Weight Outcomes of Sleeve Gastrectomy and Gastric Bypass Compared to Nonsurgical Treatment.

Objective: To investigate weight trajectories among patients with severe obesity undergoing sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and nonsurgical treatment.

Background: Although bariatric procedures are associated with substantial weight loss, few studies have compared surgical outcomes to nonsurgical treatment, particularly for SG.

Methods: In this retrospective, matched cohort study, adult patients with body mass index ≥35 kg/m2 who underwent RYGB or SG procedures from January 2005 through September 2015 were matched to 87,965 nonsurgical patients. Hierarchical linear models were used to investigate percent total weight loss (%TWL) and regain at 5 years among RYGB, SG, and nonsurgical patients, and at 10 years for RYGB and nonsurgical patients.

Results: Among 13,900 SG, 17,258 RYGB, and 87,965 nonsurgical patients, the 5-year follow-up rate was 70.9%, 72.0%, and 64.5%, respectively. At 1 year, RYGB patients had 28.4%TWL (95% confidence interval: 28.2, 28.5), SG 23.0%TWL (22.8, 23.2), and nonsurgical patients 0.2%TWL (0.1, 0.4). At 5 years, RYGB had 21.7%TWL (21.5, 22.0), SG 16.0%TWL (15.4, 16.6), and nonsurgical patients 2.2%TWL (2.0, 2.5). After 5 years, 3.7% of RYGB and 10.1% of SG patients had regained weight to within 5% of baseline. At 10 years, RYGB patients had 20.2%TWL (19.3, 21.0) and nonsurgical patients 4.8%TWL (4.0, 5.5).

Conclusions: In this study, patients with severe obesity who underwent SG and RYGB lost significantly more weight at 5 years than nonsurgical patients. Weight regain was common after surgery but regain to within 5% of baseline was rare.