Ambulatory Blood Pressure Characteristics of Patients with Alzheimer's Disease: A Multicenter Study from China

Background: Previous studies revealed that abnormal blood pressure (BP) plays an important role in the pathogenesis of Alzheimer's disease (AD). However, little is known about the ambulatory BP characteristics of AD in the mild or severe stage. Objective: We explored the ambulatory BP characteristics of AD in the mild or severe stage. Methods: In the present study, 106 AD patients (42.5% male, average age 81.6 years) were enrolled from three centers in China. Clinal BP measurements at the supine and standing positions, neurological evaluations, and the 24 h ambulatory BP monitoring were performed. Results: In the 106 AD patients, 49.2%, 36.8%, and 70% of patients had 24 h, daytime, and nighttime systolic hypertension, respectively, while 19.8%, 29.2%, and 5.7% had 24 h, daytime, and nighttime diastolic hypotension. The prevalence of the reduced and reverse dipping pattern was 34.0% and 48.1% for systolic BP and 32.1% and 45.3% for diastolic BP, respectively. The daytime diastolic BP was significantly correlated with cognitive performance. After adjustment for age, sex, and body mass index, only daytime diastolic BP was associated with remarkable cognitive deterioration (p <= 0.008). Further, AD patients in the severe stage had significantly lower levels of the 24 h, daytime, and nighttime diastolic BP, compared with those in the mild stage. Conclusion: In general, AD patients were featured with high nighttime systolic BP, low daytime diastolic BP, and abnormal circadian BP rhythm of reduced and reverse dipping. The diastolic BP, especially daytime diastolic BP, was adversely correlated with the cognitive deterioration in AD.