Roux-en-Y gastric bypass surgery or lifestyle with intensive medical management in patients with type 2 diabetes: feasibility and 1-year results of a randomized clinical trial

Abstract

Importance: Emerging data support bariatric surgery as a therapeutic strategy for management of type 2 diabetes mellitus.

Objective: To test the feasibility of methods to conduct a larger multisite trial to determine the long-term effect of Roux-en-Y gastric bypass (RYGB) surgery compared with an intensive diabetes medical and weight management (Weight Achievement and Intensive Treatment [Why WAIT]) program for type 2 diabetes.

Design, setting, and participants: A 1-year pragmatic randomized clinical trial was conducted in an academic medical institution. Participants included persons aged 21 to 65 years with type 2 diabetes diagnosed more than 1 year before the study; their body mass index was 30 to 42 (calculated as weight in kilograms divided by height in meters squared) and hemoglobin A1c (HbA1c) was greater than or equal to 6.5%. All participants were receiving antihyperglycemic medications.

Interventions: RYGB (n = 19) or Why WAIT (n = 19) including 12 weekly multidisciplinary group lifestyle, medical, and educational sessions with monthly follow-up thereafter.

Main outcomes and measures: Proportion of patients with fasting plasma glucose levels less than 126 mg/dL and HbA1c less than 6.5%, measures of cardiometabolic health, and patient-reported outcomes.

Results: At 1 year, the proportion of patients achieving HbA1c below 6.5% and fasting glucose below 126 mg/dL was higher following RYGB than Why WAIT (58% vs 16%, respectively; P = .03). Other outcomes, including HbA1c, weight, waist circumference, fat mass, lean mass, blood pressure, and triglyceride levels, decreased and high-density lipoprotein cholesterol increased more after RYGB compared with Why WAIT. Improvement in cardiovascular risk scores was greater in the surgical group. At baseline the participants exhibited moderately low self-reported quality-of-life scores reflected by Short Form-36 total, physical health, and mental health, as well as high Impact of Weight on Quality of Life-Lite and Problem Areas in Diabetes health status scores. At 1 year, improvements in Short Form-36 physical and mental health scores and Problem Areas in Diabetes scores did not differ significantly between groups. The Impact of Weight on Quality of Life-Lite score improved more with RYGB and correlated with greater weight loss compared with Why WAIT.

Conclusions and relevance: In obese patients with type 2 diabetes, RYGB produces greater weight loss and sustained improvements in HbA1c and cardiometabolic risk factors compared with medical management, with emergent differences over 1 year. Both treatments improve general quality-of-life measures, but RYGB provides greater improvement in the effect of weight on quality of life. These differences may help inform therapeutic decisions for diabetes and weight loss strategies in obese patients with type 2 diabetes until larger randomized trials are performed.

Trial registration: clinicaltrials.gov Identifier: NCT01073020.

Figure 1. Enrollment, Randomization, and Retention of the Study Participants

BMI indicates body mass index; GAD, antiglutamic acid decarboxylase antibody–positive; HbA_1c, hemoglobin A_1c; LAGB, laparoscopic adjustable gastric band; RYGB, Roux-en-Y gastric bypass; and WAIT, Weight Achievement and Intensive Treatment.

Figure 2. Changes in Cardiometabolic Outcomes Following Bariatric Surgery and Medical Management

Changes in hemoglobin A_1c (HbA_1c) (A), fasting plasma glucose (B), and body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared) (C) graphed by treatment group and time as baseline-adjusted mean, with SE indicated with limit lines. P values indicate the significant difference between groups in linear mixed model adjusted for baseline. Mean number of diabetes medications (D). Change from baseline for United Kingdom Prospective Diabetes Study (UKPDS) Risk Scores for coronary heart disease (CHD), fatal CHD, stroke, and fatal stroke. Variance indicated with the limit lines is SE (E). The relationship between total weight lost (WL) and change in fat by bioelectrical impedance (F). RYGB indicates Roux-en-Ygastric bypass; WAIT, Weight Achievement and Intensive Treatment.

Figure 3. Patient-Reported Outcomes and Change in Body Mass Index (BMI) and Impact of Weight on Quality of Life–Lite (IWQOL)

A, Short-Form 36 (SF-36). B, Problem Areas in Diabetes (PAID). C, Barriers to Being Active. D, EuroQol 5 Dimensions (EQ-5D) visual analog scale (VAS). E, IWQOL. F, Relationship between change in BMI and change in IWQOL scores. Data are graphed by treatment group and time as baseline-adjusted mean change from baseline and SE, indicated with limit lines. Baseline mean (SD) of all patient-reported outcomes are provided in the Supplement (eTable 6). RYGB indicates Roux-en-Y gastric bypass; WAIT, Weight Achievement and Intensive Treatment; and WL, weight loss. ^aP < .001 (within-group comparison). ^bP < .01 (between-group comparison). ^cP < .001 (between-group comparison). ^dP < .01 (within-group comparison). ^eP < .05 (between-group comparison).