Objective: Thiazolidinediones (TZDs) have become a powerful tool for lowering insulin resistance. The problem of cardiovascular adverse events including fluid retention and risk of heart failure, although of a low incidence, should be well known and recognized. We aimed to evaluate the effects of rosiglitazone treatment on cardiac function and show whether these effects are reversible when we continued this treatment.
Methods: Fourty-six type 2 diabetic patients -without any symptoms and findings of heart failure-were randomized to treatment with rosiglitazone, metformin and control group after receiving approval from the local Ethical Committee. There were no significant differences between the groups in the duration of diabetes, HbA1c and plasma brain natriuretic pepetide (BNP) levels, body mass index (BMI) and myocardial performance indexes (MPI) before the treatment. After three months and after six months all these parameters were repeated.
Results: After three months period with rosiglitazone treatment, plasma BNP levels increased rapidly. Except one subject we did not see any clinical adverse effect including excessive weight gain, edema, and dyspnea so we continued rosiglitazone treatment. At the end of the six months period, this rapid increase didnt continue. Similarly, lateral wall MPIs worsened after three months- although statistically nonsignificant- and then improved significantly after six months in rosiglitazone group (P=0.001). Also the changes in hemoglobin values were highly correlated with other results that provide evidence of these reversible findings.
Conclusion: Our study showed the stability and reversibility of the adverse effects of TZDs on cardiovascular function and fluid dynamics in type 2 diabetics.