Attenuated age-related carotid arterial remodeling in adults with a high level of cardiorespiratory fitness

Aim: Cardiorespiratory fitness (CRF) is independently associated with a reduced risk of cardiovascular disease. Carotid arterial remodeling, which is derived from the interplay between carotid luminal dilation and wall thickening, is also an independent predictor of cardiovascular events. We hypothesized that high CRF may be associated with reduced age-related carotid arterial remodeling. This cross-sectional study was performed to determine the relationships between CRF and age-related luminal dilation and wall thickening. Methods: A total of 771 adults (180 men and 591 women), under age 40 (young), 40-59 (middleaged), and over age 60 (older) participated in this study. Subjects in each age category were divided into either high (fit) or low (unfit) CRF groups based on VO_2peak. Carotid artery intima-media thickness (IMT) and lumen diameter were measured on ultrasound images. Carotid wall mass was calculated as ρL(πRe²-Ri²). Results: Two-way ANOVA indicated a significant interaction (p<0.01) between age and CRF in determining IMT, lumen diameter, and wall mass. In older subjects, IMT, lumen diameter, and wall mass were significantly lower (p<0.05) in the fit than in the unfit group (IMT, 0.69±0.01 vs. 0.74 ±0.01 mm; lumen diameter, 5.99±0.06 vs. 6.28±0.06 mm; wall mass, 7.41±0.25 vs. 8.71±0.25 mm3). Multiple regression analysis indicated that the value of VO_2peak was independently correlated with carotid IMT, lumen diameter and wall mass. Conclusion: The present study indicated that a high level of CRF is associated with reduced agerelated wall thickening and luminal dilation in the carotid artery.