Determinants of endothelium-dependent femoral artery vasodilation in youth

Objective: Decreased endothelium-dependent arterial dilation to reactive hyperemia has been shown in adults to be associated with various manifestations of cardiovascular diseases and cardiovascular risk factors. In a sample of children, we examined the relationships between flow-mediated femoral artery dilation and anthropometric, demographic, cardiovascular, and serum lipid variables that have been associated with cardiovascular diseases, Method: Thirty-three asymptomatic, healthy 11 to 14 years olds were randomly selected from participants in a longitudinal cardiovascular health study, There were 17 boys and 16 girls; 21 whites and 12 blacks. Sixteen had documented family history of premature myocardial infarction (ie, less than or equal to 55 years of age) in first-degree relatives and 17 did not, Measurements included fasting lipids, anthropometrics, blood pressure and heart rate at rest and during supine exercise, postural change, and forehead cold stimulation. Femoral artery dilation to reactive hyperemia was measured via high resolution ultrasound, Results: Bivariate analyses indicated flow-mediated dilation was negatively correlated with systolic pressure increases to postural change, forehead cold stimulation and dynamic exercise, greater average skinfold thickness, and body fat via dual x-ray absorptiometry and positively correlated with cardiovascular fitness (all ps<.05). Stepwise multiple regression revealed that cardiovascular fitness and systolic pressure reactivity to exercise significantly predicted flow-mediated dilation accounting for 31% of the variance (p<.01). Conclusions: Decreased flow-mediated dilation is associated with decreased cardiovascular fitness, increased systolic pressure reactivity to various stressors, and increased indices of body fatness in asymptomatic youth. Further research is warranted to better understand early relationships between this noninvasive measure of endothelial function and cardiovascular risk factors in youth.