Exercise-related changes in between-network connectivity in overweight/obese adults

PHYSIOLOGY & BEHAVIOR

卷:158

Article

Legget, Kristina T.¹  Wylie, Korey P.¹  Cornier, Marc-Andre^2,3  Melanson, Edward L.^2,4  Paschall, Courtnie J.¹  Tregellas, Jason R.^1,5 

[1] Univ Colorado, Dept Psychiat, Sch Med, Anschutz Med Campus,13001 E 17th Pl, Aurora, CO 80045 USA

[2] Univ Colorado, Dept Med, Sch Med, Div Endocrinol Metab & Diabet, Anschutz Med Campus, Aurora, CO 80045 USA

[3] Univ Colorado, Anschutz Hlth & Wellness Ctr, Anschutz Med Campus, Aurora, CO 80045 USA

[4] Univ Colorado, Sch Med, Dept Med, Div Geriatr Med, Anschutz Med Campus, Aurora, CO 80045 USA

[5] VA Med Ctr, Res Serv, Denver, CO USA

关键词: Exercise;    Obesity;    Posterior cingulate cortex;    Default mode network;    Between-network connectivity;    fMRI;   

DOI  :  10.1016/j.physbeh.2016.02.031

来源: Elsevier

【 摘 要 】

Understanding how exercise affects communication across the brain in overweight/obese individuals may provide insight into mechanisms of weight loss and maintenance. In the current study, we examined the effects of a 6-month exercise program in 11 overweight/obese individuals (mean BMI: 33.6 +/- 1.4 mg/kg(2); mean age: 38.2 +/- 3.2 years) on integrative brain hubs, which are areas with high levels of connectivity to multiple large-scale networks thought to play an important role in multimodal integration among brain regions. These integrative hubs were identified with a recently developed between-network connectivity (BNC) metric, using functional magnetic resonance imaging (fMRI). BNC utilizes a multiple regression analysis approach to assess relationships between the time series of large-scale functionally-connected brain networks (identified using independent components analysis) and the time series of each individual voxel in the brain. This approach identifies brain regions with high between-network interaction, i.e., areas with high levels of connectivity to many large-scale networks. Changes in BNC following exercise were determined using paired t-tests, with results considered significant at a whole-brain level if they exceeded a voxel-wise threshold of p < 0.01 and cluster-level family-wise error (FINE) correction for multiple comparisons of p < 0.05. Following the intervention, BNC in the posterior cingulate cortex (PCC) was significantly reduced (p < 0.001). The changes driving the observed effects were explored using Granger causality, finding significant reductions in both outgoing causal flow from the PCC to a number of networks (p < 0.05; language network, visual network, sensorimotor network, left executive control network, basal ganglia network, posterior default mode network), in addition to reductions in ingoing causal flow to the PCC from a number of networks (p < 0.05; ventral default mode network, language network, sensorimotor network, basal ganglia network). Change in BNC was related to changes in aerobic fitness level (VO2 max; p = 0.008) and perceived hunger (Three Factor Eating Questionnaire; p = 0.040). Overall, the impact of exercise on communication between large-scale networks may contribute to individual responsivity to exercise. (C) 2016 Elsevier Inc. All rights reserved.

【 授权许可】

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