IMPACT OF CHANGES IN CARDIORESPIRATORY FITNESS ON CAROTID ATHEROSCLEROSIS AND LARGE ARTERY STIFFNESS

Abstract

High levels of cardiorespiratory fitness (VO2max) are associated with reduced risk of cardiovascular morbidity and mortality, and trial-induced (experimental) increases in VO2max decrease arterial stiffness. However, little is known to what extent “real-life” changes in VO2max impact on atherosclerosis and arterial stiffness. PURPOSE We sought to investigate the relationship between changes in VO2max from adolescence (13–16 years) to adulthood (age 36) and from young adulthood (21–33 years) to adulthood, on the one hand, and carotid atherosclerosis and stiffness of the carotid, femoral and brachial arteries, on the other. METHODS Analyses of changes in VO2max from adolescence to age 36 consisted of 154 subjects (79 women), and from young adulthood to age 36 consisted of a sub-population of 118 subjects (62 women); VO2max was measured directly with a maximal running text on a treadmill. Carotid atherosclerosis (intima-media thickness) and large artery stiffness (distensibiliy and compliance coefficients) were assessed non-invasively by ultrasound imaging methods. RESULTS “Real-life” changes in VO2max were inversely but not significantly associated with carotid intima-media thickness. Changes in VO2max were inversely and significantly associated with large artery stiffness. These associations were not uniform throughout the arterial tree, being stronger and independent of changes in other risk factors in the muscular (brachial and femoral) arteries, but dependent on and possibly mediated by changes in blood pressure, HDL cholesterol and body weight in the elastic carotid artery. CONCLUSION Increases in VO2max that occur in real life are associated with less arterial stiffness. Improving VO2max by increasing physical activity levels may therefore be important for the primary prevention of cardiovascular disease. Supported by the Foundation for Science and Technology (Portugal)- grant BD/19760/99.