Cumulative exposure of women to estrogen maintained protection against certain types of postmenopausal stroke, no matter how researchers estimated such exposures in a large Chinese cohort study.
The risk of stroke was significantly lower with higher lifetime estrogen exposure from reproductive factors, according to the three composite measures.
- Reproductive lifespan: highest and lowest quartile adjusted HR 0.95 (95% CI 0.92-0.98)
- Endogenous estrogen exposure: adjusted HR 0.85 (95% CI 0.82-0.89)
- Total estrogen exposure: adjusted HR 0.87 (95% CI 0.84-0.90)
These results in total stroke apply specifically to ischemic stroke and intracerebral hemorrhage (ICH). Findings by stroke subtype support the literature showing that female study participants with longer reproductive lifespans have a lower risk of stroke. Medicine, China, and Colleagues.
“Lifetime cumulative estrogen exposure by reproductive factors employed in our study may serve as an early-warning indicator for stroke and its subtypes,” the study authors reported. neurology.
“They also have the potential to allow comprehensive and visual comparisons of individual reproductive factors, which will be of great clinical and public health importance.” may help raise awareness about gender-specific risk factors for stroke and provide guidance for effective stroke prevention, including targeting female patients with short durations of estrogen exposure with timely screening. innovation,” added the researcher.
Estrogen production ceases during the postmenopausal stage, which is thought to accompany the loss of cardiovascular protection in women.
However, treatment with estrogen and progestin is not recommended for primary prevention of chronic disease. The U.S. Preventive Services Task Force gave this hormone combination a “D” rating (not recommended) for postmenopausal women, and estrogen alone also gave a “D” rating for patients who had a hysterectomy. increase.
Stroke is the fifth leading cause of death in women in the United States. Gender-specific risk factors for stroke include high blood pressure during pregnancy and certain types of contraception.
In this study, we counted 122,939 postmenopausal women in the China Kadoorie Biobank. All had no prior stroke reported at enrollment in 2004-2008.
Median ages at menarche, menopause, and baseline were 16, 49, and 58 years, respectively.
Reproductive lifespan was defined as the number of years from menarche to menopause. Endogenous estrogen exposure is a measure minus years of pregnancy and contraceptive use, but total estrogen exposure adds to these periods of relatively high blood estrogen levels.
The median reproductive lifespan of study participants was found to be 33 years, 27.3 years for endogenous estrogen exposure and 32.5 years for total estrogen exposure.
Stroke incidence and its subtypes were collected from national registries over a median follow-up of 8.9 years. Investigators identified 15,139 new-onset stroke cases, including 12,853 ischemic stroke, 2,580 his ICH cases, and 269 subarachnoid hemorrhage cases.
In particular, Song’s group found a relatively weak association between lifetime cumulative estrogen exposure from reproductive factors and SAH stroke. The authors suggested that although the highest quartile of reproductive lifespan appeared to be at high risk for SAH, this finding may be due to limited statistical power.
They also acknowledged that this study was left open to recall bias as it relied on participants’ self-reported reproductive histories. We could not adjust for genetic factors, childhood factors, or diet, among other variables that were not.
“Lifetime estrogen exposure may be a useful indicator of risk for various types of stroke after menopause,” Song said in a press release. Further research is needed on the biological, behavioral, and social factors that may contribute to the association between obesity and stroke risk.”
Song’s group had no disclosures.
Source reference: Hou L, et al. Lifetime cumulative effects of reproductive factors on stroke and its subtypes in postmenopausal Chinese: a prospective cohort study. Neurology 2023; DOI: 10.1212/WNL.0000000000206863.