Hair nicotine levels in children with bronchopulmonary dysplasia

Abstract

Background: Tobacco smoke exposure (TSE) may increase respiratory morbidities in young children with bronchopulmonary dysplasia (BPD). Rapid respiratory rates, close proximity to a smoking caregiver, and increased dermal absorption of tobacco smoke components can contribute to systemic exposure. In this study, hair nicotine levels were used as a biomarker of chronic TSE in young children with BPD to determine if hair nicotine levels correlate with caregiver self-report of TSE and respiratory morbidities.

Methods: From 2012 to 2014, hair nicotine levels were measured from consecutive children seen in a BPD outpatient clinic and compared with caregiver questionnaires on household smoking. The relationship between respiratory morbidities and self-reported TSE or hair nicotine level was assessed.

Results: The mean hair nicotine level from 117 children was 3.1 ± 13.2 ng/mg. Hair nicotine levels were significantly higher in children from smoking households by caregiver self-report compared with caregivers who reported no smoking (8.2 ± 19.7 ng/mg vs 1.8 ± 10.7; P < .001). In households that reported smoking, hair nicotine levels were higher in children with a primary caregiver who smoked compared with a primary caregiver who did not smoke. Among children with BPD who required respiratory support (n = 50), a significant association was found between higher log hair nicotine levels and increased hospitalizations and limitation of activity.

Conclusions: Chronic TSE is common in children with BPD, with hair nicotine levels being more likely to detect TSE than caregiver self-report. Hair nicotine levels were also a better predictor of hospitalization and activity limitation in children with BPD who required respiratory support at outpatient presentation.

Keywords: bronchopulmonary dysplasia; nicotine; prematurity; respiratory outcomes; secondhand smoke; tobacco smoke exposure.

FIGURE 1

Hair nicotine levels of 117 subjects with BPD divided into no TSE and TSE by caregiver self-report. The dashed reference line depicts a ROC cutoff of −0.221 log ng/mg.

FIGURE 2

Lower log hair nicotine levels were found in BPD children of caregivers who reported no smoking in the household compared with caregivers that reported 1, 2, or ≥ 3 smokers in the household. There was a positive association between the number of smokers residing in a household and higher log nicotine level by unadjusted linear regression (P < .001 for all 117 subjects and P = .002 for the 24 households reporting smokers in the home).