Early life risk factors for adult asthma: a birth cohort study of subjects at risk

Abstract

Background: Prediction of adult asthma is important, and early prevention strategies should be targeted at those most at risk. Identifying high-risk children at an early age, however, is currently difficult.

Objective: We sought to determine those factors present in early life that predict an increased risk of adult asthma.

Methods: A prospective cohort study of subjects at risk of asthma and atopy was undertaken in Poole, England. One hundred babies of atopic parents were recruited at birth. During the first 5 years of life, subjects were recalled annually, all respiratory events were reported, and skin prick tests and total serum IgE measurements were performed. At 11 and 22 years, bronchial hyperresponsiveness was also measured. Seventy-three subjects were followed up at 5 years, 67 at 11 years, and 63 at 22 years.

Results: Twenty-three (37%) adult subjects reported wheezing within the previous 12 months. Fifteen (25%) of these subjects showed signs of bronchial hyperresponsiveness and were regarded as asthmatic. Wheezing before the age of 2 years occurred in 28% and was not significantly related to adult asthma (odds ratio, 0.3; 95% CI, 0.03-1.7; P = .19). A positive skin prick test response to hen's egg, cow's milk, or both in the first year was independently predictive of adult asthma (odds ratio, 10.7; 95% CI, 2.1-55.1; P = .001; sensitivity, 57%; specificity, 89%).

Conclusion: Prediction of adult asthma remains difficult. In this study of subjects at risk of atopy, skin sensitivity to hen's egg or cow's milk in the first year was predictive of adult asthma.