Abstract
The fraction of exhaled nitric oxide (FeNO) has been shown to predict new-onset asthma and wheeze among children and adults that were followed up for a period of up to 4 years. However, there are no studies with longer follow-up periods and few studies have focused on the persistence of wheeze symptoms present in childhood.
In 1998-1999, FeNO (at 100 mL/s) was measured in 959 adolescents aged 13-14 years, and the subjects answered a questionnaire on wheeze symptoms. A total of 414 subjects responded to the same questionnaire in 2014.
At the 15-year follow up, 23 of 101 subjects with a previous history of wheeze at age 13-14 years reported wheeze during the last 12 months. These subjects had higher FeNO at baseline (p=0.01), compared with subjects without wheeze at follow-up. Elevated FeNO (>15 ppb) in subjects with a previous history of wheeze in adolescence was related to an odds ratio of 3.5 (1.3, 9.7) for having wheeze in adulthood. This was consistent after adjusting for gender, and age and baseline lung function (adjusted odds ratio 3.6 (1.3, 10.3)). Among the 312 subjects without wheeze history in childhood, 15% reported wheeze at the follow-up but these subjects had similar FeNO at baseline as subjects without wheeze at both timepoints (p=0.31).
In conclusion, elevated FeNO levels in adolescents with a previous history of wheeze related to persistent wheeze in adulthood. Thus, symptomatic Th2-driven airway inflammation in adolescence seems to indicate increased risk of chronic airway disease. However, baseline FeNO could not identify subjects at risk of developing wheeze within 15 years, in contrast to studies with follow-up periods of up to 4 years.
- Copyright ©ERS 2015