Low Serum Vitamin D Levels Are Associated With Increased Arterial Stiffness in Youth With Type 2 Diabetes

OBJECTIVE: Adult studies demonstrate that low vitamin D (25[OH]D) is an independent risk factor for arterial stiffness. Similar studies have not been conducted in youth with type 2 diabetes mellitus (T2DM). The objective was to elicit the association between 25[OH]D and arterial stiffness in obese youth with and without T2DM. We hypothesized that 25[OH]D would be inversely correlated with arterial stiffness indices, including pulse wave velocity (PWV), augmentation index (AIx), and brachial distensibility (BrachD). RESEARCH DESIGN AND METHODS: Cross-sectional analysis was conducted in Cincinnati, OH, from 2004 to 2010. 25[OH]D, PWV, AIx, and BrachD were measured in 190 youth with T2DM, 190 obese control subjects without T2DM, and 190 lean control subjects without T2DM. Multivariate analyses were conducted to elicit the independent association between 25[OH]D and arterial stiffness indices by group. RESULTS: The mean age was 17.9 ± 3.4 years, 55% were African American, and 34% were male. The mean 25[OH]D levels were 21.27, 14.29, and 14.13 ng/mL in lean individuals, obese individuals, and obese individuals with T2DM, respectively (P < 0.01). PWV, AIx, and BrachD worsened from lean to obese to T2DM (P < 0.01). General linear models found that 25[OH]D level was independently associated with PWV in lean individuals and with AIx in the group with T2DM such that a 3 ng/mL increase in 25[OH]D was associated with an AIx decrease of 1% (baseline AIx = 5.7 ± 12.0%). CONCLUSIONS: 25[OH]D is inversely associated with some measures of arterial stiffness in lean adolescents and obese adolescents with T2DM but not in obese normoglycemic adolescents. Future studies are needed to determine if supplemental 25[OH]D is important for cardiovascular health.