Background:
Regular physical activity has been linked to a reduced risk of dementia, while loss of brain volume as measured by MRI is a marker of neurodegeneration. However, it remains unclear whether engaging in moderate or vigorous physical activity has any positive impact on brain structure and potential neuroprotective effects.
Method:
A total of 9637 healthy participants were scanned across four 1.5T MRI machines with a whole-body MR imaging protocol. Brain sequences included isotropic MP-RAGE. An ensemble of three Deep learning models corresponding to each axial, sagittal, and coronal views with FastSurfer architecture was trained on 134 participants aged 27-66 segmented 96 brain regions. Partial correlations modeled moderate to vigorous physical activity, defined as sports, fitness and recreational activities that increased respiration and pulse rate for at least 10 continuous minutes, with brain volumes. Analyses controlled for age, sex, and total intracranial volume. Benjamini-Hochberg False Discovery Rate of 5% accounted for multiple comparisons.
Result:
Average age was 52.98 ± 13.06 years ranging from 11-97 years with 52.5% biologically male. Overall, 7215 individuals (74.8%) reported moderate or vigorous physical activity on average 4.03 ± 3.48 days per week. Persons with vigorous activity were slightly older (mean age 54.3 versus 52.5 years) for non-vigorous physical activity (p < .00001) and 54.8% men versus 45.2% women undertook moderate to vigorous physical activity compared to 45.4% men and 54.6% women. Fewer women engaged in moderate to vigorous physical activity compared to men (p=9.92e-16). Accounting for age, sex, and intracranial volume co-variates and multiple comparisons, moderate to vigorous physical activity predicted larger volumes in multiple regions including: total gray matter volume (Partial R=0.09, p=2.59e-18), total white matter volume (Partial R=0.09, p=4.21e-19), hippocampus (Partial R=.098, p= 1.4e-21), frontal cortex (Partial R=0.08, p=1.06e-15), parietal lobes (Partial R=0.055, p=9.01e-8), occipital lobe (Partial R=0.071, p=5.27e-12). Whole brain volumes of gray matter and white matter were also larger with an increasing number of days engaged in moderate to vigorous physical activity (Partial R=0.105, p=6.31e-25).
Conclusion:
Engagement in moderate to vigorous physical activity was found to be associated with increased brain volumes, a metric of neural health.
Presented at the American Academy of Neurology - see link here.
