Endocrine Abstracts

JOINT358

Background: We aimed to evaluate the relationship between vitamin D status and insulin resistance (IR) according to obesity status using non-insulin-based indices in adolescents.

Methods: This cross-sectional study included data from 3, 838 adolescents (aged 12 to 18) who participated in the Korea National Health and Nutrition Examination Survey from 2008 to 2014. The subjects were divided into two groups, normal weight and overweight & obese. Blood vitamin D levels were assessed in two groups based on a threshold of 20 ng/mL of 25-hydroxyvitamin D [25(OH)D], and vitamin D deficiency was defined as <20 ng/mL. As non-insulin-based IR indices, we used triglyceride-glucose index (TyG), triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C), TyG index with body mass index (TyG-BMI), and metabolic score for IR (METS-IR).

Results: The prevalence of vitamin D deficiency in adolescents was 78.5%. Mean vitamin D levels were higher in boys, those who did strength training, and those with waist circumference below the 90th percentile. In normal weight individuals, TyG-BMI and METS-IR were significantly higher in those with vitamin D deficiency than in those with adequate vitamin D levels. This trend was also observed in individuals with the overweight and obese group, where a significant difference was found in TyG-BMI index. Even after adjusting for covariates, the association between vitamin D and IR as assessed by the METS-IR index persisted in the normal weight group.

Conclusions: Vitamin D deficiency is significantly associated with higher insulin resistance in adolescents, as measured by non-insulin-based indices. This association appears to be particularly strong in overweight and obese individuals.