Stable COPD Picture through Exhaled Breath Condensate, Questionnaires and Tests. A Proof of Concept Study

Abstract

Background: Changes in lung structures persist in stable Chronic Obstructive Pulmonary Disease (COPD), but their correlation with the clinical picture remains unclear. The purpose of this study was to assess the stable COPD picture via the relationship between exhaled breath condensate (EBC) particle concentration and the Saint George Respiratory Questionnaire (SGRQ), COPD Assessment Test (CAT), and six-minute walking test (6 MWT). Methods: 12 stable COPD and 12 healthy subjects participated in the study. The EBC was collected with Rtube and analyzed using the Accusizer FxNano. Particle concentration was measured and correlated with the findings of the tools used to assess the health status and functional profile of COPD. The results’ analysis was performed with the Spearman’s test and the Mann-Whitney U - test. Results: The COPD group presented a worse picture of health status and functional profile compared to the healthy group. Correlations were observed between components of the SGRQ and CAT. The two groups presented similar levels of EBC particle concentrations, but the number of small particles was higher in COPD subjects. A correlation of the EBC particle concentration with the activity and total score of the SGRQ was only observed in the healthy group. Conclusion: The total particle number was similar in the COPD and healthy groups. A few correlations between the EBC particles and tools used were also observed. The use of EBC particle concentration to monitor COPD status cannot be claimed with confidence because of the small sample size. Further research is necessary, particularly in large-scale groups.