title: Comparison of airway dimensions with once daily tiotropium plus indacaterol versus twice daily Advair(®) in chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Current guidelines recommend combining long-acting bronchodilators with different modes of action in patients with moderate-to-severe chronic obstructive pulmonary disease (COPD). We evaluated the effects of airway dimensions and pulmonary function with tiotropium plus indacaterol versus Advair(®).
  
  
  METHODS
  Subjects (n = 46) were randomized to receive tiotropium (18 μg once daily) plus indacaterol (150 μg once daily) or Advair(®) (50/250 μg twice daily) for 16 weeks. Airway geometry was determined by quantitative computed tomography (luminal area, Ai; total area of the airway, Ao; wall area, WA; and percentage wall area, WA/Ao and wall thickness, T). Spirometry (forced expiratory volume in 1 s, FEV1; forced vital capacity, FVC and inspiratory capacity, IC) and St. George's Respiratory Questionnaire (SGRQ) were evaluated.
  
  
  RESULTS
  Tiotropium plus indacaterol significantly increased CT-indices including Ai corrected for body surface area (Ai/BSA), and decreased WA/BSA, WA/Ao and T/√BSA compared with Advair(®) (p < 0.05, respectively). In physiological parameters, mean difference in IC was significantly higher under treatment with tiotropium plus indacaterol than Advair(®) (p < 0.05). The changes in Ai/BSA, WA/BSA, WA/Ao and T/√BSA were significantly correlated with changes in IC (r = 0.535, p = 0.011; r = -0.688, p < 0.001; r = -0.555, p = 0.002 and r = -0.542, p = 0.007; respectively). There were more significant improvements in SGRQ scores after treatment with tiotropium plus indacaterol than Advair(®).
  
  
  CONCLUSIONS
  These findings suggest that dual bronchodilation with tiotropium plus indacaterol is superior in airway geometry and lung function compared with Advair(®) in COPD.
authors.affiliation: Department of Respiratory Medicine, Atami Hospital, International University of Health and Welfare, Atami, Japan. Electronic address: hoshino@iuhw.ac.jp.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hoshino
authors.affiliation: Department of Radiology, Atami Hospital, International University of Health and Welfare, Atami, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Ohtawa
authors.affiliation: Department of Radiology, Atami Hospital, International University of Health and Welfare, Atami, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Akitsu
mesh_terms: D000368:Aged; D000420:Albuterol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D000730:Androstadienes / Q000008:administration & dosage / Q000494:pharmacology*; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000494:pharmacology; D004334:Drug Administration Schedule; D004338:Drug Combinations; D004359:Drug Therapy, Combination; D005260:Female; D000068297:Fluticasone-Salmeterol Drug Combination; D005938:Glucocorticoids / Q000008:administration & dosage / Q000494:pharmacology; D006801:Humans; D007189:Indans / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000503:physiopathology; D015363:Quinolones / Q000008:administration & dosage / Q000494:pharmacology*; D012602:Scopolamine Derivatives / Q000008:administration & dosage / Q000494:pharmacology*; D013147:Spirometry; D011795:Surveys and Questionnaires; D000069447:Tiotropium Bromide
chemical_list: D000730:Androstadienes; D001993:Bronchodilator Agents; D004338:Drug Combinations; D000068297:Fluticasone-Salmeterol Drug Combination; D005938:Glucocorticoids; D007189:Indans; D015363:Quinolones; D012602:Scopolamine Derivatives; C510790:indacaterol; D000420:Albuterol; D000069447:Tiotropium Bromide
keywords: Airway geometry; Long-acting muscarinic receptor antagonist; Long-acting β(2)-adrenergic receptor agonist; Pulmonary function; Pulmonary hyperinflation; Quantitative computed tomography