Dementia in Women Using Estrogen-Only Therapy.

This study examines the association between use of estrogen-only therapy for perimenopausal and menopausal women and risk of dementia.

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

OBJECTIVES: To assess the association between use of menopausal hormone therapy and development of dementia according to type of hormone treatment, duration of use, and age at usage. DESIGN: Nationwide, nested case-control study. SETTING: Denmark through national registries. PARTICIPANTS: 5589 incident cases of dementia and 55 890 age matched controls were identified between 2000 and 2018 from a population of all Danish women aged 50-60 years in 2000 with no history of dementia or contraindications for use of menopausal hormone therapy. MAIN OUTCOME MEASURES: Adjusted hazard ratios with 95% confidence intervals for all cause dementia defined by a first time diagnosis or first time use of dementia specific medication. RESULTS: Compared with people who had never used treatment, people who had received oestrogen-progestogen therapy had an increased rate of all cause dementia (hazard ratio 1.24 (95% confidence interval 1.17 to 1.33)). Increasing durations of use yielded higher hazard ratios, ranging from 1.21 (1.09 to 1.35) for one year or less of use to 1.74 (1.45 to 2.10) for more than 12 years of use. Oestrogen-progestogen therapy was positively associated with development of dementia for both continuous (1.31 (1.18 to 1.46)) and cyclic (1.24 (1.13 to 1.35)) regimens. Associations persisted in women who received treatment at the age 55 years or younger (1.24 (1.11 to 1.40)). Findings persisted when restricted to late onset dementia (1.21 (1.12 to 1.30)) and Alzheimer's disease (1.22 (1.07 to 1.39)). CONCLUSIONS: Menopausal hormone therapy was positively associated with development of all cause dementia and Alzheimer's disease, even in women who received treatment at the age of 55 years or younger. The increased rate of dementia was similar between continuous and cyclic treatment. Further studies are warranted to determine whether these findings represent an actual effect of menopausal hormone therapy on dementia risk, or whether they reflect an underlying predisposition in women in need of these treatments.

Vaginal estrogen and association with dementia: A nationwide population-based study.

INTRODUCTION: Use of systemic hormone therapy has been positively associated with development of dementia. Little is known about the dose-dependent effect of vaginal estradiol on dementia risk. METHODS: We assessed associations between cumulative dose of vaginal estradiol tablets and dementia in a case-control study nested in a nationwide Danish cohort of women aged 50 to 60 years at study initiation, who did not use systemic hormone therapy. Each case was age-matched to 10 female controls. RESULTS: A total of 4574 dementia cases were matched to 45,740 controls. Cumulative use of vaginal estradiol tablets was not associated with all-cause dementia; adjusted hazard ratio 1.02 (95% confidence interval [CI] 0.89-1.18) for low dose (< 750 mcg), 1.07 (0.94-1.21) for medium dose (750-2000 mcg), and 0.93 (0.84-1.03) for high dose (> 2000 mcg). Similarly, Alzheimer's disease (AD) only was not associated with vaginal estradiol. DISCUSSION: Exposure to vaginal estradiol tablets was not associated with all-cause dementia or AD only.