Association of Reproductive History With Brain MRI Biomarkers of Dementia Risk in Midlife.
Level 4 - case-series / case-control
Cross-sectional observational study
PubMed 34732544 · doi:10.1212/WNL.0000000000012941
What was done
Researchers evaluated 99 cognitively normal women (mean age 52 ± 6 years) and 29 men (mean age 52 ± 7 years) to examine associations between female reproductive history indicators and volumetric brain MRI markers. Reproductive variables included menopausal status, age at menarche and menopause, reproductive span, hysterectomy status, parity, number of pregnancies, and use of hormone therapy (HT) or hormonal contraceptives (HC). Multiple regressions assessed associations among these indicators, voxel-wise gray matter volume (GMV), and cognitive tests (memory and global cognition), adjusting for demographics, APOE ε4 status, and midlife health indicators.
What was found
The abstract reports directional associations without numerical effect sizes, test statistics, or p-values. All menopausal groups had lower GMV in Alzheimer disease-vulnerable regions compared to men, and peri- and postmenopausal women had lower temporal cortex GMV than premenopausal women. Longer reproductive span, more children and pregnancies, and use of HT and HC were positively associated with GMV in the temporal cortex, frontal cortex, and precuneus. Reproductive indicators were not directly linked to cognitive test scores, but temporal GMV was positively associated with memory and global cognition.
Why it matters
This study links proxy markers of higher lifetime estrogen exposure to preserved midlife gray matter volume in brain regions typically affected by Alzheimer disease. It suggests endocrine history may contribute to sex-specific differences in midlife neuroimaging markers of dementia risk.
Limits
The study is cross-sectional, precluding causal inference or determination of atrophy rates over time. The sample size is modest (99 women, 29 men), reproductive exposures were based on historical recall rather than measured hormone levels, and the abstract omits quantitative effect estimates, confidence intervals, and p-values.
Cited by
- context Starting estrogen and progesterone replacement therapy at midlife or perimenopause provides greater Alzheimer's risk reduction than initiating it postmenopausally.