Science Update | Does Reproductive Period Matter to Dementia Risk?
WHAT. A recent study published online in Neurology that lower levels of estradiol exposure, defined by later age at menarche and younger age at menopause, was significantly linked to increased dementia risk. Researchers used the Kaiser Permanente database to examine the records of over 15,000 women, using both health surveys and medical records from 1964 through 2017. Reproductive span was calculated as menopause age minus menarche age, with dementia diagnosis abstracted from clinical records. They found that a shorter reproductive span of less than 35 years was associated with a 20% elevated risk for dementia.
WHY IT MATTERS. Previous research has demonstrated a link between estradiol and dementia risk, mostly focused on the use of hormone replacement therapy (HRT) and lowered incidence but use of HRT is limited due to more recent findings regarding increased breast cancer risk and even, in one large study, increased dementia risk. However, this study offers interesting insight to the role exposure over one’s lifetime to the hormone estradiol may play in dementia risk and continues to raise the question of how hormonal treatment may be beneficial to those at increased risk, here due to shortened reproductive span.
THE TAKEAWAY. According to these findings, women with shortened reproductive spans may be at greater risk for dementia and should discuss with their PMP these findings and whether HRT or natural sources of estradiol might be an option for them.
Gilsanz P, Lee C, Corrada MM, Kawas CH et al. Reproductive period and risk of dementia in a diverse cohort of health care members. Neurology 2019 Mar 28. pii: 10.1212/WNL.0000000000007326. doi:10.1212/WNL.0000000000007326. [Epub ahead of print] PubMed PMID: 30923235.