Background Randomized clinical trials that have public health implications but no or low potential for commercial gain are predominantly funded by governmental (e.g., National Institutes of Health (NIH)) and not-for-profit organizations. Our objective was to develop an alternative clinical trial site funding model for judicious allocation of declining public research funds. Methods In the Vitamin D and Type 2 Diabetes (D2d) study, an NIH-supported, large clinical trial testing the effect of vitamin D supplementation on incident diabetes in 2423 participants at high risk for diabetes, a hybrid financial management model for supporting collaborating clinical sites was developed and applied. The funding model employed two reimbursement components: Core (for study start-up and partial efforts throughout the study, ~40% of the total site budget), invoiced by sites, and Performance-Based Payments (for successful enrollment of participants and completion of follow-up visits, ~60% of the total site budget), automatically issued to the sites by the Coordinating Center based on actual recruitment and visits conducted. Underperforming sites transitioned to Performance-Based Payments only. Results Recruitment occurred from October 2013 through December 2016, requiring one additional year than the 2-year projection. Median enrollment at each site was 88 participants (range 29–318; 20 to 205% of the site target). At the end of year 1, study-wide recruitment was at 12% of the target (vs. 50% projected) and 12% of the total grant award was invested. The model constantly evaluated sites’ needs and re-allocated resources to meet the study enrollment goal. If D2d had issued cost reimbursement subaward agreements and sites invoiced for their entire budget, 83% of the award would have been spent for all study activities over the first 4 years of the trial compared to 65% of the award spent (US$26M) under the hybrid model used by D2d. Conclusions It is feasible to foster a hybrid financial management approach to steward limited available public funds for research in a dynamic and consistent way that does not compromise the trial’s scientific integrity and ensures conservation of funds to complete recruitment and continue to follow up participants

Effects of 7 days of exercise training on insulin sensitivity and responsiveness in type 2 diabetes mellitus

The objectives of this study were to determine whether 1) the improvement in insulin action induced by short-term exercise training in patients with type 2 diabetes is due to an improvement in insulin sensitivity, an improvement in insulin responsiveness, or a combination of improved insulin sensitivity and responsiveness and 2) short-term exercise training results in improved suppression of hepatic glucose production by insulin. Fourteen obese patients with type 2 diabetes, age 64 ± 2 yr, underwent a two-stage hyperinsulinemic euglycemic clamp procedure, first stage 40 mU·m−2·min−1 insulin infusion, second stage 1,000 mU·m−2·min−1 insulin infusion, together with a [3-3H]glucose infusion, before and after 7 days of exercise. The training consisted of 30 min of cycling and 30 min of treadmill walking at ∼70% of maximal aerobic capacity daily for 7 days. The exercise program resulted in improvements in insulin action in the absence of weight loss. Glucose disposal rates during the euglycemic clamp were significantly increased at both hyperinsulinemic stages after training (40 mU: 1.84 ± 0.32 to 2.67 ± 0.37 mg·kg−1·min−1, P < 0.0001; 1,000 mU: 7.57 ± 0.61 to 8.84 ± 0.56 mg·kg−1·min−1, P = 0.008). Hepatic glucose production, both in the basal state (3.17 ± 0.43 vs. 2.54 ± 0.26 mg·kg−1·min−1, P = 0.05) and during the 40-mU clamp stage (1.15 ± 0.41 vs. 0.46 ± 0.20 mg·kg−1·min−1, P = 0.03), was significantly reduced after training. One week of vigorous exercise training can induce significant improvements in insulin action in type 2 diabetes. These improvements include increased peripheral insulin sensitivity and responsiveness as well as enhanced suppression of hepatic glucose production

The effects of salsalate on glycemic control in patients with type 2 diabetes: A randomized trial

BACKGROUND: Salsalate, a nonacetylated prodrug of salicylate, has been shown to decrease blood glucose concentration in small studies. OBJECTIVE: To compare the efficacy and safety of salsalate at different doses in patients with type 2 diabetes. DESIGN: Parallel randomized trial with computer-generated randomization and centralized allocation. Patients and investigators, including those assessing outcomes and performing analyses, were masked to group assignment. (ClinicalTrials.gov registration number: NCT00392678) SETTING: 3 private practices and 14 universities in the United States. PATIENTS: Persons aged 18 to 75 years with fasting plasma glucose concentrations of 12.5 mmol/L or less (≤225 mg/dL) and hemoglobin A(1c) (HbA(1c)) levels of 7.0% to 9.5% treated by diet, exercise, and oral medication at stable doses for at least 8 weeks. INTERVENTION: After a 4-week, single-masked run-in period, patients were randomly assigned to receive placebo or salsalate in dosages of 3.0, 3.5, or 4.0 g/d for 14 weeks (27 patients each) in addition to their current therapy. MEASUREMENTS: Change in HbA(1c) was the primary outcome. Adverse effects and changes in measures of coronary risk and renal function were secondary outcomes. RESULTS: Higher proportions of patients in the 3 salsalate treatment groups experienced decreases in HbA(1c) levels of 0.5% or more from baseline (P = 0.009). Mean HbA(1c) changes were −0.36% (P = 0.02) at 3.0 g/d, −0.34% (P = 0.02) at 3.5 g/d, and −0.49% (P = 0.001) at 4.0 g/d compared with placebo. Other markers of glycemic control also improved in the 3 salsalate groups, as did circulating triglyceride and adiponectin concentrations. Mild hypoglycemia was more common with salsalate; documented events occurred only in patients taking sulfonylureas. Urine albumin concentrations increased in all salsalate groups compared with placebo. The drug was otherwise well tolerated. LIMITATION: The number of patients studied and the trial duration were insufficient to warrant recommending the use of salsalate for type 2 diabetes at this time. CONCLUSION: Salsalate lowers HbA(1c) levels and improves other markers of glycemic control in patients with type 2 diabetes and may therefore provide a new avenue for treatment. Renal and cardiac safety of the drug require further evaluation. PRIMARY FUNDING SOURCE: National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health

