The influence of sex and maturation on carotid and vertebral artery hemodynamics and associations with free-living (in)activity in 6-17-year-olds.

We explored the influence of sex and maturation on resting cervical artery hemodynamics (common carotid artery, CCA; internal carotid artery, ICA; and vertebral artery, VA), free-living physical activity, and sedentary behavior in children 6-17 yr of age. In addition, we investigated the relationship between physical activity, sedentary behavior, and cervical artery hemodynamics. Seventy-eight children and adolescents, girls ( = 42; mean age, 11.4 ± 2.5 yr) and boys ( = 36; mean age, 11.0 ± 2.6 yr), completed anthropometric measures, duplex ultrasound assessment of the cervical arteries, and wore an activPAL accelerometer to assess physical activity (indexed by steps/day) and sedentary behavior for 7 days. The ICA and VA diameters were similar between prepubertal and pubertal groups, as was volumetric blood flow (); however, the CCA diameter was significantly larger in the pubertal group ( < 0.05). Boys were found to have larger diameters in all cervical arteries than girls, as well as higher , , and global cerebral blood flow ( < 0.05). The pubertal group was more sedentary (100 min/day more; < 0.05) and took 3,500 fewer steps/day than the prepubertal group ( < 0.05). Shear rate (SR) and of the cervical arteries showed no relationship to physical activity or prolonged bouts of sedentary behavior; however, a significant negative relationship was apparent between total sedentary time and internal carotid artery shear rate (ICA) after covarying for steps/day and maturation ( < 0.05). These findings provide novel insight into the potential influence sedentary behavior may have on cerebrovascular blood flow in healthy girls and boys. Cerebral blood flow is known to change with age; however, assessing these age-related changes is complex and requires consideration of pubertal status. This, to our knowledge, is the first study to investigate the influence of sex and maturation on resting cervical artery hemodynamics and subsequently explore associations with physical activity and sedentary behavior in healthy children and adolescents. Our findings suggest that habitual sedentary behavior may influence cervical artery hemodynamics in youth, independent of physical activity, maturation, and sex.