Background: There has been a concurrent increase in the prevalence of obesity and asthma in recent years in New Zealand and other countries.
Methods: Two cross sectional surveys performed in 1989 and 2000 were used to test this association in children of mean age 11.7 years. Body mass index (BMI) was calculated as weight/height2 (kg/m2) and obesity and overweight defined according to an international standard. Standard questions were used to measure the prevalence of asthma symptoms.
Results: Significant increases in the prevalence of reported symptoms and disease between 1989 and 2000 were not explained by a concurrent increase in the prevalence of obesity. In 2000, multivariate analysis showed that increasing BMI standard deviation score was significantly associated with current wheeze (p=0.002), inhaled steroid use (p=0.004), and the use of any medication (p=0.001). None of the associations was significantly different for boys or girls.
Conclusion: There is some evidence for an association of obesity with asthma symptoms and treatment but this does not explain the increasing prevalence of this disease.