Peripheral arterial disease and cognitive function.

As a marker of generalized atherosclerosis, peripheral arterial disease (PAD) has implications not only for the affected lower extremity but also to overall cardiovascular health. It confers an increased risk of non-fatal and fatal vascular events which increases with the severity of the disease. Patient-based studies have shown that individuals with advanced PAD tend to perform poorly on cognitive tests compared to controls. In population studies, PAD is associated with an increased cognitive decline independently of previous cerebrovascular disease and cardiovascular risk factors. A low ankle-brachial index (ABI) may be an early predictor of cognitive decline and of potential value in identifying individuals at increased risk of cognitive impairment. In patients with PAD, secondary preventive measures directed at decreasing the long-term systemic vascular complications may also be important to the preservation of cognitive health. However, evidence suggests that PAD patients may be undertreated with regard to atherosclerotic risk factors, as demonstrated by an undue emphasis on symptom relief rather than essential risk factor reduction. More research needs to be carried out to determine the predictors of cognitive function in PAD patients, whether subtle cognitive disturbances are related to activities of daily living, including medical treatment compliance, and whether neuroprotective strategies and atherosclerotic risk factor control positively influence cognitive function in these high-risk patients.