FeNO as a predictor of asthma control improvement after starting inhaled steroid treatment

• Introduction: The fraction of NO in exhaled air (FeNO) is a marker of inflammation in asthma. The aim of the present study was to assess, in a real-world setting, whether only high ( >= 50 ppb) FeNO levels predict improvement in asthma control when being treated with inhaled corticosteroids (ICS), as suggested by current guidelines on the clinical use of FeNO. Methods: FeNO and asthma control were assessed in a retrospective observational study in 153 non-smoking, steroid-nave, adult subjects with asthma with a mean age of 40 years both before and after 6 weeks (median follow-up time) of treatment with 500 mu g beclomethasone (median). Results: Having at the initial visit intermediate FeNO ( >= 25 and <50 ppb) and high FeNO ( >= 50 ppb), compared to normal FeNO (<25 ppb), were associated with a larger proportion of subjects achieving an improvement of Asthma Control Questionnaire (ACQ) score with >= 1 (78% and 67% vs 43%, p <0.05) or both >= 1 improvement and asthma control at follow-up (31% and 37% vs 4%, p < 0.05). These associations were consistent in multiple logistic regression models after adjustments for confounders. Conclusions: It is not only high but also intermediate FeNO levels that are associated with a significant improvement in asthma control after starting ICS treatment. This challenges current clinical guidelines stating that only high FeNO levels predict response to ICS treatment.

Ämnesord

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Nyckelord

Asthma control

ACQ

Exhaled nitric oxide

Lung function

Real-life study

Longitudinal study

Publikations- och innehållstyp

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