Estrogen therapy, atherosclerosis, and clinical cardiovascular events.

Abstract

In this issue of Circulation , Nabulsi and coworkers1 from the Atherosclerosis Risk in Communities (ARIC) Study Group report their findings on the association of age, menopause status, and hormone replacement therapy with a single measure of atherosclerosis: the average carotid artery intima-media thickness determined by B-mode ultrasound. What they discovered in the ARIC cohorts was this: there was little or no relation between menopausal staus and carotid thickness in women aged 45 to 54 who had never used hormonal therapy and who had no evidence of coronary heart disease at entry. Furthermore, for slightly older (aged 55 to 64 years) postmenopausal women, there was no relation between the number of years since menopause and carotid thickness nor between hormone use and carotid thickness. All of these findings were unexpected. Data that have been accumulated over the past few years demonstrate strong clinical benefits from estrogen use for postmenopausal women. The ARIC investigators quite logically hypothesized that there would be significant relations between carotid thickness, menopause, and hormone therapy (or lack of it) in this community-wide study, but in fact their data did not provide support for this. The investigators speculate that the association of estrogen replacement therapy with a reduction in clinical cardiovascular events after menopause may not necessarily be due to a reduction in the amount of anatomic atherosclerotic disease or inhibition of its formation, at least during the early years after menopause, but might instead be more attributable to other beneficial physiological changes brought about by estrogen compounds. The present ARIC study has a number of limitations, as the authors themselves recognize. First, the upper age limit for ARIC was 64 years, and it was revealed that the duration of hormone use in women currently using hormones at entry was 9 years. It is possible that …