Effects of Zinc Supplementation on Markers of Insulin Resistance and Lipid Profiles in Women with Polycystic Ovary Syndrome: a Randomized, Double-blind, Placebo-controlled Trial

Abstract

Objective: This study was conducted to evaluate the effects of zinc supplementation on glucose homeostasis parameters and lipid concentrations in PCOS women. We are aware of no study evaluating the effects of zinc supplementation on metabolic profiles of patients with polycystic ovary syndrome (PCOS). Methods: This randomized, double-blind, placebo-controlled trial was conducted among 52 women diagnosed with PCOS and aged 18–40 years old. Participants were randomly divided into 2 groups to receive 220 mg zinc sulfate (containing 50 mg zinc) supplements (n=26) or placebo (n=26) per day for 8 weeks. Fasting blood samples were taken at baseline and after 8 weeks’ intervention to quantify glucose, insulin and lipid concentrations. Results: After 8 weeks of intervention, subjects who received zinc supplements had significantly increased serum zinc levels (+15.6±21.8 vs. −4.1±16.7 mg/dL, P=0.001) compared with placebo. In addition, zinc-supplemented patients had reduced fasting plasma glucose (FPG) (−4.3±9.6 vs. +0.5±6.0 mg/dL, P=0.03), serum insulin levels (−3.0±2.9 vs. +1.5±8.4 µIU/mL, P=0.01), homeostasis model of assessment-insulin resistance (HOMA-IR) (−0.8±0.8 vs. +0.3±1.9, P=0.006), homeostatic model assessment-Beta cell function (HOMA-B) (−10.6±9.5 vs. +4.9±32.1, P=0.02) and increased quantitative insulin sensitivity check index (QUICKI) (+0.02±0.02 vs. −0.004±0.05, P=0.03) compared with placebo. Additionally, a significant reduction in serum triglycerides (−15.6±40.3 vs. +14.5±25.3 mg/dL, P=0.002) and VLDL-cholesterol concentrations (−3.2±8.1 vs. +2.9±5.1 mg/dL, P=0.002) was observed following the administration of zinc supplements compared with placebo. Conclusion: Taken together, 220 mg zinc sulfate supplementation per day for 8 weeks among PCOS women had beneficial effects on metabolic profiles.