Ankle--brachial index predicts level of, but not change in, cognitive function: the Edinburgh Artery Study at the 15-year follow-up.

The ankle-brachial index (ABI), a marker of generalized atherosclerosis, is related to cognitive impairment in older adults. We investigated whether ABI is associated specifically with age-related cognitive decline. We measured ABI at recruitment and 5 and 12 years later in a sample of individuals aged 55-74 years. Cognition was measured in 717 of these participants 10 years after recruitment and 5 years later. It was found that ABI was associated with the level of cognitive function, even after adjustment for estimated premorbid function and concurrently measured anxiety and depression (standardized coefficient of 0.07), but this was attenuated by anxiety and depression. ABI was not associated with change in cognitive function. In conclusion, over long time periods, low ABI may be associated with reduced cognitive function in older adults, at least partly because the associated poor health creates anxiety and depression.