title: Association between fractional exhaled nitric oxide and clinical characteristics and outcomes in patients with subacute cough.
abstract: OBJECTIVE
  To investigate the relationships between fractional exhaled nitric oxide (FENO) and clinical characteristics and outcomes in patients with subacute cough.
  
  
  METHODS
  Patients with subacute cough (n = 189) after upper respiratory tract infection were enrolled in this single-center prospective study, and were divided into low-FENO (<25 ppb) and high-FENO groups (≥25 ppb). Empirical therapies (without inhaled or systemic corticosteroids) were prescribed based on clinical experience and follow-up until the disease course reached 8 weeks. FENO values, cough symptom scores (CSS), and Leicester Cough Questionnaire (LCQ) scores were obtained, analyzed, and compared between two groups of patients.
  
  
  RESULTS
  The low-FENO and high-FENO groups comprised 136 and 53 patients, respectively. The multiple regression analysis showed that blood eosinophil count and gender were independent factors for elevated FENO (β = 1.38, 0.25, respectively). LCQ scores, total CSS, and daytime CSS were comparable between the low-FENO and high-FENO groups. The nighttime CSS of the high-FENO group were significantly higher than that of the low-FENO group (P = .03). The CSS and LCQ score were improved in both groups but were comparable between groups after 10 days treatment.
  
  
  CONCLUSIONS
  Patients with subacute cough and high-FENO levels have more severe nocturnal cough than those of patients with low-FENO levels. However, FENO levels do not appear to correlate with the clinical outcomes or treatment response. The significance of FENO in the management of subacute cough needs to be further evaluated, at least in the current empirical treatment without corticosteroids.
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, People's Republic of China.
authors.forename: Mingming
authors.identifier: http://orcid.org/0000-0002-7727-5294
authors.initials: M
authors.lastname: Jiang
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, People's Republic of China.
authors.forename: Lili
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, People's Republic of China.
authors.forename: Xiaoning
authors.initials: X
authors.lastname: Bu
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: An
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, People's Republic of China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, People's Republic of China.
authors.forename: Kewu
authors.initials: K
authors.lastname: Huang
mesh_terms: D000293:Adolescent; D000328:Adult; D001944:Breath Tests / Q000379:methods; D002908:Chronic Disease; D003371:Cough / Q000175:diagnosis* / Q000378:metabolism; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis*; D011446:Prospective Studies; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D009569:Nitric Oxide
keywords: cough; eosinophil; nitric oxide; quality of life