Correlation between blood pressure variability and cognitive impairment in patients with acute ischemic stroke

Abstract

Objective To investigate the correlation between blood pressure variability and cognitive impairment in ischemic stroke. Methods The inpatients with acute ischemic stroke were enrolled. The demographic and clinical data were collected. The coefficient of variation of blood pressure within 7 days after onset was calculated. Montreal Cognitive Assessment was used to evaluate the cognitive function at three month after onset. Multivariate logistic regression analysis was used to identify the relationship between the coefficient of variation of blood pressure within 7 days and the cognitive impairment at 3 months after onset. Results A total of 708 patients with acute ischemic stroke were enrolled in the study. At 3-month follow-up, 510 patients (72.0%) had cognitive impairment and 198 (28.0%) had normal cognitive function. The coefficient of variation for systolic blood pressure (8.3±1.2 vs. 8.7±1.4; t=-3.299, P=0.001) and coefficient of variation for diastolic blood pressure (7.8± 1.3 vs. 8.0± 1.5; t=-2.529, P=0.012) in the cognitive impairment group were significantly higher than those in the normal cognitive function group. With the first quintile as a reference, after adjusting other confounding factors, multivariate logistic regression analysis showed that cognitive impairment at 3 months after onset was significantly associated with coefficient of variation for systolic blood pressure. The odds ratios and 95% confidence intervals for the 2-5 quantile groups were 2.33 (1.18-4.6), 2.31 (1.15-4.66), 2.70 (1.29-5.65), and 4.82 (1.92-12.1), respectively (all P<0.05). Conclusion Systolic blood pressure variability in the acute phase of ischemic stroke is associated with cognitive impairment. Key words: Stroke; Brain Ischemia; Hypertension; Blood Pressure; Cognition Disorders; Neuropsychological Tests; Risk Factors