(HealthDay)—Profiles of childhood respiratory risk factors predict middle-age lung function levels and chronic obstructive pulmonary disease (COPD) risk, according to a study published in the September issue of the Annals of the American Thoracic Society.

Dinh S. Bui, from the University of Melbourne in Australia, and colleagues assessed 11 childhood risk factor profiles (documented at age 7 years) and their influence on lung function and COPD in middle age among 8,352 participants in the Tasmanian Longitudinal Health Study.

The researchers identified six risk profiles: (1) unexposed or least exposed (49 percent); (2) parental smoking (21.5 percent); (3) allergy (10 percent); (4) frequent asthma, bronchitis (8.7 percent); (5) infrequent asthma, bronchitis (8.3 percent); and (6) frequent asthma, bronchitis, allergy (2.6 percent). Profile six was most strongly associated with lower forced expiratory volume in one second (FEV1), lower FEV1/forced vital capacity, and increased COPD risk (odds ratio, 4.9) at age 53 years. Adult active asthma largely mediated the effect of six on COPD. Profiles two and four had smaller adverse effects than profile six, and profiles two and six were synergistically stronger for smokers.

"Targeting active in adulthood (i.e., a dominant mediator) and smoking (i.e., an effect modifier) may block causal pathways and lessen the effect of such established early-life exposures," the authors write.