The Effect of Puberty on Interaction between Vitamin D Status and Insulin Resistance in Obese Asian-Indian Children

Abstract

To study the effect of puberty on the relationship between serum 25-hydroxyvitamin D (25(OH)D) and parameters of insulin kinetics in obese Asian-Indian children. Material and Methods. The study population included 62 obese Asian-Indian children and adolescents in the age group of 6-17 years. Blood glucose, serum insulin, and serum 25(OH)D were measured. Total body fat was measured by dual energy X-ray absorptiometry. Indices of insulin resistance (HOMA-IR, AUC for insulin) and sensitivity (WBISI) were calculated after oral glucose tolerance test. Result. A total of 62 subjects (35 boys; mean age = 13.0 ± 3 years; BMI = 29.3 ± 4.8 kg/sq M; 19 subjects in Tanner stage 1, 11 in stage 2, 6 in stage 3, 3 in stage 4, and 23 subjects in Tanner stage 5) were studied. All study subjects were vitamin D deficient with a mean serum 25(OH)D of 8.5 ± 4.2 ng/mL. No significant relationship was observed between serum 25(OH)D and parameters of insulin kinetics in prepubertal children. However, a significant inverse correlation was seen between serum 25(OH)D and HOMAIR (r = -0.41, P = 0.03) in postpubertal subjects. Conclusion. The relationship between vitamin D status and parameters of insulin kinetics are affected by puberty.