Changes in respiratory symptoms and airway hyperresponsiveness after 27 years in a population-based sample of school children.

We wanted to test the hypothesis that childhood airway hyperresponsiveness, even in the absence of respiratory symptoms, is a risk factor for respiratory disease in adulthood. In a childhood survey of 1963, three groups of 20 children aged 8-11 yrs, were selected from a population sample: 1) a group with recurrent respiratory symptoms (symptomatic group); 2) a group with no symptoms but a positive family history of atopy; and 3) a control group. All children completed assessment of symptoms, atopy, lung function, and airway hyperresponsiveness. At the adulthood survey 27 yrs later, 85% of the original sample were reinvestigated. Only 10 out of 19 subjects (53%) of the original symptomatic group still had symptoms. The significant difference of forced expiratory volume in one second (FEV1) % predicted in childhood between the symptomatic and the control group had disappeared. The prevalence of airway hyperresponsiveness had decreased in all groups. In asymptomatic hyperresponders it had normalized at adult age. The asymptomatic hyperresponders in childhood had lower levels of lung function, both in childhood and in adulthood. In univariate and multivariate analyses, respiratory symptoms at adult age were related to childhood atopy. Results suggest that childhood atopy is a risk factor for respiratory symptoms in young adulthood, but that mild childhood airway hyperresponsiveness is not.