Dementia risk is strongly age-dependent, with the largest numbers of diagnoses occurring in people aged over 80. In this age group, women are more likely to be diagnosed with dementia than men, with estrogen exposure identified as a possible mechanism accounting for this difference. To assess the effect of long-term estrogen exposure on dementia risk in older women, the authors of an article in the September issue of Alzheimer’s and Dementia analysed data from the Swedish Prospective Population Study of Women (PPSW), evaluating the rate of dementia diagnosis in women in relation to their reproductive periods. The reproductive period (in years) was estimated based on information collected in the PPSW study on the womens’ age at menarche and menopause, number of pregnancies, months of breastfeeding and use of oral contraceptives or HRT.
During the study period examined, 291 of the 1364 women developed dementia, at an average age of just under 80 years. Longer reproductive period and later menopause was associated with an ~7% increased likelihood per year of developing Alzheimer’s disease (AD) and/or dementia. Those with the longest reproductive periods (>38 years) had the highest relative risk of dementia and AD, with almost twice the risk of developing dementia compared to women with shorter reproductive periods (<32.6 years). This may partly explain why women aged over 85 have higher dementia incidence than men of the same age.
https://alz-journals.onlinelibrary.wiley.com/doi/full/10.1002/alz.12118
