Occupational and leisure physical activity may have varying effects on inflammation 

1. Lower leisure time physical activity and higher occupational physical activity were associated with increased high-sensitivity C reactive protein (hs-CRP) levels.
2. When analyzed as continuous variables, only leisure time physical activity was strongly associated with hs-CRP levels.

Evidence Rating Level: 2 (Good)

Paradoxically, physical activity associated with one’s occupation has been shown in the literature to increase cardiovascular disease and mortality; a finding that does not hold true for physical activity associated with leisure. Though many mechanisms have been proposed, sustained systemic inflammation (measured through hs-CRP levels) may be an important contributor. In order to further study this association, the objective of the present cross-sectional study was to determine the extent to which physical activity performed during work and leisure time was associated with systemic inflammation.

The present study used data from the Copenhagen Aging and Midlife Biobank (CAMB) cohort. Of 12656 invited participants, 5304 had blood samples taken, including the hs-CRP biomarker. Occupational physical activity was measured based on self-reported job history with a job exposure matrix. Leisure time physical activity was self-reported using the CAMB questionnaire. The association between the two types of physical activity and hs-CRP was done using multivariable linear regression models as well as post-hoc analyses.

Results demonstrated that lower leisure time physical activity and higher occupational physical activity were associated with increased high-sensitivity C reactive protein (hs-CRP) levels. Furthermore, when analyzed as continuous variables, only leisure time physical activity was strongly associated with hs-CRP levels. Despite these findings, the study was limited by the risk of misclassification, as physical activity was based on job title. Nonetheless, the inclusion of a large number of participants strengthened the findings of the present study and the fact that systemic inflammation may in fact explain the physical activity paradox.

Click to read the study in British Journal of Sports Medicine 

Image: PD

©2022 2 Minute Medicine, Inc. All rights reserved. No works may be reproduced without expressed written consent from 2 Minute Medicine, Inc. Inquire about licensing here. No article should be construed as medical advice and is not intended as such by the authors or by 2 Minute Medicine, Inc.