HealthDay News — Serum 25-hydroxyvitamin D (25[OH]D) levels are associated with diabetes risk in African-Americans (AAs), according to two studies published online in Nutrition & Diabetes and BMJ Open Diabetes Research & Care.
Joshua J. Joseph, M.D., from The Ohio State University Wexner Medical Center in Columbus, and colleagues examined the association of serum 25(OH)D with incident diabetes among AAs using data from the Jackson Heart Study. Among adults without diabetes at baseline, incident diabetes was assessed over 12 years. The researchers found that during a median of 7.7 years, 584 of the 3,311 participants developed diabetes. After adjustment, the hazard ratio was 0.78 (95 percent confidence interval, 0.61 to 1.00) for 25(OH)D ≥20 versus <12 ng/mL. For the 1,671 participants with detectable 25(OH)D2 and 25(OH)D3, 25(OH)D ≥20 versus <12 ng/mL was associated with a significantly lower risk for diabetes (hazard ratio, 0.65; 95 percent confidence interval, 0.46 to 0.91).
Amaris Williams, Ph.D., also from The Ohio State University Wexner Medical Center, and colleagues examined whether the association of serum 25(OH)D with diabetes varies by adiposity among 5,611 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) without diabetes at baseline. The association was examined over nine years. The researchers found that longitudinally, a 1-ng/mL higher serum 25(OH)D was associated with a 2 percent reduction in the risk for incident diabetes before adjustment for waist circumference and with a 1 percent lower risk after adjustment for waist circumference. The largest magnitude of association of serum 25(OH)D with incident diabetes was seen at lower waist circumference. No heterogeneity was seen by race/ethnicity.
“Our MESA-study findings suggest that the inverse association between 25(OH)D and the risk of developing diabetes is similar across races and ethnicities,” Williams said in a statement.