COPD
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The development of COPD features, such as an incomplete reversibility of airway obstruction (IRAO), in smoking or non-smoking asthmatic patients, a condition often named Asthma-COPD Overlap (ACO), has been recognized for decades. However, there is a need to know more about the sub-phenotypes of this condition according to smoking. This study aimed at comparing the clinical, physiological and inflammatory features of smoking and non-smoking asthmatic patients exhibiting IRAO. ⋯ In addition, ACO had higher residual volume (145 ± 45 vs 121 ± 29% predicted, P = 0.008) and a lower carbon monoxide diffusing capacity corrected for alveolar volume (90 ± 22 vs 108 ± 20% predicted, P = 0.0008). No significant differences were observed in systemic or lower airway inflammation. In conclusion, in smokers and non-smokers, the presence of IRAO in asthmatics is associated with different phenotypes that reflect the addition of smoking-induced changes to asthma physiopathology.