Effect of metformin on the expression of tumor necrosis factor-α, Toll like receptors 2/4 and C reactive protein in obese type-2 diabetic patients

Background: The pharmacological action of metformin goes beyond mere glycemic control, decreasing markers of inflammation and contributing to the reduction of oxidative stress. Aim: To evaluate biochemical, anthropometric and pro-inflammatory markers in obese type 2 diabetic patients treated or not with metformin. Patients and Methods: Obese patients with type 2 diabetes were invited to participate in the study if they were aged more than 40 years, were not receiving insulin, did not have cardiovascular diseases and were not taking anti-inflammatory drugs. A pharmacological history was taken and patients were stratified in two groups whether they were using metformin or not. A fasting blood sample was obtained to measure blood glucose, insulin, lipid levels, C reactive protein (hsCRP) and to isolate peripheral blood mononuclear cells. RNA was isolated from these cells to measure expression of tumor necrosis factor-a (TNF-alpha), Interleukin-6 (IL-6), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappa B), Toll-Like Receptor 2/4 (TLR 2/4) and beta-2-microglobulin (B2M). Results: Thirty participants were studied. Of these, 16 subjects aged 54.4 +/- 5.5 years were treated with metformin and 14 subjects aged 54.9 +/- 6.4 years did not receive the drug. Participants receiving metformin had lower levels of hsCRP and lower mRNA relative abundance of TNF-a and TLR 2/4. There were no differences in glucose levels or lipid profile between both groups. Conclusions: Obese diabetic patients treated with metformin had lower levels of hsCRP expression of TNF-a and TLR 2/4, than their counterparts not receiving the drug. (Rev Med Chile 2012; 140: 1377-1382).