BACKGROUND: Chromium (Cr) has been known to be essential for the regulation of insulin action. Recently it has been reported that corticosteroid increases urinary loss of Cr, and that Cr supplementation recovers steroid induced diabetes mellitus. METHODS: Rats were daily treated with dexamethasone (0.2 mg/kg, ip) for first 7 days and were further treated daily with dexamethasone plus either chromium picolinate (30 mg/kg) or a placebo for a period of 14 days. RESULTS: At the end of experiment (Day 21), the control rats treated only with dexamethasone weighed 320 gram (80% of initial weight) in average, but the Cr treated rats weighed 364 gram (91% of initial weight. p<0.05). An insulin sensitivity test [subcutaneous injection of insulin (5 U/kg) plus intraperitoneal injection of glucose (30 minutes after insulin injection)] were conducted. During the insulin sensitivity tests, the area under curves (AUC(0->120 min)) of the time-glucose concentrations curves in the Cr-treated group were decreased compared to those in the control group (5250 vs 15883 mg-min/dL, p<0.01). Fasting serum insulin levels in the Cr-treated rats were clearly decreased by 46.9% compared to those in the control group (2.98 vs 5.60 ng/mL, p<0.05). CONCLUSIONS: We conclude that chromium supplementation reverse a catabolic state, and increase insulin sensitivity in dexamethasone treated rats.