Blood Pressure Variability in Older Patients with Chronic Kidney Disease.

Abstract

Background: An increased blood pressure variability (BPV) is associated with a high risk of cardiovascular events in the general population. This concept was scarcely tested in patients with chronic kidney disease (CKD). We investigated the behavior of BPV parameters in a large cohort of older patients with CKD.

Methods: This retrospective cohort study included patients ≥75 years old with eGFR ≤60 mL/min. Three systolic and diastolic consecutive blood pressure (BP) measurements were obtained automatically per visit (short term - 3 consecutive measurements) and across visits (long term - across visits). We calculated (1) standard deviation (SD); (2) coefficient of variation (SD divided by the BP average); and (3) variability independent of the mean (VIM). For each BPV parameter, patients were divided into quartiles.

Results: We included 1,063 patients (17,363 measurements). For short BPV, the higher systolic BPV (SD and VIM) was associated with older age, a lower proportion of males, and a higher proportion of patients with pulse pressure (PP) >40 mm Hg. Higher diastolic BPV (SD and VIM) was associated with lower body mass index, lower eGFR, and a higher proportion of PP >40 mm Hg (for SD). Bland-Altman plots revealed comparable results between short- and long-term BPV.

Conclusion: A higher BPV was associated with reduced renal function in older patients with CKD. Our study also suggests that short- and long-term BPV can be used with similar results. Further studies are needed to confirm the association between BPV and outcomes and understand the physiological mechanisms underlying this correlation.