Background: Factors affecting fractional exhaled nitric oxide (FeNO) in early childhood are incompletely understood. Objective: To examine the relationships between FeNO and allergic sensitization, total IgE, atopic dermatitis, rhinitis, asthma, and lung function (spirometry) in children. Methods: Children at high risk of asthma and other allergic diseases because of parental history were enrolled at birth and followed prospectively. FeNO was measured by an online technique at ages 6 and 8 years. Relationships among FeNO, various atopic characteristics, and asthma were evaluated. Results: Reproducible FeNO measurements were obtained in 64% (135/210) of 6-year-old and 93% (180/194) of 8-year-old children. There was seasonal variability in FeNO. Children with aeroallergen sensitization at ages 6 and 8 years had increased levels of FeNO compared with those not sensitized (geometric mean; 6 years, 10.9 vs 6.7 parts per billion [ppb], P < .0001; 8 years, 14.6 vs 7.1 ppb, P < .0001). FeNO was higher in children with asthma than in those without asthma at 8 years but not 6 years of age (6 years, 9.2 vs 8.3 ppb, P = .48; 8 years, 11.5 vs 9.2 ppb, P = .03). At 8 years of age, this difference was no longer significant in a multivariate model that included aeroallergen sensitization (P = .33). There were no correlations between FeNO and spirometric indices at 6 or 8 years of age. Conclusion: These findings underscore the importance of evaluating allergen sensitization status when FeNO is used as a potential biomarker in the diagnosis and/or monitoring of atopic diseases, particularly asthma.
Bibliographical noteFunding Information:
Supported by National Institutes of Health grants R01 HL61879 , P01 HL70831 , T32 AI007635 and M01 RR03186 .
Disclosure of potential conflict of interest: R. M. Burton is a consultant for Cardinal Health. J. E. Gern receives grant support from AstraZeneca and Merck. R. F. Lemanske, Jr, is a speaker for Merck, AstraZeneca, Doembecher Children's Hospital, Washington University, the Medicus Group, the Park Nicolet Institute, the American College of Allergy, Asthma & Immunology, the Los Angeles Allergy Society, the Michigan Allergy/Asthma Society, the Medical College of Wisconsin, the Fund for Medical Research and Education (Detroit), the Children's Hospital of Minnesota, the Toronto Allergy Society, the American Academy of Allergy, Asthma & Immunology, Beaumont Hospital (Detroit), the University of Illinois, the Canadian Society of Allergy and Clinical Immunology, and New York Presbyterian; is a consultant for AstraZeneca, Smith Research, Inc, the Merck Childhood Asthma Network, Novartis, Quintiles/Innovax, RC Horowitz & Co, Inc, International Meetings and Science, and Scienomics; is an author for Up-to-Date; is a textbook editor for Elsevier, Inc; and receives grant support from the National Heart, Lung, and Blood Institute. The rest of the authors have declared that they have no conflict of interest.
- Fractional exhaled nitric oxide (FeNO)
- allergic sensitization
- atopic dermatitis
- lung function