Carotid atherosclerosis and cognitive function in midlife: The beaver dam offspring study

Background: Atherosclerosis may be associated with cognitive function; however the studies are few, especially among midlife adults. Methods: Participants in the beaver dam offspring study who had cognitive test data and gradable carotid artery ultrasound scans were included (n= 2794, mean age: 49 years). Atherosclerosis was measured by carotid intima-media thickness (IMT) and the presence of plaque. Cognitive function was measured by the trail making test (TMT), grooved pegboard test (GPT) and mini-mental state examination (MMSE). Generalized cognitive function was defined by a summary score calculated from the TMT and GPT. Linear regression was used to evaluate the associations between carotid atherosclerosis and cognitive function tests. Results: Larger IMT was associated with lower GPT, MMSE and the summary score adjusting for multiple factors, the coefficients were: 13.8s (p< 0.0001), -0.6 (p= 0.007), and 0.47 (p= 0.01), respectively for 1. mm increase in IMT. Plaque scores were significantly associated with TMT-B, GPT, MMSE, and the summary score adjusting for age, sex and education. The associations remained statistically significant after further adjustments except for the association with TMT-B, which was attenuated and no longer significant. Conclusions: Our results show the significant associations between markers of carotid atherosclerosis and cognitive function in a cohort of persons aged 21-84 years. Longitudinal studies are needed to further examine these associations.