Os fatores associados à asma em crianças e adolescentes são universais? Estudo sistemático multicêntrico brasileiro / Are the factors associated with asthma in children and adolescents universal? A systematic multicenter Brazilian study

Objetivo: Comparar os fatores de risco associados à asma em escolares brasileiros habitantes de diferentes regiões do país. Método: Participaram estudantes (4-8 anos, n = 4.262; 10-14 anos, n = 10.603) matriculados em escolas privadas ou particulares de onze centros de nove cidades brasileiras, utilizando-se o protocolo do International Study of Asthma and Allergy in Childhood (ISAAC). Após a obtenção das taxas de prevalência de asma, foram selecionados de modo aleatório estudantes com asma ativa (resposta afirmativa para "sibilos nos últimos 12 meses") e sem asma (resposta negativa) mantendo-se como base a proporção 1:2. A seguir os responsáveis responderam questionário complementar ISAAC sobre fatores de risco. A análise de regressão logística identificou os fatores associados à expressão da asma nos escolares, em cada centro de origem. Resultados: Na faixa etária mais jovem, ter antecedente de rinite ou eczema atópico, história familiar de doenças alérgicas e ser exposto ao tabaco foram identificados pela maioria dos centros. Entre os adolescentes ocorreu o mesmo: ter rinite alérgica (8/11 centros), ter antecedentes familiares de doenças alérgicas (6/11), ser exposto passivamente ao tabaco (6/11), assim como a animais domésticos, sobretudo gato (5/11), nascer pré-termo, ter baixo consumo de vegetais e suco de frutas foram os fatores identificados. Conclusões: Os fatores associados ao desenvolvimento de asma em escolares brasileiros não foram uniformes. Fatores genéticos, como ter outra doença alérgica, ou familiares com doença alérgica, foram identificados pela maioria dos centros participantes. A exposição ao tabaco, assim como a animais domésticos, também mostrou ser de importância clínica.

Objective: To compare factors associated with the development of asthma in Brazilian schoolchildren residing in different geographical regions. Method: Children and adolescents (4-8 years, n = 4,262; 10-14 years, n = 10,603) enrolled in public or private schools at 11 centers from 9 Brazilian cities were screened using the protocol of the International Study of Asthma and Allergies in Childhood (ISAAC). After obtaining asthma prevalence rates, schoolchildren with active asthma (positive response for wheezing in the past 12 months) and without asthma (negative response) were randomly selected at a ratio of 1:2. Then, their parents or guardians were asked to answer the supplementary ISAAC questionnaire on risk factors. Multivariate logistic regression analysis identified factors associated with the expression of asthma among schoolchildren at each center. Results: Among children, having a history of rhinitis or atopic eczema, having a family history of allergic diseases, and being exposed to tobacco were identified as risk factors at most centers. Among adolescents, similar results were found: having allergic rhinitis (8/11 centers), having a family history of allergic diseases (6/11), being passively exposed to tobacco (6/11), being exposed to domestic animals, especially cat (5/11), having been born preterm, and having a low intake of vegetables and fruit juice were the main factors identified. Conclusion: Risk factors for the development of asthma in Brazilian schoolchildren were not unanimous. Genetic factors, such as having another allergic disease, or having family members with allergic disease, were identified by most of the participating centers. Exposure to tobacco, as well as to domestic animals, also showed to be clinically important.

Prevalence of asthma symptoms and associated factors in schoolchildren from Brazilian Amazon islands.

OBJECTIVES: To determine the prevalence of asthma symptoms among schoolchildren living on two different Brazilian Amazon islands and to identify the risk factors related to this condition. METHODS: A cross-sectional study of 400 schoolchildren (5-8 years old) using written questionnaires produced by the International Study of Asthma and Allergies in Childhood, a skin prick test (allergic sensitization), and a stool examination (for helminthic infection). Nonparametric tests were carried out, and the risk factors were identified by logistic regression. RESULTS: The prevalence of active asthma symptoms was markedly higher in children living on Outeiro Island (OI) than those living on Combú Island (CBI) (30.5% and 16.5%, respectively). The logistic regression identified several risk factors of asthma symptoms on CBI: parental history of asthma, night coughing in the past year, and "currently have a cat". On OI, the major risk factors were parental history of asthma, personal history of eczema, having two or more older siblings, and night coughing in the past year. The risk factors in common on both the islands were night coughing in the past year and parental history of asthma. CONCLUSIONS: The prevalence of asthma symptoms was higher in those with a lifestyle closer to that observed in urban areas (i.e., better sanitation and hygiene), reinforcing the protective effect of a rural environment. Different risk factors were associated with asthma symptoms in schoolchildren living on OI and on CBI. This fact may reflect the environmental individuality and particularities of each island.