Active commuting and low-grade inflammation: a population-based cross-sectional study

Abstract

Abstract Background Active commuting (i.e., walking and cycling to work) could have public health benefits while simultaneously fostering climate change mitigation. Current evidence suggests that regular physical activity decreases circulating C-reactive protein (CRP) levels. Yet, it is unclear whether active commuting is associated with lower CRP levels. Study aims: To explore the association between active commuting and CRP levels in working Finnish residents. Our hypothesis is that CRP levels are lower in active commuters than passive commuters. Methods A total of 6208 working Finnish residents were drawn from the FINRISK population surveys of years 1997, 2002, 2007 and 2012. We cross-sectionally analysed the association between active commuting, defined as the time spent walking or cycling to work daily, and high sensitivity (hs-) CRP serum levels in this sample. For the analyses, we used linear and additive models, and we adjusted for potential confounders. Results Participants who engaged in a minimum of 45 minutes of daily active commuting had 16.8% (95% confidence interval, CI: -25.6%, -7.0%) lower hs-CRP than passive commuters. The direction of the association in the main model was the same when active commuting lasted 15-29 minutes daily (% mean difference: -7.4; 95% CI: -14.1, -0.2), but the estimates lacked precision after adjusting for leisure-time physical activity and diet. In subgroup analyses, we observed associations for women. Conclusions High level of active commuting, at least 45 minutes a day, was associated with reduced low-grade inflammation; the association was driven by women. Key messages • Promoting active commuting could help reduce many chronic diseases. • Active modes of transport, such as walking and cycling, may not only be an alternative to motorized vehicles to decrease emissions, but they may also have public health benefits.