AGE-RELATED DETERIORATION IN ARTERIAL STRUCTURE AND FUNCTION IN POSTMENOPAUSAL WOMEN - IMPACT OF HORMONE REPLACEMENT THERAPY

Epidemiological evidence suggests that hormone replacement therapy (HR T) reduces morbidity and mortality from cardiovascular diseases in pos tmenopausal women. In this study, ir.dices of arterial function [total systemic arterial compliance (SAC) and carotid arterial distensibilit y coefficient (DC)], structure [carotid intima-media thickness (IMT)], and lipid profiles were compared in postmenopausal women on long-term HRT and aged-matched controls. One hundred nine women aged 44 to 77 y ears taking HRT and an age-matched group of 108 female controls were e ntered into the study. The two groups were similar for body mass index , smoking status, exercise level, alcohol intake, and blood pressure. Fasting cholesterol, low density lipoprotein, and lipoprotein(a) were reduced and high density lipoprotein increased in the HRT group. IMT i ncreased with age; SAC and DC were reduced with age in both groups. Th e HRT group had a higher mean SAC (0.42+/-0.02, versus 0.34+/-0.02 U/m m Hg, P=0.0001) and a lower mean IMT (0.67+/-0.01 versus 0.74+/-0.02 m m, P=0.006) than did controls. Subgroup analysis for estrogen versus e strogen plus progestin revealed no differences for SAC and IMT; DC, ho wever, was greater in estrogen-only users. Smokers on HRT had a higher mean SAC (0.41+/-0.02 versus 0.31+/-0.01 U/mm Hg, P=0.008) and a lowe r IMT (0.65+/-0.02 versus 0.75+/-0.03 mm, P=0.002) than did smokers no t taking such therapy. A protective effect of long-term estrogen thera py on age-related changes in arterial structure and function in postme nopausal women was evident in smokers and nonsmokers alike. Progestin appeared to counteract the effects of estrogen on carotid compliance o nly. Long-term controlled trials are needed to determine the significa nce of these findings.