Relationship of Serum Adiponectin Levels and Metformin Therapy in Patients with Type 2 Diabetes.

We performed this meta-analysis to investigate and determine the role of metformin on serum adiponectin levels in Type 2 diabetes (T2DM) patients. Embase, Web of Science, Cochrane Library PubMed, and China National Knowledge Infrastructure (CNKI) were thoroughly searched. Eligible human studies assessing the association between serum adiponectin levels and metformin in patients were included, and data were extracted and then analyzed with STATA 12.0 statistical software. Eighteen cohort studies conducted among Asians and Caucasians from 2004 to 2013 were recruited. Post-treatment serum adiponectin level (mmol/l) was higher than pre-treatment levels in T2DM patients (SMD=0.19, 95% CI=0.09-0.30, p<0.001). Country-subgroup analysis showed that serum adiponectin levels in T2DM patients increased after the treatment of metformin in Italy (SMD=0.34, 95% CI=0.09-0.59, p=0.008). Further detection method and follow-up time subgroup analyses implied a positive association of metformin with serum adiponectin level in T2DM patients by using all ELISA, PETIA, and RIA in both<12 weeks and≥12 weeks subgroups (all p<0.05). The present meta-analysis provides compelling evidence that metformin may increase serum adiponectin levels when treating T2DM. Further studies should be promoted to explore the combined efficacy of metformin with other antidiabetic drugs, or developing new predictors with antidiabetic efficacy. © Georg Thieme Verlag KG Stuttgart · New York.