Association between visit-to-visit blood pressure variability and risks of dementia in CKD patients: A nationwide observational cohort study

Abstract

Background: The association between visit-to-visit blood pressure (BP) variability and dementia risk in chronic kidney disease (CKD) patients has rarely been studied. Methods: In this retrospective observational study, individuals who received three or more general health screenings were identified in the nationwide database of Korea. Those with persistent non-dialysis-dependent CKD [estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 or dipstick albuminuria ≥1+] were included. The study exposure was systolic or diastolic BP variability, calculated as the variation independent of the mean and categorized into quartiles (Q4: The highest quartile; Q1: The lowest quartile). The risks of all-cause dementia, including Alzheimer's disease and vascular dementia, were analyzed by Cox regression adjusted for various clinical characteristics, including baseline BP and eGFR values. Results: We included 103 139 CKD patients and identified 7574 (7%) dementia events, including 5911 (6%) Alzheimer's disease cases, 886 (1%) vascular dementia events and 777 (1%) cases categorized as other types of dementia. Higher systolic BP variability was significantly associated with higher risks of all-cause dementia {[Q4 versus Q1], hazard ratio [HR] 1.173 [95% confidence interval (CI) 1.102-1.249], P for trend