Short-term Blood Pressure Variability and Incident CKD in Patients With Hypertension: Findings From the Cardiovascular and Metabolic Disease Etiology Research Center-High Risk (CMERC-HI) Study

Abstract

Rationale & objective: The association between short-term blood pressure variability (BPV) and kidney outcomes is poorly understood. This study evaluated the association between short-term BPV and kidney disease outcomes in people with hypertension.

Study design: Prospective observational cohort study.

Setting & participants: 1,173 hypertensive participants in the Cardiovascular and Metabolic Disease Etiology Research Center-High Risk (2013-2018) Study with estimated glomerular filtration rate (eGFR) ≥60mL/min/1.73m².

Exposure: Short-term BPV assessed by average real variability (ARV).

Outcome: Composite kidney disease outcome (30% decline in eGFR from baseline, new occurrence of eGFR <60mL/min/1.73m², or onset of UACR >300mg/g).

Analytical approach: Multivariable Cox regression analyses to evaluate the association between systolic and diastolic BP ARV (SBP-ARV and DBP-ARV) and outcomes.

Results: During a median follow-up of 5.4 [4.1-6.5] years, 271 events of the composite kidney disease outcome occurred (46.5 per 1,000 person-years). Multivariable Cox analysis revealed that the highest SBP-ARV and DBP-ARV tertiles were associated with a higher risk of the composite kidney disease outcome than the lowest tertiles, independent of the 24-hour SBP or DBP levels (HR, 1.64 [95% CI, 1.16-2.33], and 1.60 [95% CI, 1.15-2.24] for SBP-ARV and DBP-ARV, respectively). These associations were consistent when SBP-ARV and DBP-ARV were treated as continuous variables (HR per 1.0-unit greater SBP-ARV, 1.03 [95% CI, 1.01-1.06]; HR per 1.0-unit greater DBP-ARV, 1.04 [95% CI, 1.01-1.08]). These associations were consistent, irrespective of subgroups (age, sex, 24-hour SBP or DBP, and moderate albuminuria). However, other measures of short-term BPV including SD, coefficient of variation, and dipping patterns were not associated with the composite kidney disease outcome.

Limitations: Observational study design, the use of single measurement of 24-hour BP, lack of information on changes in antihypertensive medication during the follow-up.

Conclusions: Short-term BPV is associated with the development of a composite kidney disease outcome in hypertensive patients.

Keywords: Albuminuria; ambulatory blood pressure monitoring (ABPM); average real variability (ARV); chronic kidney disease (CKD); diastolic blood pressure (DBP); dipping status; hypertension; incident CKD; renal function; short-term blood pressure variability; systolic blood pressure (SBP).