Zinc Supplementation in Patients with Type 2 Diabetes
Does zinc supplementation affect glycemic control in patients with type 2 diabetes? A lack of zinc has been associated with a number of chronic disorders, such as cardiovascular disease and diabetes. Because zinc may affect glucose levels in both humans and animals, a team led by researchers in the School of Molecular Bioscience at the University of Sydney in Australia explored the effects of taking zinc supplements on the management of diabetes.
Their study, “Zinc and glycemic control: A meta-analysis of randomized placebo controlled supplementation trials in humans,” was published online ahead of print in November 2012. It appears in the Journal of Trace Elements in Medicine and Biology.
To gauge the effects of zinc supplementation on patients’ fasting blood glucose levels, HbA1c, serum zinc concentration, and serum insulin levels, the researchers conducted a meta-analysis of randomized trials. The analysis included 14 studies published before July 2011, and it compiled data on 3,978 participants.
The results showed that there was a small but significant reduction in patients’ fasting glucose when they took zinc supplements. Additionally, HbA1c levels generally decreased in the patients who took zinc, compared to those who did not, while patients’ plasma zinc concentrations increased significantly following supplementation. The researchers did not find significant effects in serum insulin concentrations.
The study authors conducted secondary analyses of the effects of zinc supplementation in patients with chronic metabolic disease, including type 1 diabetes, type 2 diabetes, metabolic syndrome, and obesity. They found that patients who were living with chronic diseases showed larger decreases in glucose concentrations after taking zinc than patients without chronic diseases.
The researchers conclude that their study suggests a significant though small reduction in blood glucose concentrations in patients taking zinc supplements. They argue that though this reduction is modest, the findings of the meta-analysis show that zinc supplementation may help patients with chronic metabolic disease manage hyperglycemia.