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, χ(2) = 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.