Decreased endothelium dependent arterial dilation to reactive hyperemia has been shown in adults to be associated with various manifestations of cardiovascular (CV) diseases and cardiovascular risk factors. In a sample of children we examined the relationships between flow-mediated femoral artery dilation and anthropometric, demographic, and CV parameters which have been associated with CV diseases.

Participants. 33 asymptomatic, healthy 11-14 years olds randomly selected from participants in a longitudinal CV health study. There were 17 boys and 16 girls; 21 Whites and 12 Blacks. Sixteen had documented family history of premature myocardial infarction (i.e.,≤55 yrs of age) and 17 did not.

Procedures. Following standard anthropometric measurements, body fatness was assessed via dual x-ray absorptiometry. Blood pressure and heart rate responses were assessed during supine rest and 3 stressors (i.e., postural change, forehead cold, and supine cycle ergometry). The outcome variable was echocardiographically derived flow mediated dilation of the femoral artery after 5 min. of flow occlusion via blood pressure cuff.

Results. Univariate analyses indicated decreased flow-mediated dilation was correlated with systolic pressure increases to postural change, forehead cold stimulation and dynamic exercise, greater average skinfold thickness, body fat via dual x-ray absorptiometry and decreased CV fitness(all ps <.05). Stepwise multiple regression revealed that CV fitness and systolic pressure reactivity to exercise accounted for 31% of the variance (p<.01) in flow-mediated dilation.

Conclusions. Decreased flow-mediated dilation is associated with decreased CV fitness, increased systolic pressure reactivity to various stressors and increased indices of body fatness in asymptomatic youth. Programs designed to increase CV fitness in youth may have a multitude of beneficial effects including improved endothelial function.