Association between small airway dysfunction and cardiac conditions: a Swiss urban population cross-sectional study.

Introduction Small airway dysfunction (SAD) may be an early sign of cardiopulmonary overload due to small airway mucosal thickening or be related to the oxidative stress characteristic of cardiovascular diseases. A high prevalence of SAD coexisting with chronic heart failure may be associated with an increase in all-cause mortality. We analysed the association between SAD and cardiac conditions in the PneumoLaus study. Methods PneumoLaus is based on the Swiss general urban population cohort CoLaus|PsyCoLaus. SAD was defined by maximal mid-expiratory flow (MMEF) before bronchodilatation <65% predicted or MMEF