Contrary to expectations, high-dose chromium supplementation does not improve blood-sugar control or other parameters in obese patients with poorly controlled, insulin-treated type 2 diabetes, according to a new study.

“Chromium treatment has been reported to improve glycemic control and insulin sensitivity in specific populations of patients with type 2 diabetes,” Dr. Nanne Kleefstra, of Isala Clinics, Zwolle, the Netherlands, and colleagues write.

They examined the effect of chromium treatment in a 6-month blinded study of obese insulin-dependent type 2 diabetes patients within a Western population. Participants had elevated levels of glycosylated hemoglobin (HbA1c), a common measure of blood sugar, and insulin requirements of greater than 50 units/day.

They were randomly assigned to receive placebo or 500 or 1000 micrograms of chromium daily.

A total of 53 patients were initially randomized. Of these, 46 completed the study. Overall, 17 received placebo, 14 received 500 micrograms chromium, and 15 received 1000 micrograms chromium.

According to the team, chromium did not produce any greater reductions in HbA1c than placebo. The decrease in HbA1c was similar across the three study groups.

A weak association was found between an increasing serum chromium concentration and improvement in the lipid profile.

“Further independent (larger-designed) studies may be necessary to further investigate the possible effects of chromium supplementation on glycemic control or lipid profile in Western populations,” Kleefstra and colleagues explain. “Whether it is possible to select subgroups of patients ... that may or may not benefit from chromium therapy also needs further attention.”

SOURCE: Diabetes Care March, 2006.