Thiazolidinediones and congestive heart failure in veterans with type 2 diabetes.

AIM The thiazolidinedione (TZD) class of antihyperglycaemic agents has been shown to improve glycaemic control by improving peripheral insulin sensitivity but may worsen or precipitate congestive heart failure (CHF). Randomized controlled trials have shown an increased risk of CHF in patients treated with TZDs. The use of TZDs in clinical practice has the potential to increase morbidity and health care costs. The purpose of this study was to compare the incidence of CHF in TZD and non-TZD-treated patients in a clinical setting. METHODS A retrospective cohort study of all male patients with type 2 diabetes seen in the South Central US Veterans Administration health care network between 1 October 1996 and 31 December 2004. We constructed a Cox proportional hazards model to evaluate the impact of TZD therapy on time to incidence of CHF. RESULTS Of 3956 patients, 29% (n = 1157) developed CHF during the study period. The incidence of CHF was higher in patients who received TZD medications than in those who received TZDs. After adjustment for multiple cardiac risk factors, the hazard ratio for the development of CHF for TZD versus non-TZD-treated patients was 0.69 with a 95% confidence interval of 0.60-0.79. CONCLUSIONS Patients in this cohort who received TZD medications had a lower incidence of heart failure than patients who did not receive TZDs.