Vp 1000 plus system

Aortic stiffness was assessed as cfPWV using the VP‐1000 plus system (Omron Co, Ltd, Kyoto, Japan). Participants were required to fast for 8 hours, refrain from smoking, beverages with caffeine, and vigorous physical activity in the morning of the examination day, and bring all prescription and nonprescription medications taken within 2 weeks before the day of the examination visit.28 The measurement of cfPWV was conducted after participants were supine for approximately 10 minutes.29 The cfPWV was calculated using the following formula: path length (cm) = [carotid‐femoral distance (cm)–(suprasternal notch–carotid distance (cm))]/transit time. Compared with other path length measurements (eg, suprasternal notch‐to‐femoral distance minus suprasternal notch‐to‐carotid distance; and carotid‐to‐femoral distance), this formula shows a similar correlation with cardiovascular events.30 A minimum of 2 PWV measurements were taken, and the last 2 usable measurements (ie, nonzero values) were averaged. Repeated visits conducted among a subset of participants at each field center approximately 4 to 8 weeks apart (n=79; mean age, 75.7 years; 46 women) yielded an intraclass correlation coefficient and 95% CI for single measurements of 0.70 (0.59–0.81) for cfPWV and approximately 0.82 for averaged cfPWV measurements, according to the Spearman‐Brown formula.28