The effects of rosiglitazone and metformin on inflammation and endothelial dysfunction in patients with type 2 diabetes mellitus

Abstract

Diabetic patients have a markedly increased risk of cardiovascular disease compared with non-diabetics. Two drug groups today target insulin resistance; biguanides and thiazolidinediones. In addition, these may have other effects on cardiovascular risk factors. The aim of this study was to evaluate the effects of metformin and rosiglitazone on non-traditional cardiovascular risk factors. Forty type 2 diabetic patients were randomized into metformin and rosiglitazone groups. After receiving the optimal doses, the patients were monitored for 12weeks. Biochemical parameters, lipid parameters, CRP, insulin, c-peptide, and HbA1c levels were analyzed. VWF, PAI-1, ICAM-1, TNF-α, IL-6, E-selectin, and fibrinogen levels were measured in order to assess coagulation status and endothelial dysfunction. In the metformin group, body mass index, PPG, HbA1c, IL-6, ICAM-1, and TNF-α levels were significantly decreased after 12weeks compared with the basal levels. IL-6 levels decreased from 75pg/ml±20 to 42pg/ml±9 (P 0.023) and TNF- α levels from 61pg/ml±31 to 39pg/ml±10 (P 0.018). In the rosiglitazone group, FPG, PPG, HbA1c, insulin, HOMA-IR, IL-6, and TNF-α levels decreased significantly after 12weeks compared with the basal levels. IL-6 levels decreased from 78pg/ml±21 to 41pg/ml±9 (P 0.028) and TNF-α levels from 62pg/ml±19 to 37pg/ml±10 (P 0.012). At the end of the study, no significant differences were determined between groups. Insulin resistance and type 2 diabetes are strongly associated with low grade inflammation. Both metformin and rosiglitazone were effective in controlling inflammatory markers in addition to metabolic parameters.