Zinc Supplementation Effect on Renal and Sexual Function of Men with Diabetic Nephropathy and Impotence, Result of a Randomized Double-Blind Cross over Clinical Trial - Abstract
Background: Free radical generation and oxidative stress has been hypothesized to be underlying pathogenesis of diabetic complications like nephropathy and erectal dysfunction. Zinc can reduce lipid per-oxidation and improves endothelial functions. In this study, we evaluated the effects of Zinc supplementation on the renal and sexual function of men with Type 2 diabetes. Methods: The study registry code (www.irct.ir) IRCT138806091179N3. Fifty adult type 2 diabetic men with diabetic nephropathy and erectal dysfunction were enrolled in double-blind, randomized trial. Twenty-five patients received 30 mg Zincsulfate per day and the remaining subjects received placebo for three months. Body mass index(BMI), fasting plasma glucose (FPG), blood pressure (BP), HbA1C, lipid profiles, level of Creatinine (Cr), testosterone hormone and zinc concentrations were measured at base and end of study. Albumin/Creatinine ratio (ACR) and Glumerular filtration rate (GFR) were calculated for all the participants. Sexual dysfunction was determined with International Index for Erectile Dysfunction questionnaire (IIEF-5). Results: Slight non-significant reduction versus a minimal non-significant increase in mean of ACR was seen with Zinc supplementation and placebo respectively (-3.7 ± 17.1 µg/mg vs. 2.8 ± 21.4 µg/mg; P= 0.130(. Additionally Zinc supplementation had no effect on GFR and also erectile dysfunction of diabetic patients. However, significant improvement in FPG, HbA1c, total cholesterol and HDL-cholesterol concentration were seen with zinc supplementation (p: 0.03). Conclusion: The results suggest that albuminuria, GFR and erectile function of men with type 2 DM cannot be affected by Zinc supplementation in dose of 30mg/day. More investigations with large population are needed.