Abstract
RATIONALE & OBJECTIVE: Chronic kidney disease (CKD) is associated with a high risk of cardiovascular events. However, the role of diastolic blood pressure variability (DBPV) in predicting these outcomes, particularly in comparison to systolic blood pressure variability (SBPV), remains unclear. This study aimed to assess the prognostic value of DBPV in patients with CKD. STUDY DESIGN: A retrospective cohort study was conducted. SETTING & PARTICIPANTS: A total of 1,245 adults diagnosed with CKD (stages G3a, G3b, and G4-5) from the Seventh Affiliated Hospital of Sun Yat-sen University from 2019 to 2023 were included in the study. EXPOSURES: DBPV parameters, including 24-hour DBP standard deviation (SD), coefficient of variation, and nocturnal decline rate, were measured using 24-hour ambulatory blood pressure monitoring. OUTCOMES: The primary outcome was all-cause mortality. Secondary outcomes included cardiovascular death and heart failure hospitalization. ANALYTICAL APPROACH: Cox proportional hazards models were used to analyze the associations, adjusting for multiple confounding factors, such as SBP, SBPV, and traditional cardiovascular risk factors. Interaction analyses were performed by CKD stage. The incremental predictive value of DBPV was evaluated using integrated discrimination improvement and net reclassification improvement. RESULTS: During a median follow-up of 3.2 years, higher 24-hour DBP SD was independently associated with an increased risk of all-cause mortality (hazard ratio [HR], 1.08; 95% CI, 1.03-1.13; P = 0.002) and cardiovascular death (HR 1.11; 95% CI, 1.05-1.18; P < 0.001). A nondipping DBP pattern was associated with an increased risk of heart failure hospitalization (HR 1.42; 95% CI, 1.07-1.89; P = 0.02). These associations were more pronounced in patients with stage G4-5 CKD (eg, for all-cause mortality: HR 1.15; 95% CI, 1.08-1.23; P < 0.001). DBPV provided incremental prognostic value beyond SBPV (for cardiovascular death, integrated discrimination improvement = 0.023; P = 0.004). LIMITATIONS: The study had a single-center design, lacked non-CKD and stage 1-2 CKD controls, and did not have longitudinal DBPV data. CONCLUSIONS: DBPV independently predicts adverse cardiovascular outcomes in patients with CKD, with stronger associations in advanced stages. It adds incremental value to SBPV in predicting cardiovascular events in this high-risk population.