Longitudinal predictors of bronchial hyperresponsiveness and FEV1 decline in bakers.

OBJECTIVE: To determine long-term predictors of bronchial hyperresponsiveness (BHR) and forced expiratory volume in one second (FEV1) decline. METHODS: A longitudinal study in 110 bakers in 4 industrial bakeries and 38 non-exposed workers was conducted at the workplace with a mean of 3.3 visits per subject over a period of 13 years and a mean duration of follow-up of 6 years in bakers and 8 years in non-exposed subjects. A respiratory health questionnaire was administered; occupational allergen skin prick tests, spirometry and a methacholine bronchial challenge test were performed at each visit. In each bakery, full-shift dust samples of the inhalable fraction were obtained in order to assess the exposure of each job assignment. The repeated measurements of BHR and FEV1 were analyzed using mixed effects logistic and linear regression models in subjects seen at least twice. RESULTS: BHR, respiratory symptoms and their simultaneous occurrence depended on the duration of exposure. FEV1 significantly decreased with duration of exposure and BHR at a preceding visit. This result persisted when adjusting for the effect of BHR at the current visit. The measured exposure levels were not a significant predictor for any outcome. Occupational sensitization was only a predictor of a decline in FEV1 when duration of exposure was not included. CONCLUSION: In flour-exposed industrial bakers, length of exposure and smoking are long-term determinants of BHR and of the decrease in FEV1. BHR at a preceding visit predicted lower FEV1 even when accounting for the effect of BHR at the current visit.

Association of physical job demands, smoking and alcohol abuse with subsequent premature mortality: a 9-year follow-up population-based study.

This study assessed the relationships of physical job demands (PJD), smoking, and alcohol abuse, with premature mortality before age 70 (PM-70) among the working or inactive population. The sample included 4,268 subjects aged 15 or more randomly selected in north-eastern France. They completed a mailed questionnaire (birth date, sex, weight, height, job, PJD, smoking habit, alcohol abuse (Deta questionnaire)) in 1996 and were followed for mortality until 2004 (9 yr). PJD score was defined by the cumulative number of the following high job demands at work: hammer, vibrating platform, pneumatic tools, other vibrating hand tools, screwdriver, handling objects, awkward posture, tasks at heights, machine tools, pace, working on a production line, standing about and walking. The data were analyzed using the Poisson regression model. Those with PM-70 were 126 (3.81 per 1,000 person-years). The leading causes of death were cancers (46.4% in men, 57.1% in women), cardiovascular diseases (20.2% and 11.9%), suicide (9.5% and 7.1%), respiratory diseases (6.0% and 4.8%), and digestive diseases (2.4% and 4.8%). PJD3, smoker, and alcohol abuse had adjusted risk ratios of 1.71 (95% CI 1.02-2.88), 1.76 (1.08-2.88), and 2.07 (1.31-3.26) respectively for all-cause mortality. Manual workers had a risk ratio of 1.84 (1.00-3.37) compared to the higher socio-economic classes. The men had a two-fold higher mortality rate than the women; this difference became non-significant when controlling for job, PJD, smoker and alcohol abuse. For cancer mortality the factors PJD3, smoker, and alcohol abuse had adjusted risk ratios of 2.00 (1.00-3.99), 2.34 (1.19-4.63), and 2.22 (1.17-4.20), respectively. Health promotion efforts should be directed at structural measures of task redesign and they should also concern lifestyle.