Prevalence of asthma and respiratory symptoms in dairy farmers in the French Province of the Doubs

• Published in: American journal of respiratory and critical care medicine Vol. 158; no. 5; pp. 1493 - 1498
• Main Authors: DALPHIN, J.-C, DUBIEZ, A, MONNET, E, GORA, D, WESTEEL, V, PERNET, D, POLIO, J.-C, GIBEY, R, LAPLANTE, J.-J, DEPIERRE, A
• Format: Journal Article
• Language: English
• Published: New York, NY American Lung Association 01.11.1998
• Subjects: Adult; Age Factors; Albuterol; Allergens; Allergic diseases; Asthma - epidemiology; Biological and medical sciences; Bronchitis - epidemiology; Bronchodilator Agents; Chronic Disease; Cough - epidemiology; Cross-Sectional Studies; Dairying - statistics & numerical data; Female; Forced Expiratory Volume - physiology; France - epidemiology; Humans; Immunoglobulin E - blood; Immunopathology; Male; Medical sciences; Middle Aged; Occupational Diseases - epidemiology; Prevalence; Respiratory and ent allergic diseases; Respiratory Hypersensitivity - epidemiology; Respiratory Sounds; Sex Factors; Skin Tests; Smoking - epidemiology; Spirometry; Sputum; Surveys and Questionnaires; Vital Capacity - physiology; France; Human; Immunopathology; Allergy; Spirometry; Prevalence; Respiratory disease; Exploration; Biophysics; Occupational exposure; Epidemiology; Asthma; Lung volume; Symptomatology; Immunological investigation; Risk factor; Farmer; Comparative study
• ISSN: 1073-449X; 1535-4970
• DOI: 10.1164/ajrccm.158.5.9709108

With the aim of determining whether dairy farming is associated with an excess of asthma and respiratory symptoms, we compared the respiratory status in a sample of dairy farmers (n = 265) and a control group of nonexposed subjects (n = 149). The study protocol comprised a questionnaire, spirometry, and a bronchodilatation test (400 micrograms salbutamol powder), and an allergological evaluation: serum total IgE level, Phadiatop test, and skin prick tests (SPT) for seven inhalant allergens. Cumulative prevalences of self-reported asthma and of current asthma were 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 significant differences after adjusting for age, sex, and smoking, for wheezing ever (OR: 2.7, p < 0.05), wheezing within the last year (OR: 5.2, p < 0.025), usual morning cough (OR: 5, p < 10(-)3), usual morning phlegm (OR: 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 additive effect except for chronic cough for which a positive interaction was observed (p = 0.05). Mean FEV1/VC (percentage of predicted) was statistically negatively correlated to dairy farming (p < 0.025) after adjusting for confounders. Bronchial obstruction was reversible in about 10% of subjects in both groups. In conclusion, this study mainly demonstrated an excess of respiratory symptoms in dairy farmers which is weak and nonsignificant for asthma, and high for cough, phlegm, and chronic bronchitis. It also suggested that the combined effect of farming and smoking was synergistic on chronic cough.