Reference values for exhaled nitric oxide (reveno) study

Respir Res. 2006 Jun 30;7(1):94. doi: 10.1186/1465-9921-7-94.


Background: Despite the widespread use of fractional exhaled nitric oxide (FENO) as a biomarker of airways inflammation, there are no published papers describing normal FENO values in a large group of healthy adults.

Objective: The aim of this study was to establish adult FENO reference values according to the international guidelines.

Methods: FENO was measured in 204 healthy, non-smoking adults with normal spirometry values using the on-line single-breath technique, and the results were analysed chemiluminescently.

Results: The main result of the study was the significant difference in FENO values between men and women, thus indicating that gender-based reference FENO values are necessary. The FENO levels obtained at expiratory flows of 50 ml/s ranged from 2.6 to 28.8 ppb in men, and from 1.6 to 21.5 ppb in women.

Conclusion: We propose reference FENO values for healthy adult men and women that could be used for clinical and research purposes.

Publication types

  • Multicenter Study

MeSH terms

  • Adult
  • Breath Tests* / methods
  • Female
  • Humans
  • Italy
  • Male
  • Middle Aged
  • Nitric Oxide / analysis*
  • Practice Guidelines as Topic
  • Reference Values
  • Reproducibility of Results
  • Sex Factors
  • Spirometry


  • Nitric Oxide