Exhaled nitric oxide in a Taiwanese population: age and lung function as predicting factors.
OBJECTIVE
The fractional concentration of exhaled nitric oxide (FE(NO)) has been reported to be elevated in asthma and many other lung diseases. The present study investigated reference values and determinants of FE(NO) in a Taiwanese non-smoking, healthy adult population.


METHODS
We used a chemiluminescence analyzer according to American Thoracic Society/European Respiratory Society recommendations to measure FE(NO) values in 356 adults who received a health check-up and a detailed respiratory questionnaire at Taichung Veterans General Hospital, Taiwan. Among the volunteers, 249 fulfilled our definition of healthy adults: no history of smoking or physician-diagnosed asthma; no recent upper airway infection; no chronic respiratory symptoms; and no allergic rhinitis and urticaria.


RESULTS
Among the 249 non-smoking and non-asthmatic adults, the mean (5th to 95th percentile reference range) FE(NO) was 27.9 (12.5-58.0) parts per billion. In multivariate regression analyses, age and lung function (forced vital capacity or forced expiratory volume in 1 second) were associated positively with FE(NO) values. Sex, height, weight, and ambient NO values were not associated significantly with FE(NO) values.


CONCLUSIONS
Age and lung function were predictors of FE(NO) in this population, and these factors should be considered for clinical applications of FE(NO) measurements.
Division of Chest Medicine, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
Hsu-Chung
HC
Liu
Jeng-Yuan
JY
Hsu
Ya-Wen
YW
Cheng
Ming-Chih
MC
Chou
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001944:Breath Tests / Q000379:methods*; D045853:Exhalation; D005260:Female; D006801:Humans; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis*; D012016:Reference Values; D012129:Respiratory Function Tests / Q000379:methods; D011795:Surveys and Questionnaires; D013624:Taiwan
D009569:Nitric Oxide