Dynamic compliance and reactance in older non-smokers with asthma and fixed airflow obstruction.

In asthma, abnormal mechanical properties of the airways and lung tissue leads to airway narrowing and changes in ventilation distribution [1]. Ventilation distribution is determined by the variation of time constants [2], a product of resistance×static compliance of individual lung units. Ventilation distribution is heterogeneous in healthy lungs, but even more so in airways diseases, including asthma [3]. This is because time constants are often even more heterogeneous in disease due to changes in resistances and compliances [3, 4]. Footnotes This manuscript has recently been accepted for publication in the European Respiratory Journal . It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article. Conflict of interest: Dr. Chapman has nothing to disclose. Conflict of interest: Dr. Tonga reports personal fees from GlaxoSmithKline, Roche, outside the submitted work. Conflict of interest: Dr. Rutting has nothing to disclose. Conflict of interest: Dr. Durack has nothing to disclose. Conflict of interest: Dr. Thamrin has a patent WO 2006130922 A1 issued which is broadly relevant to the work. In addition, Dr. Thamrin has intellectual property arrangements with Thorasys Medical Systems and Restech srl relating to research collaborations, but does not have any financial relationships with either company. Conflict of interest: Dr. King reports grants from University of Sydney Bridging Grant, during the conduct of the study; grants, personal fees and other from AstraZeneca, Boehringer Ingelheim, CycloPharm, GlaxoSmithKline, Novartis, Menarini, MundiPharma, grants from National Health & Medical Research Council, Asthma Foundation, Philanthropic donations via Sydney University, other from ATS and ERS, non-financial support and other from Restech, outside the submitted work;.