title: Increased prevalence of gastroesophageal reflux in patients with idiopathic pulmonary fibrosis.
abstract: Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal interstitial lung disease (ILD) of unknown etiology. Introduction of acid into the respiratory tree can produce pulmonary fibrosis. Gastroesophageal reflux (GER) has previously been associated with several other respiratory conditions, including pneumonia, bronchitis, and asthma. To investigate prospectively the possible association of GER and IPF, 17 consecutive patients with biopsy-proven IPF and eight control patients with ILD other than IPF underwent dual-channel, ambulatory esophageal pH monitoring. Sixteen of 17 patients with IPF had abnormal distal and/or proximal esophageal acid exposure compared with four of eight control patients (p = 0.02). In the patients with IPF, mean percent distal total (13.6 versus 3.34, p = 0.006), distal upright (12.4 versus 5.1, p = 0.04), distal supine (14.7 versus 0.88, p = 0.02), and proximal supine (7.48 versus 0.24, p = 0.04) esophageal acid exposure times were significantly greater than those in control patients. Only four patients with IPF (25%) with increased acid exposure had typical reflux symptoms such as heartburn or regurgitation. Patients with IPF have a high prevalence of increased esophageal acid exposure, usually without typical GER symptoms. GER in these patients tends to occur at night and extend into the proximal esophagus. Acid reflux may be a contributing factor in the pathogenesis of IPF.
authors.affiliation: Department of Medicine, Division of Gastroenterology and Pulmonary/Critical Care, and Departments of Surgery and Biostatistics, University of Washington, Seattle, Washington, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Tobin
authors.forename: C E
authors.initials: CE
authors.lastname: Pope
authors.forename: C A
authors.initials: CA
authors.lastname: Pellegrini
authors.forename: M J
authors.initials: MJ
authors.lastname: Emond
authors.forename: J
authors.initials: J
authors.lastname: Sillery
authors.forename: G
authors.initials: G
authors.lastname: Raghu
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000209:etiology; D001706:Biopsy; D001991:Bronchitis / Q000209:etiology; D002940:Circadian Rhythm; D004947:Esophagus / Q000503:physiopathology; D005260:Female; D005744:Gastric Acid; D005764:Gastroesophageal Reflux / Q000150:complications* / Q000503:physiopathology; D006356:Heartburn / Q000209:etiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory; D011014:Pneumonia / Q000209:etiology; D011187:Posture; D015995:Prevalence; D011446:Prospective Studies; D011653:Pulmonary Diffusing Capacity; D011658:Pulmonary Fibrosis / Q000209:etiology*; D012737:Sex Factors; D016683:Supine Position; D013997:Time Factors