Blood pressure variability metrics in Chronic Kidney Disease: No association across methods

Patients with chronic kidney disease (CKD) have increased blood pressure variability (BPV) linked to adverse cardiovascular outcomes. Various BPV metrics, capturing distinct temporal BP fluctuations, show prognostic significance, though their interrelationship remains unclear. Objective: To determine whether distinct metrics of BPV are interrelated in patients with CKD. Hypothesis: Metrics of very short-term, short-term, and medium-term BPV may exhibit interrelation, suggesting that short-term BPV could serve as a useful prognosticator in patients with CKD. Methods: Patients with CKD stages 3-4 were included. Very short-term BPV (beat-to-beat) was measured using finger photoplethysmography for 10 minutes while resting in a supine position. Short-term BPV was assessed through 24-hour ambulatory blood pressure monitoring (24-h ABPM), and medium-term BPV was evaluated using the average office blood pressure from six visits (visit-to-visit). BPV was quantified by standard deviation and coefficient of variation for each method. Paired-sample ANOVA was used to compare means across groups, while Pearson and Spearman correlations were applied to assess associations, depending on data distribution. Partial correlations were performed to examine associations after adjusting for relevant covariates. Results: Thirty-eight participants with CKD were included (64 ± 10 years old, 68% males, 58% Black). There was no correlation between the different methods and metrics of BPV estimated by both standard deviation and coefficient of variation, even after adjusting for various covariates, including age, sex, race, comorbidities, BP levels, and antihypertensive medications. Mean BP values were higher in Beat-to-beat BP measures compared to visit-to-visit and 24-h ABPM, both for SBP (p < 0.001) and DBP (p = 0.006). A strong correlation was observed between 24-h ABPM and visit-to-visit BP values (r = 0.631; p < 0.001), and a moderate correlation with beat-to-beat measurements (r = 0.523; p < 0.001). A weak correlation was found between beat-to-beat and visit-to-visit BP values (r = 0.361; p = 0.026). 24-h ABPM BPV was significantly higher than both beat-to-beat (p < 0.001) and visit-to-visit (p < 0.001) BPV. Conclusions: Short-term and medium-term BPV are associated with increased cardiovascular risk in CKD patients, but this relationship has yet to be demonstrated for very short-term BPV. The lack of correlation between BPV metrics may reflect distinct physiological mechanisms that modulate BPV across different time scales, such as baroreceptor sensitivity, vascular transduction, and endothelial function. Additionally, patient-dependent factors, including medications and comorbidities, may differentially influence each BPV metric. These findings suggest that different BPV metrics capture distinct aspects of BP regulation and are not interchangeable. Further studies are needed to determine the cardiovascular risk associated with high very short-term BPV. Disclosure of funding sources: NIH Grants R33AT010457, R01HL135183. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.