HealthDay News — Lifetime cumulative exposure to estrogen is associated with a reduced risk for stroke, according to a study published online Feb. 1 in Neurology.
Leying Hou, Ph.D., from Zhejiang University School of Medicine in Hangzhou, China, and colleagues examined the associations of lifetime cumulative estrogen exposure due to reproductive factors with stroke among postmenopausal Chinese women. Lifetime cumulative estrogen exposure was assessed using three indicators: reproductive life span (RLS), endogenous estrogen exposure (EEE), and total estrogen exposure (TEE).
Data were included for 122,939 postmenopausal participants aged 40 to 79 years without prior stroke at baseline. The researchers identified 15,139 new-onset stroke cases during a median follow-up of 8.9 years, including 12,853 cases of ischemic stroke (IS), 2,580 cases of intracerebral hemorrhage (ICH), and 269 cases of subarachnoid hemorrhage. Compared with the lowest quartile of RLS, the highest quartile had a significantly lower risk for total stroke, IS, and ICH (adjusted hazard ratios, 0.95, 0.95, and 0.87, respectively). A graded association was seen for the highest versus the lowest quartile of both EEE and TEE with a subsequent descending risk for total stroke (adjusted hazard ratios, 0.85 and 0.87, respectively), IS (adjusted hazard ratios, 0.86 and 0.86, respectively), and ICH (adjusted hazard ratios, 0.73 and 0.83, respectively).
“These findings might help with new ideas for stroke prevention, such as considering screenings for people who have a short lifetime exposure to estrogen,” a coauthor said in a statement.