Among obese participants with type 2 diabetes mellitus, bariatric surgery with 2 years of a low-level lifestyle intervention resulted in more disease remission than did lifestyle intervention alone, according to a study published online in JAMA Surgery. McGowan Institute for Regenerative Medicine affiliated faculty member Steven Belle, PhD, MScHyg, professor in the Department of Epidemiology, Graduate School of Public Health at the University of Pittsburgh, and a co-director in the Epidemiology Data Center in the Graduate School of Public Health, is a co-author of the study.
It remains to be established whether bariatric surgery is a durable and effective treatment for type 2 diabetes (T2DM) and how bariatric surgery compares with intensive lifestyle modification and medication management with respect to T2DM-related outcomes. As demonstrated in observational studies and several small randomized clinical trials of short duration, T2DM is greatly improved after bariatric surgery. However, more information is needed about the longer-term effectiveness and risks of all types of bariatric surgical procedures compared with lifestyle and medical management for those with T2DM and obesity, according to background information in the article.
Along with Dr. Belle, Anita Courcoulas, MD, MPH, and colleagues assessed outcomes 3 years after 61 obese participants with T2DM who were randomly assigned to either an intensive lifestyle weight loss intervention for 1 year followed by a low-level lifestyle intervention for 2 years or surgical treatments (Roux-en-Y gastric bypass [RYGB] or laparoscopic adjustable gastric banding [LAGB]) followed by low-level lifestyle intervention in years 2 and 3. Fifty participants (82 percent) were women, and 13 (21 percent) were African American.
At 3 years, any T2DM remission (partial or complete) was achieved in 40 percent (n = 8) of RYGB, 29 percent (n = 6) of LAGB, and no intensive lifestyle weight loss intervention participants, while complete remission was achieved in 15 percent of RYGB, 5 percent of LAGB, and no intensive lifestyle weight loss intervention group participants.
The use of diabetes medications was reduced more in the surgical groups than the lifestyle intervention-alone group, with 65 percent of RYGB, 33 percent of LAGB, and none of the intensive lifestyle weight loss intervention participants going from using insulin or oral medication at baseline to no medication at year 3. Average reductions in percentage of body weight at 3 years were the greatest after RYGB at 25 percent (2 percent), followed by LAGB at 15 percent (2 percent), and lifestyle treatment at 5.7 percent (2.4 percent).
The authors noted that one important aspect of this study was that more than 40 percent of the sample were individuals with class I obesity (BMI of 30 to <35) for whom data in the literature are largely lacking. “Those who underwent a surgical procedure followed by low-level lifestyle intervention were significantly more likely to achieve and maintain glycemic control than were those who received intensive and then maintenance (low-level) lifestyle therapy alone, regardless of obesity class. More than two-thirds of those in the RYGB group and nearly half of the LAGB group did not require any medications for T2DM treatment at 3 years.”
“This study provides further important evidence that at longer-term follow-up of 3 years, surgical treatments, including RYGB and LAGB, are superior to lifestyle intervention alone for the remission of T2DM in obese individuals including those with a BMI between 30 and 35. While this trial provides valuable insights, unanswered questions remain such as the impact of these treatments on long-term microvascular and macrovascular complications and the precise mechanisms by which bariatric surgical procedures induce their effects.”
Full Text (Three-year outcomes of bariatric surgery vs lifestyle intervention for type 2 diabetes mellitus treatment: a randomized clinical trial. Anita P. Courcoulas, MD, MPH, Steven H. Belle, PhD, MScHyg, Rebecca H. Neiberg, MS, Sheila K. Pierson, BS, BA, Jessie K Eagleton, MPH, Melissa A. Kalarchian, PhD, James P. DeLany, PhD, Wei Lang, PhD, John M. Jakicic, PhD. JAMA Surgery; published online July 01, 2015.)