The PAIR project had four research objectives:
Objective 1: To estimate the longitudinal association between regular physical activity and lung function decline.
Using data from 3912 adults participating in the European Community Respiratory Health Survey, we found that increased leisure-time vigorous physical activity was associated with higher lung function, especially among current smokers. This observation supports the existence of an inflammation-related biological mechanism and highlights the importance of physical activity in current smokers who are at higher risk (due to smoking) for poor lung function. We also found that participants who were active at the end of the study (by becoming or remaining active) had significantly higher lung function than those consistently inactive, suggesting that maintaining one's physical activity is necessary to achieve maximal health benefits. No association between vigorous physical activity and lung function decline was observed, a result that requires further investigation. These results were presented at several conferences, including the 2016 European Respiratory Society Congress. A manuscript was published in Thorax (Fuertes et al. 2018) (
http://thorax.bmj.com/content/early/2018/01/06/thoraxjnl-2017-210947(odnośnik otworzy się w nowym oknie)). Figure 1 here provided summarizes these findings.
Objective 2: To assess the potential mediating role of systemic inflammation in the relationship between physical activity and lung function decline.
We subsequently examined whether C-reactive protein, a biomarker for systemic inflammation, lies in the mechanistic pathway between physical activity and lung function using data on 2347 adults. However, despite the existence of a biological hypothesis and supporting scientific literature, we did not find any evidence to suggest that this was true. Other markers of inflammation and potential mechanistic pathways should be examined in future work. This work was submitted to the 2018 European Respiratory Society congress and is currently being written into a scientific publication.
Objective 3: To investigate whether biological (body mass index, co-existing chronic inflammatory diseases) and behavioural (diet, smoking) factors related to systemic inflammation may modify the link between physical activity and lung function decline.
Whether the association between physical activity and lung function differs across groups with different body-mass indices, chronic inflammatory diseases, diets and smoking behaviours was assessed. Current smokers were the only group in which associations were found to be especially strong. The results were incorporated into the recently published manuscript in which the results for Objective 1 were published (Fuertes et al. 2018).
Objective 4: To investigate whether environmental factors (air pollution, greenness, ultraviolet radiation) related to systemic inflammation may modify the link between physical activity and lung function decline.
We examined whether the association between physical activity and lung function differs by residential air pollution levels and greenness levels. We found that regular physical activity benefits lung function, largely irrespective of residential air pollution levels. Our data did however suggest that the beneficial effects of physical activity on lung function may be reduced in never-smokers living in areas with high air pollution levels. No differences in the associations were apparent across different greenness levels. These results were presented at the 2017 European Respiratory Society Congress and are currently under scientific peer-review.
