Effect of chromium supplementation on blood glucose control in individuals with type 2 diabetes

Abstract

The purpose of this study was to determine the effect of chromium supplementation on the blood glucose control of individuals with type 2 diabetes. A positive finding would result in substantial health and financial benefits for individuals with this disease. In the previous literature, some studies have found that supplementation with chromium improves blood glucose control, while others have reported no effect; hence the need for more research. This study utilized a repeated measures, double-blind, cross-over design, consisting of two study periods separated by a washout period. Both study periods, as well as the wash-out period, were two months in duration. The sample used in this study was comprised of 12 individuals (9 men and 3 women). Each study period saw half the subjects taking a 400 pg glucose tolerance factor (GTF) chromium supplement per day while the other half received a placebo. The dependent variable, or primary outcome measure of blood glucose control, was haemoglobin A1c (HbA1c). Analysis revealed no evidence of a carry-over effect between periods, so data could justifiably be pooled into change scores from pre to post. Analysis of this data using a repeated measure, within-subjects t-test found no significant differences in HbA1c after treatment with chromium as compared to the placebo. These findings support those previous studies that have found no effect of chromium supplementation on blood glucose control.