Large-Artery Stiffness Contributes to the Greater Prevalence Systolic Hypertension in Elderly Women

OBJECTIVES: To determine whether sex differences in large-artery stiffness contribute to the greater prevalence of systolic hypertension in elderly women than in elderly men. DESIGN: During a single visit arterial stiffness was assessed in the unmedicated state using four parameters. PARTICIPANTS: Three hundred seventy-four women with a mean age ± standard deviation of 72 ± 5 and 296 men aged 71 ± 5 participated. SETTING: Hypertensive patients were recruited from general practice as part of the second Australian National Blood Pressure Study in Melbourne, Australia. MEASUREMENTS: Large-artery stiffness was assessed using multiple methodologies, including aortic arch stiffness (β-index) using M-mode ultrasound and arterial compliance and augmentation index using noninvasive carotid pressure and aortic flow measurements. RESULTS: Women had greater carotid and brachial pulse pressure (PP) than men (P<.001), despite higher mean arterial pressure in men. Mean arterial compliance was lower in women (0.20±0.12 vs 0.28±0.16 mL/mmHg, P<.001) even after correction for aortic area, and aortic arch stiffness was higher (30±36 vs 23±22; P<.01). Consistent with both a stiffer proximal circulation and a shorter distance to reflection sites, women had higher augmentation index (38 ± 11 % vs 29 ± 12%, P<.001). In multivariate analysis, sex was an independent determinant of all arterial stiffness indices. CONCLUSION: Independently of known confounders, elderly hypertensive women have stiffer large arteries, greater central wave reflection, and higher PP than elderly men. Stiffer large arteries likely contribute to the greater prevalence of systolic hypertension in elderly women and may partly explain the acceleration in postmenopausal cerebrovascular and cardiac complications.