Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital of Sichuan University, Chengdu, China.
Department of Psychoradiology, Chengdu Mental Health Center, Chengdu, China.
Hum Brain Mapp. 2021 Oct 15;42(15):4857-4868. doi: 10.1002/hbm.25585. Epub 2021 Jul 8.
Although regular physical exercise has multiple positive benefits for the general population, excessive exercise may lead to exercise dependence (EXD), which is harmful to one's physical and mental health. Increasing evidence suggests that stress is a potential risk factor for the onset and development of EXD. However, little is known about the neural substrates of EXD and the underlying neuropsychological mechanism by which stress affects EXD. Herein, we investigate these issues in 86 individuals who exercise regularly by estimating their cortical gray matter volume (GMV) utilizing a voxel-based morphometry method based on structural magnetic resonance imaging. Whole-brain correlation analyses and prediction analyses showed negative relationships between EXD and GMV of the right orbitofrontal cortex (OFC), left subgenual cingulate gyrus (sgCG), and left inferior parietal lobe (IPL). Furthermore, mediation analyses found that the GMV of the right OFC was an important mediator between stress and EXD. Importantly, these results remained significant even when adjusting for sex, age, body mass index, family socioeconomic status, general intelligence and total intracranial volume, as well as depression and anxiety. Collectively, the results of the present study provide crucial evidence of the neuroanatomical basis of EXD and reveal a potential neuropsychological pathway in predicting EXD in which GMV mediates the relationship between stress and EXD.
尽管有规律的体育锻炼对一般人群有多种积极益处，但过度锻炼可能会导致锻炼依赖（EXD），这对身心健康有害。越来越多的证据表明，压力是 EXD 发病和发展的一个潜在风险因素。然而，EXD 的神经基础以及压力影响 EXD 的潜在神经心理学机制知之甚少。在此，我们通过对 86 名经常锻炼的个体进行结构磁共振成像的基于体素的形态计量学方法来估计其皮质灰质体积（GMV），从而研究了这些问题。全脑相关性分析和预测分析表明，EXD 与右侧眶额皮层（OFC）、左侧扣带回下侧（sgCG）和左侧顶下小叶（IPL）的 GMV 呈负相关。此外，中介分析发现，右侧 OFC 的 GMV 是压力和 EXD 之间的重要中介。重要的是，即使在调整了性别、年龄、体重指数、家庭社会经济地位、一般智力和总颅内体积以及抑郁和焦虑后，这些结果仍然具有统计学意义。总之，本研究的结果为 EXD 的神经解剖学基础提供了重要证据，并揭示了一种潜在的神经心理学途径，即 GMV 介导了压力和 EXD 之间的关系，从而预测 EXD。
