title: Hormone replacement therapy and stroke risk in older women.
abstract: Studies of the effect of hormone replacement therapy (HRT) on the risk of stroke in postmenopausal women have yielded divergent results. Many of the studies had small numbers of estrogen-using women and relatively young women. All were confounded because women who use estrogen are healthier than the general population. Case-control studies, which included a larger number of cases, usually were limited to stroke survivors and had problems of recall bias regarding exposure. We describe the independent risk of fatal and nonfatal stroke in a socioeconomically homogeneous cohort of older, postmenopausal, community-dwelling women in Rancho Bernardo, California, who had a high rate of past or current HRT use. During 1984-1987, estrogen use and stroke risk factors were ascertained for 1031 women over age 60 without a history of stroke in the Rancho Bernardo cohort. Stroke deaths were monitored by obtaining 100% of death certificates, and nonfatal strokes were determined through questionnaires. At baseline, the average age was 73.1 years, 27% were current estrogen users, and 45% were past estrogen users. Over 8.8 follow-up years, 263 deaths occurred, and 37 of the death certificates listed stroke as an underlying or contributing cause of death. Only 7 of current HRT users had a stroke compared with 16 former users and 14 never users. The age-adjusted odds ratio (OR) was 0.92 (95% CI = 0.56-1.50) in HRT users versus never users. Results were not materially changed in multiply adjusted analyses. Similar analyses of nonfatal strokes and transient ischemic attacks (n = 20) showed an increased risk (OR = 3.02, 95% CI = 0.70-13.08). This study provides no evidence that HRT prevents stroke in older women, but the confidence intervals are wide, suggesting that more studies are needed.
mesh_terms: D000368:Aged; D002423:Cause of Death; D002561:Cerebrovascular Disorders / Q000401:mortality / Q000517:prevention & control*; D015331:Cohort Studies; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D018570:Risk Assessment