Blood Pressure Variability and Frailty in End-Stage Kidney Disease.

Abstract

Background: High blood pressure variability (BPV) is a predictor of cardiovascular events and all-cause mortality in people with end-stage kidney disease (ESKD) and a marker of aging in geriatric populations. Nevertheless, the relationship between BPV and geriatric syndromes, such as frailty, in people with ESKD is not well understood.

Objective: To examine the association between very short-term BPV and frailty in people with ESKD and receiving hemodialysis.

Design: Cross-sectional study.

Setting: Three dialysis units in the United Kingdom.

Participants: Sixty-nine people receiving hemodialysis (median age=62.0 years, interquartile range [IQR]=19.0; 52.2% male; median dialysis vintage=1.1 years, IQR=2.4).

Measurements: Systolic and diastolic BPV were recorded using continuous, non-invasive BP monitoring (Task Force Monitor). The very low, low, and high frequency components of BPV (VLF-BPV, LF-BPV, and HF-BPV), as well as the power spectral density (PSD-BPV) and low frequency/high frequency ratio of BPV (LF/HF-BPV) were analyzed. Frailty was evaluated using the Fried frailty phenotype.

Results: Twenty-six (37.7%) participants were classified as frail and 43 (62.3%) as non-frail. Frail participants had higher median systolic (2.1, IQR=5.2 mmHg2 vs. 1.1, IQR=1.6 mmHg2, p=0.002) and diastolic HF-BPV (0.9, IQR=2.3 mmHg2 vs. 0.5, IQR=1.0 mmHg2, p=0.048) compared to their non-frail counterparts. In addition, frail participants had higher median systolic VLF-BPV (3.2, IQR=12.5 mmHg2 vs. 2.0, IQR=2.4 mmHg2, p=0.012), LF-BPV (2.0, IQR=3.8 mmHg2 vs. 1.1, IQR=2.0 mmHg2, p=0.016), and PSD-BPV (6.6, IQR=27.6 mmHg2 vs. 4.5, IQR=5.9 mmHg2, p=0.005) compared to the non-frail participants. In age- and sex-adjusted logistic regression analyses, only systolic VLF-BPV (odds ratio [OR]=1.13, 95% confidence interval [CI]:1.01-1.26, p=0.035), HF-BPV (OR=1.26, 95%CI:1.01-1.57, p=0.044), and PSD-BPV (OR=1.06, 95%CI:1.01-1.12, p=0.029) were associated with increased odds of being frail.

Conclusion: Higher systolic BPV is associated with frailty in people receiving hemodialysis. Beat-to-beat assessments of BPV through continuous, non-invasive BP monitoring may be useful in evaluating frailty in ESKD populations.