The health benefits of Roux-en-Y gastric bypass (RYGB) surgery in severely obese patients persist for six years, according to a prospective, controlled study (JAMA 2012;308:1122-1131). These benefits include weight loss and improvements in major cardiovascular and metabolic risk factors.
Previous studies reporting long-term weight loss after bariatric surgery had been limited and often with incomplete follow-up, reported the authors.
“I think the most important aspect of this paper is its long-term nature,” lead author Ted D. Adams, PhD, MPH, program director, Health and Fitness Institute, Intermountain Healthcare, Salt Lake City, said in an interview. Dr. Adams, who is also principal research investigator, Cardiovascular Genetics, University of Utah School of Medicine, Salt Lake City, added, “This is the largest and longest exclusive gastric bypass study to date.”
The study included 1,156 severely obese (body mass index [BMI] ≥35 kg/m2) participants aged 18 to 72 years. The study included 418 patients treated with RYGB. These patients were compared with two control groups: Control group 1 consisted of participants seeking RYGB surgery who did not have surgery (n=417), and control group 2 was a population-based sample without prior history of bariatric surgery (n=321).
In control group 1, said Dr. Adams, “most [patients] did not have the surgery because their insurance company wouldn’t cover the procedure.”
At six years, 92.6% of the surgical group had follow-up data, compared with 72.9% of control group 1 and 96.9% of control group 2.
“Ninety-two percent follow-up is very good—way beyond what we can usually get,” said Jaime Ponce, MD, FACS, FASMBS, president, American Society for Metabolic and Bariatric Surgery, Gainesville, Fla., who was not associated with the study.
In the surgical group, mean unadjusted weight loss from baseline to year 6 was 27.7% (95% confidence interval [CI], 26.6%-28.9%). In control group 1, weight gain over that period was 0.2% (95% CI, –1.1% to 1.4%) and in control group 2, it was 0% (95% CI, –1.2% to 1.2%).
The diabetes remission rate six years after surgery was 62% in the surgical group compared with 8% in control group 1 and 6% in control group 2. The incidence of diabetes during the six-year follow-up period was lower in the surgery group, at 2%, compared with control groups 1 and 2 at 17% and 15%, respectively.
Metabolic and cardiovascular risk profiles at six years were significantly improved after RYGB. For example, compared with the control groups, the surgery group had a decrease in fasting glucose, an increase in high-density lipoprotein cholesterol levels and improved remission rates of hypertension.
“There are three take-home messages,” Dr. Adams said. “One, dramatic weight loss at two years was pretty well maintained at six years. Two, patients who had health problems and had surgery showed a general improvement in their condition, such as diabetes being remitted. Three, those patients who didn’t have a health problem, such as diabetes, were less likely to develop it after surgery.”
“It’s very relevant,” Dr. Ponce said. “There were tremendous benefits with the surgical group. The control groups showed if you don’t do surgery, the patients will continue to have diabetes. The longer you leave it alone, the more problems you’ll have.”
Dr. Ponce also noted the vast economic savings that could be realized with bariatric surgery. “The cost of bariatric surgery is about $20,000. The cost of caring for the average patient with diabetes is $6,000 to $8,000 a year. In two and a half years, [with diabetes in remission,] you would have paid for the surgery cost. … [The study] sends a message to insurance companies when they’re denying coverage.”
The study’s major limitation, said Dr. Ponce, is that it was not randomized. “There may be a little bit of bias, but it’s probably minimal.”
Dr. Adams said that a 10-year follow-up study is planned. Of concern are psychosocial factors and the increased incidence of suicide in the surgical group. “The numbers of suicides were small, but nevertheless it’s a flag,” said Dr. Adams.
The study was funded by the National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Diseases.