Bronchodilator responsiveness in chronic obstructive pulmonary disease: prevalence, significance, and clinical implications.

PURPOSE OF REVIEW: Bronchodilator responsiveness (BDR) is often considered a key feature distinguishing asthma from chronic obstructive pulmonary disease (COPD). However, recent evidence suggests that BDR alone may not be a reliable discriminator between these conditions. There is still no consensus on BDR definitions and testing protocols. Additionally, it remains unclear whether BDR is linked to a specific COPD phenotype or influences treatment responses. Our review of recent literature attempts to clarify some of these issues.

RECENT FINDINGS: A significant proportion of COPD patients demonstrate BDR, but the variability in testing procedures and definitions makes it challenging to draw any definite conclusion. There is no evident association between BDR and specific COPD characteristics. A few studies suggest that BDR may be associated with marginally better treatment response and disease outcomes in COPD. The impact of recent changes in BDR definitions on clinical practice remains to be fully understood.

SUMMARY: There is still no clear, clinically relevant threshold to define BDR. BDR is an unreliable discriminator to differentiate asthma from COPD and is not consistently linked to any specific COPD phenotype, treatment response, or disease outcomes. Further research is needed to refine the definitions and implications of BDR in COPD.