Characteristics of brachial-ankle pulse wave velocity in Japanese children

Differences in arterial compliance among normotensive adolescent groups: Collins arterial compliance in adolescents

Decreased arterial compliance is an important predictor of cardiovascular risk. Pulse wave velocity correlates well with arterial compliance. Gender and ethnic differences in adult populations have been described. However, few data are available evaluating arterial compliance in adolescent subjects. Using a simple noninvasive oscillometric technique, brachial-ankle pulse wave velocity (baPWV) was measured as an index of arterial stiffness. Measurements were performed on a cross-sectional (65% African American, 52% female) sample of 205 normotensive (blood pressure <95% for gender, height, and age) adolescents with a mean age of 15.9 years (range, 12-21 years). The 205 adolescent subjects include 106 females and 99 males. In these adolescents, the mean baPWV was higher for males (1,096 cm/s) than for females (1,039 cm/s; p < 0.0024; 95% confidence interval [CI], 0.2051-0.9349), and for African Americans (1,080 cm/s) than for whites (1,040 cm/s; p < 0.0438; 95% CI, 0.0112-0.7888). Multiple regression analyses found a three-way interaction among gender, ethnicity, and age. The effect of age on baPWV was greater among African Americans (slope = 18.1 cm/s/year) and males (slope = 21.6) than among whites (slope = 11.0) and females (slope = 11.3), although these differences did not reach statistical significance. Differences in arterial compliance are already present and detectable in normotensive adolescent subjects. Decreased arterial compliance among adolescent groups correlates with the known adult risk for cardiovascular events among the same ethnic and gender groups.

Arterial function in youth: window into cardiovascular risk

Noninvasive measures of arterial function, such as intima-media thickness (IMT), endothelial function, and arterial stiffness are associated with and are prognostic of cardiovascular events in adults. Postmortem evidence, however, has established that the atherosclerotic process starts in childhood. Furthermore, cardiovascular morbidities in childhood disrupt arterial health and may lead to adverse outcomes in adulthood. Thus it is important to examine the developmental changes in IMT, endothelial function, and arterial stiffness in healthy youth in contrast to the arterial health profile of youth with cardiovascular morbidities and to examine the effect of lifestyle interventions. In healthy youth, IMT may increase slightly, arterial stiffness increases, but there is no change in endothelial function from 5 to 20 years of age. In youth with cardiovascular risk factors there are larger increases in IMT and arterial stiffness, and reductions in endothelial function compared with healthy youth. The reduced arterial function in youth with cardiovascular risk factors may be related to the atherosclerotic process. Exercise and physical activity appear to exert a protective effect on arterial function, and exercise training can improve arterial function in children with cardiovascular risk factors. Furthermore, although diet alone can improve arterial function in children, the combination of exercise and diet appears to be more effective than either intervention alone. Future studies need to focus on the mechanism by which exercise and diet improve arterial function, the most effective types of diet and exercise, and if intervening in childhood leads to favorable outcomes in adulthood.

Association between brachial-ankle pulse wave velocity and cardiovascular risk factors in healthy adolescents

OBJECTIVE

To investigate the associations between cardiovascular risk factors and arterial stiffness, measured as brachial-ankle pulse wave velocity (baPWV), in healthy adolescents.

STUDY DESIGN

In this cross-sectional study, 178 male and 84 female adolescents, aged 12 to 18 years, were recruited. Total homocysteine levels, serum lipid profiles, high-sensitivity C-reactive protein (hs-CRP) levels, fasting glucose levels, fasting insulin levels, and baPWV were measured.

RESULTS

baPWV was significantly higher in male adolescents than in female adolescents. In both sex groups, baPWV was positively correlated with body mass index (BMI), waist circumference, waist-hip ratio, systolic and diastolic blood pressures, fasting insulin levels, homeostatic model assessment of insulin resistance, triglyceride levels, hs-CRP levels, and total homocysteine levels. In male adolescents, age, total cholesterol level, low-density lipoprotein cholesterol levels, and white blood cell counts were positively correlated with baPWV, and, in female adolescents, high-density lipoprotein cholesterol levels were negatively correlated with baPWV. In multivariate analysis, sex, mean blood pressure, BMI, and total homocysteine levels were found to be independent factors associated with baPWV.

CONCLUSION

Blood pressure, BMI, sex, and total homocysteine levels were independently associated with arterial stiffness, measured as baPWV, in healthy adolescents, suggesting that these risk factors may be associated with an increased risk of atherosclerosis in adolescents.