A large study using data from the UK Biobank found that hormone replacement therapy use was associated with a lower risk of dementia, with stronger associations observed in some subgroups. The findings were published in the journal Alzheimer’s & Dementia.
Researchers analysed data from 183,450 postmenopausal women participating in the UK Biobank, an ongoing cohort study of more than 500,000 people aged 37 to 73 years at baseline. Participants were followed for an average of 13.3 years.
The study covered over 2.43 million person-years of follow-up, during which 3,948 cases of dementia were diagnosed. Women who had used hormone replacement therapy for at least one year had a 10% lower risk of all-cause dementia compared with non-users. The association was stronger among women who had undergone surgical menopause, women carrying the APOE ε4 allele and those with lower endogenous oestrogen exposure.
The researchers also found that the association varied according to the age at which hormone replacement therapy was initiated. Starting hormone replacement therapy between the ages of 46 and 56 was associated with the strongest reduction in dementia risk.
The study authors cautioned that the findings demonstrate an association rather than a causal relationship. As an observational study, further research is needed to investigate the potential relationship.
https://doi.org/10.1002/alz.71679
