title: Influence of age and postmenopausal estrogen replacement therapy on carotid arterial stiffness in women.
abstract: OBJECTIVE
  This study examines the influence of age and current estrogen replacement therapy (ERT) on common carotid arterial (CCA) stiffness in women.
  
  
  METHODS
  The subjects comprised 172 women (age 55.6 +/- 16.4 years) from the Baltimore Longitudinal Study of Aging, including 37 current postmenopausal ERT users. The ERT users included 18 women taking estrogen alone and 19 women taking estrogen and progesterone. Bilateral CCA were examined by B-mode carotid ultrasonography, and the stiffness index was defined as the logarithm of the ratio of systolic to diastolic blood pressure (BP) divided by the fractional diameter increase during the cardiac cycle.
  
  
  RESULTS
  The stiffness 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 cardiovascular risk factors (model r2 = 0.59, p < 0.0001). The stiffness index was similar in both ERT users with and without progesterone and lower than in postmenopausal nonusers (p < 0.05) after considering the age effects.
  
  
  CONCLUSIONS
  Age-associated increases in CCA stiffness are reduced by postmenopausal ERT.
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D001794:Blood Pressure / Q000187:drug effects; D017536:Carotid Artery, Common / Q000187:drug effects / Q000502:physiology*; D004548:Elasticity; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D011374:Progesterone / Q000008:administration & dosage