Donald Simonson

Patients with worrisome levels of obesity and poor control of their Type 2 diabetes face two dramatically different options to improve their health: surgery or significant lifestyle changes. In a randomized controlled clinical trial, scientists from BWH and Joslin Diabetes Center found that patients who underwent a form of weight-loss surgery known as Roux-en-Y gastric bypass did significantly better after three years than those who followed an intensive diabetes- and weight-management program.

“Our study demonstrates that in patients with mild-moderate obesity and Type 2 diabetes, gastric bypass surgery leads to a sustained reduction in weight, improvement in glycemic control and decrease in cardiovascular risk, compared to a medical diabetes- and weight-management program,” said lead author Donald Simonson, MD, ScD, MPH, of the Division of Endocrinology, Diabetes and Hypertension.

Other BWH contributors to the research include Florencia Halperin, MD, medical director of the Program for Weight Management, and Ashley Vernon, MD, a member of the Center for Metabolic and Bariatric Surgery.

The paper, which will be published the April issue of Diabetes Care, provided the results from the SLIMM-T2D (Surgery or Lifestyle with Intensive Medical Management in the Treatment of Type 2 Diabetes) study, which randomly assigned 38 obese patients with Type 2 diabetes to Roux-en-Y gastric bypass surgery at BWH or an intensive lifestyle management program at Joslin. Initially, participants had an average weight of 230 pounds and body mass index (BMI) of 36.3.

After three years, patients who underwent surgery experienced far more weight loss, dropping 55 pounds on average. Those in the lifestyle-management intervention lost an average of 11 pounds over the same period.

Additionally, patients in the surgery group lowered their blood sugar to a greater degree, seeing hemoglobin A1c levels drop 1.79 percentage points. In comparison, patients in the lifestyle-management program experienced a 0.39 percentage point decrease. Those who received surgery also showed significantly lower risk of coronary heart disease and stroke.

‘A Viable Option’

Although patients given the lifestyle-management program made encouraging initial progress in both weight loss and diabetes control, investigators noted that those improvements dropped noticeably over time.

“Patients who had the gastric bypass procedure had superior ability to sustain changes both in weight and blood sugar, and they did so requiring less medication for their diabetes, their blood pressure and their lipids,” said Allison Goldfine, MD, head of clinical research at Joslin during the trial and senior author on the paper.

Participants from both groups reported improvements in overall quality of life. Those who were assigned the surgical intervention experienced greater improvement in physical functioning, self-esteem and work performance, and weight loss had a significantly higher effect on their quality of life compared to the other group.

“As a result of these findings, we expect that more physicians will consider gastric bypass surgery as a viable option for patients with Type 2 diabetes and mild to moderate obesity when previous attempts to lose weight and improve glycemic control have not been successful,” said Simonson.

The Roux-en-Y gastric bypass procedure is done laparoscopically through small cuts in the abdomen. Surgeons form a small pouch at the top of the stomach and connect the pouch to the middle of the small intestine.

Joslin’s 12-week intensive lifestyle-management program included a change in diabetes medications to enhance weight reduction, structured dietary intervention with lower carbohydrates and higher protein and meal replacement, an exercise program with emphasis on strength training, and weekly educational and support sessions.

Goldfine emphasized that treatment must be personalized for all patients with obesity and diabetes, as gastric bypass surgery may not always be the best option. She noted that today’s surgical procedures and intensive lifestyle-management techniques both take advantage of major medical advances achieved in the past decade or two.

“Older surgical procedures were much more invasive, with much higher surgical risk and complication rates, and older types of procedures had higher failure rates over time,” she said. “Laparoscopic surgery made the biggest impact on the surgical experience and recovery, but we have improved surgical techniques all the way from preoperative evaluations to better postoperative care.”