Vitamin D Deficiency and Coronary Artery Calcification in Subjects With Type 1 Diabetes

OBJECTIVE-The objective of this study is to examine the relationship among serum levels of 25-hydroxyvitamin D (25[OH]D), polymorphisms in vitamin D-associated genes, and the presence and progression of coronary artery calcification (CAC) in adults with type 1 diabetes. RESEARCH DESIGN AND METHODS-This prospective study included 374 non-Hispanic white individuals with type I diabetes (mean age 40 +/- 9 years; 46% were male). CAC was measured at the baseline and 3- and 6-year follow-up visits were determined by electron beam computed tomography. Serum 25 [OH] D levels were measured by liquid chromatography tandem mass spectrometry at the 3-year visit. RESULTS-Normal (>30 ng/mL), insufficient (20-30 ng/mL), and deficient (<20 ng/mL) 25-D levels were present in 65%, 25%, and 10% of the individuals with type I diabetes, respectively. 25[OH]D deficiency was associated with the presence of CAC at the 3-year visit, odds ratio (OR) = 3.3 (95% CI 1.6-7.0), adjusting for age, sex, and hours of daylight. In subjects free of CAC at the 3-year visit, 25 [OH]D deficiency predicted the development of CAC over the next 3 years in those with the vitamin D receptor MIT CC genotype (OR = 6.5 [1.1-40.2], P = 0.04) than in those with the CT or TT genotype (OR = 1.6 [0.3-8.6], P = 0.57). CONCLUSIONS-Vitamin D deficiency independently predicts prevalence and development of CAC, a marker of coronary artery plaque burden, in individuals with type 1 diabetes.