Association Between Longitudinal Blood Pressure Trajectory and the Progression of Chronic Kidney Disease: Results From the KNOW-CKD

Abstract

Studies on the longitudinal temporal trend of blood pressure (BP) and its impact on kidney function are scarce. Here, we evaluated the association of dynamic changes in systolic blood pressure (SBP) over time with adverse kidney outcomes. We analyzed 1837 participants from the KNOW-CKD (Korean Cohort Study for Outcomes in Patients With Chronic Kidney Disease). The main exposure was 3 distinct SBP trajectories determined by the latent class mixed model (decreasing, stable, and increasing) using 3 SBP measurements at 0, 6, and 12 months. The primary outcome was CKD progression, defined as a composite of halving estimated glomerular filtration rate from baseline value or onset of end-stage kidney disease. SBP declined from 144 to 120 mm Hg in the decreasing SBP trajectory group and rose from 114 to 136 mm Hg in the increasing trajectory group within 1 year. During 6576 person-years of follow-up (median, 3.7 years), the composite outcome occurred in 521 (28.4%) participants. There were fewer primary outcome events in the decreasing (30.6%) and stable (26.5%) SBP trajectory groups than in the increasing trajectory group (33.0%). In the multivariable-adjusted cause-specific hazards model, increasing SBP trajectory was associated with a 1.28-fold higher risk for adverse kidney outcome compared with stable SBP trajectory. However, the risk for the primary outcome did not differ between the decreasing and stable SBP trajectory groups. In this longitudinal CKD cohort study, compared with stable SBP trajectory, increasing SBP trajectory was associated with higher risk for adverse kidney outcome, whereas decreasing SBP trajectory showed similar risk.