Title : Determinants of arterial compliance and vascular resistance in healthy children and adolescents
Abstract:
Backgroud: Early exposure to cardiovascular risk factors during childhood is associated with
impaired arterial distensibility, as well as other vascular alterations, suggesting that biomarkers of vascular aging can be used to identify children and adolescents at risk. Reduced arterial compliance and increased vascular resistance are the earliest detectable manifestations of adverse structural and functional changes in the vessel wall, leading to arterial system stiffening.
Objectives: To investigate predictors and propose reference equations for arterial compliance and vascular resistance, assessed in central (Cc and Rc) and peripheral (Cp and Rp) regions, in healthy children and adolescents.
Methods: A cross-sectional, observational study was conducted with n=235 healthy children and adolescents aged 5 to 19 years. Cardiovascular parameters were assessed using the oscillometric method for brachial artery pressure measurement, providing a non-invasive estimate of central blood pressure via the Mobil-O-Graph® (IEM, Stolberg, Germany). Based on cardiovascular parameters, compliance (stroke volume index/peripheral or central pulse pressure, Cp=iSVI/PPp or Cc=iSVI/PPc) and resistance (peripheral or central pulse pressure index/stroke volume index, Rp=PPp/iSVI or Rc=PPc/iSVI) were evaluated. The stroke volume index was calculated as the ratio of stroke volume to body surface area. Additionally, anthropometric data, physical activity profile (Physical Activity Questionnaire for Children), and quality of life (Pediatric Quality of Life Inventory™) were assessed.
Results: Participants were categorized by age group into children (n=133) and adolescents (n=102) and by sex into male (n=112) and female (n=114) for comparison of mean values across the four groups. This categorization was also used to analyze the association between different variables and C and R. Predictors of Cp included age group, body mass index (BMI), waist-to-height ratio (WHtR), central pulse pressure (PPc), and augmentation index adjusted to 75 bpm (AIx@75). For Cc, identified predictors were age, BMI, WHtR, peripheral systolic blood pressure (SBPp), and AIx@75. The coefficients of determination for Cc and Cp were 40.2% and 43.2%, respectively. Predictors of Rp included age, BMI, WHtR, heart rate (HR), and AIx@75. Predictors of Rc were age, BMI, WHtR, SBPp, and AIx@75. The coefficients of determination for Rc and Rp were 41.9% and 36.9%, respectively. Variables related to physical activity profile and quality of life were not considered predictors of C & R.
Conclusion: For the first time, we identified independent predictors of central and peripheral arterial compliance and vascular resistance. These findings highlight the importance of factors such as age, body composition, and arterial stiffness indices (PP and AIx) in predicting arterial compliance and central and peripheral vascular stiffness. Reference equations for arterial compliance and vascular resistance may facilitate the early diagnosis of atherosclerosis and provide an objective measure of the vascular effects of interventions aimed at modifying cardiovascular risk factors.
