Objective: To examine the prevalence and natural course of asthma from childhood to adolescence in a population-based, Greek birth cohort and to identify associated factors.
Methods: Longitudinal information on asthma symptoms, physician diagnosed and treated, was available for 2133 children at 7 and 18 years of age.
Results: The prevalence of current asthma was 9.0% and 5.0% at 7 and 18 years, respectively. The prevalence of lifetime asthma was 26.3% at 18 years. More than half of the children (58.2%) with early onset asthma were asymptomatic at 7 years and only 7.6% continued to have symptoms during adolescence. However, in 48.2% of those with late onset asthma, symptoms persisted up to 18 years. Logistic regression analyses showed that male gender, family history of atopy, active adolescent smoking and maternal smoking were significantly positively associated with lifetime asthma at 18 years. In addition, smoking during pregnancy was associated with an increased risk for persistence of asthma symptoms at 18 years. Asthma during childhood and active adolescent smoking were positively associated, and daily consumption of fruit and vegetables was negatively associated with current asthma at 18 years of age. Finally, children who were breastfed had a lower risk for lifetime asthma at 7 years.
Conclusion: The prevalence of asthma symptoms at 7 and 18 years of age was low throughout Greece. Our results suggest that, among others, nutrition is an important correlate of asthma in Greek children.