Young COPD in the Swedish National Airway Register

<bold>Background:</bold> Chronic Obstructive Pulmonary Disease (COPD) is commonly diagnosed at older age. Patients with a diagnosis at younger age might represent a different phenotype. We aimed to characterize patients with young COPD. <bold>Method:</bold> In 2019, physician diagnosed primary care patients with COPD (n=39179; 55.8% female) were identified in the Swedish National Airway Register and categorized either young (≤50 years, n=395) or higher middle age and above (>50 years, n=29297) patients, as proposed by the Global Initiative for Chronic Obstructive Lung Disease 2023. Differences related to the burden of the disease, comorbidities and treatment were studied. <bold>Results:</bold> Young COPD was associated with a better lung function (mean FEV₁% pred; 69.8 vs 61.6, p<0.001), higher Body Mass Index (mean; 28.3 vs 26.5, p<0.001), fewer exacerbations (25.8 vs 31.2%, p=0.026), less dyspnea (mMRC ≥2; 7.8% vs 15.3%, p=0.001), but similar COPD Assessment Test scores (mean CAT; 13.3 vs 12.5, p=0.102) compared with older patients. Young patients had fewer comorbidities compared to older patients; diabetes (11.1 vs. 20.1%, p<0.001), heart disease (3.3 vs 26.6%, p<0.001) and hypertension (23.3 vs 63.0%, p<0.001), while depression/anxiety (33.9 vs 26.0%, p<0.001) were more common in young age. Differences were found in pharmacological treatment between young COPD and older patients: only ICS (8.4 vs 2.2%, p<0.001), ICS+LABA (10.6 vs 7.8%, p=0.050) and ICS+LABA+LAMA (17.7 vs 28.7%, p<0.001). <bold>Conclusions:</bold> Young COPD was less severe and associated with less cardiovascular comorbidity but higher BMI and more depression/anxiety than COPD of middle age and above. Differences were found in pharmacological treatment between the groups.