Arterial distensibility in children and teenagers: normal evolution and the effect of childhood vasculitis

Abstract

Background: Polyarteritis nodosa is a necrotising vasculitis of the medium sized and small muscular arteries. The inflammatory and subsequent reparative processes may alter the arterial mechanical properties. The effect of vasculitic damage on arterial distensibility has never been explored however. Aim: To determine the normal values and the effect of childhood vasculitis on arterial distensibility in children and teenagers. Methods: Distensibility of the brachioradial arterial segment was studied using pulse wave velocity (PWV ∝1/'distensibility), in 13 children with polyarteritis nodosa at a median age of 11.8 (range 4.9-16) years. As a control group, 155 healthy schoolchildren (6-18 years, 81 boys) were studied. PWV was assessed using a photoplethysmographic technique; blood pressure was measured by an automatic sphygmomanometer (Dinamap). Data from patients were expressed as z scores adjusted for age and compared to a population mean of 0 by a single sample t test. Determinants of PWV in normal children were assessed by univariate and multivariate linear regression analyses. Results: Age, height, weight, and systolic blood pressure correlated individually with the brachioradial PWV. Multivariate analysis identified age as the only independent determinant. Ten of the patients were in clinical remission, while three had evidence of disease activity at the time of study. The PWV in the patient group as a whole was significantly greater than those in healthy children (mean z score +0.99). Raised C reactive protein concentration (>2 mg/dl) in the three patients with active disease was associated with a higher PWV when compared to those in remission (z score +2.78 v +0.45). The diastolic blood pressure of the patients was higher than those of the controls (z score +1.04) while the systolic pressure was similar (z score −0.36). Conclusions: PWV in the brachioradial arterial segment increases gradually during childhood independent of body weight, height, mass, and blood pressure. Increased PWV, and hence decreased distensibility, in this peripheral arterial segment occurs in polyarteritis nodosa and is amplified during acute inflammatory exacerbation.

Age-related factors that confound peripheral pulse timing characteristics in Caucasian children

“…11,12 In this study, a trough in arterial distensibility was unable to be located at the age of 10 years as reported. 7 This is perhaps expected as progressive medial degeneration is probably the major underlying factor; however, this needs further clarification. Present study suggests that childhood PTT is dependent on BP, HR and peripheral path length.…”

“…7,8 Furthermore, there is a strong correlation between the linear increase in arterial stiffness and increasing age. In order to assess changes in arterial stiffness, noninvasive methods like PWV 1,2 and PTT 9,10 have been devised.…”

“…2,5,6 The significance of age-related changes in AC in normal children has not been well-studied due to difficulties in the interpretation of methods for measuring AC in vivo. 7,8 A commonly used method for such measurement is based on the principle of pulse wave velocity (PWV). [1][2][3][4]7 This velocity is related to compliance at physiological transmural pressures and is affected both by BP and rate of pressure change.…”

“…7,8 A commonly used method for such measurement is based on the principle of pulse wave velocity (PWV). [1][2][3][4]7 This velocity is related to compliance at physiological transmural pressures and is affected both by BP and rate of pressure change. 6,7 There are few methods that have been derived to measure PWV.…”

“…[1][2][3][4]7 This velocity is related to compliance at physiological transmural pressures and is affected both by BP and rate of pressure change. 6,7 There are few methods that have been derived to measure PWV. Pulse transit time (PTT) measurement has shown its potential in this area over the recent decades.…”