P158: association Between Ambulatory Arterial Stiffness Index, Markers of Blood Pressure Variability and Indices of Subclinical Vascular Damage in Obese Children

Abstract

Objective

Ambulatory Arterial Stiffness Index (AASI) and symmetric AASI (sAASI) have been proposed as indices of arterial stiffness obtained by 24hour ambulatory blood pressure monitoring (ABPM). ABPM allows the analysis of indices of BP variability like day and night SD, BP dipping, weighted 24-h SD (wSD), average real variability (ARV). Aim of the present study was to address the relationship between these indices and other markers of vascular subclinical damage in children.

Design and Method

45 obese children were included. Children underwent vascular measurements, including: (i) office and 24-hour ambulatory BP; (ii) brachial flow-mediated dilatation (FMD), carotid intima media thickness (cIMT), and distensibility (cDC); (iii) systemic arterial stiffness (SIDVP). From ABPM we calculate AASI, sAASI, ARV, SD, SD, systolic and diastolic dipping and wSD.

Results

ARV showed a significant correlation with SIDVP (r = 0.379; p = 0.023). AASI but not sAASI correlated with FMD (r = 0.361; p = 0.031). In the population divided in hypertensive (n = 11)/normotensive (n = 34), ARV was associated with SIDVP only in normotensive (r = 0.446; p = 0.015). In normotensive, z score-BMI was correlated with both sAASI and wSD (respectively 0.340; p = 0.049 and 0.423; p = 0.014), wSD correlated with FMD (r = 0.384; p = 0.048); in hypertensive children, ARV correlated with FMD (r = 0.828; p = 0.011; rspearman = 0.738; p = 0.037). No indices of BP variability correlated with cIMT or cDC.

Conclusions

BP variability, in particular ARV, shows a correlation with systemic but not local vascular stiffness in a sample of obese children, suggesting a relation between daily BP variability and arterial elastic properties. Further studies, especially perspective ones, are needed to clarify the path-ophysiological significance of these relations.