Hormone therapy is widely used to treat menopausal symptoms such as hot flushes and night sweats. But scientists have long debated whether it affects dementia risk.
A new study adds another piece to this puzzle. It suggests that an Alzheimer’s biomarker may help identify which women are more vulnerable to dementia with certain hormone therapies.
Researchers analysed blood samples from 2,766 women recruited into a clinical trial in 1996 to 1999. They then followed participants until 2021 to examine whether levels of plasma p-tau217 at the start of the study were linked to people developing dementia, and whether this relationship differed depending on whether participants had used hormone therapy.
Plasma p-tau217 is a biomarker for Alzheimer’s disease, a measurable biological signal of the condition. Higher levels in the blood are linked to brain changes associated with Alzheimer’s.
The study compared women who received a placebo or two types of hormone therapy. One was combined hormone therapy containing oestrogen and progesterone, usually prescribed for women who still have their womb. The other was oestrogen-only therapy, typically given after hysterectomy.
Women with higher levels of the Alzheimer’s biomarker had a substantially greater risk of developing dementia. In the study’s main analysis, higher baseline p-tau217 levels were associated with about three times the risk.
However, the relationship differed depending on the type of hormone therapy used. Among women assigned to combined hormone therapy, higher biomarker levels were linked to roughly four times the risk of dementia. This pattern was not seen among women using oestrogen-only therapy.

Article continues on The Conversation: https://theconversation.com/hormone-therapy-and-dementia-risk-what-a-new-study-says-about-menopause-treatment-277987