Bariatric Surgery vs Lifestyle Intervention for Diabetes Treatment

5-Year Outcomes From a Randomized Trial

Anita P. Courcoulas; James W. Gallagher; Rebecca H. Neiberg; Emily B. Eagleton; James P. DeLany; Wei Lang; Suriya Punchai; William Gourash; John M. Jakicic


J Clin Endocrinol Metab. 2020;105(3) 

In This Article

Abstract and Introduction


Context: Questions remain about bariatric surgery for type 2 diabetes mellitus (T2DM) treatment.

Objective: Compare the remission of T2DM following surgical or nonsurgical treatments.

Design, setting, and participants: Randomized controlled trial at the University of Pittsburgh, in the United States. Five-year follow-up from February 2015 until June 2016.

Interventions: 61 participants with obesity and T2DM who were initially randomized to either bariatric surgical treatments (Roux-en-Y gastric bypass [RYGB] or laparoscopic adjustable gastric banding [LAGB]) or an intensive lifestyle weight loss intervention (LWLI) program for 1 year. Lower level lifestyle weight loss interventions (LLLIs) were then delivered for 4 years.

Main Outcomes and Measures: Diabetes remission assessed at 5 years.

Results: The mean age of the patients was 47 ± 6.6 years, 82% were women, and 21% African American. Mean hemoglobin A1c level 7.8% ± 1.9%, body mass index (BMI) 35.7 ± 3.1 kg/m2, and 26 participants (43%) had BMI < 35 kg/m2. Partial or complete T2DM remission was achieved by 30% (n = 6) of RYGB, 19% (n = 4) of LAGB, and no LWLI participants (P = .0208). At 5 years those in the RYGB group had the largest percentage of individuals (56%) not requiring any medications for T2DM compared with those in the LAGB (45%) and LWLI (0%) groups (P = .0065). Mean reductions in percent body weight at 5 years was the greatest after RYGB 25.2% ± 2.1%, followed by LAGB 12.7% ± 2.0% and lifestyle treatment 5.1% ± 2.5% (all pairwise P < .01).

Conclusions: Surgical treatments are more effective than lifestyle intervention alone for T2DM treatment.


Obesity and type 2 diabetes mellitus (T2DM) are closely correlated chronic conditions with an increasing prevalence worldwide.[1] There is growing literature and observational and randomized control trials (RCTs) demonstrating bariatric/metabolic surgery can be a safe, effective, and durable treatment for both obesity and T2DM.[2–4] A consensus statement from the 2nd Diabetes Surgery Summit (DSS-II) published a treatment algorithm recommending bariatric/metabolic surgery as treatment for T2DM for patients with class III obesity (BMI [body mass index] ≥ 40 kg/m2) and in patients with class II obesity (BMI 35–39.9 kg/m2) when hyperglycemia is not sufficiently controlled with lifestyle and medical treatments.[5] DSS-II also recommended the consideration of bariatric/metabolic surgery for treatment of T2DM in class I obesity (BMI 30–34.9 kg/m2) if hyperglycemia is inadequately controlled despite optimal treatment with either oral or injectable medications. Despite these recommendations, even more data are needed about the long-term effectiveness, safety, and durability of surgical versus nonsurgical treatments for T2DM in those with class I obesity.[6] To date, published RCTs have shown bariatric surgery of all types is significantly superior to medical or lifestyle interventions in achieving and maintaining remission of T2DM but all studies are relatively small and more longer-term data are needed to address durability and longer-term safety of these comparative outcomes.[3,4,7–9]

We have previously reported at 1 and 3 years for bariatric surgery (Roux-en-Y gastric bypass [RYGB] and laparoscopic adjustable gastric band [LAGB]) plus low-level lifestyle intervention (LLLI) are superior to intensive lifestyle weight loss intervention (LWLI) alone for T2DM remission and other glycemic control endpoints.[9,10] In this longer-term study, we now report 5-year results evaluating the outcome of 2 types of bariatric surgery (RYGB, LAGB) and an LWLI for 1 year, followed by 4 years of LLLI for all 3 treatment groups that were modeled after the Look AHEAD (Action for Health in Diabetes) and Diabetes Prevention Program trials.[11,12] This report addresses comparative efficacy of surgical and nonsurgical treatments for T2DM remission and reports other glycemic control outcomes, weight change, lipids, blood pressure, and adverse events. These results will contribute additional high-level evidence about the relative efficacy of different surgical versus nonsurgical treatments for T2DM, particularly in lower BMI individuals.