25-Hydroxyvitamin D Concentrations and Cardiometabolic Risk in Children and Adolescents with Excess Weight: A Retrospective Cross-Sectional Study

Abstract

Introduction: Vitamin D insufficiency is common among children and adolescents with excess weight; however, its role as an independent marker of cardiometabolic risk remains controversial. Objective: To investigate the association between serum 25-hydroxyvitamin D [25(OH)D] concentrations and cardiometabolic risk markers in children and adolescents with overweight or obesity, as well as to identify factors independently associated with 25(OH)D concentrations. Methods: This retrospective cross-sectional study included children and adolescents aged 5 to 16 years with overweight or obesity followed at a pediatric endocrinology outpatient clinic. Serum 25(OH)D concentrations were classified as deficient (<20 ng/mL), insufficient (20 to <30 ng/mL), or sufficient (≥30 ng/mL). Clinical, anthropometric, and cardiometabolic parameters were assessed. Multiple linear regression and age-stratified analyses (<10 and ≥10 years) were performed. Results: A total of 325 participants were included (mean age, 10.1±2.2 years; 56.3% with obesity). The median 25(OH)D concentration was 29.0 ng/mL (IQR: 24.4–34.1). Vitamin D deficiency and insufficiency were observed in 7.1% and 47.4% of participants, respectively. In the multivariable model (n=287), older age (β=−0.98; 95% CI: −1.68 to −0.28; p=0.007) and higher HDL-cholesterol concentrations (β=−0.150; 95% CI: −0.235 to −0.064; p<0.001) were associated with lower 25(OH)D concentrations. No associations were observed with BMI z-score, glucose, LDL-cholesterol, triglycerides, waist circumference, sex, or pubertal stage. Conclusions: Serum 25(OH)D concentrations below 30 ng/mL were common among children and adolescents with excess weight. Older age and higher HDL-cholesterol concentrations were inversely associated with 25(OH)D, whereas the other markers evaluated showed no independent associations. The model's limited explanatory power and the cross-sectional design limit causal inferences.