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


Study Participants

Of the 69 participants who underwent randomization from October 2009 to March 2012, 7 (10%, 3 RYGB, 1 LAGB, 3 LWLI) declined to undergo their assigned treatment and 1 patient was excluded on the day of the scheduled operation (RYGB) due to current smoking. Of these 61 participants, 82% were women and 21% were African American. The mean values for age were 47.3 ± 6.6 years, 35.7 ± 3.1 kg/m2 for BMI, and 100.5 ± 13.7 kg for baseline weight. Forty-three percent of the participants (26 people) had had a baseline BMI less than 35 kg/m2 (class I obesity). The mean duration of T2DM prior to randomization was 6.5 ± 4.8 years, with a mean baseline HbA1c level of 7.8% ± 1.9% and fasting plasma glucose of 171.3 ± 72.5 mg/dL. The baseline characteristics of all three groups can be found in Table 1.

Primary Endpoints

Of these 61 participants, there were 2 participants from RYGB and 5 participants from LWLI had no follow-up data at all; there were another 2 participants from RYGB, 1 participant from LAGB, and 1 participant from LWLI had no year 5 data. At 5 years, 6 (30%) RYGB participants attained at least partial T2DM remission, compared to 4 (19%) in LAGB, and none in LWLI (P = .0208) (Figure 1). For RYGB, 4 of the 6 experienced at least partial remission continuously at each annual visit over years 1 to 5, and 2 of the 6 were in any (partial or complete) remission years 1 to 3 and then again at year 5. Complete remission of T2DM at 5 years was achieved by only 1 (5.0%) RYGB participant and none in either LAGB or LWLI groups (P = .66). Figure 1 also shows a decline in T2DM remission (either partial or complete) over time in both surgical intervention arms: from 60% at 1 year to 40% at 3 years and 30% at 5 years for RYGB and from 29% at 1 and 3 years to 19% at 5 years for LAGB. No one in the LWLI group experienced remission at any of the annual time points.

Figure 1.

Prevalence of any remission (partial or complete) by treatment group and year*. *Results calculated using the intention to treat (ITT) analysis.

Glycemic Control and Medications

At 5 years, both surgical procedures plus LLLI were superior to lifestyle intervention alone (LWLI) in achieving glycemic control defined by HbA1c and fasting plasma glucose levels.[15] The RYGB group achieved the largest improvement in both HbA1c, (mean SD, −1.46% [0.39]), and FPG (–49.1 mg/dL [15.96]), comparing baseline to 5 year levels (HbA1c: P < .0001 for RYGB vs LWLI; FPG: P = .0919 for RYGB vs LWLI).[15] The LAGB group showed improvements in HbA1c (–0.62% [0.35]) at 5 years (P = .0078 for LAGB vs LWLI) and FPG improved an average of 35.4 mg/dL [15.08] (P = .2602 for LAGB vs. LWLI). At 5 years, the RYGB group had the largest share of participants (56%) who no longer required any medications compared with those in the LAGB (45%) and LWLI (0%) groups (P = .0065) (Figure 2).

Figure 2.

Diabetes medication usage by treatment group.

Body Weight

At 5 years, reductions in body weight, BMI, and waist circumference were greatest in patients treated with RYGB followed by LAGB and finally LWLI. (Table 2) These reductions in the RYGB were significantly greater than the LAGB group (all P < .0005). Figure 3 shows the adjusted mean percent weight change from baseline to year 5 by treatment group. By year 5, RYGB demonstrated (mean [SD]) –25.2% [2.09%] change in weight compared with baseline, while LAGB (–12.7% [1.98%]) and LWLI (–5.14% [2.46%]) showed smaller changes (all P < .009). Similarly, the mean of weight loss in kilograms from baseline to year 5 was highest in RYGB (–24.9 kg [2.12]) compared with LAGB (–12.6 kg [2.01], P < .001) and LWLI (–4.5kg [2.51], P < .001) (Table 2).

Figure 3.

Percent weight change from baseline by treatment group.

Lipids and Blood Pressure

At 5 years, the RYGB group demonstrated the greatest improvements in triglyceride levels (P = .0003) and high-density lipoprotein levels (P = .0042) compared with LWLI. (Table 2) The RYGB group had the greatest improvements in systolic blood pressure compared to LAGB and LWLI (P < .009 for both) and significantly improved diastolic blood pressure compared with LAGB (P = .0078) (Table 2). The results for RYGB compared with LAGB for other lipids and LAGB compared with LWLI for blood pressure and lipid measures were inconsistent and not significant (Table 2).

Adverse Events

For events and complications occurring more than 30 days after randomization, participants in the LWLI experienced primarily orthopedic related events with 10 individuals undergoing orthopedic procedures in the 5-year follow-up period. There were orthopedic events and procedures for participants in the RYGB[5] and LAGB[8] cohorts as well. There were no deaths in any of the groups, 1 cardiovascular event in the RYGB group requiring a coronary stent placement and 2 cardiovascular/blood pressure-related events (hypertension and hypotension) in LAGB participants. One participant in LWLI underwent a crossover bariatric surgical procedure to LAGB. One RYGB participant developed an anastomotic ulcer requiring an operation, and 2 LAGB participants underwent a revisional bariatric procedures. The complete list of 65 adverse events in 32 participants can be found in Table 3.