Longitudinal changes in .VO2max: associations with carotid IMT and arterial stiffness.

PURPOSE: High levels of cardiorespiratory fitness (.VO2max) are associated with reduced risk of cardiovascular morbidity and mortality. However, little is known to what extent longitudinal changes in .VO2max affect arterial wall thickness and stiffness, i.e., two major risk factors for cardiovascular disease. We therefore investigated the relationship between changes in .VO2max from adolescence (13-16 yr) to adulthood (age 36) and from young adulthood (21-32 yr) to age 36, and carotid intima-media thickness (IMT) and stiffness of the carotid, femoral, and brachial arteries, at age 36.

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 subpopulation of 118 subjects (62 women). Throughout the years, .VO2max was measured directly with a maximal running test on a treadmill. When the subjects had the mean age of 36, carotid IMT and large artery stiffness (distensibility and compliance coefficients) were assessed noninvasively by ultrasound imaging methods.

RESULTS: Longitudinal changes in .VO2max were not significantly associated with carotid IMT. 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 concomitant changes in HDL cholesterol and body weight in the elastic carotid artery.

CONCLUSION: Increases in .VO2max that occur from adolescence up to age 36 are associated with less arterial stiffness. Improving .VO2max by increasing physical activity levels may therefore contribute to a reduction in mortality from cardiovascular disease through decreasing arterial stiffness.