Is There a Role for Metformin in the Treatment of Childhood Obesity?

Abstract

Childhood obesity often seems like an intractable problem, with a rising incidence, especially of severe obesity, over the last few decades and few effective treatment options. Lifestyle changes, including dietary modification and exercise, are effective only in a minority of patients, with significant and sustained weight loss most likely to occur in the setting of costly multidisciplinary programs. Thus, clinicians often turn to pharmacotherapy. Currently there is only 1 medication, orlistat, that is approved for childhood obesity, but its effect on weight is modest and its acceptability is limited by side effects related to decreased fat absorption. Metformin is the mainstay of treatment of type 2 diabetes in both children and adults, with effects mainly on improving insulin sensitivity and decreasing hepatic glucose output. Since 2000, there have been a large number of studies that have examined the use of metformin as a weight-loss drug in children with obesity. Although each study has been unique in its size, design, and the patient populations studied, the theme that emerges, as summarized in a systematic review in 2014 based on 14 randomized clinical trials,1 is that “metformin provides a statistically significant, but very modest reduction in BMI when combined with lifestyle interventions over the short term.” The latest addition to this literature, published in this issue of Pediatrics , is a study from Spain, “Metformin for obesity in prepubertal and pubertal children: A Randomized Controlled Trial,”2 which offers some benefit compared with previous clinical trials but leaves more questions unanswered … Address correspondence to Paul Kaplowitz, MD, Division of Endocrinology, Children’s National Health System, 111 Michigan Ave NW, Washington, DC 20010. E-mail: pkaplowi{at}childrensnational.org