Baseline Body Mass Index and the Efficacy of Hypoglycemic Treatment in Type 2 Diabetes: A Meta-Analysis

Aim The aim of this study is to compare the effects of hypoglycemic treatments in groups of patients categorized according to the mean baseline body mass indexes (BMIs). Methods Studies were identified by a literature search and all the studies were double blind, placebo-controlled randomized trials in type 2 diabetes patients; study length of >= 12 weeks with the efficacy evaluated by changes in HbA1c from baseline in groups. The electronic search was first conducted in January 2015 and repeated in June 2015. Results 227 studies were included. Treatment with sulfonylureas was compared with placebo in overweight patients and resulted in a significantly greater change in the HbA1c levels (weighted mean difference (WMD), -1.39%) compared to obese patients (WMD, -0.77%)(p<0.05). Treatment with metformin in overweight patients resulted in a comparable change in the HbA1c levels (WMD, -0.99%) compared to obese patients (WMD, -1.06%)(p>0.05). Treatment with alpha glucosidase inhibitors in normal weight patients was associated with a HbA1c change (WMD, -0.94%) that was comparable that in overweight (WMD, -0.72%) and obese patients (WMD, -0.56%)(p>0.05). Treatment with thiazolidinediones in normal weight patients was associated with a HbA1c change (WMD, -1.04%) that was comparable with that in overweight (WMD, -1.02%) and obese patients (WMD, -0.88%)(p>0.05). Treatment with DPP-4 inhibitors in normal weight patients was associated with a HbA1c change (WMD, -0.93%) that was comparable with that in overweight (WMD, -0.66%) and obese patients (WMD, -0.61%)(p>0.05). In total, of the seven hypoglycemic agents, regression analysis indicated that the mean baseline BMI was not associated with the mean HbA1c changes from baseline. Conclusion In each kind of hypoglycemic therapy in type 2 diabetes, the baseline BMI was not associated with the efficacy of HbA1c changes from baseline.