Prevalence and predictors of airway hyperresponsiveness in asthma, COPD, and overlap-findings from a large real-life population

Abstract

<b>Background:</b> Airway hyperresponsiveness (AHR) is a hallmark in asthma. The response to an indirect bronchoprovocation test with mannitol is associated with airway inflammation through multiple inflammatory mediators. AHR has also been observed in COPD and asthma-COPD overlap (ACO), but the underlying drivers of AHR in these groups are less clear <b>Aim:</b> The aim of this study was to describe the prevalence and predictors of AHR in a real-life population of patients with asthma, COPD, and ACO. <b>Methods:</b> Data are acquired from the large real-life BREATHE Study of a population of 1492. Mannitol tests were performed on all patients with an FEV1 &gt; 70% of predicted, and T2 markers were assessed with blood eosinophils and Fraction of exhaled nitric oxide (FeNO). <b>Results:</b> The proportion of patients with a positive mannitol test was comparable in all three groups: Asthma (n=331): 48%, COPD (n=46): 44% and ACO (n=47): 64%. In a regression analysis including FeNO, blood eosinophils, FEV1% of predicted and pack years, AHR to mannitol in asthma patients was independently predicted by the level of FeNO (OR:1.02(95% Cl, 1.01-1.02), P=0.00) as well as the number of pack years (OR:1.02(95% Cl, 1.00-1.04), P=0.030). In patients with COPD, FEV1% of predicted was the only predictor of AHR (OR: 0.90(95%Cl, 0.80-1.00), P=0.045). In patients with ACO, number of pack years was the sole predictor of AHR (OR: 0.90(95%Cl, 0.80-1.00), P=0.051). <b>Conclusion:</b> AHR to mannitol was equally prevalent in patients with asthma, COPD or ACO, but predictors differed across diseases, and further studies of the drivers of AHR are needed.