TY - JOUR

T1 - Systemic hormone therapy and dementia

T2 - A nested case-control and co-twin control study

AU - Lokkegaard, Laura Ekstrom

AU - Thinggaard, Mikael

AU - Nygaard, Marianne

AU - Hallas, Jesper

AU - Osler, Merete

AU - Christensen, Kaare

PY - 2022

Y1 - 2022

N2 - Objective: The effect of systemic hormone therapy (HT) on dementia risk is unclear. Our aim was to investigate the association between HT and dementia.Study design: This register-based study consists of a nested case-control study and a co-twin control design, which controls for familial confounding, including shared genetics.Main outcome measures: Through Danish national registries from 1995 to 2011, we identified: a) 2700 female singletons with incident dementia and 13,492 matched controls; b) 288 female twins with incident dementia and co-twins without dementia. Data on HT and education were retrieved, and analyses were performed using conditional logistic regression and McNemar's chi(2)-test. HT use decreased dramatically after the Women's Health Initiative study results were published in 2002, and the analyses were stratified accordingly to account for potentially different HT user characteristics.Results: The odds ratio (OR) for the association between systemic HT and dementia was 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 was found for systemic HT before 2003 in both populations, with an OR of 1.14, 95% CI = [1.01-1.28] in singletons and an OR of 2.20, 95% CI = [1.04-4.65] in twins.Conclusion: Using Danish nationwide registries and controlling for education and for familial factors in a subsample, systemic HT was found to be associated with increased dementia risk if used before 2003, when HT was more commonly prescribed.

AB - Objective: The effect of systemic hormone therapy (HT) on dementia risk is unclear. Our aim was to investigate the association between HT and dementia.Study design: This register-based study consists of a nested case-control study and a co-twin control design, which controls for familial confounding, including shared genetics.Main outcome measures: Through Danish national registries from 1995 to 2011, we identified: a) 2700 female singletons with incident dementia and 13,492 matched controls; b) 288 female twins with incident dementia and co-twins without dementia. Data on HT and education were retrieved, and analyses were performed using conditional logistic regression and McNemar's chi(2)-test. HT use decreased dramatically after the Women's Health Initiative study results were published in 2002, and the analyses were stratified accordingly to account for potentially different HT user characteristics.Results: The odds ratio (OR) for the association between systemic HT and dementia was 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 was found for systemic HT before 2003 in both populations, with an OR of 1.14, 95% CI = [1.01-1.28] in singletons and an OR of 2.20, 95% CI = [1.04-4.65] in twins.Conclusion: Using Danish nationwide registries and controlling for education and for familial factors in a subsample, systemic HT was found to be associated with increased dementia risk if used before 2003, when HT was more commonly prescribed.

KW - Postmenopausal hormone therapy

KW - Twins

KW - Register data

KW - Population-based study

KW - MILD COGNITIVE IMPAIRMENT

KW - HEALTH INITIATIVE MEMORY

KW - REPLACEMENT THERAPY

KW - POSTMENOPAUSAL WOMEN

KW - ALZHEIMERS-DISEASE

KW - ALL-CAUSE

KW - RISK

KW - PREVENTION

KW - MORTALITY

KW - DENMARK

U2 - 10.1016/j.maturitas.2022.04.007

DO - 10.1016/j.maturitas.2022.04.007

M3 - Journal article

C2 - 36184115

VL - 165

SP - 113

EP - 119

JO - Maturitas

JF - Maturitas

SN - 0378-5122

ER -