#64 Predictors of chronic obstructive pulmonary disease among office and school workers

Abstract

PURPOSE: The aim of this analysis was to identify predictors of chronic obstructive pulmonary disease (COPD) in office and school workers, a subset of the population generally assumed to have a low prevalence of COPD and limited exposure to chemicals and dusts at work. METHODS: National Health and Nutrition Examination Survey (NHANES III) data on 2486 US office workers were analyzed, using SUDAAN to estimate population prevalence of COPD. COPD was defined as FEV 1 /FVC<70% and FEV 1 <80% predicted. Based on the literature, risk factors evaluated for airflow obstruction included age, race, sex, body size, education, poverty/income ratio, smoking, alcohol, serum antioxidants, dietary fats , coffee, energy use during exercise, and employment duration. Logistic regression was used to develop a multivariate model to estimate risk of COPD. RESULTS: The population prevalence of COPD among US office and school workers was estimated at 4.7% compared with 8.1% in other US workers. As expected, current smoking was a strong predictor of COPD. After adjusting for age, race, sex, and current smoking, workers with COPD had significantly (p < 0.02) greater mean duration of employment, pack years, alcohol intake, body mass index (BMI), coffee consumption, and dietary fat and cholesterol. Workers with COPD had lower mean serum selenium and energy use during exercise. In multivariate modeling, employment duration, cigarette smoking, age, race, alcohol, use of propane fuel at home, serum antioxidant (selenium), BMI, and exercise were found to explain COPD risk. Compared to other sources of home heat, propane fuel was associated with a 4.2-fold risk of COPD (95% CI 1.2–15.1). Duration of employment as an office or school worker for more than 10 years (vs. < 10 years) was associated with a 1.8-fold (95% CI 1.0–3.3) excess risk of COPD. CONCLUSION: Multivariate modeling revealed several risk factors for COPD amenable to modification, including smoking, alcohol, and propane fuel. Selenium and exercise were found to be protective. The predictive model developed in multivariate logistic regression analysis suggests that, after controlling for other risk factors, working as an office or school worker for 45 years is associated with a 2.4-fold excess risk of COPD.