Greater Age-Related Reductions in Central Arterial Compliance in Resistance-Trained Men

Abstract

Reductions in the compliance of central arteries exert a number of adverse effects on systemic cardiovascular function and disease risk. Using the cross-sectional study design, we determined the relation between chronic resistance training and carotid arterial compliance. A total of 62 healthy normotensive men, 20 to 39 years of age (young) and 40 to 60 years of age (middle-aged), who were either sedentary or resistance-trained, were studied. In both activity groups, carotid arterial compliance (simultaneous ultrasound and applanation tonometry) was lower (P<0.05) in the middle-aged compared with the young men. There was no significant difference between young sedentary and resistance-trained men. In the middle-aged group, carotid arterial compliance in the resistance-trained men was approximately 30% lower (P<0.01) than their sedentary peers. Femoral artery compliance and arm pulse wave velocity (measures of peripheral artery stiffness) were not different among any groups. Left ventricular hypertrophy index (echocardiography) was greater (P<0.05) in resistance-trained compared with sedentary men and was associated with carotid arterial compliance (r=-0.35; P<0.01). We concluded that (1) resistance training is associated with the smaller central arterial compliance in healthy middle-aged men; (2) age-related reductions in arterial compliance was greater in resistance-trained men than in sedentary men; and (3) the lower arterial compliance in the resistance-trained men is associated with left ventricular hypertrophy. In marked contrast to the beneficial effect of regular aerobic exercise, the present findings are not consistent with the idea that resistance training exerts beneficial influences on arterial wall buffering functions.

Attenuated Increases in Blood Pressure by Dynamic Resistance Exercise in Middle-Aged Men

“…In contrast to our hypothesis, these results suggest that BP responses during dynamic resistance exercise may be attenuated with advancing age at either individual relative or absolute intensity, despite age-related stiffening of the arteries. Previous studies have suggested that the arteries of middleaged men appear to be stiffer than those of young men based on measurements of carotid arterial compliance, β-stiffness, augmentation index, and baPWV (5,6,22,23,30). Our results also showed that arterial stiffening develops at a greater rate in middle-aged men than in young men.…”

“…The right common carotid artery intima-media thickness (IMT) was measured from images obtained using an ultrasound machine equipped with a high-resolution linear-array broad-band transducer as described previously (23,24). Ultrasound images were analyzed using computerized image analysis software (NIH Image 1.63).…”

“…A combination of ultrasound imaging of the pulsatile right common carotid artery with simultaneous applanation of tonometrically obtained arterial pressure from the contralateral carotid artery permits noninvasive determination of arterial compliance (23)(24)(25). The carotid artery diameter was measured from images obtained using an ultrasound machine equipped with a high-resolution linear-array transducer.…”

“…As baseline levels of BP are subject to hold-down force, the pressure signal obtained by tonometry was calibrated by equating the carotid mean arterial and diastolic BP to the brachial artery value (23)(24)(25). In addition to arterial compliance (27), we also calculated the β-stiffness index, which provides an index of arterial compliance adjusted for distending pressure (28).…”

“…, where D1 and D0 are the maximal and minimum diameters, and P1 and P0 are the highest and lowest BPs, respectively (23)(24)(25). The day-to-day coeffi-cients of variation were 2±1%, 7±3%, and 5±2% for the carotid artery diameter, pulse pressure, and arterial compliance, respectively.…”