Exercise-Related Physical Activity Relates to Brain Volumes in 10,125 Individuals

Article type: Research Article

Authors: Raji, Cyrus A.^{a; b; *} | Meysami, Somayeh^{c; d} | Hashemi, Sam^{e; f} | Garg, Saurabh^{b; f} | Akbari, Nasrin^{e; f} | Ahmed, Gouda^{e; f} | Chodakiewitz, Yosef Gavriel^e | Nguyen, Thanh Duc^{e; f} | Niotis, Kellyann^{g; h} | Merrill, David A.^{c; d; i} | Attariwala, Rajpaul^{e; f; j}

Affiliations: [a] Washington University School of Medicine in St Louis, Mallinckrodt Institute of Radiology, St. Louis, MO, USA | [b] Department of Neurology, Washington University in St. Louis, MO, USA | [c] Pacific Brain Health Center, Pacific Neuroscience Institute and Foundation, Santa Monica, CA, USA | [d] Saint John’s Cancer Institute at Providence Saint John’s Health Center, Santa Monica, CA, USA | [e] Prenuvo, VA, Canada | [f] Voxelwise Imaging Technology, VA, Canada | [g] Early Medical, Austin, TX, USA | [h] The Institute for Neurodegenerative Diseases-Florida, Boca Raton, FL, USA | [i] Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA | [j] AIM Medical Imaging, VA, Canada

Correspondence: [*] Correspondence to: Cyrus A. Raji, MD, PhD, Washington University School of Medicine in St Louis, Mallinckrodt Institute of Radiology, St. Louis, MO 63105, USA. E-mail: craji@wustl.edu

Abstract: Background:The potential neuroprotective effects of regular physical activity on brain structure are unclear, despite links between activity and reduced dementia risk. Objective:To investigate the relationships between regular moderate to vigorous physical activity and quantified brain volumes on magnetic resonance neuroimaging. Methods:A total of 10,125 healthy participants underwent whole-body MRI scans, with brain sequences including isotropic MP-RAGE. Three deep learning models analyzed axial, sagittal, and coronal views from the scans. Moderate to vigorous physical activity, defined by activities increasing respiration and pulse rate for at least 10 continuous minutes, was modeled with brain volumes via partial correlations. Analyses adjusted for age, sex, and total intracranial volume, and a 5% Benjamini-Hochberg False Discovery Rate addressed multiple comparisons. Results:Participant average age was 52.98±13.04 years (range 18–97) and 52.3% were biologically male. Of these, 7,606 (75.1%) reported engaging in moderate or vigorous physical activity approximately 4.05±3.43 days per week. Those with vigorous activity were slightly younger (p < 0.00001), and fewer women compared to men engaged in such activities (p = 3.76e-15). Adjusting for age, sex, body mass index, and multiple comparisons, increased days of moderate to vigorous activity correlated with larger normalized brain volumes in multiple regions including: total gray matter (Partial R = 0.05, p = 1.22e-7), white matter (Partial R = 0.06, p = 9.34e-11), hippocampus (Partial R = 0.05, p = 5.96e-7), and frontal, parietal, and occipital lobes (Partial R = 0.04, p≤1.06e-5). Conclusions:Exercise-related physical activity is associated with increased brain volumes, indicating potential neuroprotective effects.

Keywords: Alzheimer’s disease, brain volumes, deep learning, magnetic resonance imaging, physical activity

DOI: 10.3233/JAD-230740

Journal: Journal of Alzheimer's Disease, vol. 97, no. 2, pp. 829-839, 2024