Early sex differences in central arterial wave reflection are mediated by different timing of forward and reflected pressure waves

Non-invasive assessment of central arterial pulse wave augmentation has been proved to be useful in predicting cardiovascular adverse events. Previous studies have shown that pre-pubescent girls had greater central augmentation pressure compared with height-matched boys. This study sought to investigate which factors contribute to the body height-independent sexual differences in central arterial wave reflection observed in childhood. This cross-sectional study involved 819 children and adolescents (6-18 years of age) of both sexes. Phenotypes of central haemodynamic were obtained by radial applanation tonometry. Heart rate corrected augmentation index (Aix@75) was greater in girls compared with boys (2.9 ± 10.7 vs -1.7 ± 12.9%, P < .001) as well as the central augmented pressure (cAP; 1.3 ± 3.3 vs 0.1 ± 3.8 mm Hg, P < .001), even adjusting for age, heart rate and body height. Left ventricular ejection duration (ED) was longer (320 ± 26 vs 314 ± 24 ms, P = .004) and time to inflection point (Tr) was shorter in girls (139 ± 14 vs 141 ± 21 ms, P = .014). The reduction of Aix@75 with increasing body height was steeper in boys (-0.499 ± 0.030 vs -0.428 ± 0.036%/cm, P < .001) as well as the reduction of cAP with increasing body height (-0.108 ± 0.010 vs -0.066 ± 0.013 mm Hg/cm, P < .001). Body height-independent sexual differences observed in the pulse wave reflection indices from early adolescence were mediated by different timing of forward and reflected pressure waves.