Systemic hormone therapy and dementia: A nested case-control and co-twin control study.

Area of Science:

• Neuroscience
• Epidemiology
• Women's Health

Background:

• The impact of systemic hormone therapy (HT) on dementia risk remains uncertain.
• Previous studies have yielded conflicting results regarding this association.

Purpose of the Study:

• To investigate the association between systemic hormone therapy (HT) and the risk of developing dementia.
• To control for potential confounding factors, including genetics and education.

Main Methods:

• A Danish register-based study utilized a nested case-control design and a co-twin control design.
• Data included 2700 female dementia cases and 13,492 controls, plus 288 female twins with dementia and their co-twins.
• Analyses accounted for HT use patterns before and after 2002, when the Women's Health Initiative study results were published.

Main Results:

• Systemic HT showed an odds ratio (OR) of 1.05 (95% CI [0.93-1.19]) in singletons and 2.10 (95% CI [0.99-4.46]) in twins.
• A statistically significant association between HT and dementia was found for use before 2003 (OR 1.14 in singletons, OR 2.20 in twins).

Conclusions:

• Systemic hormone therapy (HT) use, particularly before 2003, is associated with an increased risk of dementia.
• Findings were consistent across singleton and twin analyses, suggesting a potential link even after controlling for familial confounding.