# Aortic Pulse Wave Velocity and Extracellular Water Expansion in Hemodialysis Patients

## TL;DR

The study finds that higher extracellular water in hemodialysis patients is linked to increased arterial stiffness, suggesting better volume control could reduce cardiovascular risk.

## Contribution

The study provides new evidence linking extracellular water expansion to arterial stiffness in hemodialysis patients using bioimpedance measurements.

## Key findings

- Higher extracellular water/total body water ratio is independently associated with increased aortic pulse wave velocity.
- Volume overload, as measured by bioimpedance, correlates with arterial stiffness in hemodialysis patients.
- Age-adjusted analysis confirms the independent association between extracellular water and arterial stiffness.

## Abstract

Pulse wave velocity (PWV), a measurement of arterial stiffness, is a risk factor for cardiovascular mortality in hemodialysis patients. Debate continues as to whether PWV is increased by volume overload. As such, we reviewed the association between volume overload and PWV.

We measured aortic PWV (aPWV) in hemodialysis patients attending routine dialysis sessions with contemporaneous measurements of extracellular water/total body water (ECW/TBW) ratios using multifrequency bioimpedance.

A total of 102 patients, 63.7% male, mean age 63.5 ± 15.9 years, 44.1% diabetic, median dialysis duration 22.2 (4.9–52.8) months, weight 73.7 ± 15.8 kg, and central systolic blood pressure 157 ± 35 mmHg had a mean aPWV of 10.1 ± 2.5 m/s. Patients dialyzed with a low dialysate calcium (median 1.0 [1.0–1.25] mmol/L). Patients with aPWV of ≥ 10 m/s were older (72.9 ± 10.3 vs. 52.6 ± 14.4 years, p < 0.01) with a higher ECW/TBW ratio (40.6 ± 1.3 vs. 39.6 ± 1.7, p < 0.001), with no differences in active vitamin D3 or calcium‐containing medications. Aortic PWV was associated with age (r = 0.9, p < 0.001) and ECW/TBW (r = 0.33, p = < 0.001), and after adjusting aPWV for age, ECW/TBW remained higher (40.5 ± 1.5 vs. 39.5 ± 1.5, p < 0.001). On multivariable testing, ECW/TBW remained independently associated with a raised aPWV (odds ratio [OR] 1.59 (95% confidence intervals [CI] 1.06–2.41), p = 0.026), and after age adjustment (OR 1.74 (95% CI 1.19–2.53, p = 0.004)).

This study highlights the association between volume overload, as determined by bioimpedance in hemodialysis patients, and arterial stiffness measured by aPWV. These results would reinforce the importance of improving volume control in hemodialysis patients to reduce cardiovascular risk.