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.