From October 2003 to August 2007, researchers from the Glaser Pediatric Research Network conducted a multicenter, randomized, double-blind, placebo-controlled trial to determine if daily therapy with extended-release metformin reduces body mass index (BMI) in obese adolescents as compared with placebo. Inclusion criteria required participants to be 13 to 17 years old, have a BMI >95th percentile for age and sex, and weigh less than 136 kg. Participants were excluded from the study if they had a previous diabetes mellitus diagnosis, had ever used medication to treat diabetes mellitus or promote weight loss, were using medications that increase metformin levels, had a history of recent glucocorticoid therapy, had been diagnosed with a medical condition predisposing to obesity, had attended a formal weight loss program in the past six months, or had undergone a surgical procedure to treat obesity.
All patients were enrolled in a lifestyle intervention program to increase physical activity and optimize diet (the Weigh of Life LITE program developed at Texas Children’s Hospital). Participants were seen eight times during the study. A DXA scan and an abdominal CT scan, to evaluate abdominal fat, were performed at 48 weeks and at the end of the study. The last dose of study drugs was administered at week 48 followed by a 48-week monitoring period.
A total of 39 children with a mean BMI of 35.9 were enrolled in each group. The mean age was approximately 15 years and two thirds of study participants were girls. Only 27 and 19 subjects in each group were measured at weeks 52 and 100, respectively. There were no significant differences between metformin and placebo groups for any class of adverse events. At 52 weeks, the metformin-treated group had a significant decline in mean BMI compared to the placebo group (decrease of 0.9 [Standard Error 0.5] compared to a 0.2 [Standard Error 0.5; P=.03] increase). BMI differences persisted for the metformin and placebo groups for 12 to 24 weeks after drug treatment. Thereafter the mean BMI in the metformin group increased towards the placebo group. No significant differences with regard to body composition, abdominal fat, or insulin indices were observed between the metformin and placebo groups.
The authors conclude that the addition of metformin to a lifestyle modification program has a small yet significant effect in reducing the BMI of obese adolescents.
Researchers are evaluating multiple methods of tackling the epidemic of childhood obesity in the US. Community-based programs have looked at addressing food environments.1 Other studies have looked at the effectiveness of childhood obesity treatment programs containing drug and surgical interventions, family support, healthy dietary and lifestyle education, and physical activity through community- and school-based programs.2,3
The current clinical approach to management of pediatric obesity involves behavioral therapy directed...