title: Comparison of clinical characteristics of chronic cough due to non-acid and acid gastroesophageal reflux.
abstract: OBJECTIVE
  Little is known about non-acid gastroesophageal reflux-induced chronic cough (GERC). The purpose of the study is to explore the clinical characteristics of non-acid GERC.
  
  
  METHODS
  Clinical symptoms, cough symptom score, capsaicin cough sensitivity, gastroesophageal reflux diagnostic questionnaire (GerdQ) score, findings of multichannel intraluminal impedance-pH monitoring (MII-pH) and response to pharmacological anti-reflux therapy were retrospectively reviewed in 38 patients with non-acid GERC and compared with those of 49 patients with acid GERC.
  
  
  RESULTS
  Non-acid GERC had the similar cough character, cough symptom score, and capsaicin cough sensitivity to acid GERC. However, non-acid GERC had less frequent regurgitation (15.8% vs 57.1%, χ(2)  = 13.346, P = 0.000) and heartburn (7.9% vs 32.7%, χ(2)  = 7.686, P  = 0.006), and lower GerdQ score (7.4 ± 1.4 vs 10.6 ± 2.1, t = -6.700, P = 0.003) than acid GERC. Moreover, MII-pH revealed more weakly acidic reflux episodes, gas reflux episodes and a higher symptom association probability (SAP) for non-acid reflux but lower DeMeester score, acidic reflux episodes and SAP for acid reflux in non-acid GERC than in acid GERC. Non-acid GERC usually responded to the standard anti-reflux therapy but with delayed cough resolution or attenuation when compared with acid GERC. Fewer patients with non-acid GERC needed an augmented acid suppressive therapy or treatment with baclofen.
  
  
  CONCLUSIONS
  There are some differences in the clinical manifestations between non-acid and acid GERC, but MII-pH is essential to diagnose non-acid GERC.
authors.affiliation: Department of Respiratory Medicine, Tongji Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Xianghuai
authors.initials: X
authors.lastname: Xu
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Yang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
authors.forename: Li
authors.initials: L
authors.lastname: Yu
authors.forename: Siwei
authors.initials: S
authors.lastname: Liang
authors.forename: Hanjing
authors.initials: H
authors.lastname: Lü
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Qiu
mesh_terms: D000328:Adult; D000897:Anti-Ulcer Agents / Q000627:therapeutic use; D001418:Baclofen / Q000627:therapeutic use; D002211:Capsaicin; D002908:Chronic Disease; D003371:Cough / Q000175:diagnosis* / Q000209:etiology* / Q000628:therapy; D004294:Domperidone / Q000627:therapeutic use; D050782:Esophageal pH Monitoring; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications* / Q000175:diagnosis* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009125:Muscle Relaxants, Central / Q000627:therapeutic use; D009853:Omeprazole / Q000627:therapeutic use; D012189:Retrospective Studies; D011795:Surveys and Questionnaires
chemical_list: D000897:Anti-Ulcer Agents; D009125:Muscle Relaxants, Central; D004294:Domperidone; D001418:Baclofen; D009853:Omeprazole; D002211:Capsaicin
keywords: clinical feature; cough; electric impedance; esophageal PH monitoring; gastroesophageal reflux