Inverse associations between cardiometabolic risk factors and 25-hydroxyvitamin D in obese American children and adolescents.

Objectives: To examine the association between 25-hydroxyvitamin D [25(OH)D] concentrations and cardiometabolic risk factors in obese American children.

Methods: A cross-sectional study was conducted on 209 obese children (55% females, 25.8% black) aged between 6 and 19 years old. Study measurements included plasma 25(OH)D concentrations, blood pressure, lipids and oxidized LDL levels, insulin resistance (IR) indices from glucose, insulin and 5 hour oral glucose tolerance test.

Results: Fifty-one percent of the children had vitamin D deficiency. Older age [OR (95% CI) = 1.16 (1.00, 1.35)], black race/ethnicity [15.39 (5.79, 40.92)], winter/spring season [3.46 (1.69, 7.02)] and higher body mass index (BMI) [1.05 (0.99, 1.11)] were associated with increased odds of having vitamin D deficiency. None of cardiometabolic risk factors examined were significantly associated with vitamin D deficiency in age, race/ethnicity, season, and BMI adjusted models. In age, race/ethnicity, season and BMI adjusted models, total cholesterol (β = -0.001, P = 0.013), non-HDL-C (β = -0.001, P = 0.014), and oxidized LDL (β = -0.087, P = 0.045) were inversely associated with log-transformed 25(OH)D. An approximate 10 mg/dl increase in total cholesterol or in non-HDL-C was associated with an approximate 1.3% decrease in the geometric mean of 25(OH)D concentration. Further a 10% increase in ox-LDL levels was associated with an approximate 0.8% decrease in the geometric mean of 25(OH)D.

Conclusion: Vitamin D deficiency is prevalent in obese American children. There was evidence that some cardiometabolic risk factors including lipid levels and oxidized LDL levels were significantly inversely associated with 25(OH)D concentration in our sample. Am. J. Hum. Biol. 28:736-742, 2016. © 2016 Wiley Periodicals, Inc.