Volume 10 Supplement 1

Canadian Society of Allergy and Clinical Immunology Annual Scientific Meeting 2013

Open Access

Are known biomarkers for asthma present in early infancy?

  • M Ayanna Boyce1Email author,
  • Sanja Stanojevic2,
  • Krzysztof Kowalik3,
  • Susan Balkovec2,
  • Felix Ratjen2,
  • Malcolm R Sears4 and
  • Padmaja Subbarao2
Allergy, Asthma & Clinical Immunology201410(Suppl 1):A48

https://doi.org/10.1186/1710-1492-10-S1-A48

Published: 3 March 2014

Background

Exhaled nitric oxide (FENO) is a biomarker for eosinophilic airway inflammation [1]. Elevated FENO has been proposed as a marker for diagnosing asthma and predicting asthma exacerbations [2]. We wished to examine the association between known asthma risk factors and FENO. A sub cohort of children (n=222) participating in the Canadian Healthy Infant Longitudinal Development (CHILD) study underwent infant pulmonary function tests (IPFTs) during the first year of life.

Methods

Risk factors were obtained from a subset of available CHILD questionnaires administered prenatally and 3 times during the first year of life. FENO was collected using a multiple-breath sampling technique during quiet tidal breathing at the 3 month visit, 1 year visit, or both visits. Prenatal smoke exposure was defined as any maternal smoking, including mothers who stopped or cut down on smoking during pregnancy. Postnatal smoke exposure was defined as any exposure in or away from the home up to 1 year of age. Parental asthma was defined as self-reported or doctor diagnosed asthma. Parental atopic status was confirmed by allergy skin tests. T-tests with Bonferroni correction for multiple comparisons were used to compare FENO in the exposed and unexposed groups (α=0.004).

Results

At the 3 month visit, 134 infants attended the IPFT lab, and 84 of 117 attempted eNO tests were successfully analyzed; mean FENO was 16.8±8.1ppb. At the 1 year visit, 181 infants attended the IPFT lab and 138 of 158 attempted eNO tests were successfully analyzed; mean FENO was 15.3±9.7ppb. Prenatal smoking rates were low (3% and 6%) and showed no association with FENO (Table 1). Postnatal smoke exposure was also not associated with FENO. FENO was not statistically different in infants whose mothers or fathers had a history of asthma or atopic status, compared to those without. Having siblings was not significantly associated with FENO after applying the Bonferroni correction.

Table 1

Variable

Testing Time Point

Sample Size

Mean ± SD (ppb)

P value

Prenatal Smoke Exposure

3 months

Yes

2

13.12 ± 0.8

0.072

  

No

57

15.40 ± 7.7

 
 

1 Year

Yes

6

21.12 ± 14.6

0.405

  

No

100

15.63 ± 9.5

 

Postnatal Smoke Exposure

3 months

Yes

14

15.13 ± 7.5

0.471

  

No

64

16.76 ± 7.6

 
 

1 Year

Yes

38

13.72 ± 8.2

0.233

  

No

99

15.73 ± 10.1

 

Maternal Atopic Status

3 months

Yes

47

16.72 ± 7.5

0.458

  

No

19

15.19 ± 7.5

 
 

1 Year

Yes

87

15.11 ± 10.0

0.638

  

No

40

15.94 ± 8.9

 

Maternal Asthma

3 months

Yes

16

17.23 ± 8.2

0.495

  

No

49

15.62 ± 7.5

 
 

1 Year

Yes

29

14.50 ± 7.9

0.460

  

No

88

15.86 ± 10.3

 

Paternal Atopic Status

3 months

Yes

55

16.32 ± 7.4

0.925

  

No

12

16.07 ± 8.4

 
 

1 Year

Yes

87

15.13 ± 9.4

0.085

  

No

21

19.24 ± 9.5

 

Paternal Asthma

3 months

Yes

10

15.45 ± 10.0

0.962

  

No

48

15.28 ± 7.2

 
 

1 Year

Yes

20

19.42 ± 10.1

0.081

  

No

80

14.89 ± 9.5

 

Sibling

3 months

Yes

30

13.54 ± 8.2

0.065

  

No

29

17.17 ± 6.5

 
 

1 Year

Yes

46

13.27 ± 10.0

0.015

  

No

60

17.98 ± 9.4

 

Conclusions

Smoke exposure was not related to FENO, however no nicotine biomarker was assessed and smoking rates were low. Maternal and paternal histories were not associated with FENO levels in healthy children up to 1 year of age. None of the risk factors were statistically significantly associated with FENO, however infants with siblings were observed to have a lower FENO than infants without siblings at the 1 year visit. A larger sample size is required to increase the power of these tests. Further factors must be studied to explain the variation in FENO measures seen.

Authors’ Affiliations

(1)
Faculty of Applied Health Sciences, University of Waterloo
(2)
Respiratory Medicine, Hospital for Sick Children
(3)
Department of Physiology, McGill University
(4)
Department of Medicine, McMaster University

References

  1. Gabriele C, Jaddoe VW, van Mastrigt E, Arends LR, Hofman A, Moll HA, de Jongste JC: Exhaled nitric oxide and the risk of wheezing in infancy: the Generation R Study. Eur Respir J. 2012, 39: 567-572.View ArticlePubMedGoogle Scholar
  2. American Thoracic Society: ATS/ERS Recommendations for Standardized Procedures for the Online and Offline Measurement of Exhaled Lower Respiratory Nitric Oxide and Nasal Nitric Oxide, 2005. Am J Respir Crit Care Med. 2005, 171: 912-930.View ArticleGoogle Scholar

Copyright

© Boyce et al; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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