Study shows link between RYGB surgery in obese patients and sustained long-term weight loss

The JAMA Network JournalsAug 31 2016

Obese patients who underwent Roux-en-Y gastric bypass (RYGB) lost much more weight than those who did not and were able to sustain most of this weight loss 10 years after surgery, according to a study published online by JAMA Surgery.

Prior research has demonstrated that bariatric surgery is the most effective intervention for inducing weight loss among obese patients. Much of this evidence is based on relatively short 1- to 3-year follow-up from randomized clinical trials. Matthew L. Maciejewski, Ph.D., of the Durham Veterans Affairs Medical Center and Duke University, Durham, N.C., and colleagues examined differences in weight change up to 10 years after surgery in 1,787 veterans who underwent RYGB (573 of 700 eligible [82 percent] with 10-year follow-up), and 5,305 nonsurgical matches (1,274 of 1,889 eligible [67 percent] with 10-year follow-up). Differences in weight change up to 4 years were compared among veterans undergoing RYGB (n = 1,785), sleeve gastrectomy (SG; n = 379), and adjustable gastric banding (AGB; n = 246).

The 1,787 patients undergoing RYGB and the 5,305 nonsurgical matches had an average age of 52 years. Patients undergoing RYGB and nonsurgical matches had an average body mass index of 47.7 and 47.1, respectively, and were predominantly male (73 percent and 74 percent, respectively). Patients undergoing RYGB lost 21 percent more of their baseline weight at 10 years than nonsurgical matches. A total of 405 of 564 patients undergoing RYGB (72 percent) had more than 20 percent estimated weight loss, and 224 of 564 (40 percent) had more than 30 percent estimated weight loss at 10 years compared with 134 of 1,247 (11 percent) and 48 of 1,247 (3.9 percent), respectively, of nonsurgical matches. Only 19 of 564 patients undergoing RYGB (3.4 percent) regained weight back to within an estimated 5 percent of their baseline weight by 10 years.

At 4 years, patients undergoing RYGB lost 28 percent of their baseline weight, patients undergoing AGB lost 11 percent, and patients undergoing SG lost 18 percent. Patients undergoing RYGB lost 17 percent more of their baseline weight than patients undergoing AGB and 10 percent more than patients undergoing SG.

The authors note that the results of this study provide further evidence of the beneficial association between surgery and long-term weight loss that has been demonstrated in shorter-term studies of younger, predominantly female populations.

"More evidence is needed on postsurgical complications, disease resolution, and long-term mental health outcomes to help surgical candidates choose the procedure that is best for them. Engaging patients in a high-quality shared decision-making conversation about their weight loss treatment options (including no treatment) is critical because prior studies have found that patients have unrealistic expectations of the weight loss that bariatric surgery will help them achieve. Untreated severely obese patients are unlikely to achieve significant weight loss, although the nonsurgical matches in our study experienced modest weight loss, most likely because of age-related changes," the researchers write.