Effect of zinc supplementation on insulin resistance and components of the metabolic syndrome in prepubertal obese children

OBJECTIVE: Zinc, an essential trace element and a component of many enzymes, is involved in the synthesis, storage and release of insulin. The aim of the present study was to assess the effect of zinc supplementation on insulin resistance and components of the metabolic syndrome in prepubertal obese children. DESIGN: This triple-masked, randomized, placebo-controlled cross-over trial was conducted among 60 obese Iranian children in 2008. Pertinent clinical findings, fasting serum glucose, insulin and lipid profile were assessed. Participants were randomly assigned to two groups of equal number; one group received 20mg elemental zinc and the other group received placebo on a regular daily basis for eight weeks. After a 4-week wash-out period, the groups were crossed over. RESULTS: The mean age of participants was 9.1 +/- 1.1 years. After receiving zinc, the mean fasting plasma glucose (FPG), insulin and HOMA-IR decreased significantly, while body mass index (BMI), waist circumference (WC), LDL-C and triglycerides (TG) did not significantly change. After receiving placebo, the mean FPG, insulin and HOMA-IR increased significantly, while BMI, WC, LDL-C and TG showed a non-significant increase. CONCLUSION: Besides lifestyle modification, zinc supplementation might be considered as a useful and safe additional intervention treatment for improvement of cardiometabolic risk factors related to childhood obesity.