Risk Factors for Early, Persistent, and Late-onset Wheezing in Young Children

Abstract

Wheezing in childhood is not a single disorder and different wheezing-associated respiratory ill- nesses have been recently described. We investigated the association between wheezing conditions and familial, pre-, peri-, and postnatal risk factors. We studied 16,333 children, 6 to 7 yr old, enrolled in a population-based study. Standardized questionnaires were filled in by parents. A total of 1,221 children had transient early wheezing, 671 had persistent wheezing, 918 had late-onset wheezing, and 13,523 never had wheezing or asthma (control group). Maternal asthma or chronic obstructive airway disease were significantly (p , 0.0001) more associated with persistent wheezing than with transient early and late-onset wheezing. The same pattern was observed for exposure to maternal smoke during pregnancy. Having a mother . 35 yr old was protective against transient early wheez- ing (odds ratio (OR): 0.68, 95% confidence intervals (95% CI): 0.53 to 0.86). Breast feeding > 6 mo was slightly protective against transient early wheezing (OR: 0.82, 95% CI: 0.68 to 0.97), whereas it was a moderate risk factor for late-onset wheezing (OR: 1.22, 95% CI: 0.99 to 1.50). On the contrary, having siblings and attending a day care center were both risk factors for transient early wheezing (OR: 1.41 (95% CI: 1.21 to 1.64) and 1.70 (95% CI: 1.48 to 1.96), respectively) and protective factors against wheezing of late onset (OR: 0.83 (95% CI: 0.70 to 0.97) and 0.72 (95% CI: 0.59 to 0.88)). There was a stronger (p , 0.0001) positive association between personal history of eczema or aller- gic rhinitis and persistent and late-onset wheezing than transient early wheezing. Our findings sug- gest a different contribution of risk factors to wheezing conditions in childhood. Rusconi F, Galassi C, Corbo GM, Forastiere F, Biggeri A, Ciccone G, Renzoni E, and the SIDRIA Collaborative Group. Risk factors for early, persistent, and late-onset wheezing in young children. AM J RESPIR CRIT CARE MED 1999;160:1617-1622.