Asthma/Obstructive Pulmonary Disease Overlap

Update on Definition, Biomarkers, and Therapeutics

August Generoso; John Oppenheimer


Curr Opin Allergy Clin Immunol. 2020;20(1):43-47. 

In This Article

Prevalence and Natural History

As there is no clear definition of ACO, true prevalence remains unknown, though has been reported to range from as low as 12% to as high as 61% of patients with lower respiratory illness.[7] Diagnosis is highly age-dependent with the diagnosis more likely to be made in older patients or in smokers.[3] Van Boven et al.[8] found that in comparison to patients with COPD (n = 22 778), patients with ACO (n = 5093) were more frequently women, younger, had less smoking exposure, and had higher rates of certain comorbidities such as allergic rhinitis, anxiety, gastroesophageal reflux disease, and osteoporosis.

As for prognosis, the Copenhagen City Heart Study (n = 8382) found that patients with ACO and late-onset asthma had higher rates of FEV1 decline and exacerbations, with poorer prognosis.[5] Meanwhile, Cosio et al.[9] found that ACO patients were predominantly men, receiving ICS, and had a better 1-year prognosis than clinically similar patients with COPD only. The significant disparity in findings among these studies further reinforces the need to better define and stratify ACO.