Ankle brachial index as a predictor of cognitive impairment in the general population: ten-year follow-up of the Edinburgh Artery Study.
OBJECTIVE
To determine whether the ankle brachial index (ABI, a marker of generalized atherosclerosis) is associated with cognitive impairment after 10 years in older people.


METHODS
Cohort study (Edinburgh Artery Study).


METHODS
Eleven general practices in Edinburgh, Scotland.


METHODS
Seven hundred seventeen men and women aged 55 to 74 from the general population, followed for 10 years.


METHODS
ABI measured at baseline and major cognitive functions (including premorbid function using the National Adult Reading Test, NART) tested after 10 years.


RESULTS
After adjustment for age and sex, a low ABI was associated with lower scoring (bottom tertile vs top tertile) on Raven's Matrices (odds ratio (OR)=1.6, 95% confidence interval (CI) =1.0-2.6), Verbal Fluency (OR =1.8, 95% CI =1.1-3.0), and Digit Symbol Test (OR =2.3, 95% CI =1.3-4.2), suggesting that the ABI is predictive of poorer performance in nonverbal reasoning, verbal fluency, and information processing speed. The association between ABI and the Digit Symbol Test remained significant after further adjustment for premorbid cognitive function (tested using the NART), suggesting that the ABI is also predictive of decline in information processing speed (from premorbid ability to that measured here in older age).


CONCLUSIONS
The ABI may be useful in identifying older individuals at higher risk of cognitive impairment. In the future, preventive measures developed to target individuals with a low ABI should consider measures to reduce vascular-related cognitive decline as well as cardiovascular events, in an effort to reduce the incidence and consequences of subsequent cognitive impairment and dementia.
Price
Jacqueline F
JF
Wolfson Unit for Prevention of Peripheral Vascular Diseases, Department of Public Health Sciences, Division of Community Health Sciences, University of Edinburgh, Teviot Place Edinburgh, Scotland. Jackie.Price@ed.ac.uk
McDowell
Sarah
S
Whiteman
Martha C
MC
Deary
Ian J
IJ
Stewart
Marlene C
MC
Fowkes
F Gerald R
FG
D000368:Aged; D000842:Ankle / Q000098:blood supply*; D001794:Blood Pressure / Q000502:physiology*; D001916:Brachial Artery / Q000502:physiology*; D003072:Cognition Disorders / Q000209:etiology / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D016491:Peripheral Vascular Diseases / Q000453:epidemiology / Q000503:physiopathology*; D011237:Predictive Value of Tests; D018570:Risk Assessment; D012606:Scotland