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 BP variability and dementia risk in chronic kidney disease (CKD) patients has rarely been studied. Methods In this retrospective observational study, individuals who received ≥3 general health screenings were identified in the nationwide database of Korea. Those with persistent non-dialysis dependent CKD (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: highest quartile, Q1: 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 vs. Q1), HR 1.173 (1.102,1.249), P (for trend) <0.001]. The results were also significant for the risk of Alzheimer's disease [HR 1.162 (1.083,1.248), P < .001] and vascular dementia [HR 1.282 (1.064,1.545), P = .039]. The results were similar when diastolic BP variability was the exposure, as high diastolic BP variability was significantly associated with higher risks of all-cause dementia [HR 1.191 (1.117,1.270), P < .001]. Conclusion Higher variabilities in visit-to-visit BP variability are significantly associated with a higher risk of dementia in CKD patients.

Visit-to-visit blood pressure variability and risk of dementia in chronic kidney disease patients: why are blood pressure changes so important in cognitive functions?

“…Park et al . [ 1 ] conducted an observational cohort study of 103 139 patients to investigate the association between visit-to-visit blood pressure (BP) variability and the risk of dementia in patients with chronic kidney disease (CKD). While BP variability is related to dementia in the general population, this study analyzed the association between BP variability and dementia in CKD patients.…”

“…Park et al . [ 1 ] conducted a large-scale, multicenter study with multiple BP measurements and multiple variables to better assess the relationship between BP variability and dementia in 103 139 CKD patients among 11 651 753 people who underwent three or more screenings. All-cause dementia was more common in patients with higher visit-to-visit systolic BP variability [quartile (Q)1: 17.4; Q2: 17.6; Q3: 18.6 and Q4: 24.3 per 1000 person-years)] and this was also the case for Alzheimer's and vascular dementia as individual entities (Figure 1 A and B ).…”

“… ( A ) Association between BP variability and incidence of dementia in CKD patients. ( B ) Incidence rates of dementia according to dementia types and systolic BP variability [ 1 ]. …”

“…They also confirmed that the risk of dementia was higher in patients with CKD, defined as eGFR <60 mL/min/1.73 m 2 , in line with the current literature [ 13 ]. However, higher visit-to-visit BP variability was observed in patients who were more sedentary, currently smoking or patients with diabetes mellitus and hypertension, which may confound or magnify the effect of BP variability [ 1 ].…”

“…The study by Park et al . [ 1 ] has some limitations. The prevalence of CKD among the source population was lower than reported previously for general populations.…”