Arterial Stiffness, Fatness, and Physical Fitness

Arterial distensibility and its converse stiffness have come of age as physiological concepts1 and now as a target for intervention. The central hypothesis sustained so far is that an individual’s “arterial stiffness” measured as aortic pulse wave velocity (PWV) is a convenient, integrated index of vascular pathology over a person’s life course, more precise and reliable than other risk factors individually. For example, blood pressure (BP), whether casual or 24 hour, is more sensitive to stimuli and, therefore, more variable. Arterial distensibility is in part dependent on BP, yet its prognostic power is because of its “independence” from BP, including pulse pressure.2 It appears to indicate the general burden of atherosclerotic disease and subclinical damage from multiple risk factors over time: the “wear and tear” of constant distension and recoil (part of “aging”), effects of smoking, lipid metabolism, (hyper)glycemia, ethnicity, how family history expresses itself, etc.3 European hypertension guidelines now include PWV as a recommended but optional measure. The relationship of arterial distensibility with cardiac function and structure, known as aorto-ventricular coupling, is tantalizing because, as a bioengineering feedback loop, cause and effect are still unclear. Many other key questions remain, most critically related to the natural history of arterial stiffness but also fundamental ones of basic structural biology in the vessel wall. A clue to the natural history of arterial stiffness is published in this issue of Hypertension , an Australian study of 9- to 10-year-old, generally prepubescent schoolchildren.4 The study shows a clear relationship among degree of body fat, physical fitness, and arterial stiffness, measured by carotid-femoral PWV. The link of PWV with fitness was not independent of body fat. Why should this article be of interest, being only cross-sectional, whereby association may well …