Background Arterial stiffness measured as pulse wave velocity is regarded as one of the markers of target organ damage in hypertensive adults. Pulse wave analysis adds the information about central blood pressure, backward pulse wave, cardiac output and total peripheral resistance. However, there are no data regarding the usefulness of measurements of pulse wave velocity, central blood pressure, augmentation pressure and augmentation index in assessment of risk of target organ damage in hypertensive children. The aim of the study was to estimate the relationship of pulse wave velocity and pulse wave analysis with established markers of target organ damage (left ventricular mass index, carotid intimamedia thickness, carotid wall cross sectional area) in children with untreated primary hypertension.

Material and methods Ninety-five patients (14.9 ± 2.5 years; 23 girls) referred as newly diagnosed primary hypertension were included in the study. Pulse wave velocity and pulse wave analysis were measured by oscillometric method using Vicorder device. Pulse wave velocity and carotid intima-media thickness were expressed as absolute and SDS values regarding recently published normative values.

Results In 95 patients referred with elevated blood pressure and who underwent full diagnostic process, normotension was diagnosed in 32, prehypertension in 12, ambulatory hypertension in 7 and severe ambulatory hypertension in 44 patients. Patients with left ventricular hypertrophy had significantly greater 24h systolic, diastolic and mean blood pressure and tendency to the greater augmentation pressure than patients without left ventricular hypertrophy. There were no differences in pulse wave velocity and central blood pressure between patients with left ventricular hypertrophy and/or carotid intima-media thickness > 2SDS and patients without target organ damage. The comparison of patients divided into four groups according to blood pressure status revealed that only patients with severe ambulatory hypertension had significantly greater augmentation pressure and central blood pressure compared with other groups. However, groups did not differ regarding pulse wave velocity. Pulse wave velocity correlated with uric acid (p = 0.001; r = 0.357) and LDL-cholesterol (p = 0.01; r = 0.242), but not with target organ damage. Augmentation pressure and augmentation index correlated with triglycerides (p = 0.003; r = 0.307; p = 0.002; r = 0.319). The stepwise regression analysis revealed that only augmentation index and 24h systolic blood pressure predicted left ventricular mass index (R2 = 0.095; B = 0.308; p = 0.006 and R2 = 0,142; Augmentation Index: B = 0.280; p = 0.011; ABPM SBP: B = 0.218; p = 0.047 respectively).

Conclusions In children with primary hypertension, blood pressure status, central blood pressure, augmentation pressure and augmentation index, but not pulse wave velocity, correlate with left ventricular hypertrophy. However, pulse wave velocity correlates with biochemical risk factors of target organ damage. The lack of direct association between pulse wave velocity and target organ damage may be due relatively modest elevation of blood pressure and short duration of hypertensive disease in children with primary hypertension.