Peripheral and Central Aortic Pressure, Wave-Derived Reflection Parameters, Local and Regional Arterial Stiffness and Structural Parameters in Children and Adolescents: Impact of Body Mass Index Variations

Abstract

Aim: The aim was to analyze and compare the associations between body mass index (BMI) and structural and functional cardiovascular variables measured in children and adolescents.

Methods: 609 healthy subjects (mean age/range 12/4-18 years, 45% females) were studied. Subjects' BMI and the corresponding z-scores (z-BMI) were determined. Cardiovascular measurements: peripheral and aortic blood pressure (BP), aortic wave-derived parameters, common carotid, femoral and brachial artery diameters and stiffness, carotid intima-media thickness, carotid-radial and carotid-femoral pulse wave velocity (crPWV, cfPWV) and cfPWV/crPWV ratio. Cardiovascular data were standardized (z-scores) using equations (fractional polynomials) obtained from a sub-group (reference population, n = 241) non-exposed to cardiovascular risk factors (CVRFs). Simple and multiple regression models were obtained for the associations between cardiovascular z-scores and z-BMI and/or z-BMI, age, sex and CVRFs.

Results: z-BMI was associated with standardized cardiovascular variables, regardless of age, sex and CVRFs. BP (peripheral rather than aortic) was the variable with the greatest variations associated with z-BMI. Systolic (SBP) and pulse pressure (PP; in that order) were the variables with the highest variations associated with z-BMI. Carotid, but not femoral or brachial stiffness showed BP-dependent variations associated with z-BMI. Arterial diameters were associated with z-BMI, without differences among arteries.

Conclusion: In children and adolescents, z-BMI was gradually and positively associated with haemodynamic (peripheral and central BP) and vascular parameters (structural and functional) with independence of age, sex and other CVRFs (Dyslipidemia, Hypertension, Smoke, Diabetes). There were differences in the associations depending on the arteries studied and on whether central or peripheral haemodynamic parameters were analyzed.

Keywords: Adolescents; Aortic pressure; Arterial stiffness; Blood pressure; Body mass index; Children; Intima–media thickness.