Comparison of early type 2 diabetes improvement after gastric bypass and sleeve gastrectomy: medication cessation at discharge predicts 1-year outcomes

Background: Although weight loss-dependent type 2 diabetes (T2D) improvement after sleeve gastrectomy (SG) is well documented, whether SG has a weight-independent impact on T2D is less studied. Objectives: To evaluate early, weight-independent T2D improvement after SG and Roux-en-Y gastric bypass (RYGB) and its relationship to longer-term T2D outcomes. Setting: University Hospital, United States. Methods: We completed a retrospective cohort study of patients with T2D who underwent SG (n = 187) or RYGB (n = 246) from 2010 to 2015. Pre- and postoperative parameters, including demographic characteristics, T2D characteristics, and T2D medication requirements, blood glucose, glycosylated hemoglobin, weight, and body mass index, were reviewed. Results: T2D improved within days after both SG and RYGB, with more patients off T2D medications after SG than RYGB (39% versus 25%, respectively; P < .01) at the time of discharge (2.5 +/- .8 versus 2.7 +/- 1 d; P = .04). Over the initial postoperative 12 months, T2D medication cessation rates remained relatively stable after SG but continued to improve after RYGB (at 12 mo: 52% versus 68%, respectively; P < .05). T2D medication cessation at discharge predicts 12-month T2D medication cessation (92% [RYGB] and 78% [SG] positive predictive value). In a mixed-effects regression model adjusting for weight loss and severity of diabetes, discharge T2D medication cessation remained a significant predictor of T2D outcomes after both RYGB (odds ratio, 51; 95% confidence interval, 16.1-161; P < .0001) and SG (6.4; 95% confidence interval, 2.8-14.7; P < .0001). Conclusions: Both SG and RYGB lead to high rates of T2D medication cessation within days of surgery, suggesting both operations activate weight loss-independent anti-T2D pathways. T2D medication cessation at discharge is predictive of 12-month T2D outcomes, particularly in noninsulin requiring patients. By 1 year after the surgery, RYGB leads to more weight loss and higher rates of T2D medication cessation than SG. (C) 2019 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.