Body composition modify the association between ambient particulate matter and lung function among asthma patients

The effect of ambient PM₁₀ and PM_2.5 on lung function modified by body muscle and adipose tissue is not fully understood at present. Our aims were to investigate the association between seasonal average air pollutants and lung function in asthmatic patients modified by body composition indicators. In this cross-sectional study, we recruited 914 doctor-diagnosed asthmatic patients, and performed interaction and stratified analysis using the median values of total body muscle (TBM), total body fat (TBF), and percentage body fat (PBF) as well as body mass index (BMI) =25 as the cutoff points of the high/low body composition groups. The adjusted R² values of the developed LUR models of PM_2.5 and PM₁₀ were 91.4% and 90.5% and also verified by cross-validation, respectively. After adjusting for confounding factors, we found that TBM significantly modified the association between PM₁₀ and lung function among asthma patients (interaction P value <0.05). In the low TBM group, seasonal average concentrations of PM₁₀ estimated by the LUR model increased by 10 μg/m³, and negative associations with lung function indicators were observed. For obese patients with BMI>25 and high TBF, the increase in PM₁₀ was associated with the decrease in lung function. The asthma patients with obesity and low total body muscle were more susceptible to adverse effects of PM₁₀ on lung function.