Infant sleeping environment and asthma at 7 years: a prospective cohort study.

Objectives: We investigated the role of infant bedding items, as part of a composite bedding environment, in the development of childhood wheezing.

Methods: This prospective cohort investigation involved 863 children who participated in an infant survey in 1988 and an asthma study in Tasmania, Australia, in 1995. The derived 3 composite infant bedding categories corresponded to increasing numbers of house dust mite (HDM)-rich bedding items used. Outcomes measured included recent and frequent wheezing.

Results: Composite infant bedding used was associated with recent wheezing. Effects increased at increasing levels of HDM-rich bedding items used. Effects were further enhanced by home environmental factors of bedroom heating, recent bedroom painting, and absence of bedroom carpeting. When any 2 or more of these environmental factors were present, a strong dose-response relationship was evident.

Conclusions: Our results show that bedding exposures in infancy are prospectively associated with childhood wheezing and that home environmental conditions may modify this association.