The addition of metformin to a lifestyle modification program may help female adolescents lose weight if they also make dietary changes, according to findings published in the June issue of the Journal of Pediatrics.

In a randomized, double-blind study, Dr. Kathryn Love-Osborne, of Denver Health and Hospitals, Colorado, and colleagues evaluated the effect of adding metformin versus placebo to a program of personal diet and exercise goal-setting for 85 obese adolescents with insulin resistance.

The subjects were an average of 15.7 years old, and had a mean body mass index of 39.7. Of the 85 subjects, 71% were female, 58% were Hispanic, and 34% were African American.

The researchers report that goal-setting alone did not lead to significant weight loss in this population. No overall differences were observed between the metformin and placebo groups in weight loss or measures of glucose metabolism.

However, a significant decrease in body mass index was seen in females receiving metformin but not in those taking placebo. Sixty percent of participants who were metformin-adherent and who decreased food portion sizes had a decrease in body mass index of more than 5%.

Source: Journal of Pediatrics 2008;152:817-822.