RESUMEN
<p><b>OBJECTIVE</b>To investigate the effects of combined application of Xuezhikang Capsule (XZK) and hypotensive drugs on the dynamic blood pressure (DBP), pulse pressure index (PPI), pulse wave velocity (PWV) and smoothness index (SI), and to study the relationship between SI and related factors (age, BP, dynamic PPI, and vascular elasticity).</p><p><b>METHODS</b>One hundred and ten patients with essential hypertension were randomly assigned to 2 groups: 54 in the control group and 56 in the treated group. Both were treated with hypertensive drugs, but with oral medication of XZK given additionally to the treated group at the dose of 60 mg, twice a day. PWV and DBP were measured before treatment and at the terminal of a 6-month treatment. Meantime, the 24-h average systolic and diastolic pressures were recorded to calculate the 24-h dynamic pulse pressure (24 hPP), PPI, SI of systolic and diastolic blood pressure (SISBP and SIDBP) for comparing the changes between groups and analyzing the SI related factors.</p><p><b>RESULTS</b>All patients' blood pressure levels were well controlled; after a 6-month treatment, the PP and PPI in the treated group were 45 +/- 8 mm Hg and 0.35 +/- 0.08 respectively, which were significantly lower than those in the control group (51 +/- 10 mm Hg and 0.38 +/- 0.05, P < 0.05); while SISBP and SIDBP in the treated group were higher than those in the control group (1.37 +/- 0.16 vs 1.26 +/- 0.20, P < 0.01; and 1.28 +/- 0.14 vs 1.18 +/- 0.23, P < 0.05) respectively; and PWV in the former was significantly lower than that in the latter group (10.4 +/- 3.68 m/s vs 12.5 +/- 4.27 m/s, P < 0.05). Multiple factor stepwise regression analysis showed that the SISBP was negatively correlated with age, PPI and PWV, while the SIDBP was negatively correlated with PPI (P < 0.01).</p><p><b>CONCLUSION</b>The combined application of XZK and hypotensive drugs can decrease PP and PPI, improve the endothelial function and arterial elasticity, enhance the efficacy of treatment on SI. After treatment SI shows a significant negative correlation with PPI, PWV and age in patients.</p>