Effects of aging on blood flow volumes, velocities, mean vessel diameters, and vessel elasticities of the common carotid artery in healthy volunteers

A longitudinal study

Abstract

We examined the effects of age on the blood flow volumes, blood flow velocities, mean vessel diameters, and vessel elasticities in common carotid arteries using a quantitative ultrasonic measurement system. This device consisted of an improved ultrasonic Doppler velocimeter and an echotracking system controlled by a microprocessor (QFM-2000XA, NIHON KOHDEN), which were used to measure the vessel diameter and wall motion. The subjects comprised 37 healthy volunteers (19 males and 18 females, mean age = 50.5 years, range= 44 to 79 years, in 1995) without hypertension, diabetes mellitus or hyperlipidemia. The measurements were made in 1991 and 1995. The blood flow volumes did not change between 1991 and 1995. However, the blood flow velocities were significantly decreased ('91, 21.6 ± 3.4 cm/sec; '95, 19.8 ± 3.4 cm/sec) (p<0.05). The mean vessel diameters were significantly increased ('91, 7.4 ± 0.6 mm; '95, 7.7 ± 0.7 mm) (p<0.05), and the vessel elasticities were significantly decreased ('91, 4.7 ± 1.2%; '95, 3.9 ± 1.1%) (p<0.005). No differences in results for males and females, or for subjects younger and older than 60 years of age, were obtained. These findings suggest that the flow velocities, mean vessel diameters and changes in ratio of vessel diameters for the mean vessel diameters of the common carotid arteries underwent significant change through aging over a period of only 4 years in healthy volunteers who had no atherothrombotic risk factors.