Roux-en-Y Gastric Bypass Surgery and Diabetes Remission

Study Questions:

Does Roux-en-Y gastric bypass (RYGB) surgery increase the rates of diabetes remission, and micro- and macrovascular complications among patients with type 2 diabetes mellitus (T2DM) and obesity?


Data from a population-based cohort study of individuals with T2DM living in Northern Denmark were used for the present analysis. Data from the Civil Registration System were linked to the Danish National Patients Registry, the Danish National Health Service Prescription Database (DNHPD), and national data on laboratory and clinical testing. A total of 1,111 adults with T2DM who received a RYGB surgery (2006–2015) were compared to 1,074 individuals also with T2DM who did not undergo a RYGB. Diabetes remission was defined as no glucose-lowering drug use with glycated hemoglobin (HbA1c) <48 mmol/mol (<6.5%), or metformin monotherapy with HbA1c <42 mmol/mol (<6.0%). The median follow-up time was 5.3 (interquartile range [IQR], 4.0-6.3) years in the RYGB cohort and 5.2 (IQR, 3.9-6.2) years in the comparison cohort.


In the RYGB cohort, the median age was 46.8 (IQR, 39.9-54.3) years, 63.5% were women, and median diabetes duration was 3.6 (IQR, 1.1-7.0) years at the index date, similar to the comparison cohort. At 1 year of follow-up, 74% of the cohort treated by RYGB experienced diabetes remission, while 27% had relapsed after 5 years. Predictors of nonremission were age >50 years, diabetes duration >5 years, use of glucose-lowering drugs other than metformin, and baseline HbA1c >53 mmol/mol (>7.0%). Compared with the nonoperated cohort using adjusted Cox regression (5.3 years of follow-up), the cohort treated by RYGB had 47% lower risk of microvascular complications (hazard ratio [HR], 0.53; 95% confidence interval [CI], 0.38-0.73) and a statistically nonsignificant 24% lower risk of macrovascular complications (HR, 0.76; 95% CI, 0.49-1.18). Diabetes remission versus nonremission at 1 year was associated with a reduced HR of 0.43 (95% CI, 0.25-0.72) for microvascular complications and with HR 0.76 (95% CI, 0.40-1.45) for macrovascular complications.


The authors concluded that in routine clinical care, three out of four individuals with T2DM and obesity treated by RYGB experienced diabetes remission after 1 year. However, 27% of these individuals relapsed at 5 years of follow-up. RYGB was associated with a substantially decreased risk of microvascular complications and nonsignificantly fewer macrovascular complications, with early diabetes remission as a clear predictor of reduced microvascular complications.


These data support prior evidence, which suggests that RYGB is associated with T2DM remission and reduction in risk for microvascular, and possibly macrovascular, complications. In addition, these results suggest specific predictors for T2DM remission including older age, duration of T2DM, and higher HbA1c. Healthcare providers are recommended to discuss the rates of DM remission, and the need for ongoing monitoring and continued lifestyle modifications is warranted.

Clinical Topics: Diabetes and Cardiometabolic Disease, Prevention

Keywords: Diabetes Complications, Diabetes Mellitus, Type 2, Gastric Bypass, Hemoglobin A, Life Style, Metabolic Syndrome X, Metformin, Obesity, Primary Prevention, Risk Reduction Behavior, Surgical Procedures, Elective

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