title: Impulse Oscillometry and Spirometry Small-Airway Parameters in Mild to Moderate Bronchiectasis.
abstract: BACKGROUND
  Both impulse oscillometry and spirometry can reflect small-airway disorders. The objective of this work was to investigate the diagnostic value of impulse oscillometry and spirometry small-airway parameters and their correlation with radiology, disease severity, and sputum bacteriology in mild to moderate bronchiectasis (bronchiectasis severity index <9) and to validate these findings in sensitivity analyses (mild bronchiectasis).
  
  
  METHODS
  We recruited 94 subjects with mild to moderate bronchiectasis and 26 healthy subjects. The diagnostic value of small-airway parameters was compared using the receiver operating characteristic curve. Chest high-resolution computed tomography (HRCT), impulse oscillometry measurement, spirometry, and sputum culture were performed. Correlation between small-airway parameters and clinical indices was determined, adjusting for age, sex, body mass index, and smoking history. Sensitivity analyses were repeated when excluding subjects with bronchiectasis severity index ≥9 or HRCT score ≥13.
  
  
  RESULTS
  Impulse oscillometry and spirometry small-airway parameters could discriminate mild to moderate bronchiectasis from healthy subjects and correlated significantly with HRCT score and the number of bronchiectatic lobes and the bronchiectasis severity index (all P < .01). Small-airway parameters were more aberrant in subjects with dyshomogeneity and cystic bronchiectasis but were independent of Pseudomonas aeruginosa isolation or the location of predominant bronchiectatic lobes. Spirometry, but not impulse oscillometry, small-airway parameters differed statistically between subjects with isolated peripheral-airway bronchiectasis and those with peripheral plus central-airway bronchiectasis (all P < .01). Subgroup analyses yielded similar findings, except for the lack of correlation between small-airway parameters and clinical parameters in subjects with HRCT score ≤6.
  
  
  CONCLUSIONS
  Impulse oscillometry and spirometry small-airway parameters have similar diagnostic value in reflecting peripheral-airway disorders and correlate with the HRCT scores, the bronchiectasis severity index, and the number of bronchiectatic lobes in mild to moderate bronchiectasis. Assessment of small-airway parameters should be incorporated in future lung function investigations in bronchiectasis.
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Wei-Jie
authors.initials: WJ
authors.lastname: Guan
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Yuan
authors.affiliation: Department of Respiratory and Critical Care Medicine, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
authors.forename: Yong-Hua
authors.initials: YH
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Hui-Min
authors.initials: HM
authors.lastname: Li
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China.
authors.forename: Jin-Ping
authors.initials: JP
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China. nanshan@vip.163.com chenrc@vip.163.com.
authors.forename: Rong-Chang
authors.initials: RC
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, Guangdong, China. nanshan@vip.163.com chenrc@vip.163.com.
authors.forename: Nan-Shan
authors.initials: NS
authors.lastname: Zhong
mesh_terms: D000328:Adult; D001980:Bronchi / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001987:Bronchiectasis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009991:Oscillometry / Q000379:methods*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013147:Spirometry; D013183:Sputum / Q000382:microbiology; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: bronchiectasis; bronchiectasis severity index; impulse oscillometry; small-airway parameter; spirometry