Lack of effect of dietary chromium supplementation on glucose tolerance, plasma insulin and lipoprotein levels in patients with type 2 diabetes

Chromium is essential for the regulation of insulin action, thereby influen cing carbohydrate and lipid metabolism. An uncontrolled pilot study was des igned to measure the habitual daily intake of chromium in a group of health y individuals with type 2 diabetes and to monitor the effect Of daily suppl ementation with high chromium yeast on glucose tolerance. plasma insulin an d lipoproteins. Twelve free-living adults with type 2 diabetes underwent a glucose tolerance test (GTT) on recruitment, at I weeks (after a 7-d duplic ate diet collection) and at 12 weeks (following 8 weeks daily supplementati on with 100 mu g of chromium). Urine samples were collected on the day befo re and the day of each GTT. Blood samples were taken at half hourly interva ls for 3 hours during the GTT and the plasma glucose, cholesterol, triglyce ride, HDL, LDL and insulin concentration measured. The chromium content of diets and urine samples was determined. Fasting glucose concentrations and glucose area under the curve profiles did not alter significantly post supp lementation with the chromium rich yeast. No significant changes in insulin and lipoprotein concentrations were observed. The results of this study do not support the hypothesis that individuals with type 2 diabetes benefit f rom yeast-based chromium supplements (100 mu g/day).