Domains of physical activity and brain volumes: A population-based study.

Observational studies and intervention trials suggest that physical activity (PA) is beneficial for human brain morphology, especially in older individuals. Few population-based studies examined whether domain-specific PA is associated with brain volumes. Accordingly, we studied putative associations of PA during leisure time, sports and work with volumes of the hippocampus, the prefrontal cortex, the temporal lobe, gray matter (GM), white matter (WM) and total brain (TBV) after 5.9 years by applying volumetric analysis and voxel-based morphometry (VBM) with SPM 8/VBM 8 to brain magnetic resonance imaging data of 834 participants (447 women) aged 25 to 83 years from the population-based Study of Health in Pomerania. The Baecke questionnaire was used to assess domain-specific PA (Leisure time, Sport, and Work Index) at baseline. After correcting for multiple testing, volumetric analyses did not show any significant association of domain-specific PA and volumes of the hippocampus, the prefrontal cortex, the temporal lobe, GM, WM and TBV. Multivariable-adjusted VBM analyses of the associations between PA domains with GM and WM volumes did not reveal any statistically significant results. Region of interest analyses revealed a statistically significant cluster of increased GM volume in the bilateral anterior cingulate cortex in association with PA during sports. In conclusion, the overall results contrast with the findings from previous studies that found significant associations between PA and brain volumes. In addition, it remains unclear whether a differential association exists between domains of PA and brain volumes. Thus, future studies with larger sample size and prospective design are needed to investigate potential domain-specific associations of PA with brain volumes.