Ambulatory Blood Pressure Variability, Progression of Kidney Disease, and Cardiovascular Outcomes in the Chronic Renal Insufficiency Cohort.

BACKGROUND

Patients with chronic kidney disease (CKD) have abnormal blood pressure patterns which may affect 24-hour ambulatory blood pressure variability (ABPV). However, little is known about the association between ABPV and adverse outcomes among those with CKD.

METHODS

Using data from the Chronic Renal Insufficiency Cohort (CRIC) Study, we assessed 24-hour, daytime, and nighttime systolic ABPV using average real-time variability (ARV); the sum of the absolute differences between consecutive blood pressure readings divided by the total number of readings minus one. Cox proportional hazard models were used to evaluate the association of ARV with a 50% reduction in estimated glomerular filtration rate or end-stage kidney disease or adverse cardiovascular (CV) events.

RESULTS

Of 1,502 CRIC participants included in this analysis, 44% were female, and the mean age was 63 ± 10 years. Factors associated with higher tertile of ARV included older age, higher body mass index, higher urine protein-to-creatinine ratio, lower estimated glomerular filtration rate, diabetes, hypertension, dyslipidemia, and atherosclerotic heart disease. In unadjusted models, 24-hour systolic ARV was associated with both adverse kidney outcomes (hazard ratio (HR): 1.16, 95% confidence interval (CI): 1.06-1.27) and CV events (HR: 1.35, 95% CI: 1.22-1.50). In adjusted models that included clinical and sociodemographic factors, 24-hour systolic ARV was not significantly associated with adverse kidney outcomes (HR: 1.02, 95% CI: 0.91-1.14) or CV events (HR: 0.93, 95% CI: 0.84-1.04). Similarly, daytime and nighttime ARV were not significantly associated with kidney and CV events in adjusted analyses.

CONCLUSIONS

In a large cohort of patients with CKD, ABPV was not independently associated with adverse kidney and CV outcomes.