Menopausal hormone therapy and dementia: nationwide, nested case-control study

Area of Science:

• Reproductive Health and Endocrinology
• Neuroscience and Aging

Background:

• Menopausal hormone therapy (MHT) is widely used for symptom management during menopause.
• The long-term effects of MHT on cognitive health, specifically dementia risk, require further elucidation.

Purpose of the Study:

• To investigate the association between menopausal hormone therapy use and the development of dementia.
• To examine how hormone treatment type, duration, and age at initiation influence dementia risk.

Main Methods:

• A nationwide nested case-control study was conducted in Denmark, utilizing national health registries.
• 5,589 incident dementia cases and 55,890 age-matched controls were identified among women aged 50-60 years between 2000 and 2018.
• Adjusted hazard ratios (HR) with 95% confidence intervals (CI) were calculated for all-cause dementia.

Main Results:

• Estrogen-progestogen therapy was associated with an increased rate of all-cause dementia (HR 1.24; 95% CI 1.17-1.33) compared to non-users.
• Dementia risk increased with longer durations of MHT use, from HR 1.21 (95% CI 1.09-1.35) for ≤1 year to HR 1.74 (95% CI 1.45-2.10) for >12 years.
• Associations persisted across continuous and cyclic regimens and in women initiating MHT at age 55 or younger, and were observed for Alzheimer's disease.

Conclusions:

• Menopausal hormone therapy, especially estrogen-progestogen types, is positively associated with the development of dementia, including Alzheimer's disease.
• The increased dementia risk was observed even with early initiation (≤55 years) and varied durations of MHT.
• Further research is needed to confirm causality and understand potential underlying predispositions in women using MHT.