Does Metabolic Surgery Lead to Diabetes Remission in Patients with BMI < 30 kg/m2?: a Meta-analysis

BACKGROUND: Bariatric surgery has demonstrated to be effective in remission of type 2 diabetes in obese patients, but it is unclear in non-obese patients. The aim of this study is to investigate if metabolic surgery is effective in diabetes resolution in patients with BMI < 30 kg/m2. MATERIALS AND METHODS: A systematic review was performed and the content of the PubMed, Ovid, and the Cochrane Library databases covering the period January 2008 to April 2018 was searched. Studies with metabolic surgery performed in patients with type 2 diabetes, BMI < 30 kg/m2 and a follow-up ≥ 6 months were included. Type 2 diabetes remission rate and metabolic parameters changes were measured. A meta-analysis was conducted with the selected studies. RESULTS: Twenty-six studies were included in the meta-analysis (1105 patients). The mixed-effects meta-analysis model for overall diabetes remission rate produced an estimate of 43% (95% IC 34-53%, p < 0.001). Moderator effects of the variables race, preoperative HbA1c, BMI, months of follow-up, duration of diabetes, and age on diabetes remission were also assessed, with no significant effects being found in any of them. A reduction in BMI (- 3.57 kg/m2), fasting blood glucose (- 55.93 mg/dL) and HbA1c (- 2.08%) was observed after surgery. CONCLUSIONS: Metabolic surgery could be effective in remission of type 2 diabetes in BMI < 30 kg/m2 patients but randomized and long-term studies are necessary. The scientific community should agree in a single definition of type 2 diabetes remission, in order to know the real effect of metabolic surgery in this group of patients.