Gastric bypass surgery successful for long-term weight loss, remission of type 2 diabetes in the severely obese

Severely obese patients who underwent gastric bypass surgery showed favorable outcomes more than a decade later, including weight loss and remission of type 2 diabetes, a study published in the New England Journal of Medicine states.

While scientists have been conducting research on bariatric surgery for years, few long-term or controlled studies exist, Ted D. Adams, PhD, MPH, and co-authors wrote in their paper. Adams and his team gathered a pool of 1,156 patients diagnosed with severe obesity and followed them for a total of 12 years, checking in with the subjects two, six and then 12 years after more than a third of them completed Roux-en-Y gastric bypass surgery.

Not all of the researchers’ patients went under the knife, according to the study—418 underwent bariatric surgery to shrink their stomachs, while 417 of the patients had sought out information on the surgery but decided not to go through with it (non-surgery group 1) and 321 individuals who didn’t consider surgery at all (non-surgery group 2). The group of patients who chose not to have surgery largely chose not to do so because of insufficient insurance coverage, Adams and co-authors wrote.

The scientists completed clinical examinations on all patients at baseline and monitored 90 percent of that original pool for 12 years, making note of presence of type 2 diabetes, hypertension and dyslipidemia in those subjects.

The surgery group lost on average 45 kg during that time, compared to non-surgery group 1’s average of 2.9 kg. The second group of non-surgery patients lost, on average, no weight during the 12 years. Adams and colleagues also found that after just two years, type 2 diabetes had remitted in 75 percent of previously diabetic patients in the surgery group—a much higher number than in either non-surgery cohort. Although that percentage steadily declined over the 12 years of research, 51 percent of surgery patients still hadn’t experienced a remission of type 2 diabetes by the end of the research period.

The authors said remission of diabetes was much more likely to be a success in patients who underwent the Roux-en-Y gastric bypass surgery before starting treatment with insulin.

“Successful remission of type 2 diabetes was strongly predicted by baseline medication status,” Adams and co-authors explained in their research. “Remission of type 2 diabetes at 12 years was observed in 16 of 22 patients in the surgery group who had type 2 diabetes but had not been receiving antidiabetic medications at baseline, as compared with 24 of 43 patients with diabetes who had been receiving only oral medications at baseline and three of 19 patients with diabetes who had been receiving insulin, with or without additional oral antidiabetic medication, at baseline.”

According to the study, mean weight loss in the surgery group stabilized after about six years, remaining at roughly the same level through year 12. Other aspects of metabolic health in the surgery patients also saw favorable outcomes: rates of both hypertension and dyslipidemia were better in those individuals than in the non-surgery groups, and new-onset diabetes was all but erased for the population. Adams and colleagues wrote these results indicate gastric bypass surgery can indeed result in significant, long-term durability of weight loss and, therefore, the improvement of health and quality of life in severely obese patients.