Occupational and environmental risk factors for idiopathic pulmonary fibrosis: A case-control study

Abstract

Background: Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease of unknown etiology. The aim of this study was to evaluate the environmental and occupational risk factors of IPF. Methods: This hospital-based, case-control study included 206 patients with IPF selected from the Seoul National University Bundang Hospital Interstitial Lung Disease registry and 167 controls without lung disease. Data on occupation, lifestyle, transportation, and types of environmental and occupational dust exposure were obtained using a questionnaire. IPF diagnosis was confirmed based on the recent guidelines, and the possibility of hypersensitivity pneumonitis was excluded. Multiple logistic regression was performed to determine the risk factors for IPF. Results: After adjusting for age and sex, ever-smokers (odds ratio [OR], 2.35; 95 % confidence interval [CI]: 1.51-3.68) and individuals who smoked more than 30 pack-years (OR, 2.79; 95%CI: 1.70-4.68) showed an increased risk for IPF. Any occupational dust exposure (adjusted OR, 2.08; 95%CI: 1.19-3.72), especially exposure to chemicals (adjusted OR, 3.52; 99%CI: 1.56-9.05), was associated with IPF after adjusting for age, sex, and smoking. Conclusions: Smoking and occupational dust exposure are associated with an increased risk for IPF. Both factors have dose and duration-dependent relationships with the risk for IPF.