Heart diseases and long-term risk of dementia and Alzheimer's disease: a population-based CAIDE study.
BACKGROUND
Many cardiovascular risk factors are shown to increase the risk of dementia and Alzheimer's disease (AD), but the impact of heart disease on later development of dementia is still unclear.


OBJECTIVE
The aim of the study was to investigate the long-term risk of dementia and Alzheimer's disease (AD) related to midlife and late-life atrial fibrillation (AF), heart failure (HF), and coronary artery disease (CAD) in a population-based study with a follow-up of over 25 years.


METHODS
Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study includes 2000 participants who were randomly selected from four separate, population-based samples originally studied in midlife (1972, 1977, 1982, or 1987). Re-examinations were carried out in 1998 and 2005-2008. Altogether 1,510 (75.5%) persons participated in at least one re-examination, and 127 (8.4%) persons were diagnosed with dementia (of which 102 had AD).


RESULTS
AF in late-life was an independent risk factor for dementia (HR 2.61, 95% CI 1.05-6.47; p = 0.039) and AD (HR 2.54, 95% CI 1.04-6.16; p = 0.040) in the fully adjusted analyses. The association was even stronger among the apolipoprotein E (APOE) ε4 non-carriers. Late-life HF, but not CAD, tended to increase the risks as well. Heart diseases diagnosed at midlife did not increase the risk of later dementia and AD.


CONCLUSIONS
Late-life heart diseases increase the subsequent risk of dementia and AD. Prevention and effective treatment of heart diseases may be important also from the perspective of brain health and cognitive functioning.
Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland.
Minna
M
Rusanen
Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland Aging Research Center, Karolinska Institutet, Stockholm, Sweden Karolinska Institutet Alzheimer's Disease Research Center, Stockholm, Sweden.
Miia
M
Kivipelto
Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland.
Esko
E
Levälahti
Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland Hospital District of North Karelia, Joensuu, Finland.
Tiina
T
Laatikainen
Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland Department of Public Health, University of Helsinki, Helsinki, Finland South Ostrobothnia Central Hospital, Seinäjoki, Finland.
Jaakko
J
Tuomilehto
Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland Department of Neurology, Kuopio University Hospital, Kuopio, Finland.
Hilkka
H
Soininen
Karolinska Institutet Alzheimer's Disease Research Center, Stockholm, Sweden Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki, Finland.
Tiia
T
Ngandu
D000367:Age Factors; D000368:Aged; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000235:genetics; D053327:Apolipoprotein E4 / Q000235:genetics; D001281:Atrial Fibrillation / Q000453:epidemiology* / Q000235:genetics; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000453:epidemiology* / Q000235:genetics; D003704:Dementia / Q000453:epidemiology* / Q000235:genetics; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006333:Heart Failure / Q000453:epidemiology* / Q000235:genetics; D006801:Humans; D008297:Male; D012306:Risk; D012307:Risk Factors; D012959:Socioeconomic Factors
D053327:Apolipoprotein E4
Alzheimer disease; atrial fibrillation; cohort studies; coronary artery disease; dementia; heart failure; risk factors