Physical Fitness Components And Cortical And Subcortical Brain Volume In Overweight/obese Children

Abstract

PURPOSE: To examine the association between the key components of physical fitness (i.e. cardiorespiratory fitness, speed-agility and muscular fitness) and brain structural volume in overweight/obese children. METHODS: A total of 101 overweight/obese children aged 8-11 years were recruited from Granada, Spain. The physical fitness components were assessed following the ALPHA health-related fitness test battery. T1-weighted images were acquired with a 3.0 Tesla Siemens Magnetom Tim Trio system. Gray matter tissue was calculated using Diffeomorphic Anatomical Registration Through Exponentiated Lie algebra (DARTEL). All analyses were controlled for sex, peak high velocity offset, parent education, body mass index and total brain volume. The statistical threshold was calculated with AlphaSim and further Hayasaka adjusted to account for the non-isotropic smoothness of structural images. RESULTS: Cardiorespiratory fitness was related to greater gray matter volumes (P< 0.001, k=58) in 9 out of all regions with β ranging from 0.493 to 0.584; specifically in frontal regions (i.e. premotor cortex and medial primary motor cortex), superior parietal cortex, subcortical regions (i.e. hippocampus and caudate), temporal regions (i.e. middle and inferior temporal gyri and parahippocampal gyrus) and calcarine cortex. Speed-agility was associated with greater gray matter volumes (P< 0.001, k=54) in 2 regions (i.e. the inferior frontal gyrus and the superior temporal gyrus) with β ranging from 0.564 to 0.611. Muscular fitness was not independently associated with greater gray matter volume in any brain regions. No brain regions showed statistically significant negative associations between components of physical fitness and gray matter volume. CONCLUSIONS: Cardiorespiratory fitness and speed-agility, but not muscular fitness, might independently be associated with greater volume of numerous cortical and subcortical brain structures. Importantly, those associated brain structures are different for each fitness component. These findings suggest that the development of cardiorespiratory fitness and speed-agility might positively affect development of distinctive brain regions and contribute to counteract the harmful effect of overweight and obesity on brain structure during childhood.