Low serum 25-hydroxyvitamin D levels are associated with obesity and atherogenesis in adolescent boys.

Purpose We investigated the relationship of 25-hydroxyvitamin D (25(OH)D) levels with obesity and atherosclerosis in Japanese adolescents. Methods We examined 492 children (247 boys and 245 girls) aged 12-13 years. The serum 25(OH)D levels were compared among underweight, healthy weight, and overweight children. Spearman's correlation coefficient analysis was performed to examine the relationship of the 25(OH)D levels with the body mass index (BMI), plasma lipids, and blood pressure and to compare the latter between the normal (≥20 ng/mL) and low (<20 ng/mL) 25(OH)D groups. Further, we performed multiple regression analysis to assess the effect on the 25(OH)D levels. Results The serum 25(OH)D levels were significantly lower in overweight (20.5±2.7 ng/mL) than in healthy-weight boys (22.4±3.3 ng/mL) (P=0.004). Spearman's correlation coefficients comparing the relationship of the 25(OH)D levels with the BMI, high-density lipoprotein cholesterol (HDL-C), and atherogenic index indicated significance in boys [ρ=-0.238 (P<0.0001), ρ=0.197 (P=0.002), and ρ=-0.146 (P=0.022), respectively]. In boys, the multiple regression analysis results showed that the BMI and HDL-C had negative and positive effects on the 25(OH)D levels, respectively. The first was higher and the latter was lower in boys with low than in those with normal 25(OH)D levels, respectively (P<0.05). No significant correlations were detected in girls. Conclusion Low serum 25(OH)D levels were associated with obesity and atherogenic risk in adolescent boys only. This sex difference was probably mediated by body composition, sun exposure, estrogen, and adiponectin, which are characteristics of puberty.