Gastric Banding May Allow for Significant Weight Loss in Obese Teens

February 18, 2010 — Gastric banding may be more effective than lifestyle intervention in achieving weight loss in obese adolescents, according to the results of a prospective, randomized controlled trial reported in the February 10 issue of the Journal of the American Medical Association (JAMA).

"Adolescent obesity is a common and serious health problem affecting more than 5 million young people in the United States alone," write Paul E. O'Brien, MD, FRACS, and colleagues of Monash University and the Centre for Adolescent Health, Royal Children's Hospital, Melbourne, Australia, and colleagues. "Bariatric surgery is being evaluated as a possible treatment option. Laparoscopic adjustable gastric banding (gastric banding) has the potential to provide a safe and effective treatment."

The goal of this study was to compare the outcomes on adolescent obesity of gastric banding vs an optimal lifestyle program. The lifestyle program consisted of reduced energy intake and increased activity. Between May 2005 and September 2008, a total of 50 adolescents aged 14 to 18 years with body mass index (BMI) of more than 35 kg/m2 were recruited from the Melbourne, Australia, community and randomly assigned to a supervised lifestyle intervention or to undergo gastric banding. During 2-year follow-up, the primary study endpoint was weight loss, and secondary endpoints were change in metabolic syndrome, insulin resistance, quality of life, and adverse outcomes.

In the gastric banding group, 24 of 25 patients completed the study vs 18 of 25 in the lifestyle group. Loss of more than 50% of excess weight, corrected for age, occurred in 21 patients (84%) in the gastric banding group and in 3 patients (12%) in the lifestyle group.

In the gastric banding group, mean weight loss was 34.6 kg (95% confidence interval [CI], 30.2 - 39.0 kg), representing an excess weight loss of 78.8% (95% CI, 66.6% - 91.0%), loss of 12.7 BMI units (95% CI, 11.3 - 14.2), and a BMI z score change from 2.39 (95% CI, 2.05 - 2.73) to 1.32 (95% CI, 0.98 - 1.66). In the lifestyle group, mean weight loss was 3.0 kg (95% CI, 2.1 - 8.1), representing an excess weight loss of 13.2% (95% CI, 2.6% - 21.0%), 1.3 BMI units (95% CI, 0.4 - 2.9), and a BMI z score change from 2.41 (95% CI, 2.21 - 2.66) to 2.26 (95% CI, 1.91 - 2.43).

Metabolic syndrome was present at entry in 9 participants (36%) in the gastric banding group and in 10 participants (40%) in the lifestyle group, but at 24 months, none of the gastric banding group had the metabolic syndrome (P = .008) vs 4 (22%) of the 18 completers in the lifestyle group (P = .13). Participants in the gastric banding group also reported improved quality of life. Although there were no perioperative adverse events, 8 surgical revisions (33%) were required in 7 patients either for proximal pouch dilatation or tubing injury during follow-up.

"Among obese adolescent participants, use of gastric banding compared with lifestyle intervention resulted in a greater percentage achieving a loss of 50% of excess weight, corrected for age," the study authors write. "There were associated benefits to health and quality of life."

Limitations of this study include lack of generalizability to the general obese adolescent population in the community, possible recruitment bias, study not powered to measure differences in adverse events or in health measures other than differences in weight outcomes, and follow-up limited to 2 years. In addition, the investigators used an intent-to-treat analysis for the primary outcome of weight change but used the completer's analysis for secondary outcomes.

"In this study, gastric banding proved to be an effective intervention leading to a substantial and durable reduction in obesity and to better health," the study authors conclude. "The adolescent and parents must understand the importance of careful adherence to recommended eating behaviors and of seeking early consultation if symptoms of reflux, heartburn, or vomiting occur. As importantly, they should be in a setting in which they can maintain contact with health professionals who understand the process of care."

In an accompanying editorial, JAMA contributing editor Edward H. Livingston, MD, from the University of Texas Southwestern Medical Center in Dallas, notes that this study shows that randomized controlled trials can and should be performed to evaluate surgical technologies.

