Physical fitness, hippocampal functional connectivity and academic performance in children with overweight/obesity: The ActiveBrains project

Abstract

ObjectivesPhysical fitness is a modifiable factor associated with enhanced brain health during childhood. To our knowledge, the present study is the first to examine: (i) whether physical fitness components (i.e., cardiorespiratory, motor and muscular fitness) are associated with resting state functional connectivity of hippocampal seeds to different cortical regions in children with overweight/obesity, and (ii) whether resting state hippocampal functional connectivity is coupled with better academic performance. Patients and methodsIn this cross-sectional study, a total of 99 children with overweight/obesity aged 8–11 years were recruited from Granada, Spain (November 2014 to February 2016). The physical fitness components were assessed following the ALPHA health-related fitness test battery. T1-weighted and resting-state fMRI images were acquired with a 3.0 Tesla Siemens Magnetom Tim Trio system. Academic performance was assessed by the Woodcock-Muñoz standardized test. Hippocampal seed-based procedures with post-hoc regression analyses were performed. ResultsIn the fully adjusted models, cardiorespiratory fitness was independently associated with greater hippocampal connectivity between anterior hippocampus and frontal regions (β ranging from 0.423 to 0.424, p < 0.001). Motor fitness was independently associated with diminished hippocampal connectivity between posterior hippocampus and frontal regions (β ranging from −0.583 to −0.694, p < 0.001). However, muscular fitness was not independently associated with hippocampal functional connectivity. Positive resting state hippocampal functional connectivity was related to better written expression (β ranging from 0.209 to 0.245; p < 0.05). ConclusionsPhysical fitness components may associate with functional connectivity between hippocampal subregions and frontal regions, independent of hippocampal volume, in children with overweight/obesity. Particularly, cardiorespiratory fitness may enhance anterior hippocampal functional connectivity and motor fitness may diminish posterior hippocampal functional connectivity. In addition, resting state hippocampal functional connectivity may relate to better written expression.