Overweight, asthma symptoms, atopy and pulmonary function in children of 4-12 years of age: findings from the SCAALA cohort in Salvador, Bahia, Brazil.

OBJECTIVE

To evaluate the association between overweight and the occurrence of asthma and atopy in a cohort of children of 4-12 years of age living in the city of Salvador in 2005.

DESIGN

Cross-sectional study nested in a cohort.

SETTING

The metropolitan region of Salvador, Bahia, Brazil.

SUBJECTS

The study included 1129 children of 4-12 years age who presented complete information on the variables used here. Skin tests for allergy, spirometry, faecal parasitology, serum IgE and anthropometric surveys were conducted. Poisson's multivariate regression was adopted.

RESULTS

Wheezing was found in 29·1% and asthma in 22·8% of children, both conditions being more common in those under 6 years of age and 34% more common in overweight children (prevalence ratio (PR) = 1·34; 95% CI 1·07, 1·67) following adjustment. The ratio between forced expiratory volume in 1s and forced vital capacity was associated with overweight (PR = 1·35; 95% CI 1·11, 1·61). No statistically significant association was found between overweight and allergen-specific IgE or with wheezing.

CONCLUSIONS

These results are in agreement with the hypothesis that overweight is associated with asthma and pulmonary function, even following adjustment for intervening variables known to be associated with the pathogeny of asthma.