Impaired cognitive performance in asymptomatic peripheral arterial disease: relation to C-reactive protein and D-dimer levels

Background and purpose: asymptomatic peripheral arterial disease (APAD), a highly prevalent condition in the general older population, is associated with an increased risk of cerebrovascular events because of co-existing clinical or subclinical cerebral atherosclerosis. The purpose of this study was to investigate whether cognitive function is impaired in stroke- and transient ischaemic attack-free patients with APAD, and whether inflammatory and haemostatic markers are associated independently with neuropsychological performance. Methods: cognitive performances of 164 well-functioning, community-dwelling patients with APAD were compared with those of 164 age-, gender- and education-matched healthy control subjects on six neuropsychological tests. Levels of C-reactive protein (CRP), D-dimer and fibrinogen were also analysed in all participants. Results: patients with APAD scored significantly worse (P < 0.0001) than control subjects on five cognitive tests assessing domains of verbal working memory, attention, perceptuomotor speed, mental flexibility, visuoconstructive skills and visual memory. Multiple linear regression analyses showed that CRP and D-dimer were significant, independent predictors of poorer performances on four and three cognitive tests, respectively, within patients with APAD. Conclusions: patients with APAD show cognitive impairment in a range of psychometric tests, and CRP and D-dimer appear to be independent negative predictors of some cognitive performances. These findings suggest the need for screening for APAD among at-risk subjects in order to identify patients to be treated for prevention of functional decline and dementia. They also support the hypothesis that inflammation and hypercoagulability are implicated in the pathophysiology of cognitive dysfunction associated with APAD.