Carotid atherosclerosis promotes the progression of Alzheimer's disease: A three-year prospective study

Although cerebrovascular diseases have been considered as risk factors for cognitive decline and dementia, the associations between atherosclerosis and Alzheimer's disease (AD) have not been fully examined and remain controversial. The aim of this three-year prospective study was to investigate whether arotid artery atherosclerosis accelerates cognitive impairment in AD patients. The association of carotid intimal medial thickness (IMT) with prospective trajectories of cognitive function was assessed among 521 patients with light to moderate AD, and 437 AD patients were followed up annually for 3 years. Participants underwent initial carotid ultrasonography and repeated neuropsychological testing every year. Mixed-effects regression analyses were adjusted to estimate the effect of carotid IMT and other adjusting variables. The results of the present study indicated that carotid IMT was significantly associated with various measures of cognitive function. Furthermore, AD patients with higher carotid IMT values had a faster decline in cognitive scores in a variety of neuropsychological tests, particularly in verbal and non-verbal memory, semantic fluency and executive function. The present prospective study showed that carotid atherosclerosis is a predictive factor regarding the progression of cognitive impairment in AD patients, suggesting that early detection and treatment of vascular risk factors may prevent or at least postpone the evolution of the disease.