Comparison of 5-year glycemic outcomes after sleeve gastrectomy and Roux-en-Y gastric bypass in patients with pre-operative dysglycemia.

OBJECTIVE: The long-term effects of bariatric surgery on glucose metabolism are well established; however, comparative data regarding glycemic outcomes after laparoscopic sleeve gastrectomy (LSG) and Roux-en-Y gastric bypass (RNYGB) in patients with pre-operative dysglycemia remain limited. This study aimed to compare 5-year glycemic outcomes following LSG and RNYGB in patients with prediabetes or Type 2 diabetes mellitus. METHODS: This retrospective cohort study included patients with pre-operative dysglycemia (HbA1c ≥5.7%) who underwent primary LSG or RNYGB between January 2010 and December 2021 at a tertiary referral center and had at least 5 years of follow-up. Demographic characteristics, HbA1c levels, weight loss outcomes, and glycemic status were evaluated. Glycemic status was categorized as diabetes, prediabetes, or normal glycemia according to HbA1c levels. RESULTS: A total of 142 patients were included, of whom 107 underwent LSG and 35 underwent RNYGB. Baseline HbA1c levels were similar between groups (7.70±1.83% vs. 6.87±1.53%, p=0.619). At 5 years, mean HbA1c was significantly lower in the RNYGB group compared with the LSG group (5.57±0.64% vs. 5.85±0.68%, p=0.033). Total weight loss percentage was greater after RNYGB (28.13±13.79% vs. 24.04±10.72%), although the difference was not statistically significant (p=0.084). Significant improvement in glycemic status was observed following bariatric surgery (p<0.001). At 5 years, normal glycemia was achieved in 44 (41.1%) patients after LSG and 22 (62.9%) patients after RNYGB, whereas persistent diabetes was observed in 10 (9.3%) and 2 (5.7%) patients, respectively. CONCLUSION: Bariatric surgery resulted in significant long-term improvement in glycemic status among patients with pre-operative dysglycemia. Although both LSG and RNYGB effectively reduced the prevalence of diabetes and prediabetes, RNYGB was associated with lower HbA1c levels and a higher proportion of patients achieving normal glycemia at 5 years. These findings suggest that RNYGB may provide superior long-term glycemic outcomes in patients with obesity-associated dysglycemia.