Background: Occupational exposure to dusts, gases and fumes has been associated with reduced FEV1 and sputum production in COPD patients. The effect of occupational exposure on other characteristics of COPD, especially those reflecting emphysema, has not been studied in these patients. Methods: We studied 338 patients hospitalized for a first exacerbation of COPD in 9 Spanish hospitals, obtaining full occupational history in a face-to-face interview; job codes were linked to a job exposure matrix for semi-quantitative estimation of exposure to mineral/biological dust, and gases/fumes for each job held. Patients underwent spirometry, diffusing capacity testing and analysis of gases in stable conditions. Quality of life, dyspnea and chronic bronchitis symptoms were determined with a questionnaire interview. A high- resolution CT scan was available in 133 patients. Results: 94% of the patients included were men, with a mean age of 68(8.5) years and a mean FEV1% predicted 52 (16). High exposure to gases or fumes was associated with chronic bronchitis, and exposure to mineral dust and gases/fumes was associated with higher scores for symptom perception in the St. George’s questionnaire. No occupational agent was associated with a lower FEV1. High exposure to all occupational agents was associated with better lung diffusion capacity, in long-term quitters. In the subgroup with CT data, patients with emphysema had 18% lower DLCO compared to those without emphysema. Conclusions: In our cohort of COPD patients, high exposure to gases or fumes was associated with chronic bronchitis, and high exposure to all occupational agents was consistently associated with better diffusion capacity in long-term quitters.

The PAC-COPD Study is funded by grants from the Fondo de Investigación Sanitaria (FIS PI020541), Ministry of Health, Spain; Agència d’Avaluació de Tecnologia i Recerca Mèdiques (AATRM 035/20/02), Catalan Government; Spanish Society of Pulmonology and Thoracic Surgery (SEPAR 2002/137); Catalan Pulmonology Foundation (FUCAP 2003 Beca Maria Ravà); Red RESPIRA (RTIC C03/11); Red RCESP (RTIC C03/09); Fondo de Investigación Sanitaria (PI052486); Fondo de Investigación Sanitaria (PI052302); Fondo de Investigación Sanitaria (PI060684); Fundació La Marató de TV3 (num. 041110); and Novartis Farmacèutica, Spain. CIBERESP and CIBERES are funded by Instituto de Salud Carlos III, Ministry of Health, Spain. Judith Garcia-Aymerich has a researcher contract from Instituto de Salud Carlos III (CP05/00118), Ministry of Health, Spain