PREVALENCE OF ASTHMA AND RESPIRATORY SYMPTOMS IN DAIRY FARMERS IN THEFRENCH PROVINCE OF THE DOUBS

With the aim of determining whether dairy farming is associated with a n excess of asthma and respiratory symptoms, we compared the respirato ry status in a sample of dairy farmers (n = 265) and a control group o f nonexposed subjects (n = 149). The study protocol comprised a questi onnaire, spirometry, and a bronchodilatation test (400 mu g salbutamol powder), and an allergological evaluation: serum total IgE level, Pha diatop test, and skin prick tests (SPT) for seven inhalant allergens. Cumulative prevalences of self-reported asthma and of current asthma w ere respectively 5.3% and 1.5% in farmers, and respectively 3.4% and 1 .3% in control subjects (both NS). Prevalences of all the respiratory symptoms studied were higher in farmers, with statistically significan t differences after adjusting for age, sex, and smoking, for wheezing ever (OR: 2.7, p < 0.05), wheezing within the last year (OR: 5.5 p <0. 025), usual morning cough (OR: 5, p < 10(-3)), usual morning phlegm (O R: 11.3, p < 10(-4)), and chronic bronchitis (OR: 11.8, p < 0.01). The effect of exposure on these symptoms was more pronounced than, or of the same magnitude as that of smoking. Smoking and exposure had an add itive effect except for chronic cough for which a positive interaction was observed (p = 0.05). Mean FFV1/VC (percentage of predicted) was s tatistically negatively correlated to dairy farming (p < 0.025) after adjusting for confounders. Bronchial obstruction was reversible in abo ut 10% of subjects in both groups. In conclusion, this study mainly de monstrated an excess of respiratory symptoms in dairy farmers which is weak and nonsignificant for asthma, and high for cough, phlegm, and c hronic bronchitis. It also suggested that the combined effect of farmi ng and smoking was synergistic on chronic cough.