This is one of three Journal Notes this week that will cover studies from the Journal of the American Medical Association’s special issue on obesity.

Obesity in the United States is rapidly becoming a national public health problem. In children and adolescents, obesity may lead to the same medical complications found in adults, including hypertension , type 2 diabetes , liver disorders, and sleep disturbances. It also predisposes them to complications unique to childhood and adolescence, such as certain orthopedic problems and the long-term psychological consequences of social exclusion at a young age.

As the number of children and adolescents with severe obesity increases, parents and physicians are looking to more intensive treatments, such as pharmacotherapy and surgery. Unfortunately, few well-designed studies have been conducted to assess the effectiveness of these approaches in children and adolescents. In one of the first such studies, researchers found that sibutramine, a drug commonly used to promote weight loss in adults, combined with behavioral therapy resulted in significantly greater weight loss than behavioral therapy alone in obese adolescents.

About the study

The study included 82 adolescents between the ages of 13 and 17, who had a body mass index (BMI) of 32 to 44. Phase I of the study was a randomized, double-blind, placebo controlled trial in which the participants received either behavioral therapy and sibutramine or behavioral therapy and placebo for six months. Phase II was an open-label extension in which all the participants received both behavioral therapy and sibutramine for six additional months.

Behavioral therapy consisted of a family-based behavioral weight loss program in which all of the participants were instructed to follow a 1200 to 1500 calorie per day diet, engage in some type of aerobic activity for 120 minutes per week or more, and keep a daily eating and activity log. The researchers measured the percentage change in BMI, monitored blood pressure and pulse, and recorded how hungry the participants were.

The findings

During Phase I, participants receiving both behavioral therapy and sibutramine lost an average of 7.8 kg (17.2 lbs.) and reduced their BMI by 8.5%. This weight loss was significantly greater than the 3.2 kg (7.0 lbs) and 4.0 % reduction seen in the participants receiving placebo and behavioral therapy. Participants in the sibutramine group also reported a significantly reduced level of hunger than those in the placebo group. In Phase II of the study, participants who had been treated with sibutramine in Phase I gained 0.8 kg (1.8 lbs) with continued use of the medication, however, those who switched from placebo to sibutramine lost an additional 1.3 kg (2.9 lbs).

How does this affect you?

The study concluded that adding sibutramine to a comprehensive behavioral program induced significantly more weight loss than did behavioral therapy alone. These findings suggest that adult weight loss medications may be of benefit to adolescents. However, the researchers recommend more studies be conducted to assess the benefits and costs of pharmacologic treatment in adolescents. Until this data is available, the researchers conclude that medications for weight loss in adolescents and children should be considered experimental.

Researchers must also bear in mind that obesity is one of the most stigmatizing and least socially acceptable conditions in childhood and may impact far more than a child’s physical health. A second study published in this issue, found that severely obese children and adolescents have a significantly lower health-related quality of life (physical, emotional, social, and school functioning) than healthy children. Indeed this study found that the risk of lower health related quality of life in obese children was equal to that of children receiving chemotherapy for cancer.

Therefore, the researchers conducting this second study concluded that physicians, parents, and teachers must be aware of the risk for impaired quality of life in obese children and adolescents and propose that future studies of targeted interventions, such as the sibutramine study, include an assessment of quality of life before, during, and after treatment.

In an accompanying editorial, researchers note that it remains exceedingly difficult for overweight children and adolescents to lose weight, and even more difficult for them to sustain that weight loss long term. The ultimate goal must be to prevent childhood obesity in the first place.