Sitting-induced hemodynamic changes and association with sitting intolerance in children and adolescents: a cross-sectional study

Hemodynamic alteration with postural change from supine to sitting has been unclear in the young. In the cross-sectional study, 686 participants (371 boys and 315 girls, aged 6–18 years) were recruited from 4 schools in Kaifeng city, the central area of China. The active sitting test was performed to obtain heart rate (HR) and blood pressure (BP) changes from supine to sitting in children and adolescents. Hemodynamic change-associated sitting intolerance was analyzed. In the study participants, the 95th percentile (P(95)) values of changes in HR and BP within 3 min from supine to sitting were 25 beats/min and 18/19 mm Hg, respectively. Sixty-six participants had sitting intolerance symptoms. Compared with participants without sitting intolerance symptoms, those with symptoms more frequently had HR increase ≥ P(95) or BP increase ≥ P(95) within 3 min from supine to sitting (P < 0.001). Risk factors for sitting intolerance were age (odds ratio 1.218, 95% confidence interval 1.072–1.384, P = 0.002) and changes in HR or BP ≥ P(95) within 3 min after sitting (odds ratio 2.902, 95% confidence interval 1.572–5.357, P = 0.001). We firstly showed hemodynamic changing profiles from supine to sitting and their association with sitting intolerance in children and adolescents. Sitting tachycardia is likely suggested with a change in HR ≥ 25 beats/min and sitting hypertension with a change in BP ≥ 20/20 mm Hg when changing from supine to sitting within 3 min. The age and changes in HR or BP were independent risk factors for sitting intolerance.