Vitamin D and its Relation with Insulin Resistance in Obese Children

Abstract

Background: Deficiency of vitamin D leads to mal skeletal growth in children; moreover it is becoming an epidemic throughout the world. Decrease level of vitamin D can cause diverse of skeletal disorders in children like rickets, osteopenia etc. The relationship of vitamin D, obesity and insulin resistance is still not clear in the literature. Vitamin D deficiency may induce the altered glucose tolerance in obese children. Therefore the present study was designed to investigate the relationship of vitamin D and insulin resistance in obese children. Methods: The present study was a cross sectional type of study which was conducted in paediatric department of TMMC & RC, Moradabad. This study included 120 obese children (60 males and 60 females) of mean age 12 ± 2.6 years in group I. Control group II contained 100 healthy none obese children (50 males and 50 females) of 12.2 ± 1.8 years. Insulin resistance was calculated from fasting plasma measurements using HOMA-IR (insulin (mU/L) × glucose (mmol/l)/22.5). Insulin resistance criteria were HOMA-IR >2.5 for children. Vitamin D was measured by ELISA method (kit manufactured by Cayman chemical company, Ann Arbor, USA). Results: There was an insignificant difference in the FBG (>0.05) of group I obese children and group II control. Insulin (<0.05) and HOMA-IR (<0.01) were significantly low in obese children in comparison of none-obese children. Vitamin D (<0.01) was significantly lower in obese children compare to healthy children. vitamin D was negatively correlated with BMI (r = -0.42, r2 =0.1764, p<0.05) in obese children. There was a negative correlation between vitamin D and insulin resistance (r = -0.52, r2 =0.2704, p<0.05) in obese children. Conclusion: Present study suggests that there was strong relation between insulin resistance and obesity. Vitamin D was negatively correlated with BMI and insulin resistance. These findings strongly suggest vitamin D level may found insufficient or deficient in obese children. Therefore, obese children should be screened for vitamin D deficiency for their normal skeletal growth.