The prevalence of wheezing and its association with serum zinc concentration in children and adolescents in Brazil.

OBJECTIVE: To assess the influence of zinc serum status on the prevalence of wheezing in a sample of children and adolescents in Northeastern Brazil. RESEARCH METHODS AND PROCEDURES: This is a cross-sectional study which included 592 students of 6-12 years old, from the public elementary schools of São Francisco do Conde, Bahia, Northeastern Brazil. Report of wheezing in the past 12 months was collected using a questionnaire of the International Study of Asthma and Allergies in Childhood Program (ISAAC) phase III, adapted to Portuguese. The determination of serum Zn levels was performed using a flame atomic absorption spectrometer. Data on anthropometric status, level of physical activity, pubertal development and socioeconomic information, for each participant were obtained. Multivariate logistic regression analyses were used to assess the associations of interest. RESULTS: Of the students, 8.6% (95% CI 6.30-10.9) reported having wheezing. The mean (SD) serum zinc level was 114 (22.9 µg/dL). The results of the multiple logistic regression analysis showed, after adjustments, positive and significant association between low serum zinc levels and wheezing. Students categorized as being below the median for serum Zn concentration presented an almost 1.9-fold increase in the wheezing prevalence ratio (OR=1.9; 95% CI 1.03-3.53). CONCLUSION: The main findings of this study suggest that the level of zinc may influence the risk of wheezing in late childhood on the study population.

Food and nutrition insecurity: a marker of vulnerability to asthma symptoms.

OBJECTIVE: To evaluate the association between food and nutrition insecurity and asthma in children from Latin America. DESIGN: Cross-sectional study. SETTING: São Francisco do Conde, Bahia, north-eastern Brazil. SUBJECTS: The study included 1307 children aged 6-12 years from public elementary schools. Asthma symptoms were collected using a questionnaire that was translated and adapted from the International Study of Asthma and Allergies in Childhood, phase III. The diagnosis of asthma was determined based on reports of wheezing in the previous 12 months. The Brazilian Food Insecurity Scale was used to identify food insecurity. We also obtained demographic, socio-economic and anthropometric information for each participant. We used multivariate logistic regression analyses to assess the associations of interest. RESULTS: Of the children surveyed, 10·4% had a history of wheezing and 64·5% had some degree of food and nutrition insecurity. We found a positive dose-response relationship and statistically significant associations of asthma with moderate (OR = 1·71, 95% CI 1·01, 2·89) and severe (OR = 2·51, 95% CI 1·28, 4·93) food and nutrition insecurity. CONCLUSIONS: The results show that moderate and severe food and nutrition insecurity are markers of vulnerability to wheezing. It is important to note that the results of studies in this field have potential implications for social policies that promote food security. Further studies to identify the mechanisms involved in the relationship between food and nutrition insecurity and asthma are needed.

Dietary Patterns and Wheezing in the Midst of Nutritional Transition: A Study in Brazil.

To assess the influence of dietary patterns on the prevalence of wheezing in the child and adolescent population in Northeastern Brazil. This is a cross-sectional study of male and female students, 6-12 years old, from the public elementary schools of São Francisco do Conde, Bahia, Northeastern Brazil. The report of wheezing in the past 12 months was collected using a questionnaire from the International Study of Asthma and Allergies in Childhood Program phase III, adapted to Portuguese. Consumption patterns were derived from principal component analysis based on the frequency of consumption of 97 food items by the food frequency questionnaire. We also obtained the anthropometric status, level of physical activity, pubertal development, and socioeconomic information, for each participant. Multivariate logistic regression analyses were used to assess the associations of interest. Of the children surveyed, 10.6% reported having wheezing. We identified 2 dietary patterns named Western and Prudent. We found a positive statistically significant association of the Western pattern with wheeze (odds ratio=1.77, 95% confidence interval: 1.10-2.84) after adjustment for total energy intake and controlling for potential confounders. The results showed that the Western dietary pattern was associated with wheezing. Our result is according with previous findings reported in several other studies.