RESUMEN
Within-subject (difference between paired tests, or coefficient of variation [c. var.] of three consecutive measurements) and between-subjects (standard deviation of the mean group) variability were assessed for the variables derived from the single-breath nitrogen (SBN2) test in a group of healthy, asymptomatic subjects (n = 289) aged 20-64 years, from a rural area in North-East France. Duplicate measurements in 99 subjects showed excellent agreement between the two attempts (correlation coefficients between 0.94 and 0.98) for static lung volumes and the alveolar N2 slope (PIII); closing volumes (CV) were more variable (r = 0.77 for absolute value, 0.79 for % VC) while closing capacities (CC) were in intermediate position (r = 0.86 for absolute value, and 0.88 for % TLC). The variability of three consecutive measures in 190 subjects showed the coefficients of variation to be low for static volumes and closing capacity (2.4-7.4%) and higher for PIII (15.1%) and CV or CV/VC (18.2 and 17.8%). The analysis of variance did not detect significant differences between the three sets of measurements, with the exception of a progressive increase of vital capacity (VC), and decrease in residual volume (RV) from test 1 to test 3, the total lung capacity being the same. Variability was uninfluenced by age or sex, except a higher c. var. for female VC as compared to males (2.8 vs. 2.2%, P = 0.02) and a higher variability of TLC (2.9 vs. 2.3%, P = 0.03) and VC (2.8 vs. 1.9%, P = 0.003) in people older than 40 years as opposed to those younger than 40 years.
Asunto(s)
Nitrógeno , Pruebas de Función Respiratoria/normas , Adolescente , Adulto , Anciano , Pruebas Respiratorias , Computadores , Femenino , Francia , Humanos , Masculino , Persona de Mediana Edad , Alveolos Pulmonares/fisiología , Valores de Referencia , Población RuralRESUMEN
Prick tests were performed with "pneumallergerns" (mites, cereal dusts, animal dander, pollens, moulds--totalling 35 allergens) among 742 agricultural workers of the Meuse department (North East of France) as part of an epidemiological study on respiratory and immuno-allergological problems. Among those with positive skin tests, 47.9% had positive skin tests for mites, 22.4% for cereal dusts, 10.7% for animals, 12.7% for pollens and 7.8% for moulds. Polysensitization was frequent (19.5% of the population). When the skin test was positive for main house dust mites it frequently was positive for storage mites, too. Among vegetal dusts sensitization, soy bean allergy yielded the highest frequency (6.5%). As for animal sensitization, cow dander was the most frequently observed positive test. Sensitization to pollens and moulds was comparatively rare. This study shows the large frequency and diversity of "latent allergy" to pneumallergens among agricultural workers.