Airway hyperresponsiveness in chronic obstructive pulmonary disease: AÂ marker of asthma-chronic obstructive pulmonary disease overlap syndrome?

AHR is common in patients with mild-to-moderate COPD, affecting 1 in 4 patients and identifies a distinct subset of patients who have increased risk of disease progression and mortality. AHR may represent a spectrum of the asthma-COPD overlap phenotype that urgently requires disease modification.