title: Albuterol inhalation increases FeNO level in steroid-naive asthmatics but not COPD patients with reversibility.
abstract: BACKGROUND
  Fractional exhaled nitric oxide (FeNO) has been used as a marker of airway inflammation. Airway caliber is related to the level of FeNO in asthmatics.
  
  
  OBJECTIVE
  This study aimed to investigate whether airway obstruction could interfere with real FENO levels and if different FeNO changes after albuterol inhalation could assist in distinguishing asthma from chronic obstructive pulmonary disease (COPD).
  
  
  METHODS
  FeNO and spirometry measurements were performed before and after albuterol inhalation in the following three patient groups: 30 steroid-naive asthmatics, 25 asthmatics inhaling corticosteroids/long-acting β(2)-adrenergic agonists for at least 1 month and 20 COPD patients. Bronchodilator test (BDT) results were positive in all patients enrolled. The correlations among FeNO levels, pulmonary function and sputum eosinophil counts were analyzed.
  
  
  RESULTS
  FeNO increased significantly after albuterol inhalation in steroid-naive asthmatics but not in ICS-treated asthmatics or COPD patients. The FeNO levels demonstrated no significant correlation with spirometry results or sputum eosinophil counts before or after inhaling bronchodilator in all three groups. Both the levels of FeNO and changes in FENO after albuterol inhalation in steroid-naive asthma patients were higher than those in ICS-treated asthmatics and COPD patients (P < 0.001). The differences remained after proper adjustment for confounding factors (gender, age, smoking pack-years, ICS-treated and pulmonary function index).
  
  
  CONCLUSIONS
  Our results support the role of FeNO in differentiating asthmatics from COPD patients with positive BDT. FeNO detection after albuterol inhalation should be encouraged in steroid-naive asthma patients with airway obstruction.
authors.affiliation: Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
authors.forename: Haijin
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.affiliation: Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Lv
authors.affiliation: Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
authors.forename: Hangming
authors.initials: H
authors.lastname: Dong
authors.affiliation: Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
authors.forename: Lihong
authors.initials: L
authors.lastname: Yao
authors.affiliation: Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
authors.forename: Guanhua
authors.initials: G
authors.lastname: Xiao
authors.affiliation: Department of Respiratory and Critical Care Medicine, Chronic Airways Diseases Laboratory, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
authors.forename: Shaoxi
authors.initials: S
authors.lastname: Cai
mesh_terms: D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D058666:Adrenergic beta-2 Receptor Agonists / Q000008:administration & dosage; D000328:Adult; D000420:Albuterol / Q000008:administration & dosage*; D001249:Asthma / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology; D001993:Bronchodilator Agents / Q000008:administration & dosage; D003937:Diagnosis, Differential; D004804:Eosinophils / Q000276:immunology; D045853:Exhalation; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism*; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D012907:Smoking / Q000009:adverse effects; D013147:Spirometry / Q000379:methods; D013183:Sputum / Q000276:immunology
chemical_list: D000305:Adrenal Cortex Hormones; D058666:Adrenergic beta-2 Receptor Agonists; D001993:Bronchodilator Agents; D009569:Nitric Oxide; D000420:Albuterol
keywords: airway calibers - asthma - COPD - fractional exhaled nitric oxide - positive bronchodilator test