title: Early COPD patients with lung hyperinflation associated with poorer lung function but better bronchodilator responsiveness.
abstract: BACKGROUND
  It is unknown whether aggressive medication strategies should be used for early COPD with or without lung hyperinflation. We aimed to explore the characteristics and bronchodilator responsiveness of early COPD patients (stages I and II) with/without lung hyperinflation.
  
  
  METHODS
  Four hundred and six patients with COPD who performed both lung volume and bronchodilation tests were retrospectively analyzed. Residual volume to total lung capacity >120% of predicted values indicated lung hyperinflation. The characteristics and bronchodilator responsiveness were compared between the patients with and without lung hyperinflation across all stages of COPD.
  
  
  RESULTS
  The percentages of patients with lung hyperinflation were 72.7% in the entire cohort, 19.4% in stage I, 68.5% in stage II, 95.3% in stage III, and 100.0% in stage IV. The patients with lung hyperinflation exhibited poorer lung function but better bronchodilator responsiveness of both forced expiratory volume in 1 second and forced vital capacity than those without lung hyperinflation during early COPD (t=2.21-5.70,P=0.000-0.029), especially in stage I, while age, body mass index, smoking status, smoking history, and disease duration were similar between the two subgroups in the same stages. From stages I to IV of subgroups with lung hyperinflation, stage I patients had the best bronchodilator responsiveness. Use of bronchodilator responsiveness of forced vital capacity to detect the presence of lung hyperinflation in COPD patients showed relatively high sensitivities (69.5%-75.3%) and specificities (70.3%-75.7%).
  
  
  CONCLUSIONS
  We demonstrated the novel finding that early COPD patients with lung hyperinflation are associated with poorer lung function but better bronchodilator responsiveness and established a simple method for detecting lung hyperinflation.
authors: State Key Laboratory of Respiratory Disease, China National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Diseases, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, People's Republic of China.
authors: Chunlan
authors: C
authors: Chen
authors: State Key Laboratory of Respiratory Disease, China National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Diseases, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, People's Republic of China.
authors: Wenhua
authors: W
authors: Jian
authors: State Key Laboratory of Respiratory Disease, China National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Diseases, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, People's Republic of China.
authors: Yi
authors: Y
authors: Gao
authors: State Key Laboratory of Respiratory Disease, China National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Diseases, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, People's Republic of China.
authors: Yanqing
authors: Y
authors: Xie
authors: State Key Laboratory of Respiratory Disease, China National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Diseases, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, People's Republic of China.
authors: Yan
authors: Y
authors: Song
authors: State Key Laboratory of Respiratory Disease, China National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Diseases, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, People's Republic of China.
authors: Jinping
authors: J
authors: Zheng
mesh_terms: D000368:Aged; D019540:Area Under Curve; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D016009:Chi-Square Distribution; D005240:Feasibility Studies; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D016015:Logistic Models; D008168:Lung / Q000187:drug effects* / Q000503:physiopathology; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D012372:ROC Curve; D012115:Residual Volume; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014109:Total Lung Capacity; D016896:Treatment Outcome; D014797:Vital Capacity
chemical_list: D001993:Bronchodilator Agents
keywords: GOLD I; GOLD II; RV/TLC; bronchodilation test