Bariatric surgery is an extremely effective glucose-lowering therapy for type 2 diabetes. To date only one RCT comparing surgery to standard diabetes care 1 has reported outcomes beyond 3 years: a study of obese Italians in whom surgery delivered sustained improvement in cardiovascular risk despite a substantial rate of diabetes recurrence at five years. Our RCT of multidisciplinary medical care (MDC) compared to MDC combined with gastric band (GB) surgery in overweight people (BMI 25 to 30kg/m2) showed GB surgery induced diabetes remission in 44% of participants at two years and also delivered broader cardiovascular benefits 2. Five-year outcomes for 45 participants (20 male, 25 female) are expected in June 2016. We will present outcomes for 23 assigned to receive multidisciplinary medical care (MDC) and 22 assigned MDC combined with GB surgery. The primary outcome was diabetes remission, based on OGTT. As of May 2016, 20 MDC and 19 MDC+GB participants had completed 5-year follow-up. Mean±SD weight loss after surgery was maintained during years 3 to 5, being 13±6 percent of baseline weight. One MDC and four MDC+GB participants were in diabetes remission at five years (p=0.18) and the respective HbA1c levels of the two groups were 7.6±0.4 and 6.5±0.2% respectively (p=0.02) despite greater use of glucose-lowering medication by the MDC group. Lower blood pressure and higher HDL cholesterol in the MDC+GB group delivered sustained reduction of cardiovascular risk. One MDC+GB participant underwent revision surgery after two years. We provisionally conclude that sustained weight loss from GB surgery does not induce diabetes remission in the longer term but nonetheless is an effective and acceptable T2D therapy that reduces medication burden and decreases cardiovascular risk in overweight but not obese people with type 2 diabetes.
1: Lancet. 2015;38:964-973; 2. Lancet D&E 2014;2:545-52