Introduction: Aortic pulse wave velocity (PWV) independently predicts end-organ damage and mortality. However, these relationships have only been assessed at rest. Considering light exercise (‘ambulatory’) conditions better represent chronic BP exposure, we developed a technique to approximate ambulatory aortic PWV (AaPWV). This study aimed to determine the reproducibility of the technique and relation of AaPWV to end-organ damage.

Methods: Carefully screened healthy younger (n=17, 30±8 years) and older (n=18, 54±8 years) untreated men underwent comprehensive cardiovascular assessment at rest and whilst ‘ambulatory’ (during low intensity semi-recumbent cycling). Applanation tonometry was used to assess AaPWV (carotid-to-femoral arterial sites) and central BP. All participants underwent 24-hour ambulatory BP (24-ABP). Kidney function was assessed by estimated glomerular filtration rate (eGFR). Fifteen participants had testing repeated within 30±19 days.

Results: AaPWV had excellent reproducibility (mean difference=−0.35±0.61 m/s, ICC=0.874, p<0.001). For all participants, AaPWV was 23±17% higher than resting aortic PWV (6.0±1.0 vs. 7.4±1.2 m/s, p<0.001). In younger men, eGFR (114±23 ml/min/1.73 m²) was not correlated to resting aortic PWV (r=−0.031, p=0.906) or AaPWV (r=−0.117, p=0.655). Similarly, in older men, eGFR (105±12 ml/min/1.73 m²) was not related to resting aortic PWV (r=−0.400, p=0.100). However, AaPWV was significantly correlated with eGFR on univariate analysis in older men (see figure, r=−0.633, p=0.005), and this was maintained after correction for age, BMI and 24-ABP (β=−0.606, p=0.017).

Conclusions: AaPWV is highly reproducible and independently associated with kidney function in apparently healthy older men. Further studies to determine the physiology and clinical relevance of raised AaPWV are warranted.