PT - JOURNAL ARTICLE AU - Alain Van Muylem AU - Alain Michils TI - Asthma control is not related to large airways function DP - 2014 Sep 01 TA - European Respiratory Journal PG - P3970 VI - 44 IP - Suppl 58 4099 - http://erj.ersjournals.com/content/44/Suppl_58/P3970.short 4100 - http://erj.ersjournals.com/content/44/Suppl_58/P3970.full SO - Eur Respir J2014 Sep 01; 44 AB - Background: It is still controversial whether asthma control is influenced by large or small airways functional impairments.Aim: To assess the ability of large and small airways related standard pulmonary function indices to reflect asthma control improvement over time.Methods: FEV1, FEF75, FVC, airway resistance (Rva), and specific Rva (SRva) were measured at 1rst and 2nd visit in 490 asthma patients. Changes were expressed in percentage of 1rst visit value. Asthma control was assessed by asthma control questionnaire (ACQ) score. A significant improvement of asthma control was defined as a decrease of ACQ score by more than 1. A ROC curve analysis was performed, and indices results were assessed by comparing the area under the curve (AUC) to 0.5.Results: 207 improvements were observed. Mean changes for FEV1, FEF75, FVC, Rva, and SRva were 13, 32, 7, 49 and 40%, respectively (p<0.001).The AUC's for FEV1, FEF75, and FVC were 0.656, 0.612, and 0.630 (p<0.001), respectively for ACQ improvement's capture. The AUC's for Rva and SRva were 0.523, and 0.550 (p>0.05), respectively.Discussion: Though varying significantly, Rva and SRva, indices very likely reflecting large airways function, did not bring any contribution to the capture of asthma control improvement whereas indices associated, at least to some extent, to small airways function did.Conclusion: This strongly suggests that small airways dysfunction is primarily involved in the asthma process.