Associations between arterial stiffness and cardiovascular disease risk factors among black South African children

Background. A limited number of studies have researched the associations between conventional cardiovascular disease (CVD) risk factors and arterial stiffness in children. Objectives. To explore the associations between specific conventional CVD risk factors and arterial stiffness in black South African (SA) children. Methods. This cross-sectional study included 59 children (male:17; female:42). The mean age (and associated standard deviation) of the participants was 11.15 (1.40) years. Conventional CVD risk factors included body mass index (BMI), waist circumference (WC), hip circumference, systolic blood pressure (SBP), resting heart rate (RHR), peak oxygen consumption (VO(2)peak) and physical activity. Pearson's correlation was used to measure associations between arterial stiffness, expressed as the stiffness index (SI), and CVD risk factors. Hierarchical multiple regression analysis adjusting for age was performed to identify associations between the independent variables (VO(2)peak, SBP, BMI, physical activity, RHR and WC) and the dependent variable (SI). Results. Arterial stiffness was found to be significantly positively correlated with age (r=0.52; p=0.03) and significantly negatively correlated with VO(2)peak (r=-0.53; p=0.03) in male participants. Following regression analysis, the association with age (r(2)=0.27; p=0.03) and SI remained significantly independent. When means were combined across the two gender groups, age (r-0.27; p-0.04) and RHR (r-0.26; p-0.05) were found to be significantly positively correlated with SI. Following regression analysis, both age (r(2) -0.07; p-0.04) and RHR (r(2)=0.15; p=0.02) remained significantly independently associated with SI. Conclusion. Age and RHR appear to be strong predictors of arterial stiffness in black SA children.