Blood Pressure Variability is Associated With Lower Cognitive Function: An Elderly Cohort Study in Hong Kong

Cognitive impairment is a major geriatric health issue with significant public health burdens. Emerging evidence suggests blood pressure variability (BPV), particularly its dynamic fluctuations, may contribute to cognitive impairment pathogenesis through cerebrovascular damage. This study aims to investigate the prospective association between BPV, and cognitive impairment based on a cohort of community-dwelling older adults from Hong Kong. Based on a prospective cohort study with data collection of regular blood pressure (BP) measurements and health surveys in Hong Kong, participants older than 55 years were included and cognitive function was evaluated with the Montreal Cognitive Assessment. Demographic, social, and disease history information were adjusted. BPV was defined as standard deviation (SD) and categorized as high, medium, and low by a machine learning method. Logistic and quantile regression was conducted to explore the association between cognitive function and BPV. 573 participants with a mean age of 72 years, 96.2% of whom were women, with a mean follow-up of approximately eight months and a mean of 19 BP measurements. After adjustment, higher systolic BPV was associated with an increased risk of MCI (OR: 1.16; 95% CI: 1.03-1.31), but not diastolic BPV. Participants classified as having a high level of BPV showed a 5.6-fold risk for MCI compared with low BPV participants, especially among participants with lower cognitive levels. Higher systolic BPV was independently associated with an increased risk of MCI in older adults. Incorporating BPV assessment into routine monitoring could enhance early detection of cognitive decline in older adult populations.