Postural Changes in Measures of Arterial Stiffness in Hypertensive Subjects on Antihypertensive Drug Therapy: A Prospective, Pilot Study

Prospective study with a controlled arm to know if there are variations of measures of arterial stiffness with posture in subjects with hypertension on antihypertensive medications. We studied postural variations of measures of arterial stiffness in 21 subjects with diagnosed hypertension on antihypertensive medications and compared them with 21 normotensive subjects. All subjects underwent pulse-wave analysis on SphygmoCor in the morning between 8 am to 10 am initially in supine and then in sitting position after 3 minutes. Summary measures on demographics, and blood pressure characteristics at sitting and supine positions are obtained. Differences between characteristics at supine and sitting position are compared using nonparametric paired test of Wilcoxon signed-rank test. A value of p < 0.05 was accepted as statistically significant. Antihypertensive medications decreased the supine aortic augmentation pressure (AAP) and augmentation index (AI) but not significantly. When subgroups of patients with antihypertensive treatment were analyzed, it was noted that angiotensin-converting enzyme inhibitor and angiotensin receptor blocker group (12) decreased AAP and AI significantly in supine position compared with patients on other antihypertensive medications (9) (p-value 0.034 and 0.038, respectively). There was no significant difference in other groups of calcium channel blockers, β-blockers, or diuretics. However, in normotensive control arm, there was an increase in AAP and AI in the supine position. In hypertensive subjects, on antihypertensive, there was reduction in AAP and AI in supine position compared with those of normotensives. The significance of the decrease in AAP and AI in supine position on antihypertensive needs to be studied further.