Effects of metformin on blood and urine pro-inflammatory mediators in patients with type 2 diabetes

Background: metformin has been used for the treatment of type 2 diabetes by suppressing hepatic gluconeogenesis. it has been shown that the subclinical inflammatory responses play important roles in the pathogenesis of type 2 diabetes. in the present study,we determined the effects of metformin on the levels of pro-inflammatory cytokines (i.e.,il-6,tnf-α,and mcp-1) and anti-inflammatory mediator il-10 in blood and urine of patients with type 2 diabetes. there were 210 patients with type 2 diabetes,which were randomized into metformin (n = 112) and non-metformin (gliclazide,acarbose,and repaglinide,n = 98) groups. the levels of cytokines were measured by the elisa. results: we found that metformin reduced the levels of il-6 in blood and mcp-1 in urine,but increased il-10 levels in blood of patients with type 2 diabetes. there were no significant differences of tnf-α between metformin and non-metformin groups. furthermore,compared to individual drug treatment,metformin significantly reduced the levels of serum il-6 and tnf-α,as well as urine mcp-1. when the patients were stratified based on the durations and doses of metformin,we found that there was only change (i.e.,increase) in serum il-10 levels in patients with metformin for more than 1 year compared to treatment for less than 1 year. metformin (1.5 g) treatment reduced the urinary levels of mcp-1 as compared with dose of 1.0 g in patients with type 2 diabetes. conclusion: metformin reduces inflammatory responses without influence on renal function in type 2 diabetic patients. © 2016 the author(s).