Pulse wave velocity (PWV, m s^-1), a marker of arterial stiffness, is an important independent cardiovascular risk factor in hypertension and a new therapeutic target. There is some evidence that a drug-induced reduction in PWV, particularly with angiotensin-converting enzyme inhibitors, independently of blood pressure reduction may confer a survival advantage [1]. Previous studies have shown that most commonly used antihypertensives, with the exception of diuretics and possibly some β-adrenoceptor blockers, reduce PWV. With the advent of combined low dose anti-hypertensive agents, and the increasing use of three and four antihypertensives to control blood pressure, we need to determine their cumulative effect on arterial stiffness.

The aim was to study the effect of a low-dose antihypertensive drug combination on arterial stiffness compared with montherapy.

In this study we randomized 96 untreated hypertensive patients (mean age 50  ± 1, 34 females) to either atenolol 50 mg, bendrofluazide 2.5 mg, captopril 50 mg twice daily, amlodipine 5 mg or a polypill, containing a quarter of each of the four drugs, in a parallel group design, for 1 month. Blood pressure (BP) and heart rate were measured with an oscillometric device (Omron HEM 705-CP) in the morning about 2-4 h after drug administration. Carotid-femoral PWV was measured with the Complior using the foot to foot method at baseline and 1 month after treatment. Changes in blood pressure and PWV from baseline were calculated. Between treatment group differences, in relation to these changes, were analyzed with one-way analysis of variance ( anova) and Tukey-Kramer HSD test. The statistical analysis was performed with JMPin version 5.1 and results expressed as mean ± SEM. Two sided statistical tests were performed with p < 0.05 considered significant.

There was no difference in age or blood pressure levels at baseline between the five different groups. The reduction in PWV with the polypill (1.7  ± 0.2) was significantly greater ( p < 0.05) than with atenolol (0.8  ± 2), captopril (0.8  ± 2), amlodipine (0.3  ± 2) or bendrofluazide (0.2  ± 2). There was a non-significant trend for a greater reduction in systolic blood pressure (27  ± 3, p = 0.06) with the combination compared with the individual drugs where the systolic blood pressure fall varied from 9  ± 4 to 19  ± 3 mmHg. There was no difference in the diastolic blood pressure fall between different treatments.

A low-dose polypill in hypertension may be more effective in reducing arterial stiffness in hypertension compared with monotherapy at therapeutic dose.