Adults with prediabetes randomly assigned daily zinc supplementation saw improved fasting plasma glucose over 6 months vs. those assigned a placebo, study findings show.
In a pilot, double blind, randomized controlled trial, Md. Rafiqul Islam, MD, of the Center for Clinical Epidemiology and Biostatistics at the University of Newcastle and the Hunter Medical Research Institute in Newcastle, Australia, and colleagues analyzed data from 55 adults with prediabetes identified from the Bangladesh Institute of Health Sciences Hospital database (mean age, 44 years; 28 men; mean baseline fasting blood glucose, 5.8 mmol/L). Researchers randomly assigned participants to 30 mg zinc sulfate (n = 28) or placebo (n = 27) once daily for 6 months. Participants received biweekly phone calls to check adherence to therapy. All participants completed an in-person interview and a 24-hour food frequency questionnaire, underwent blood draws, and received healthy eating and lifestyle advice. Primary outcome was reduction in fasting blood glucose level over 6 months; secondary outcomes included insulin resistance, insulin sensitivity, beta-cell function, serum zinc concentration and lipid profiles.
At 6 months, the zinc group had improved its mean fasting blood glucose concentration compared with both baseline (5.37 mmol/L vs. 5.8 mmol/L; P < .001) and placebo (5.37 mmol/L vs. 5.69 mmol/L; P < .001). Researchers also observed statistically significant improvements in beta-cell function, insulin sensitivity and insulin resistance.
Both groups saw serum zinc levels increase to equal levels of 67 ppb at 6 months, which researchers attributed to increased care and nutrition during the study period. No participants developed type 2 diabetes during the study period.
“Despite the small sample size, we demonstrate a real potential for zinc supplementation to improve glucose handling,” the researchers wrote. “This effect may be substantial enough to prevent or, at least, delay progression of prediabetes.” – by Regina Schaffer
The researchers report no relevant financial disclosures.