A meta-analysis of the effect of thiazolidinediones on blood pressure

In epidemiologic studies, insulin resistance is associated with hypertension. Thiazolidinediones (TZDs) are antidiabetic agents that decrease insulin resistance. Multiple clinical trials have evaluated the effect of TZDs on blood pressure (BP) with inconsistent results. The aim of this study was to estimate the effect of TZDs on BP. The authors searched PubMed for clinical trials published in English. A total of 37 clinical trials that reported a change in BP were included in the analysis. Trials with independent-group design and trials with pre-post design were evaluated separately. When compared with baseline, TZDs lowered systolic BP by 4.70 mm Hg (95% confidence interval, -6.13 to -3.27) and diastolic BP by 3.79 mm Hg (95% confidence interval, -5.82 to -1.77). When compared with placebo, TZDs lowered systolic BP by 3.47 mm Hg (95% confidence interval, -4.91 to -2.02) and diastolic BP by 1.84 mm Hg (95% confidence interval, -3.43 to -0.25). Thus, TZDs lower both systolic and diastolic BP, albeit the BP-lowering effect is small and may not be of clinical significance.