Blood Pressure Variability and Progression of Clinical Alzheimer Disease

Abstract

Blood pressure variability (BPV) has been shown to have predictive value over blood pressure (BP) levels alone in stroke patients. We assessed whether BPV predicts cognitive and functional decline in Alzheimer disease, using data from a randomized trial (NILVAD [A European Multicentre Double-blind Placebo-controlled Phase III Trial of Nilvadipine in Mild to Moderate Alzheimer's Disease]). Patients with mild-to-moderate Alzheimer disease were included if they had ≥3 office BP measurements available to determine visit-to-visit BPV. Day-to-day BPV was assessed using home BP measurements in a subsample. The variation independent of mean was used to calculate BPV. Outcomes were change in Alzheimer's Disease Assessment Scale-cognitive subscale-12 and Disability Assessment for Dementia after 1 and 1.5 years. A total of 460 patients aged 72.1 (SD=8.1) years, with mean BP of 134.0/75.1 (10.9/6.3) mm Hg were included. After 1 year, patients in the highest quartile of BPV had deteriorated more on Alzheimer's Disease Assessment Scale-cognitive subscale compared with patients in the lowest quartile (systolic: β, 2.24 [95% CI, 0.11-4.38], P=0.040; diastolic: β, 2.54 [95% CI, 0.33-4.75] P=0.024). This association was still present after 1.5 years (systolic: β, 2.86 [95% CI, 0.35-5.36], P=0.026; diastolic: β, 3.30 [95% CI, 0.67-5.93], P=0.014). There was no effect of visit-to-visit BPV on Disability Assessment for Dementia. Day-to-day BPV was available for 46 patients. Significant associations were observed between day-to-day BPV and deterioration on Alzheimer's Disease Assessment Scale-cognitive subscale (systolic: P=0.036) and Disability Assessment for Dementia (systolic: P=0.020; diastolic: P=0.007) after 1 year, but not after 1.5 years. All associations were adjusted for potential confounders, including intervention group. In conclusion, this post hoc analysis indicates that higher visit-to-visit and day-to-day BPV might be associated with progression of Alzheimer disease. Targeting BPV may be a future target to slow decline in patients with Alzheimer disease. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT02017340.

Keywords: Alzheimer disease; activities of daily living; blood pressure; cognition; hypertension.