Long-term impact of weight loss for people with overweight but not obesity, and with type 2 diabetes: 10-year outcomes of a randomized trial of gastric band surgery.

Abstract

Randomized trials reporting 5-year outcomes have shown bariatric surgery to induce diabetes remission and improve cardiovascular risk. However, the longer-term effects of surgery are uncertain, with only one randomized trial reporting 10-year diabetes outcomes in people with obesity. We aimed to compare 10-year diabetes outcomes of people who are overweight but not obese, randomly assigned to receive either multidisciplinary diabetes care, or multidisciplinary diabetes care combined with gastric band (GB) surgery. Between 2009 and 2011, 51 adults were randomized. After 5 years, they were discharged to receive community care and reassessed after 10 years. The primary outcome was diabetes remission, defined as glycated haemoglobin (HbA1c) <6.5% (48 mmol/mol) without glucose-lowering medication. Forty-one participants (20 medical and 21 GB) completed the 10-year assessment. The median (Q1, Q3) weight loss in the GB group was 9.8 (6.7, 16.3)% at 10 years compared with 5.6 (3.4, 7.6)% in the medical group (median difference 4.2%; p=.008). Diabetes remission occurred in five GB participants and no medical participants (relative risk 0.76, 95% CI: 0.55-0.93, p=.048). GB participants used fewer glucose-lowering medications at 10 years but HbA1c, fasting glucose, calculated cardiovascular risk, quality-of-life and incident diabetes complications did not differ significantly between the groups. When compared with medical care, GB surgery achieved greater weight loss and modestly increased the likelihood of diabetes remission. However, it did not improve HbA1c, cardiovascular risk or quality of life.