Elevated Intakes of Supplemental Chromium Improve Glucose and Insulin Variables in Individuals With Type 2 Diabetes

Abstract

Chromium is an essential nutrient involved in normal carbohydrate and lipid metabolism. The chromium requirement is postulated to increase with increased glucose intolerance and diabetes. The objective of this study was to test the hypothesis that the elevated intake of supplemental chromium is involved in the control of type 2 diabetes. Individuals being treated for type 2 diabetes (180 men and women) were divided randomly into three groups and supplemented with: 1) placebo, 2) 1.92 μmol (100 μg) Cr as chromium picolinate two times per day, or 3) 9.6 μmol (500 μg) Cr two times per day. Subjects continued to take their normal medications and were instructed not to change their normal eating and living habits. HbA_1c values improved significantly after 2 months in the group receiving 19.2 pmol (1,000 pg) Cr per day and was lower in both chromium groups after 4 months (placebo, 8.5 ± 0.2%; 3.85 pmol Cr, 7.5 ± 0.2%; 19.2 pmol Cr, 6.6 ± 0.1%). Fasting glucose was lower in the 19.2-μmol group after 2 and 4 months (4-month values: placebo, 8.8 ± 0.3 mmol/1; 19.2 μmol Cr, 7.1 ± 0.2 mmol/1). Two-hour glucose values were also significantly lower for the subjects consuming 19.2 μmol supplemental Cr after both 2 and 4 months (4-month values: placebo, 12.3 ± 0.4 mmol/1; 19.2 μmol Cr, 10.5 ± 0.2 mmol/1). Fasting and 2-h insulin values decreased significantly in both groups receiving supplemental chromium after 2 and 4 months. Plasma total cholesterol also decreased after 4 months in the subjects receiving 19.2 μmol/day Cr. These data demonstrate that supplemental chromium had significant beneficial effects on HbA_1c, glucose, insulin, and cholesterol variables in subjects with type 2 diabetes. The beneficial effects of chromium in individuals with diabetes were observed at levels higher than the upper limit of the Estimated Safe and Adequate Daily Dietary Intake.