Aim: FeNO is increasingly used clinically as a biomarker of eosinophilic
airway inflammation. However, as many factors influence FeNO values, careful clinical interpretation is required. The aim of our systematic review was to evaluate whether ethnicity influences FeNO values in healthy subjects.
Method: Using systematic review methodology, we conducted a PubMed
search and included all studies in the last 10 years (2004–2014) that examined whether ethnicity affected FeNO measurements. Titles and abstracts were screened by one author before full text reviews.
Results: From 23 potential studies, nine were included in the review. The
majority of studies included children and/or adolescents with only one study
involving both children and adults. A variety of statistical analyses approach es were used. There were eight ethnic groups studied in total; none were Australian Aboriginal or Torres Strait Islander ethnicity. All data sets indicated differences between FeNO results of non-Caucasian ethnicities compared to Caucasians. Overall, ethnicity was considered a significant factor in seven studies with increased FeNO levels reported in six studies when compared to Caucasian data.
Conclusion: Ethnicity is a likely influence on measured FeNO values. Thus,
there is a need for development of normal reference data for specific ethnic
groups if FeNO is to be validly used in the clinical setting.