Determinants of aortic pulse wave velocity adjusted for age in peritoneal dialysis patients

Pulse wave velocity (PWV) is a recognised risk factor for mortality and cardiovascular disease in peritoneal dialysis (PD) patients. However, debate continues as to which factors increase PWV. We reviewed the effect of volume overload and calcium balance on PWV.

Aortic PWV (aoPWV) was measured in PD patients attending for routine assessments of peritoneal membrane function, with assessments of extracellular water with bioimpedance and cardiac biomarkers.

A total of 122 patients were included (55.6% male; mean age = 64.8 ± 15.3 years; 36.1% diabetic; median dialysis vintage = 19.5 (7.9-37.3) months; weight = 72.7 ± 16.4 kg; mean aoPWV = 9.9 ± 2.2 m/s). Patients with elevated aoPWV (>2 standard deviations above the age-adjusted mean) were compared to those within the expected range. We found that increased adjusted aoPWV was associated on receiver operator curves (ROC) with younger age (ROC = 0.15, p < 0.001), higher sodium removal (ROC = 0.69, p = 0.002), greater use of hypertonic dialysates (ROC = 0.68, p = 0.04), higher PD ultrafiltration (ROC = 0.68, p = 0.005) and elevated N-terminal probrain natriuretic peptide (NTproBNP; ROC = 0.62, p = 0.38), but with lower residual kidney function (KtVurine; 0.34, p = 0.023). On multivariable analysis, both younger age (OR = 0.90; 95% confidence interval (CI) = 0.86-0.95; p < 0.001) and higher log-transformed NTproBNP (OR = 3.24; 95% CI = 1.05-9.96; p = 0.04) remained independently associated with a raised adjusted aoPWV.

This study demonstrates that, after adjusting for age, elevated aoPWV is associated with an increased NTproBNP, suggesting that volume overload increases arterial stiffness. These results reinforce the importance of improving volume control in PD patients to reduce cardiovascular risk.