Background: A semi-automated devise for oscillometric measurement (Vicorder) of carotid-femoral pulse wave velocity (cfPWV) has been considered to be especially suited for multicenter studies in children and adolescents.
Methods: Within a healthy pediatric population (156 boys/158 girls; mean age 10.8 years, range 5.0-19.6 years), the transit time of the pulse wave was measured oscillometrically (Vicorder) between a carotid and femoral cuff. For calculation of cfPWV, the traveled path length was set to 80% of the direct distance between both sites of measurement. Reference tables were generated using the maximum-likelihood curve-fitting technique and SD scores were calculated. Normalizing the same set of data with reference values specific for applanation tonometry yielded Z(at)values. Effects of sex, age, height, weight, BMI, blood pressure (BP), and heart rate on cfPWV as well as the correlation between sex-specific age-related and height-related Z(osci) and Z(at)were investigated.
Results: Sex-specific reference values and curves for cfPWV as a function of age and height are presented. cfPWV correlated positively with age, height, weight, SBP, mean arterial BP, and sex (each P < 0.005). Multiple regression analysis identified age, sex, and mean arterial pressure as significant independent predictors of cfPWV explaining 42% of the overall variability. Strong linear relationships between Z(osci) and Z(at) were noted and per sex a set of age and height-related equation for conversion was derived: Z(at),age = -0.22 + 0.68 × Z(osci),age; r = 0.98 and Z(at),height = -0.33 + 0.66 × Z(osci),height; r = 0.99 in boys and Z(at),age = -0.61 + 0.81 × Z(osci),age; r = 0.98 and Z(at),height = -0.73 + 0.72 × Z(osci),height; r = 0.97 in girls (each P < 0.001).
Conclusion: A strong linear association between height-related oscillometric and tonometric Z-scores was observed. Age-related Z-scores are of limited value when comparing results across different populations and methods.