Values in Elderly People for Exhaled Nitric Oxide Study

Ageing population is constantly increasing due to rising life expectancy; consequently, the percentage of the elderly patients with asthma is increasing, as well. Fractional exhaled nitric oxide (FeNO) is a biomarker of lung inflammation, and currently it is widely used in clinical practice for asthma diagnosis and monitoring. Yet, there are no data about normal values of FeNO in patients of more than 65 years of age with normal lung function. The aim of this study was to establish adult FeNO reference values for subjects older than 65 years, according to the international guidelines. FeNO was measured in 303 healthy, nonsmoking adults more than 65 years of age, with normal spirometry values measured using the online single-breath technique. The results were analyzed by chemiluminescent detection. The FeNO levels obtained range from 5.00 to 29.9 ppb, with a mean value of 12.48 ± 2.80 ppb. A significant association of FeNO levels with age (p < 0.05) was observed. There was no difference in FeNO values between men and women unlike what was observed in younger patients. FeNO levels in healthy controls over 65 years of age are influenced by age as in younger adults. However, there is no difference in FeNO values in male and female seniors, in contrast with what was found in younger adults in other studies. These data can be useful for the clinician to interpret the values of FeNO assessed during clinical practice.