Associations Between Brain Network Connectivity, Cardiorespiratory Fitness, And Negative Affect In Healthy Adults

The well-elucidated protective effects of cardiorespiratory fitness against negative affect presumably involve fitness-related adaptations in brain networks. However, it is unknown if large-scale brain network connectivity is associated with cardiorespiratory fitness-related associations with negative affect. PURPOSE: To determine relationships between cardiorespiratory fitness, negative affect, and resting-state brain network connectivity in healthy adults. METHODS: Resting state MRI data were analyzed in 587 healthy adults aged 36-100 years from the Human Connectome Project in Aging (HCP-A) study. The relationship between fitness, estimated using the 2-minute walk test, and negative affect, measured as a composite of self-reported fear, anger, sadness, and stress-related scores, was determined by linear regression. Using a Bayesian analysis, posterior probabilities were determined for associations between both fitness and negative affect and functional connectivity within and between large-scale brain networks. RESULTS: Greater negative affect composite score (p = .004) and anger-hostility (p = .003) were each related to lower fitness after controlling for age, sex, and years of education. Further, fitness was related to greater within-network connectivity for a thalamus network and somatomotor network, as well as greater between-network connectivity for visual and somatomotor networks, visual and dorsal attention networks, and somatomotor and dorsal attention networks (posterior probabilities > .95). Anger-hostility specifically was associated with greater within-network connectivity for the visual, dorsal attention, and temporoparietal networks, as well as greater between-network connectivity for somatomotor and dorsal attention networks, and somatomotor and control networks (posterior probabilities > .95). CONCLUSIONS: Throughout the lifespan, greater cardiorespiratory fitness may protect against unpleasant mood. Further, fitness and anger-hostility exert partially-overlapping associations with large-scale brain network connectivity, suggesting that within and between network connectivity may be one mechanism for the protective effect of fitness on mood. Supported by: NIH-National Institute on Aging, R56AG078366