Cambios en la prevalencia de síntomas de asma e hiperreactividad bronquial en el seguimiento de dos cohortes poblacionales de la ciudad de Huelva

Résumé

Objective: To analyze the changes in the prevalence of asthmatic symptoms and bronchial hyper-reactive (BHR) conditions, which occur with age, in two groups of adolescents and young adults from the city of Huelva. Material and Methods: A second follow-up evaluation was performed on the two populations studied between 1991 and 1993: adolescents between 11 and 16 years of age (n = 714), included in the Study of Breathing Illnesses of Huelva (EERH-I), and young adults 20-44 years old (n=271), included in the European Study of Breathing Illnesses (ECRHS-I) of the city of Huelva. A questionnaire about breathing symptoms (BS) and a non-specific test of bronchial hyper-reactivity with methacholine (MT) were administered. In the second evaluation, carried out with an average followup of 9 years, it was possible to study 401 of those ¿child-adolescents¿ and 204 of those ¿young adults.¿ The same as in the previous phase, both populations were administered the same questionnaire about breathing symptoms, a spirometry and a non-specific bronchial provocation test with methacholine was performed. The prevalence of wheezing, BHR and asthma found in the same population (children or adults) was compared in both cross samples (1991 and 2001). The results obtained were compared between both populations. Results: Between the years 1991 and 2001, both in adolescents and adults, the breathing symptoms increased, especially wheezing and dyspnea, at rest and at exercise. Bronchial hyper-reactivity had a clear increase in the adolescents (p < 0.001) and only a slight increase in the adults (NS). As a consequence of the above, the epidemiologic diagnosis of asthma (wheezing + BHR) increased significantly in adolescents. Another outstanding fact in the children was that only half of those medically diagnosed with asthma received treatment for their asthma, and amongst these, there were fewer that said they had experienced wheezing in the last 12 months. The discrepancy between wheezing and the diagnosis of asthma was more evident in adults.Conclusions: In the 90s and in the city of Huelva, a city with a high prevalence of wheezing and medium-low level of bronchial hyper-reactivity (BHR) and asthma, BS and the HR have increased during adolescence and stabilized in adulthood. This could be explained both by the natural evolution of the disease and by the different influences of the environmental conditions at the different ages