Cardiovascular disease risk factors and their association with peripheral and central blood pressures in children and adolescents

Background and Aims: There is evidence that central blood pressure (cBP) may improve risk profiling and that risk factors for cBP may be distinct from those for peripheral brachial blood pressure (pBP). Blood pressure tracks strongly from childhood into adulthood, but there is limited evidence regarding risk factors for cBP in children and adolescents. Accordingly, we sought to compare the association between early life anthropometric risk factors with cBP and pBP in children and adolescents. Methods: 97 healthy children and adolescents aged 2 to 20 years were prospectively recruited (mean age 11.2 years [SD 5.1]; stratified into five sex-balanced age groups). Hemodynamic measures were obtained using an appropriately-sized brachial cuff and cBP was measured at the carotid artery using applanation tonometry (SphygmoCor XCEL, AtCor Medical, Australia). Results: In univariate analysis, systolic cBP and pBP increased significantly with age (P < 0.0001) but there was no association with sex. In multivariable analysis, BMI z-score was associated with both higher cBP (3.5 mmHg per 1 kg/m2 [95% CI: 1.0, 5.9], P = 0.005) and pBP (2.4 mmHg per 1 kg/m2 [95% CI: 0.1, 4.7], P = 0.04), adjusted for age and sex. There was weak evidence that these associations were stronger in older children (cBP older: 5.2 mm Hg per 1 kg/m2 [95% CI 1.6, 8.7]; cBP younger: 1.1 mm Hg per 1 kg/m2 [95% CI -2.3, 4.5]; PHETEROGENEITY= 0.09). These associations were independent of height z-score. Conclusions: BMI is independently associated with systolic cBP in childhood and adolescence. This association may become stronger with age during childhood.