Functional Predictors Discriminating Asthma-COPD Overlap (ACO) from Chronic Obstructive Pulmonary Disease (COPD).

Background: A significant proportion of patients with obstructive lung disease have clinical and functional features of both asthma and chronic obstructive pulmonary disease (COPD), referred to as the asthma-COPD overlap (ACO). The distinction of these phenotypes, however, is not yet well-established due to the lack of defining clinical and/or functional criteria. The aim of our investigations was to assess the discriminating power of various lung function parameters on the assessment of ACO. Methods: From databases of 4 pulmonary centers, a total of 540 patients (231 males, 309 females), including 372 patients with asthma, 77 patients with ACO and 91 patients with COPD, were retrospectively collected, and gradients among combinations of explanatory variables of spirometric (FEV1, FEV1/FVC, FEF25-75), plethysmographic (sReff, sGeff, the aerodynamic work of breathing at rest; sWOB), static lung volumes, including trapped gases and measurements of the carbon monoxide transfer (DLCO, KCO) were explored using multiple factor analysis (MFA). The discriminating power of lung function parameters with respect to ACO was assessed using linear discriminant analysis (LDA). Results: LDA revealed that parameters of airway dynamics (sWOB, sReff, sGeff) combined with parameters of static lung volumes such as functional residual capacity (FRCpleth) and trapped gas at FRC (VTG FRC) are valuable and potentially important tools discriminating between asthma, ACO and COPD. Moreover, sWOB significantly contributes to the diagnosis of obstructive airway diseases, independent from the state of pulmonary hyperinflation, whilst the diffusion capacity for carbon monoxide (DLCO) significantly differentiates between the 3 diagnostic classes. Conclusion: The complexity of COPD with its components of interaction and their heterogeneity, especially in discrimination from ACO, may well be differentiated if patients are explored by a whole set of target parameters evaluating, interactionally, flow limitation, airway dynamics, pulmonary hyperinflation, small airways dysfunction and gas exchange disturbances assessing specific functional deficits.

Speech-guided breathing retraining in asthma: a randomised controlled crossover trial in real-life outpatient settings.

BACKGROUND: Breathing retraining techniques have received increased attention in the management of asthma, because there is growing evidence of the usefulness of such methods in improving quality of life, reducing symptoms and reducing bronchodilator use. Our study investigated the effect of anthroposophic therapeutic speech (ATS), which uses sounds and syllabic rhythm to improve articulation, breathing and cardiorespiratory interaction, in patients with asthma in a real-life outpatient setting. METHODS: In a randomised controlled crossover trial, patients with asthma in three centres in Switzerland and Germany were randomised to either receive 11 ATS sessions or to wait. Subsequently, patients changed either to wait or to receive ATS. Primary outcomes were changes from the beginning to the end of each phase in the Asthma Quality of Life Questionnaire (AQLQ) and spirometry parameters. Secondary outcomes were changes in inhaled glucocorticoids, the Asthma Control Test (ACT), peak flow and asthma exacerbations. RESULTS: Altogether, 63 patients were randomised, of which 56 were enrolled and 49 completed the study. Statistically significant differences between the ATS groups and waiting control groups were found for the overall AQLQ score (d = 0.86, p = 0.001) and the domain scores for symptoms, activity limitation and emotional function as well as ACT score (d = 0.53, p = 0.048). No significant differences were observed in spirometry parameters, inhaled glucocorticoids, peak flow and days without asthma exacerbation per week. No serious adverse events occurred during ATS sessions. CONCLUSIONS: ATS significantly improves asthma control and quality of life in patients with asthma. Whether ATS may improve lung function remains to be shown. TRIAL REGISTRATION: ClinicalTrials.gov NCT02501824 . Retrospectively registered on 8 July 2015.