Abstract
Premenopausal women have less frequent cardiovascular disease (CVD) than men: following menopause the risk of mortality from CVD in females increases markedly. Post-ischemic dilatation of the brachial artery has been used previously as an index of endothelium-mediated vasodilation. Using this index, we have now examined a group of premenopausal and postmenopausal women some of whom were on estrogen replacement therapy (ERT).
All subjects were normotensive and normoglycemic. Fourteen healthy females and fourteen healthy males were investigated. Nineteen postmenopausal females were also examined: eleven were on ERT and eight were not on ERT. Ischemia was induced by insufflating a cuff over the forearm for five minutes, Doppler ultrasonography was used to measure baseline brachial artery diameter prior to inflation and following cuff deflation.
Post-ischemic median dilatation in males was 4.20% (interquartile range 2.13-5.56%) and 11.48% (IR 8.70-14.29%) in age-matched premenopausal fe males (p<.01). For those on ERT the post-ischemic median dilatation was 8.11% (IR 6.01-11.60%) and 2.82% (IR 1.32-3.28%) for those without ERT (p<.01). Premenopausal women dilated significantly more after ischemia than did postmenopausal women not taking ERT. (p<.01).