Age-related Changes in Baroreflex Sensitivity and Cardiac Autonomic Tone in Children Mirrored by Regional Brain Gray Matter Volume Trajectories

INTRODUCTION: The baroreflex and central autonomic brain regions together control the cardiovascular system. Baroreflex sensitivity (BRS) decreases with age in adults. Age-related changes in brain regions for cardiovascular control in children are unknown. We studied age-related changes in BRS, cardiac autonomic tone, and gray matter volume (GMV) of brain regions associated with cardiovascular control. METHODS: Beat-to-beat blood pressure (BP) and heart rate (HR) were recorded in 49 children (6–14 years old). Spontaneous BRS was calculated by the sequence method. Cardiac autonomic tone was measured by spectral analysis of HR variability. GMV was measured using voxel-based morphometry (VBM) in 112 healthy children (5–18 years old). RESULTS: Age-related changes in BRS were significantly different in children <10 years and ≥10 years. Age-related changes in GMV in regions of interest (ROI) were also significantly different between children <10 and ≥10 years and between children <11 and ≥11 years. However, age-related changes in cardiac autonomic tone were progressive. CONCLUSIONS: Significant changes in BRS trajectories between <10 and ≥10 years may be associated with similar age-related changes of GMV in brain ROI. This new knowledge will guide future studies examining whether childhood cardiovascular disruption manifests as deviated maturation trajectories of specific brain regions.