Cerebral blood flow and cerebrovascular reactivity are modified by maturational stage and exercise training status during youth

Abstract

New Findings What is the central question of this study? Gonadal hormones modulate cerebrovascular function while insulin‐like growth factor 1 (IGF‐1) facilitates exercise‐mediated cerebral angiogenesis; puberty is a critical period of neurodevelopment alongside elevated gonadal hormone and IGF‐1 activity: but whether exercise training across puberty enhances cerebrovascular function is unkown. What is the main finding and its importance? Cerebral blood flow is elevated in endurance trained adolescent males when compared to untrained counterparts. However, cerebrovascular reactivity to hypercapnia is faster in trained vs. untrained children, but not adolescents. Exercise‐induced improvements in cerebrovascular function are attainable as early as the first decade of life. AbstractGlobal cerebral blood flow (gCBF) and cerebrovascular reactivity to hypercapnia () are modulated by gonadal hormone activity, while insulin‐like growth factor 1 facilitates exercise‐mediated cerebral angiogenesis in adults. Whether critical periods of heightened hormonal and neural development during puberty represent an opportunity to further enhance gCBF and is currently unknown. Therefore, we used duplex ultrasound to assess gCBF and in n = 128 adolescents characterised as endurance‐exercise trained (males: n = 30, females: n = 36) or untrained (males: n = 29, females: n = 33). Participants were further categorised as pre‐ (males: n = 35, females: n = 33) or post‐ (males: n = 24, females: n = 36) peak height velocity (PHV) to determine pubertal or ‘maturity’ status. Three‐factor ANOVA was used to identify main and interaction effects of maturity status, biological sex and training status on gCBF and . Data are reported as group means (SD). Pre‐PHV youth demonstrated elevated gCBF and slower mean response times than post‐PHV counterparts (both: P ≤ 0.001). gCBF was only elevated in post‐PHV trained males when compared to untrained counterparts (634 (43) vs. 578 (46) ml min−1; P = 0.007). However, mean response time was faster in pre‐ (72 (20) vs. 95 (29) s; P ≤ 0.001), but not post‐PHV (P = 0.721) trained youth when compared to untrained counterparts. Cardiorespiratory fitness was associated with gCBF in post‐PHV youth (r2 = 0.19; P ≤ 0.001) and mean response time in pre‐PHV youth (r2 = 0.13; P = 0.014). Higher cardiorespiratory fitness during adolescence can elevate gCBF while exercise training during childhood primes the development of cerebrovascular function, highlighting the importance of exercise training during the early stages of life in shaping the cerebrovascular phenotype.

Habitual exercise in youth: A ʻbrainyʼ idea

“…Coupled with the most recent findings from Talbot, Perkins, Tallon et al (2023), this suggests that exercise training in adolescents may be necessary to counteract the negative consequences of higher sedentary time on cerebral haemodynamics.…”

“…In a separate study byTalbot et al, they reported that pre-PHV-trained children had a smaller increase in cerebral pulsatility of the posterior cerebral artery (PCA) during a visual stimulus, compared with untrained pre-PHV children.The interpretation is that trained children had better dampening function in the PCA, compared with untrained children. Thus, both findings from examining the cerebrovascular kinetics during a ʻstressʼ revealed exercise training adaptations in the pre-PHV cohort, prior to maturation.The faster ICA mean response time to hypercapnia in pre-PHV children(Talbot, Perkins, Tallon et al, 2023) is an interesting finding and brings to light questions for the field. For example, what is the physiological or clinical significance of a faster response to hypercapnia in children prior to reaching PHV or maturation?…”

“…This age range is often under-represented in research but can offer important insight concerning the trajectory of health. It is also unclear what the consequences of a lack of habitual exercise are for cerebrovascular health in youth.To address this gap in the literature, in an article in this issue of Experimental Physiology, Talbot et al investigated both cerebral blood flow (CBF) and cerebrovascular reactivity to carbon dioxide in youth, while accounting for different stages of maturation (using a somatic measure of maturity -predicted age at peak height velocity or PHV) (Talbot, Perkins, Tallon et al, 2023). This study required a considerable number of participants to account for sex, maturation and training status.…”

“…Brugniaux et al, 2014). The study byTalbot et al investigated how maturation, sex and training status were related to the cerebrovascular response to steady state elevations in carbon dioxide (CO 2 )(Talbot, Perkins, Tallon et al, 2023). While there were no significant training effects on cerebrovascular reactivity to hypercapnia, the authors reported that pre-PHV-trained children had a faster cerebrovascular response compared with the untrained group.…”

“…To address this gap in the literature, in an article in this issue of Experimental Physiology , Talbot et al. investigated both cerebral blood flow (CBF) and cerebrovascular reactivity to carbon dioxide in youth, while accounting for different stages of maturation (using a somatic measure of maturity – predicted age at peak height velocity or PHV) (Talbot, Perkins, Tallon et al., 2023 ). This study required a considerable number of participants to account for sex, maturation and training status.…”