"The quality of evidence in support of bariatric surgery is poor, resulting in substantial controversy regarding its use for obesity treatment," Dr. Livingston writes. "Many insurance companies in the United States will not pay for bariatric surgeries, and their decision to not cover this treatment is based on the lack of compelling, universally accepted evidence in its favor. Studies such as the one by O'Brien et al go a long way toward providing the evidence necessary to evaluate the benefits and risks of bariatric surgery."

The National Health and Medical Research Council supported this study. Allergan provided the laparoscopic adjustable gastric bands used in the study and provided an unrestricted research support grant to the Centre for Obesity Research and Education. One of the study authors (Dr. Dixon) has disclosed various financial relationships with Allergan, Bariatric Advantage, Scientific Intake, SP Health Co, Optifast, Abbott Australasia, Eli Lilly Australia, Merck Sharp & Dohme Australia, Nestle Australia, and Roche Products Australia. Dr. Livingston has disclosed no relevant financial relationships.

JAMA. 2010;303:519-526, 559-560.

Clinical Context

Obesity is a severe problem in the United States, and this problem is pronounced among adolescents. According to the authors of the current study, 17.4% of teenagers in the United States were obese in 2004. The prevalence of obesity had increased in adolescents since 2000.

Lifestyle interventions are first-line therapy for obesity, but these programs have a lackluster record of efficacy among adolescents, with modest weight loss noted for up to 12 months and a return of weight gain after the intervention. Bariatric surgery may promote more significant and sustained weight loss for obese adolescents, and the current trial puts this hypothesis to the test.


Study Highlights

The study was completed between 2005 and 2008 in Melbourne, Australia. Patients eligible for study participation were between the ages of 14 and 18 years and had a BMI of more than 35 kg/m2. All participants also had a complication of obesity, such as hypertension, back pain, physical limitations, or psychosocial difficulties.
Patients did not pay any medical costs during the trial.
All participants completed a 2-week baseline assessment of diet and physical activity and then a 2-month program to promote better exercise and food choices.
Participants were randomly assigned to a lifestyle program or laparoscopic gastric banding surgery. Participants in the lifestyle program were placed on individualized diet plans ranging between 800 and 2000 kcal/day. They also received 6 weeks of instruction with a personal trainer, with a goal of 30 minutes of daily exercise.
The other randomized group received gastric banding within 1 month of their treatment assignment. Eating rules focused on 3 or fewer meals a day, each approximately 125 mL in size.
Participants were observed for 2 years. The main study outcome was the percentage of individuals who lost more than 50% of excess body weight. Researchers also followed BMI, health measures, quality of life, and adverse events related to study interventions.
50 participants underwent randomization, and 24 of 25 participants in the gastric banding group completed the study, as did 18 of 25 participants in the lifestyle program. Baseline data were similar in comparing randomized groups.
The mean age of participants was 16 years, and 32% of subjects were boys. The mean BMI was 41 kg/m2, and the mean BMI percentile for age exceeded 99%.
84% of participants in the gastric banding group lost more than 50% of excess body weight, which was significantly more vs the lifestyle cohort (12%).
The mean weight loss in the gastric banding group was 34.6 kg, representing 78.8% of excess weight. The mean BMI z score decreased from 2.39 to 1.32 in the gastric banding group.
The mean weight loss in the lifestyle group was 3 kg, representing 13.2% of excess weight. The mean BMI z score decreased from 2.41 to 2.26 in the lifestyle group.
Insulin sensitivity improved in the gastric banding group vs the lifestyle group, and the metabolic syndrome resolved in 9 participants in the gastric banding group. However, blood pressure and serum lipid values were similar in comparing the gastric banding group vs the lifestyle group.
Although there were no significant complications of gastric banding surgery in the 30 days after the operation, 7 patients required 8 revision procedures during follow-up.
Gastric banding was associated with better quality-of-life scores vs the lifestyle program.

Clinical Implications

A total of 17.4% of teenagers in the United States were obese in 2004. The prevalence of obesity had increased in adolescents since 2000. Lifestyle interventions among obese adolescents are associated with modest weight loss for up to 12 months and a return of weight gain after the intervention.
The current study demonstrates that laparoscopic gastric banding is associated with superior outcomes for excess weight loss, total weight loss, insulin resistance, and quality-of-life scores vs a lifestyle program in a small cohort of obese adolescents. Nearly 30% of adolescents who received gastric banding required some revision of the procedure.