The effect of age on vascular compliance in man: which are the appropriate measures?

Vascular compliance declines rapidly with age and measures of arterial compliance may help understanding of the aging process. Of the different measures of vascular compliance, those more closely related to chronological age need to be identified. These measures may help in the estimation of 'biological age'. We measured pulse wave velocity as the carotid-finger interval, carotid-toe interval and QKD interval (time between the Q wave and the arrival of the diastolic Korotkoff sound (K) over the brachial artery in diastoly (D)); central aortic compliance (CAC) and SV/PP (the stroke volume divided by pulse pressure in the brachial artery). Thirty-six volunteers were studied (30 men), ages 20 to 84, mean 49 years, to give the relationship of these measurements with age. CAC, the QKD interval and the carotid-toe interval were most closely related to age (r = -0.51, -0.60 and -0.58 respectively), After adjustment for age, the only measure related to brood pressure was the carotid-finger interval; b for diastolic blood pressure = -0.83 (P = 0.01), the higher the pressure the shorter the interval. Measurements of CAC, QKD interval and carotid-toe interval may be employed to assess the impact of age on vascular compliance. Measures of peripheral vascular compliance, such as the carotid-finger interval, may prove useful in assessing the relationship between blood pressure and vascular compliance.