Relationship of endotoxin and tobacco smoke exposure to wheeze and diurnal peak expiratory flow variability in children and adolescents
Article first published online: 27 JAN 2011
© 2011 The Authors. Respirology © 2011 Asian Pacific Society of Respirology
Volume 16, Issue 2, pages 332–339, February 2011
How to Cite
LAWSON, J. A., DOSMAN, J. A., RENNIE, D. C., BEACH, J., NEWMAN, S. C. and SENTHILSELVAN, A. (2011), Relationship of endotoxin and tobacco smoke exposure to wheeze and diurnal peak expiratory flow variability in children and adolescents. Respirology, 16: 332–339. doi: 10.1111/j.1440-1843.2010.01911.x
- Issue published online: 27 JAN 2011
- Article first published online: 27 JAN 2011
- Accepted manuscript online: 8 DEC 2010 06:10AM EST
- Received 10 July 2010; invited to revise 3 August 2010; revised 17 October 2010; accepted 31 October 2010 (Associate Editor: Chi Chiu Leung).
- asthma and wheeze;
- diurnal peak flow variation;
- tobacco smoke
Background and objective: The relationship between endotoxin exposure and asthma severity (wheeze and airways obstruction) is not well described. The effects of endotoxin and tobacco smoke exposure on self-reported wheeze and diurnal PEF variability (DV-PEF) were examined in children aged 6–18 years with asthma or wheeze.
Methods: A cross-sectional study was performed in a rural area. From this study, children who reported wheeze in the previous 12 months or a physician diagnosis of asthma (n = 98) were selected for a case–control study. These subjects, who were the basis for the present analysis, completed: (i) a home environmental assessment, including dust collection to measure endotoxin levels: (ii) a clinic visit, including saliva collection to measure cotinine levels; and (iii) 2 week monitoring of twice daily symptom records, including wheeze, and PEF to calculate DV-PEF.
Results: Among these children, 22.4% reported wheeze during the monitoring period. Greater DV-PEF was associated with higher endotoxin loads in play areas (P < 0.05). The association between salivary cotinine levels and high DV-PEF was modified by gender. In females, higher cotinine levels were associated with an increased risk of high DV-PEF compared with lower cotinine levels (P < 0.05), but this was not observed among males.
Conclusions: Higher endotoxin exposure was associated with greater DV-PEF among children with asthma or wheeze. While previous studies have suggested that endotoxin exposure protects against the development of asthma, individuals with the disease should avoid high exposure levels to limit exacerbations. The effect of tobacco smoke exposure on lung health may differ between male and female children.