Commentary on the Youth Vascular Consortium's 'Expert consensus documents'.

Two major articles in the Journal review childhood arterial function, one the literature, the other methodology complemented by another elsewhere, with a different method focus and presents reference values. Studies of pulse wave velocity (PWV) measured in young children followed into adulthood are just emerging. Like blood pressure (BP), PWV, the index of stiffening, tracks as it rises over time. The carotid arteries are useful indicators, but the vital measurement pathway is from the heart to the descending, distensible aorta's bifurcation. Doppler methods do that well but are too slow to detect real change over time. Tonometry is widely used, requiring two probes for the transit time but is hampered by lack of simultaneous BP recording and few childhood studies calibrating measured or height-adjusted length against magnetic resonance measures. Length errors are compounded in repeat studies by differing probe positions. Cuff-based methods allow 24-h recordings and much wider clinical use; their potential 'imprecision' alienates engineers but are calibrated. Intervention studies as randomized trials in children, adolescents, and young adults can overcome these issues; there are huge preventive opportunities to show the public. Children at school are likely to grasp the notion of how the heart connects to its major blood vessel, what stiffening means, why that is troublesome - and how to keep vessels healthier. Try re-measuring PWV after running, upstairs, or on the flat!