Preoperative Factors Predicting Remission of Type 2 Diabetes Mellitus After Roux-en-Y Gastric Bypass Surgery for Obesity

Roux-en-Y gastric bypass (RYGB) is an effective treatment for morbid obesity. This bariatric procedure has also been noted to resolve hyperglycaemia in up to 70% of obese diabetics. We evaluated outcomes in diabetic patients undergoing RYGB in our institution, aiming to identify factors predicting diabetes remission. One hundred ten type 2 diabetic (T2DM) patients undergoing RYGB were studied. Baseline demographics, diabetic status pre- and post-surgery and outcomes were evaluated. Outcomes were compared to a matched non-diabetic cohort. The mean age of the patients was 45 +/- 11. The majority (70%; n = 77) were female and the mean baseline body mass index was 47 +/- 7. Mean (+/- SD range) excess weight loss at 6, 12 and 24 months was 58.3 +/- 26.4% (30.5-167%), 63.2 +/- 17.2% (0-99.2%) and 84.1 +/- 21.3% (16.5-121%), respectively. Diabetic medication was discontinued in 68.4% patients and reduced in a further 14.3%. Mean preoperative HbA1c was 7.1 +/- 2.0 and mean postoperative HbA1c 5.48 +/- 0.2. Patients with a baseline HbA1c > 10 had a 50% rate of remission compared to 77.3% with an HbA1c of 6.5-7.9. The mean duration of T2DM preoperatively was 5.5 +/- 7 years. A preoperative duration of T2DM greater than 10 years was shown to significantly reduce the chances of remission (p = 0.005). RYGB for morbid obesity achieves significant weight reduction in diabetic patients with remission of pre-surgical hyperglycaemia in the majority. The study supports findings that a shorter duration and better control of diabetes prior to surgery corresponds to a higher rate of remission. It supports the argument for early surgical intervention in the morbidly obese diabetic patient.