Gastric Banding May Allow Significant Weight Loss in Obese Teens

From Medscape Medical News
Laurie Barclay, MD

February 9, 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. 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.