Combined treatment of irbesartan and diltiazem ameliorates endothelium dependent vasodilatation in hypertensives.

OBJECTIVE

Endothelial function is of prognostic importance for hypertensives. The aim of this study was to investigate the effects of irbesartan combined with diltiazem on the endothelium-dependent vasodilatation in essential hypertensive (EH) patients in China.

METHODS

A total of 150 Chinese hypertensives aged from 40 to 80 years old were assigned into three groups: irbesartan treated(150 mg/d, n = 46), diltiazem treated (90 mg/d, n = 51), and combined therapy group (irbesartan 150 mg/d+ diltiazem 90 mg/d, n = 53). Forty age and gender-matched normotensives without clinical manifestation of cardiovascular diseases served as controls. High-resolution ultrasonography was used to assess flow-mediated dilatation (FMD) and nitroglycerin-mediated dilatation (NMD) in the brachial artery. Left ventricular mass index (LVMI) was calculated. Fibrinogen (Fg) was determined by Clauss and Stago auto analyzer. Blood pressure was measured using mercury sphygmomanometers.

RESULTS

FMD and NMD were lower in combined treatment group compared to normotensives before treatment at baseline [FMD(8.39 ± 3.04)% vs. (11.21 ± 3.88)%, NMD (13.96 ± 5.71)% vs. (16.78 ± 6.22)%, p < 0.05]. FMD was improved significantly after the combined therapy [(10.72 ± 3.46)% vs. (8.39 ± 3.04)%, p < 0.05]. No significant difference in NMD was found among three hypertensive groups after therapy. Moreover, FMD increased significantly with the prolongation of treatment. After stratification of age, FMD in younger EH patients under 65 years old was markedly increased after treatment within 1 year, whereas FMD in EH patients over 65 years old showed a significant increase after 3-year therapy. In addition, LVMI was reduced in hypertensives after combined therapy [(99.1 ± 17.9) g/m2 vs. (90.6 ± 16.2) g/m2, p < 0.01]. Logistic analysis showed that age was an important risk factor for FMD.

CONCLUSIONS

Combined therapy of irbesartan with diltiazem ameliorated endothelial function.