Smoking, hypercholesterolaemia and hypertension as risk factors for cognitive impairment in older adults.

BACKGROUND

the prevalence of all types of cognitive impairment, including dementia, is increasing but knowledge of aetiological factors is still evolving.

OBJECTIVE

this study aimed to evaluate the association between cardiovascular risk factors and cognitive function in older persons.

DESIGN, SETTING AND SUBJECTS: a population-based cohort design involving 2,312 men and women (aged 50-75) enrolled in the University of Edinburgh Aspirin for Asymptomatic Atherosclerosis trial.

METHODS

cognitive tests included the Mill Hill Vocabulary Scale, auditory verbal learning test (AVLT), digit symbol test, verbal fluency test (VFT), Raven's Progressive Matrices and the trail making test. A 'g' score (measure of general intelligence) was computed for each subject. Regression analysis was used to evaluate the association between relevant variables.

RESULTS

higher diastolic BP was negatively associated with AVLT (β = -0.153, P < 0.01), and with an estimated decline on AVLT (β = -0.125, P < 0.01). Smoking was negatively associated with all the cognitive variables except VFT. The total cholesterol level was not associated with cognitive function or estimated decline.

CONCLUSIONS

smoking and elevated blood pressure may be risk factors for cognitive decline, and thus potential targets for preventive and therapeutic interventions.