The circadian rhythm of arterial blood pressure in Alzheimer disease (AD) patients without hypertension

Abstract

Objectives. The circadian rhythm (CR) of arterial blood pressure (ABP) in Alzheimer disease (AD) patients was examined in a case–control clinical study. Methods. This study was constructed using the case–control method and investigates non-hypertensive AD patients, compared with normotensive controls from a primary care setting. Twenty-four-hour ABP was measured with an automatic oscillometric device and recorded every 30 min throughout the day and night. Extreme dipper, dipper, non-dipper and reverse-dipper patterns were defined as those individuals with > 20%, 10–20%, < 10% and no fall in nocturnal ABP relative to daytime values. Results. There were significant differences in ABP dipper status between cases and controls (cases – 16.15%, 60.00%, 17.70% and 6.15% vs controls – 3.19%, 31.9 2%, 42.02% and 22.88% for reverse dipper, non-dipper, dipper and extreme dipper, respectively, df = 3, χ2 = 56.76, p < 0.001). Compared with normal controls, AD patients had significantly higher 24-h mean blood pressure, 24-h mean systolic blood pressure (SBP), night mean SBP, night mean pulse pressure (PP) and 24-h mean PP. There were no significant differences in 24-h mean diastolic blood pressure (DBP), daytime mean DBP or night-time mean DBP, and no significant differences in daytime mean SBP. Conclusions. The circadian rhythm of ABP in AD patents differed from normal controls, perhaps from higher night SBP in AD patents.