Zinc supplementation ameliorates type 2 diabetes markers through the enhancement of total antioxidant capacity in overweight patients.

Background: Evidence show that the recommended dose of zinc may not be sufficient for controlling pathological conditions such as type 2 diabetes mellitus (T2DM).

Aim: This study aimed to evaluate the effects of zinc supplementation on the oxidative status in overweight T2DM. In addition, the routine glycaemic parameters were determined and compared in zinc-treated and placebo groups.

Methods: In this randomised, double-blind, placebo-controlled trial, 70 patients with T2DM were selected. They were divided into two groups for supplementation of 50 mg zinc gluconate or placebo (zinc group, n=35; placebo group, n=35) per day for 8 weeks. Blood samples were collected from all the individuals in the zinc group and controls for analysis.

Results: The results showed that zinc supplementation to patients with T2DM for 8 weeks significantly inhibited serum levels of lipid peroxidation (25%), nitrotyrosine (30%) and total oxidant status levels (25%, p<0.05). Nevertheless, the total antioxidant capacity was significantly elevated (16%) following zinc intake by patients with T2DM.

Conclusions: These data, together with our previous report, may suggest that the control in the glycaemic condition in overweight patients with T2DM is correlated with the antioxidative/oxidative balance following intake of 50 mg zinc supplementation for 8 weeks. Under these circumstances, the clinical and glycaemic indices, including fasting blood glucose, insulin, haemoglobin A1c and homeostasis model of assessment-insulin resistance, were controlled.

Trial Registration Number: IRCT2015083102.