Importance: The prevalence of early-onset type 2 diabetes mellitus (T2DM), which responds poorly to medical treatment, is increasing. Bariatric surgery has been well recognized for its effectiveness in the remission of T2DM, but its effectiveness and durability in the remission of early-onset T2DM has not yet been explored.
Objective: To compare the short- and long-term outcomes of bariatric surgery with a specific focus on the rate of remission of T2DM in patients with early-onset (age <40 years) and late-onset (age ≥40 years) T2DM.
Design, setting, and participants: In this cohort study, 558 Taiwanese patients (339 with early-onset T2DM and 219 with late-onset T2DM) with a body mass index (calculated as weight in kilograms divided by height in meters squared) above 25 underwent bariatric surgery to ameliorate T2DM between January 1, 2007, and December 31, 2013. Patients were followed up for at least 1 year. Preoperative, perioperative, and postoperative clinical and laboratory data were prospectively collected and compared between the 2 groups.
Main outcomes and measures: Rate of remission of T2DM (hemoglobin A1C <6.0% without antiglycemic medication) was the primary outcome measure.
Results: Of the 558 patients (345 women) in the study, mean (SD) ages were 33.5 (7.5) for those with early-onset T2DM and 50.6 (6.5) with late onset T2DM. Those with early-onset T2DM had higher mean (SD) preoperative BMI and hemoglobin A1C values (39.4 [8.5] and 8.7% [3.8%] of total hemoglobin [to convert hemoglobin to a proportion of total hemoglobin, multiply by 0.01], respectively) than did patients with late-onset T2DM (36.7 [7.5] and 8.2% [1.6%], respectively). Distribution of surgical procedures and major complications were similar between the 2 groups. At 1 year, patients with early-onset T2DM achieved greater weight loss than those with late-onset T2DM, although the difference was not statistically significant. A higher rate of complete remission of T2DM was observed in patients with early-onset T2DM than in those with late-onset disease (193 [56.9%] vs 110 [50.2%]; P = .02). At 5 years, patients with early-onset T2DM still maintained a higher rate of weight loss (mean [SD], 30.4% [11.8%] vs 21.6% [11.7%]; P = .002) and higher rate of remission (47 of 72 [65.3%] vs 26 of 48 [54.2%]; P = .04) than did those with late-onset disease. Age at bariatric surgery, duration of T2DM, and preoperative C-peptide level were independent predictors of remission. The remission rate was directly related to extent of weight loss. Multivariate analysis confirmed the higher rate of remission in the group with early-onset T2DM.
Conclusions and relevance: This article describes the largest long-term study examining bariatric surgery for patients with early-onset T2DM. Bariatric surgery may achieve better and more long-lasting glycemic control in select patients with early-onset T2DM than in those with late-onset T2DM.