Effect of the definition of type II diabetes remission in the evaluation of bariatric surgery for metabolic disorders

Background: The American Diabetes Association recently defined remission of type II diabetes as a return to normal measures of glucose metabolism (haemoglobin (Hb) A1c below 6 per cent, fasting glucose less than 5·6 mmol/l) at least 1 year after bariatric surgery without hypoglycaemic medication. A previously used common definition was: being off diabetes medication with normal fasting blood glucose level or HbA1c below 6 per cent. This study evaluated the proportion of patients achieving complete remission of type II diabetes following bariatric surgery according to these definitions. Methods: This was a retrospective review of data collected prospectively in three bariatric centres on patients undergoing gastric bypass, sleeve gastrectomy and gastric banding. Results: Some 1006 patients underwent surgery, of whom 209 had type II diabetes. Median follow‐up was 23 (range 12–75) months. HbA1c was reduced after operation in all three surgical groups (P < 0·001). A total of 72 (34·4 per cent) of 209 patients had complete remission of diabetes, according to the new definition; the remission rates were 40·6 per cent (65 of 160) after gastric bypass, 26 per cent (5 of 19) after sleeve gastrectomy and 7 per cent (2 of 30) after gastric banding (P < 0·001 between groups). The remission rate for gastric bypass was significantly lower with the new definition than with the previously used definition (40·6 versus 57·5 per cent; P = 0·003). Conclusion: Expectations of patients and clinicians may have to be adjusted as regards remission of type II diabetes after bariatric surgery. Focusing on improved glycaemic control rather than remission may better reflect the benefit of this type of surgery and facilitate improved glycaemic control after surgery. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. Definition of diabetes affects outcome