Comparative Effectiveness of Vertical Sleeve Gastrectomy Versus Roux-en-Y Gastric Bypass for Diabetes Treatment: A Claims-based Cohort Study

Objective: The aim of the study was to compare diabetes outcomes following vertical sleeve gastrectomy (VSG) and Roux-en-Y gastric bypass (RYGB).

Background: There are few comparative studies on diabetes outcomes after VSG and RYGB.

Methods: We used a US-wide commercial insurance claims database to identify adults with diabetes undergoing VSG or RYGB in 2010 to 2016. We matched patients on baseline insulin use, total diabetes medication burden, age, presence of diabetes complications, and follow-up duration, and used adjusted Cox proportional hazards models to compare diabetes medication discontinuation between procedures. We used difference-in-differences analyses to compare changes in medication use intensity up to 2 years after surgery.

Results: The matched cohort included 1111 VSG and 922 RYGB patients: 16% were younger than 40 years, 11% were 60 years or older, 67% were women, 67% had a body mass index of 40 kg/m2 or higher, and 23% were on insulin at the time of surgery. Thirteen percent were lost to follow-up at 1 year, and 30% at 2 years after surgery. Patients with VSG were less likely than matched RYGB patients to discontinue all diabetes medications (hazard ratio 0.80, 95% confidence interval 0.72-0.88). Although both groups had substantial decreases in medication use after surgery, RYGB patients had an 86% (32%, 140%) lower total diabetes medication dose than VSG by the second half of postoperative year 2.

Conclusions: In a large claims-based, nationwide cohort of bariatric patients with diabetes, those undergoing RYGB were more likely to come off all medications than those undergoing VSG. Patients with diabetes should consider this potential benefit of RYGB when making informed decisions about obesity treatments.