Secondhand Smoke Exposure and Sleep-Related Breathing Problems in Toddlers

BACKGROUND: Adequate sleep during childhood is an important component of overall health and wellbeing for children. Secondhand smoke (SHS) exposure has been linked to a greater risk of sleep-disordered breathing. OBJECTIVE: Our objective was to investigate relationships between SHS exposure and sleep-related breathing problems in healthy toddlers aged 2 to 5 years. We hypothesized that there is an independent relationship between objectively measured SHS exposure and presence of sleep-related breathing problems by parental report. METHODS: A convenience sample of 149 healthy children ages 2 to 5 years was recruited from an academic pediatric primary care center for this cross-sectional study; 138 had complete data that were analyzed. Current SHS exposure was determined by hair nicotine level. Presence of sleeprelated breathing problems was assessed by 1 survey item. Inflammation was determined by serum C-reactive protein (CRP) level. Analysis in Stata 15 included a series of multivariate logistic regression models, controlling for individual-level demographics and body mass index z scores according to mediation analysis procedures for dichotomous outcomes. RESULTS: Approximately 24% of parents reported their child snored, gasped, or had difficulty breathing at night sometimes, most of the time, or almost always. Regression models with mediation analysis indicate that SHS exposure significantly increased the odds of reporting the child had sleep-related breathing problems, and 18% of this relationship is explained by log serum CRP levels. CONCLUSIONS: Although the cross-sectional nature of this study limits causality, evidence suggests a relationship exists between SHS exposure, as measured by log hair nicotine and sleep-related breathing problems at night.