White matter integrity in physically fit older adults

Authors

B. Y. Tseng, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, University of Texas Southwestern Medical Center
T. Gundapuneedi, University of Texas Southwestern Medical Center
M. A. Khan, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, University of Texas Southwestern Medical Center
R. Diaz-Arrastia, Uniformed Services University of the Health Sciences
B. D. Levine, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, University of Texas Southwestern Medical Center
H. Lu, University of Texas Southwestern Medical Center
H. Huang, University of Texas Southwestern Medical Center
R. Zhang, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, University of Texas Southwestern Medical CenterFollow

Date of this Version

2013

Citation

NeuroImage 82 (2013) 510–516

Comments

This article is a U.S. government work, and is not subject to copyright in the United States.

Abstract

Background: White matter (WM) integrity declines with normal aging. Physical activity may attenuate age-related WM integrity changes and improve cognitive function. This study examined brain WM integrity in Masters athletes who have engaged in life-long aerobic exercise training. We tested the hypothesis that life-long aerobic training is associated with improved brain WM integrity in older adults. Methods: Ten Masters athletes (3 females, age = 72.2 ± 5.3 years, endurance training >15 years) and 10 sedentary older adults similar in age and educational level (2 females, age = 74.5 ± 4.3 years) participated. MRI fluid-attenuated-inversion-recovery (FLAIR) images were acquired to assess white matter hyperintensities (WMH) volume. Diffusion tensor imaging (DTI) was performed to evaluate the WM microstructural integrity with a DTI-derived metric, fractional anisotropy (FA) and mean diffusivity (MD). Results: After normalization to whole-brain volume, Masters athletes showed an 83% reduction in deep WMH volume relative to their sedentary counterparts (0.05 ± 0.05% vs. 0.29 ± 0.29%, p b 0.05). In addition, we found an inverse relationship between aerobic fitness (VO2max) and deep WMH volume (r = −0.78, p < 0.001). Using TBSS, Masters athletes showed higher FA values in the right superior corona radiata (SCR), both sides of superior longitudinal fasciculus (SLF), right inferior fronto-occipital fasciculus (IFO), and left inferior longitudinal fasciculus (ILF). In addition, Masters athletes also showed lower MD values in the left posterior thalamic radiation (PTR) and left cingulum hippocampus. Conclusions: These findings suggest that life-long exercise is associated with reducedWMH and may preserveWM fiber microstructural integrity related to motor control and coordination in older adults.