The scientists, led by Darrell M. Wilson, randomly assigned 77 obese adolescents aged 13 to 18 years to a program of physical activity and diet and a daily dose of metformin XR (2,000 milligrams) or placebo for 48 weeks. Of which 39 took the drug and 38 placebo. Participants were followed for an additional 48 weeks.

According to the authors, metaformin XR had a small but significant impact on BMI during the 52 weeks of the study. The average BMI increased by about 0.2 in the placebo group and decreased 0.9 in the metformin XR. The researchers note that the difference between groups was maintained between 12 and 24 weeks after cessation of study drug. Then, the average BMI of the group taking metformin increased toward the control group.

The researchers conclude that the results indicate that metaformin may have an important role in the treatment of adolescent obesity and needed long-term studies to characterize the effects of treatment on risk of diseases associated with obesity in this population.