Increases in peripheral systolic pressure levels and Z-score associate gradual aortic pressure increase and functional arterial impairment in children and adolescents

Abstract

Background: Arterial changes associated with children and adolescents high blood pressure (HBP) states would vary depending on the arterial type, arterial indexes considered and/or on blood pressure (BP) levels. Aims: To determine in children and adolescents: 1) if there is gradual structural-functional arterial impairment associated with gradual peripheral (brachial) systolic BP (pSBP) level or z-score increases, and 2) whether subjects with HBP levels and those with normal BP differ in the profiles of arterial changes associated with pSBP deviations. Methods: 1005 asymptomatic children and adolescents were included. Clinical, anthropometric and arterial non-invasive evaluations were performed. Heart rate, brachial BP, aortic BP and wavederived parameters (i.e. augmentation index), carotid and femoral diameters, blood velocities and elastic modulus, carotid intima-media thickness and aortic pulse wave velocity, were obtained. Two groups were assembled: Reference (without cardiovascular risk factors (CVRFs); n=379) and HBP (n=175). Additionally, subjects were ascribed to groups according to their pSBP z-scores (z-score ≤ 0, 0< z-score < 1 or z-score ≥ 1). Age and sex-related mean and standard deviation equations were obtained for each variable (Reference group). Using those equations, data (entire population) were converted into z-scores. Groups were compared (absolute and z-scored variables) before and after adjusting for cofactors (ANOVA/ANCOVA). Linear regression analyses were done considering: pSBP and z-pSBP (independent) and absolute levels and z-scores for hemodynamic and arterial indexes (dependent variables). Differences in hemodynamic and arterial levels and z-scores variations (dependent) associated with variations in pSBP and z-pSBP (independent variable) were assessed. The slopes of the models for Reference and HBP groups were compared. Conclusion: HBP states associate hemodynamic and arterial changes not explained by exposure to other CVRFs, anthropometric or demographic factors. The higher the pSBP deviations from ageand sex-expected mean value in the Reference group, the higher the hemodynamic and arterial indexes deviation. The pSBP-related variations in hemodynamic and arterial indexes would not differ depending on whether HBP states are present or not.