Effects of Vitamin D Supplementation on Insulin Sensitivity and Secretion in Prediabetes

CONTEXT: Vitamin D regulates glucose homeostasis pathways, but effects of vitamin D supplementation on β-cell function remain unclear. OBJECTIVE: To investigate the effects of vitamin D3 supplementation on insulin sensitivity and β-cell function. METHODS: This is a prespecified secondary analysis of the Vitamin D and Type 2 Diabetes study. Overweight/obese adults at high risk for type 2 diabetes (prediabetes) were randomly treated with vitamin D3 4000 IU or matching placebo daily for 24 months. MAIN OUTCOME: Disposition index (DI), as an estimate of β-cell function, was calculated as the product of Homeostasis Model Assessment 2 indices derived from C-peptide values (HOMA2%Scpep) and C-peptide response during the first 30 minutes of a 75-g oral glucose tolerance test (OGTT). RESULTS: Mean age was 60.5 ± 9.8 years and body mass index was 31.9 ± 4.4 kg/m2. Mean serum 25(OH)D level increased from 27.9 ± 10.3 ng/mL at baseline to 54.9 ng/mL at 2 years in the vitamin D group and was unchanged (28.5 ± 10.0 ng/mL) in the placebo group. The baseline DI predicted incident diabetes independent of the intervention. In the entire cohort, there were no significant differences in changes in DI, HOMA2%Scpep, or C-peptide response between the 2 groups. Among participants with baseline 25(OH)D level /mL, the mean percent differences for DI between the vitamin D and placebo groups was 8.5 (95% CI, 0.2-16.8). CONCLUSIONS: Supplementation with vitamin D3 for 24 months did not improve an OGTT-derived index of β-cell function in people with prediabetes not selected based on baseline vitamin D status; however, there was benefit among those with very low baseline vitamin D status

Salicylate(Salsalate) in patients with type 2 diabetes: A randomized trial.

BACKGROUND: Short-duration studies show that salsalate improves glycemia in type 2 diabetes mellitus (T2DM). OBJECTIVE: To assess 1-year efficacy and safety of salsalate in T2DM. DESIGN: Placebo-controlled, parallel trial; computerized randomization and centralized allocation, with patients, providers, and researchers blinded to assignment. (ClinicalTrials.gov: NCT00799643) SETTING: 3 private practices and 18 academic centers in the United States. PATIENTS: Persons aged 18 to 75 years with fasting glucose levels of 12.5 mmol/L or less (≤225 mg/dL) and hemoglobin A(1c) (HbA(1c)) levels of 7.0% to 9.5% who were treated for diabetes. INTERVENTION: 286 participants were randomly assigned (between January 2009 and July 2011) to 48 weeks of placebo (n = 140) or salsalate, 3.5 g/d (n = 146), in addition to current therapies, and 283 participants were analyzed (placebo, n = 137; salsalate, n = 146). MEASUREMENTS: Change in hemoglobin A(1c) level (primary outcome) and safety and efficacy measures. RESULTS: The mean HbA(1c) level over 48 weeks was 0.37% lower in the salsalate group than in the placebo group (95% CI, −0.53% to −0.21%; P < 0.001). Glycemia improved despite more reductions in concomitant diabetes medications in salsalate recipients than in placebo recipients. Lower circulating leukocyte, neutrophil, and lymphocyte counts show the anti-inflammatory effects of salsalate. Adiponectin and hematocrit levels increased more and fasting glucose, uric acid, and triglyceride levels decreased with salsalate, but weight and low-density lipoprotein cholesterol levels also increased. Urinary albumin levels increased but reversed on discontinuation; estimated glomerular filtration rates were unchanged. LIMITATION: Trial duration and number of patients studied were insufficient to determine long-term risk–benefit of salsalate in T2DM. CONCLUSION: Salsalate improves glycemia in patients with T2DM and decreases inflammatory mediators. Continued evaluation of mixed cardiorenal signals is warranted. PRIMARY FUNDING SOURCE: National Institutes of Health