Blood pressure variability predicts cognitive decline in Alzheimer's disease patients.

The aim of our study was to evaluate whether blood pressure variability influences the rate of cognitive decline in Alzheimer's disease (AD). Two hundred and forty AD patients were periodically evaluated for a 12-month period. The blood pressure (BP) status of each patient was defined through mean and coefficient of variation for both systolic and diastolic BP. Progression of cognitive decline was investigated using the Mini Mental State Examination administered at entry and at the end of follow-up. Among the considered BP indices, only systolic BP variability explained the decrease in the Mini Mental State Examination score after adjustment for confounding variables (multiple linear regression: R(2) = 0.603, adjusted R(2) = 0.513; p < 0.001; logistic regression model: odds ratio = 2.882, 95% confidence interval = 1.772-4.495; p < 0.001). The receiver operating characteristic analysis for evaluating the ability of systolic BP variability to predict a faster cognitive decline presented an area under the curve of 0.913 (95% confidence interval = 0.874-0.953; p < 0.001). Our results suggest that BP variability may be added to the list of the potential vascular risk factors and included in the evaluation of AD patients to better define their risk profile.