Association between occupational exposure and lung function, respiratory symptoms, and high-resolution computed tomography imaging in COPDGene

RATIONALE: Although occupational exposure to dust and fumes is considered a risk factor for chronic obstructive pulmonary disease, this determination has been limited by reliance on spirometry alone to assess disease severity in predominantly male populations. OBJECTIVES: To determine the effect of occupational exposure on lung function, respiratory symptoms, and findings of emphysema and airway wall thickness measured using quantitative computed tomography in men and women. METHODS: COPDGene is a multicenter study of current and former smokers that underwent standardized volumetric chest computed tomography scans to assess airways, % emphysema, and % gas trapping. Spirometry and a respiratory questionnaire including occupational history were also analyzed in 9,614 subjects (4,496 women). Logistic regression and analysis of covariance was used to assess associations with exposure. MEASUREMENTS AND MAIN RESULTS: Occupational exposure to both dust and fumes was reported by 47.9% of men and 20.1% of women. Adjusting for age, race, body mass index, education, and current and lifetime smoking, the odds ratios for persons with dust and fume exposures for chronic cough, chronic phlegm, persistent wheeze, and Global Initiative for Chronic Obstructive Lung Disease stages 2 and higher chronic obstructive pulmonary disease were significantly elevated and similar for men (1.83, 1.84, 2.0, 1.61, respectively) and women (1.65, 1.82, 1.98, 1.90, respectively). The % predicted FEV1 was similarly lower in those with exposure in men (70.7 +/- 0.8 vs. 76.0 +/- 0.9; P < 0.001) and women (70.5 +/- 0.8 vs. 77.2 +/- 0.8; P < 0.001). Percent emphysema and gas trapping was greater in those exposed to dust and fumes in men and women. In men, but not in women, persons with exposure had a greater mean square root wall area of 10-mm internal perimeter airways. CONCLUSIONS: Occupational exposure to dust and fumes in men and women is similarly associated with airflow obstruction, respiratory symptoms, more emphysema, and gas trapping in men and women.