Late Breaking Abstract - Prevalence of interstitial lung abnormalities in a Swedish population-based sample

Abstract

<b>Introduction:</b> Interstitial lung abnormalities (ILA) are incidental findings on computed tomography (CT). These patterns can present as an early stage of fibrotic lung diseases. Our aim was to estimate the prevalence of ILA in the Swedish population and its association with demographics, chronic diseases, symptoms and lung function. <b>Methods:</b> Participants in the population-based Swedish CArdioPulmonary BioImage Study (SCAPIS) who had undergone a chest CT, were included. ILA were divided in nonfibrotic (ground-glass opacities, cysts and reticular pattern without bronchiectasis) and fibrotic (honeycombing and reticular pattern with traction bronchiectasis). The significance level after Bonferroni correction was &lt;0.001. <b>Results:</b> Out of 29 521 participants aged 50-64 years, 2 870 (9.7%) had ILA of which 2 736 (9.3%) were nonfibrotic and 134 (0.5%) fibrotic. Individuals with ILA were older (58.5±4.3 vs 57.4±4.3, p&lt;0.001), had more pack-years (18.2±14.4 vs 15.4±12.9, p&lt;0.001), chronic bronchitis (7.1% vs 4.9%, p&lt;0.001), hypertension (25.9% vs 22.5%, p&lt;0.001), previous myocardial infarction or angina pectoris (3.3% vs 2.2%, p&lt;0.001), dyspnea (Modified Medical Research Council Dyspnea Scale ³2 2.6% vs 1.7%, p&lt;0.001) and lower lung volumes (FVC% 101.5±13.6 vs 102.8±12.9, p&lt;0.001) compared with no ILA. Persons with fibrotic ILA were older (60.0±4.1 vs 58.4±4.3, p&lt;0.001) and higher proportion were males (59.7% vs 46.8%, p&lt;0.004) compared with nonfibrotic ILA. <b>Conclusions:</b> ILA was a common finding in this middle-aged population. Individuals with ILA were older, smoked more, had more chronic diseases, dyspnea and lower lung volumes compared with no ILA. Fibrotic ILA resembled idiopathic pulmonary fibrosis.