Determine the Effects of Zinc Supplementation on Insulin Resistance, Lipid Profiles and Blood Glucose in Obese People

Background: Obesity as one of the most important health problems in the world, involved in the incidence of many chronic disorders. Obese individuals have lower level of vitamins and minerals such as zinc. Zinc is one of trace elements involved in synthesis, storage, release and action of insulin and in pathway of fat and carbohydrate metabolism. This study conducted to assay the effects of zinc supplementation on the insulin resistance, lipid profiles and blood sugar in obese people. Methods: This randomized, double blind, placebo-controlled clinical trial was performed on 60 obese people (BMI >30 kg/m2). Duration of intervention was one month. The eligible participants divided in two equal groups: intervention and placebo, randomly. Intervention group received a 30mg/d zinc pill and placebo group received 30mg/d starch. The concentration of serum insulin, insulin resistance index (HOMA-IR), lipid profiles and fasting blood glucose were determined in onset and at the end of study. Results: Zinc supplementation resulted in a significant reduction in serum insulin concentration, insulin resistance index and serum triglyceride at the end of intervention (p<0.05). However, these results were not significant in placebo group. In contrast, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and fasting blood, sugar (FBS) did not change significantly. Conclusion: Zinc supplement had positive effect on the reduction of insulin concentration and insulin resistance index. More studies with longer period of intervention suggested for disclose more mechanisms in this field