Secondhand Smoke Exposure Linked to Sleep Problems in Children With Asthma

From Medscape Medical News
Laurie Barclay, MD

January 20, 2010 — Exposure to secondhand smoke (SHS) is associated with increased sleep problems among children with asthma, according to the results of a study reported online January 18 and to be published in the February print issue of Pediatrics.

"Adult and adolescent smokers report difficulties with sleep," write Kimberly Yolton, PhD, from Cincinnati Children's Hospital Medical Center in Cincinnati, Ohio, and colleagues. "Young children who are exposed to tobacco smoke have poorer sleep quality. Children with asthma report more sleep problems and are more sensitive to the respiratory effects of tobacco smoke."

The goal of this study was to analyze the association between exposure to SHS and child sleep patterns among a group of 219 children with asthma who were enrolled in an asthma intervention trial and who had regular exposure to tobacco smoke at home. SHS exposure was measured with serum cotinine levels, and the Children's Sleep Habits Questionnaire was used to evaluate sleep patterns based on parental reports.

Statistical analyses allowed adjustment for covariates of age, sex, race, maternal marital status, education, income, prenatal tobacco exposure, maternal depression, Home Observation for Measurement of the Environment total score, household density, asthma severity, and use of asthma medications.

SHS exposure was associated with longer sleep-onset delay (P = .004), sleep-disordered breathing (P = .02), parasomnias (P = .002), daytime sleepiness (P = .022), and overall sleep disturbance (P = .0002).

"We conclude that exposure to SHS is associated with increased sleep problems among children with asthma," the study authors write. "As SHS exposure increased, parents reported that their children had longer delays in sleep onset, more-frequent parasomnias and sleep-disordered breathing, increased daytime sleepiness, and greater overall sleep disturbance."

Limitations of this study include lack of generalizability to children without asthma; wide variance of the degree of SHS exposure; sleep data based only on parental reports; and lack of information on prematurity, which could be an important contributor to sleep problems.

"We report significant associations between SHS exposure, as measured with a biological marker (serum cotinine levels), and sleep problems in children with asthma," the study authors conclude. "Reduction in SHS exposure is an area with the potential for significant impact in the pediatric population."

The National Institutes of Health supported this study. The study authors have disclosed no relevant financial relationships.

Pediatrics. Published online January 18, 2010. Abstract