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 illnesses 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 wheezing (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 allergic rhinitis and persistent and late-onset wheezing than transient early wheezing. Our findings suggest a different contribution of risk factors to wheezing conditions in childhood.

Breast-feeding and atopic disease: A cohort study from childhood to middle age

“…[7][8][9][10][11][12] We are the first to analyze data from early childhood well into middle age. Spanning this extensive period covers the current gap in understanding of the effect of breast-feeding on asthma risk.…”

“…Further support comes from other studies finding that risk of early transient wheeze caused by respiratory tract infections is reduced by breast-feeding. 10,11,31 In particular, an Italian study that found breast-feeding for more than 3 months was protective against the development of transient early wheezing but was a risk factor for late-onset wheeze. 11 Why does breast-feeding appear to increase the risk of asthma and allergies after the age of 7 years?…”

“…10,11,31 In particular, an Italian study that found breast-feeding for more than 3 months was protective against the development of transient early wheezing but was a risk factor for late-onset wheeze. 11 Why does breast-feeding appear to increase the risk of asthma and allergies after the age of 7 years? Possible explanations include maternal transmission of IgE responses and other factors related to the hygiene hypothesis such as a lack of exposure to infections in early life.…”

“…6 However, several prospective birth cohort studies have found breast-feeding to be a risk factor for asthma rather than a protective factor. [7][8][9][10][11][12] Although several studies have examined risk of asthma and atopy into early adolescence, 10,13,14 fewer have followed subjects into adulthood 12 and none into middle age. The differing duration of follow-up may explain the discrepancies between studies.…”

Maternal Complications and Procedures in Pregnancy and at Birth and Wheezing Phenotypes in Children

“…In a report published in 1999 (19), we found associations between a number of pre-, peri-, and early postnatal factors and different wheezing phenotypes in a large multicenter crosssectional population-based study, the SIDRIA (Italian Studies of Respiratory Disorders in Childhood and the Environment) phase 1 study, an extension of the International Study on Asthma and Allergies in Childhood (ISAAC) phase 1 study (20). The enrolled children were categorized, on the basis of criteria derived from Martinez and coworkers (21), as transient early wheezers (children with wheezing in the first 2 yr of life but not at school age), persistent wheezers (children who continued to wheeze at school age), late-onset wheezers (children who did not wheeze in the first years of life but who wheezed when 6-7 yr old), or nonwheezers (all other children).…”