Surgical Versus Medical Treatment of Type 2 Diabetes Mellitus in Nonseverely Obese Patients: A Systematic Review and Meta-analysis

OBJECTIVE:To compare surgical versus medical treatment of type 2 diabetes mellitus (T2DM) remission and comorbidities in patients with a body mass index (BMI) less than 35 kg/m. BACKGROUND:Obesity surgery can achieve remission of T2DM and its comorbidities. Metabolic surgery has been proposed as a treatment option for diabetic patients with BMI less than 35 kg/m but the efficacy of metabolic surgery has not been conclusively determined. METHODS:A systematic literature search identified randomized (RCT) and nonrandomized comparative observational clinical studies (OCS) evaluating surgical versus medical T2DM treatment in patients with BMI less than 35kg/m. The primary outcome was T2DM remission. Additional analyses comprised glycemic control, BMI, HbA1c level, remission of comorbidities, and safety. Random effects meta-analyses were calculated and presented as weighted odds ratio (OR) or mean difference (MD) with 95% confidence intervals (95% CI). RESULTS:Five RCTs and 6 OCSs (706 total T2DM patients) were included. Follow-up ranged from 12 to 36 months. Metabolic surgery was associated with a higher T2DM remission rate (OR14.1, 95% CI6.7–29.9, P < 0.001), higher rate of glycemic control (OR8.0, 95% CI4.2–15.2, P < 0.001) and lower HbA1c level (MD−1.4%, 95% CI −1.9% to −0.9%, P < 0.001) than medical treatment. BMI (MD−5.5 kg/m, 95% CI−6.7 to −4.3 kg/m, P < 0.001), rate of arterial hypertension (OR0.25, 95% CI0.12–0.50, P < 0.001) and dyslipidemia (OR0.21, 95% CI0.10–0.44, P < 0.001) were lower after surgery. CONCLUSION:Metabolic surgery is superior to medical treatment for short-term remission of T2DM and comorbidities. Further RCTs should address the long-term effects on T2DM complications and mortality.