Influence of age and postmenopausal estrogen replacement therapy on carotid arterial stiffness in women

Objective: This study examines the influence of age and current estrogen re placement therapy (ERT) on common carotid arterial (CCA) stiffness in women . Methods: The subjects comprised 172 women (age 55.6+/-16.4 years) from th e Baltimore Longitudinal Study of Aging, including 37 current postmenopausa l ERT users. The ERT users included 18 women taking estrogen alone and 19 w omen taking estrogen and progesterone. Bilateral CCA were examined by B-mod e carotid ultrasonography, and the stiffness index was defined as the logar ithm of the ratio of systolic to diastolic blood pressure (BP) divided by t he fractional diameter increase during the cardiac cycle. Results: The stif fness index increased linearly with age (r=0.69, p<0.001), and was lower in ERT users than in postmenopausal nonusers (8.0+/-2.0 vs 9.7+/-3.1, p<0.01) . Furthermore, the effects of age (beta=0.67, p<0.0001) and ERT (beta=-0.23 , p<0.001) on the stiffness index persisted after adjustments for systolic BP (beta=0.23, p<0.01), diastolic BP (beta=-0.26, p<0.001) and other cardio vascular risk factors (model r(2)=0.59, p<0.0001). The stiffness index was similar in both ERT users with and without progesterone and lower than in p ostmenopausal nonusers (p<0.05) after considering the age effects. Conclusi on: Age-associated increases in CCA stiffness are reduced by postmenopausal ERT. (C) 1999 Elsevier Science B.V. All rights reserved.