Ankle-to-brachial index and dementia: the Honolulu-Asia Aging Study.
BACKGROUND
Measurement of the ankle-to-brachial index (ABI) is a noninvasive test to assess peripheral arterial disease. A low ABI is a strong correlate of cardiovascular disease and subsequent mortality. Evidence indicates the existence of vascular components in the pathogenesis of dementia. Here, we examine the association of ABI with dementia and subtypes.


RESULTS
Data are from the Honolulu-Asia Aging Study (HAAS), a prospective community-based study of 3734 Japanese American men 71 to 93 years of age at baseline in 1991 to 1993. The analysis included 2588 men who were free of dementia at the first assessment, had an ABI measure, and were examined up to 2 more times for dementia between 1994 and 1999. The sample included 240 incident cases of dementia (144 of Alzheimer's disease, 46 of vascular dementia, and 50 of dementia of other causes). Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated from Cox proportional-hazards models with age as the time scale after adjustment for education, year of birth, high blood pressure, body mass index, diabetes mellitus, cholesterol concentration, smoking status, alcohol consumption, and apolipoprotein E epsilon4 allele. A low ABI was associated with an increased risk of dementia and vascular dementia (HR, 1.66; 95% CI, 1.16 to 2.37; and HR, 2.25; 95% CI, 1.07 to 4.73, respectively). ABI was weakly associated with Alzheimer's disease (HR, 1.57; 95% CI, 0.98 to 2.53), particularly in the apolipoprotein E epsilon4 carriers (HR, 1.43; 95% CI, 1.02 to 1.96).


CONCLUSIONS
These results suggest that ABI, a measure of atherosclerosis, is associated with the incidence of total dementia, vascular dementia, and Alzheimer's disease in carriers of the apolipoprotein E epsilon4 allele.
Laurin
Danielle
D
Laval University Geriatrics Research Unit, Centre de recherche du CHA, and Faculty of Pharmacy, Laval University, Quebec City, Quebec, Canada.
Masaki
Kamal H
KH
White
Lon R
LR
Launer
Lenore J
LJ
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000208:ethnology*; D000544:Alzheimer Disease / Q000208:ethnology / Q000503:physiopathology; D000843:Ankle Joint / Q000098:blood supply; D053327:Apolipoprotein E4 / Q000235:genetics; D044466:Asian People / Q000706:statistics & numerical data*; D001916:Brachial Artery / Q000502:physiology; D003704:Dementia / Q000208:ethnology* / Q000503:physiopathology*; D006254:Hawaii / Q000453:epidemiology; D006801:Humans; D020961:Lewy Body Disease / Q000208:ethnology / Q000503:physiopathology; D008137:Longitudinal Studies; D008297:Male; D016491:Peripheral Vascular Diseases / Q000175:diagnosis* / Q000208:ethnology* / Q000503:physiopathology; D020774:Pick Disease of the Brain / Q000208:ethnology / Q000503:physiopathology; D015995:Prevalence; D016016:Proportional Hazards Models; D012307:Risk Factors; D013494:Supranuclear Palsy, Progressive / Q000208:ethnology / Q000503:physiopathology
D053327:Apolipoprotein E4