Aim: Measurement of blood pressure together with applanation tonometry at the radial artery allows the reproducible assessment of various indexes of arterial stiffness, including the peripheral (PPp) and central (PPc) pulse pressures and the peripheral (AIp) and central (AIp) augmentation indexes. We defined preliminary diagnostic thresholds, using the distributional characteristics of these haemodynamic measurements in a reference population.

Methods: We randomly recruited 870 subjects from 3 European populations. PPp was the average difference between systolic and diastolic BP measured five times. For measurement of PPc, AIp and AIc, we used the SphygmoCor device. We selected subjects without hypertension, diabetes, dyslipidemia or previous and concomitant cardiovascular disease.

Results: Study population included 228 men and 306 women (mean age 34.9 years). All haemodynamic measurements were curvilinearly related to age and AIp and AIc were lower in men than in women. In men at age 40, the upper 95% prediction bands of the relations of the haemodynamic measurements with age approximated to 60 mmHg for PPp, 40 mmHg for PPc, 90% for AIp, and 30% for AIc. For PPc, AIp and AIc, these thresholds must be adjusted for age, leading to more lower and higher thresholds at younger and older age, respectively. In addition, in women of any age, the AIp and AIc thresholds must be increased by 10% and 7%, respectively.

Conclusion: Pending validation in prospective outcome studies, distributional characteristics of arterial stiffness indexes in a reference population can be used to generate operational thresholds for use in clinical practice.