title: The prevalence of gastro-esophageal reflux disease and esophageal dysmotility in Chinese patients with idiopathic pulmonary fibrosis.
abstract: BACKGROUND
  The cause of idiopathic pulmonary fibrosis (IPF) remains unknown, yet gastro-esophageal reflux disease (GERD) is highly prevalent in this population. GERD prevalence was studied, and esophageal function tests (EFT) were assessed in Chinese IPF patients.
  
  
  METHODS
  We prospectively studied 69 IPF patients who undertook both stationary High Resolution esophageal Manometry/Impedance (HRiM) and 24-hour esophageal Multi-Channel Intraluminal Impedance with pH Recordings (MII/pH). Patients were divided into GERD+ and GERD- groups according to pH results. Controls were HRiM treated healthy volunteers, and patients without IPF received HRiM and MII/pH diagnosed with GERD.
  
  
  RESULTS
  69 IPF patients, 62 healthy volunteers, and 88 IPF negative GERD patients were selected. GERD prevalence in IPF was 43/69 (62.3%), and 58.1% of patients presented with at least one typical symptom. Symptoms had a sensitivity of 58.1%, a specificity of 61.6%, a positive predictive value of 71.4% and a negative predictive of 47.1%. Compared with healthy volunteers, IPF patients had significantly decreased lower esophageal sphincter pressure (LESP), upper esophageal sphincter pressure (UESP) and complete bolus transit rate (CBTR). By contrast, IPF patients had increased total bolus transit time and prevalence of weak peristalsis. MII/pH showed that one third of IPF patients had abnormal distal and proximal reflux, especially non-acid reflux. Compared with GERD patients without IPF, GERD patients with IPF had significantly decreased CBTR and UESP with increased bolus exposure time.
  
  
  CONCLUSIONS
  GERD prevalence in IPF was high, but symptoms alone were an unreliable predictor of reflux. IPF patients had lower LESP and UESP, impaired esophageal peristalsis and bolus clearance function with more proximal reflux events.
authors.affiliation: Digestive Department, Beijing Chao-Yang Hospital, Capital Medical University, No.8 Gong Ren Ti Yu Chang South Road, Chao Yang District, Beijing, 100020, China. gaofeng4321@sina.com.
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.affiliation: The Functional Gut Clinic, London, W1G 6NB, United Kingdom. anthonyhobson@hotmail.com.
authors.forename: Anthony Robert
authors.initials: AR
authors.lastname: Hobson
authors.affiliation: Digestive Department, Beijing Chao-Yang Hospital, Capital Medical University, No.8 Gong Ren Ti Yu Chang South Road, Chao Yang District, Beijing, 100020, China. shangmed@163.com.
authors.forename: Zhan Min
authors.initials: ZM
authors.lastname: Shang
authors.affiliation: Digestive Department, Beijing Chao-Yang Hospital, Capital Medical University, No.8 Gong Ren Ti Yu Chang South Road, Chao Yang District, Beijing, 100020, China. peiyanxiang1972@126.com.
authors.forename: Yan Xiang
authors.initials: YX
authors.lastname: Pei
authors.affiliation: Digestive Department, Beijing Chao-Yang Hospital, Capital Medical University, No.8 Gong Ren Ti Yu Chang South Road, Chao Yang District, Beijing, 100020, China. gy71@sina.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Digestive Department, Beijing Chao-Yang Hospital, Capital Medical University, No.8 Gong Ren Ti Yu Chang South Road, Chao Yang District, Beijing, 100020, China. 1wjx@163.com.
authors.forename: Jian Xin
authors.initials: JX
authors.lastname: Wang
authors.affiliation: Digestive Department, Beijing Chao-Yang Hospital, Capital Medical University, No.8 Gong Ren Ti Yu Chang South Road, Chao Yang District, Beijing, 100020, China. gaoxiaocong07@sina.com.
authors.forename: Wan Nong
authors.initials: WN
authors.lastname: Huang
mesh_terms: D002681:China / Q000453:epidemiology; D015154:Esophageal Motility Disorders / Q000453:epidemiology* / Q000503:physiopathology; D049630:Esophageal Sphincter, Lower / Q000503:physiopathology; D049631:Esophageal Sphincter, Upper / Q000503:physiopathology; D050782:Esophageal pH Monitoring; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000453:epidemiology*; D008297:Male; D008365:Manometry; D008875:Middle Aged; D010528:Peristalsis; D010992:Plethysmography, Impedance; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies