Age dependence of brachial cuff-based ambulatory PWV in end-stage kidney disease patients undergoing long-term peritoneal dialysis.

BACKGROUND The newly introduced device Mobil-O-Graph (IEM, Stolberg, Germany) combines brachial cuff oscillometry and pulse wave analysis, enabling the determination of pulse wave velocity (PWV) via complex mathematic algorithms during 24-h ambulatory blood pressure monitoring (ABPM). However, the determinants of oscillometric PWV in the end-stage kidney disease (ESKD) population remain poorly understood. METHODS In this study, 81 ESKD patients undergoing long-term peritoneal dialysis underwent 24-h ABPM with the Mobil-O-Graph device. The association of 24-h oscillometric PWV with several demographic, clinical and haemodynamic parameters was explored using linear regression analysis. RESULTS In univariate analysis, among 21 risk factors, 24-h PWV exhibited a positive relationship with age, body mass index, overhydration assessed via bioimpedance spectroscopy, diabetic status, history of dyslipidaemia and coronary heart disease, and it had a negative relationship with female sex and 24-h heart rate. In stepwise multivariate analysis, age (β: 0.883), 24-h systolic blood pressure (BP) (β: 0.217) and 24-h heart rate (β: -0.083) were the only three factors that remained as independent determinants of 24-h PWV (adjusted R2 = 0.929). These associations were not modified when all 21 risk factors were analysed conjointly or when the model included only variables shown to be significant in univariate comparisons. CONCLUSION The present study shows that age together with simultaneously assessed oscillometric BP and heart rate are the major determinants of Mobil-O-Graph-derived PWV, explaining >90% of the total variation of this marker. This age dependence of oscillometric PWV limits the validity of this marker to detect the premature vascular ageing, a unique characteristic of vascular remodelling in ESKD.