Arterial compliance in young children: the role of aerobic fitness

BACKGROUND: Reduced arterial compliance is reflective of vascular dysfunction, which promotes the atherosclerotic process, and is therefore an important predictor of vascular disease. In adults, obesity, age, aerobic fitness, oestrogens and race influence arterial compliance. Although stature and blood pressure are known to influence compliance in children, other determinants are less established. This investigation sought to determine the predictors of arterial compliance in children, assess the extent to which aerobic fitness is related to compliance, and compare compliance between girls and boys. METHODS: Participants (99 children aged 9-11 years, 55 boys) were assessed for aerobic fitness, physical activity level, blood pressure, body mass, percentage fat mass, height, maturity and arterial compliance (large and small). Predictors of compliance were determined using stepwise regression. Second, children were divided into quartiles according to fitness, and arterial compliance was compared using analysis of covariance (ANCOVA). Finally, differences in compliance between girls and boys were assessed using ANCOVA. RESULTS: We found that fitness, blood pressure and height accounted for 37% of the variance in large artery compliance. Mass, fitness, maturity and blood pressure accounted for 44% of the variance in small artery compliance. Children in the highest fitness quartile had greater compliance than children in the two lowest quartiles, by as much as 34%. There were no differences in compliance between girls and boys after adjusting for covariates. DISCUSSION: These data show that aerobic fitness is associated with arterial compliance in 9-11-year-old children, supporting the concept that physical fitness may exert a protective effect on the cardiovascular system.