Mediating effect of periostin on lung function
We performed an in-depth analysis of the potential role of periostin in mediating the association between the level of urinary phthalate metabolites and Rrs5 (Fig. 2). The results indicated that a higher Σ3LMWP level had a significant and direct association with a higher Rrs5 (β: 0.084, 95% CI: 0.005 to 0.14, P = 0.04), and that some of the effect of Σ3LMWP was mediated by an increased periostin level (β: 0.013, 95% CI: 0.002 to 0.030, P< 0.001). Periostin mediates the relationship between Σ3LMWP level and Rrs5 (13.9% mediation, 95% CI: 10.7 to 77.0; P <.001).