title: Pulmonary function and gastroesophageal reflux in systemic sclerosis.
abstract: OBJECTIVE
  To determine the relations among esophageal dysfunction, gastroesophageal reflux, and lung involvement in patients with systemic sclerosis.
  
  
  METHODS
  Retrospective review of esophageal motility, esophageal pH, and pulmonary function data.
  
  
  METHODS
  University hospital outpatient clinic and community.
  
  
  METHODS
  39 consecutively referred patients who were grouped according to the presence or absence of abnormal distal (pH < 4.0 for > 5% of the 24-hour monitoring period) or proximal (pH < 4.0 for > 1% of the 24-hour period) gastroesophageal acid reflux. Patients were also grouped according to the presence or absence of distal esophageal peristalsis.
  
  
  METHODS
  Esophageal manometry, dual-probe (distal and proximal) esophageal 24-hour pH measurements, and pulmonary function studies (forced vital capacity, forced expiratory volume at 1 second, total lung capacity, and single-breath carbon monoxide diffusing capacity [DLco]).
  
  
  RESULTS
  The mean total lung capacity (values as percentage predicted) was 87.1% +/- 11.2% (SD) for patients with abnormal proximal reflux and 77.8% +/- 21.6% for patients with normal proximal reflux (difference, 9.3%; 95% CI, -1.4% to 20.0%). The mean forced vital capacity for these patients was 91.1% +/- 12.4% and 85.4% +/- 25.6%, respectively (difference, 5.7%; CI, -6.9% to 18.1%). The mean total lung capacity was 83.8% +/- 15.4% for patients with abnormal distal reflux and 77.9% +/- 22.7% for patients with normal distal reflux (difference, 5.9%; CI, -7.6% to 19.4%). Among potential confounders of pulmonary measures, only smoking was related to decreased pulmonary function (smoking related to decreased DLco P < 0.01). Smoking was more common in patients with abnormal distal reflux than in those with normal distal reflux (65% compared with 25%, P = 0.03). After adjusting for smoking, the difference in mean DLco between patients with abnormal compared with normal distal reflux was 7.19% (Cl, -8.5% to 22.9%).
  
  
  CONCLUSIONS
  Important measures of lung volume indicative of interstitial lung disease (total lung capacity, forced vital capacity) do not appear to be related to abnormal gastroesophageal acid reflux in patients with systemic sclerosis.
authors.affiliation: Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania.
authors.forename: M B
authors.initials: MB
authors.lastname: Troshinsky
authors.forename: G C
authors.initials: GC
authors.lastname: Kane
authors.forename: J
authors.initials: J
authors.lastname: Varga
authors.forename: J R
authors.initials: JR
authors.lastname: Cater
authors.forename: J E
authors.initials: JE
authors.lastname: Fish
authors.forename: S A
authors.initials: SA
authors.lastname: Jimenez
authors.forename: D O
authors.initials: DO
authors.lastname: Castell
mesh_terms: D004947:Esophagus / Q000503:physiopathology; D005260:Female; D005764:Gastroesophageal Reflux / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008168:Lung / Q000503:physiopathology*; D008171:Lung Diseases / Q000209:etiology; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D012595:Scleroderma, Systemic / Q000150:complications / Q000503:physiopathology*; D012907:Smoking / Q000009:adverse effects