Does Zinc Supplementation Reduce the Extent of Oxidative Stress Damage in Diabetics? A Randomised Placebo-controlled Study.

Study participants

Forty male type 2 diabetics, recruited from the outpatient clinic at the National University Hospital, Singapore, will be randomized to receive two tablets of either 100 mg zinc gluconate (GNC, USA) or placebo (99% microcystalline cellulose, 1% magnesium stearate) per day for 3 months. Subjects aged 21 years and above who fulfilled the American Diabetes Association criteria for the diagnosis of type 2 diabetes mellitus will be included in this study. We will exclude those who: had consumed over-the counter or prescription drugs, vitamin/mineral supplements or traditional Chinese remedies, suffered acute infection less than 30-days prior to the start of the study, had been diagnosed with active neuropsychiatric disease or hematological diseases, had hemoglobin less than 10g/dL, had previous use of narcotic drugs or regular alcohol intake in excess of 14 units per week. Each participant will provide written informed consent prior to their participation in this study.

Supplementation and sampling of blood and urine

A hospital research pharmacist will be engaged to randomize, blind the assigned treatment groups and count the remaining tablets so as to assess compliance. Blood and spot urine samples will be taken following an 8-hour fast at baseline (before supplementation), days 3 and 7, months 1, 2 and 3 during supplementation and 1 month following the intake of zinc or placebo (washout). An aliquot of blood will be collected in plain or EDTA tubes for serum or plasma separation respectively.

Markers of oxidative damage