A large population-based imaging data found an association between objectively assessed physical activity and brain volume that was evident only in older (age, >60 years) participants. Physical activity was also associated with both right and left hippocampal volumes. The study was published in the Journal of Internal Medicine.
Authors used UK Biobank data collected between 2013 and 2016 involving 5272 adults (age, 55.4±7.5 years). For measuring physical activity, participants continuously wore Axivity AX3 triaxial accelerometer for 7 days. Images of brain were obtained by structural MRI using a standard Siemens Skyra 3T running VD13A SP4.
After adjusting for all covariates, per standard deviation increase in physical activity was associated with grey matter volume (standardised coefficient β, 0.03; P=.01). This association was more evident in older adults aged 60-69 years (P=.028) but not in younger participants between 40 and 59 years of age. Physical activity was also associated with both left (β, 0.52; P=.046) and right hippocampal volume (β, 0.59; P=.024). No association was observed between physical activity and total white matter (P=.30).
Authors believe that these findings are consistent with existing evidence and present stronger association in older adults where atrophy is more advanced. Association of physical activity with left and right hippocampal volumes may have relevance to neurodegenerative diseases such as Alzheimer’s.
