Fractional exhaled nitric oxide levels as a predictor of long-term prognoses in patients with mild asthma.
BACKGROUND
There is a growing belief that patients with bronchial asthma (BA) should be provided an individualized and optimized treatment plan. We aimed to clarify the predictors of long-term prognoses in patients with mild BA.


METHODS
We conducted a retrospective study of consecutive patients who were newly diagnosed with mild BA at Iwate Medical University from 2011 to 2013, focusing on achievement of full asthma control based on the Asthma Control Test as an indicator of prognosis. Predictors were identified on the basis of a chart review.


RESULTS
Among 71 patients with mild BA, 37 patients completed regular clinic visits for 1 year. Nineteen (51.4%) of these patients achieved full asthma control. Current smoking and the fractional exhaled nitric oxide (FeNO) level at the first patient visit were identified by multivariate logistic regression as possible predictors of the discontinuation of clinic visits and achievement of full asthma control, respectively. Low FeNO levels at the first clinic visit yielded a receiver operating characteristic-area under the curve of 0.860 (95% confidence interval [CI]=0.774-0.975) for the achievement of full asthma control. Using an FeNO cut-off level of 34 parts per billion yielded a sensitivity of 76.5% (95% CI=59.5-88.2%) and specificity of 73.7% (95% CI=58.5-84.2%).


CONCLUSIONS
Our preliminary results suggested that patients with newly diagnosed mild BA who display higher FeNO levels at their first clinic visits should be appropriately educated during early visits to receive optimal treatment and complete regular clinic visits.
Department of Pulmonary Medicine, Allergy and Rheumatology, Iwate Medical University, School of Medicine, Morioka, Japan. Electronic address: yamam@iwate-med.ac.jp.
Masahiro
M
Yamashita
Department of Pulmonary Medicine, Allergy and Rheumatology, Iwate Medical University, School of Medicine, Morioka, Japan. Electronic address: mitsues@iwate-med.ac.jp.
Mitsue
M
Shibanai
Department of Pulmonary Medicine, Allergy and Rheumatology, Iwate Medical University, School of Medicine, Morioka, Japan. Electronic address: ksekimur@iwate-med.ac.jp.
Kenshi
K
Sekimura
Department of Pulmonary Medicine, Allergy and Rheumatology, Iwate Medical University, School of Medicine, Morioka, Japan. Electronic address: hnitanai-imc@sound.ocn.ne.jp.
Hiroo
H
Nitanai
Department of Pharmacology, Ehime University Graduate School of Medicine, Toon, Japan. Electronic address: ogasawam@m.ehime-u.ac.jp.
Masahito
M
Ogasawara
Department of Pulmonary Medicine, Allergy and Rheumatology, Iwate Medical University, School of Medicine, Morioka, Japan. Electronic address: hkobayas@iwate-med.ac.jp.
Hitoshi
H
Kobayashi
Department of Pulmonary Medicine, Allergy and Rheumatology, Iwate Medical University, School of Medicine, Morioka, Japan. Electronic address: kyamauch@iwate-med.ac.jp.
Kohei
K
Yamauchi
D001249:Asthma / Q000175:diagnosis*; D015415:Biomarkers / Q000032:analysis*; D001944:Breath Tests / Q000379:methods*; D006801:Humans; D016015:Logistic Models; D009569:Nitric Oxide / Q000032:analysis*; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors
D015415:Biomarkers; D009569:Nitric Oxide
FeNO; Individualization; Inhaled corticosteroid therapy; Mild asthma; Prognosis