Associations of cognitive impairment and longitudinal change in cognitive function with the risk of stroke events in middle-aged to older Chinese

Background Associations of cognitive impairment and longitudinal change in cognition with the risk of stroke events are unclear in older populations. Method Study data was obtained from the Guangzhou Biobank Cohort Study; 200 participants with a stroke history and an equal volume of participants who were age- and sex-matched, were respectively selected as the cases and the controls; a total of 26,064 participants at baseline and all with fatal stroke in a mean follow-up of 14.3 (standard deviation = 3.2) years, were included in a prospective cohort study. Conditional logistic regression and the Cox proportional hazard regression were used. Results Cognitive impairment was not associated with the risk of nonfatal stroke, with adjusted odd ratio (aOR) = 0.87 (95% confidence intervals (CI) 0.44–1.74, P = 0.70), when median cognition was taken as the reference. Cognitive impairment was respectively associated with an increased risk of fatal all strokes (adjusted hazard ratio (aHR) = 1.38, 95% CI 1.16–1.64, P < 0.001) and fatal ischaemic stroke (aHR = 1.39, 95% CI 1.10–1.77, P = 0.007), compared to median cognition; the Delayed Word Recall Test (DWRT) score was associated with a decreasing trend for the risk of fatal all strokes in a restricted cubic spline analysis; longitudinal DWRT score decline was associated with the increased risks of fatal all strokes (aHR = 1.42, 95% CI 1.11–1.82, P = 0.006) and fatal haemorrhagic stroke (aHR = 1.75, 95% CI 1.10–2.78, P = 0.02), compared to longitudinal DWRT score rise. Conclusions Cognitive impairment and longitudinal change in the DWRT score decline were associated with the increased risks of fatal strokes in middle-aged to older Chinese.