title: Marked improvement in nocturnal gastroesophageal reflux in a large cohort of patients with obstructive sleep apnea treated with continuous positive airway pressure.
abstract: BACKGROUND
  Nocturnal gastroesophageal reflux (nGER) is common in patients with obstructive sleep apnea (OSA). Small, short-term studies have shown that treatment with nasal continuous positive airway pressure (CPAP) decreases esophageal acid exposure.
  
  
  OBJECTIVE
  To examine the relationship between OSA and nGER, and the effect of CPAP on nGER, in a long-term follow-up study of a large cohort of patients with OSA and nGER.
  
  
  METHODS
  We prospectively studied 331 patients diagnosed as having OSA between October 1, 1993, and November 30, 2000. At baseline, patients graded their frequency of nGER symptoms on a scale of 1 (never) to 5 (always). All patients were prescribed CPAP for their OSA. At follow-up, the frequency of nGER symptoms was obtained by telephone interview.
  
  
  RESULTS
  Of the 331 patients with OSA, nGER was present in 204 (62%) before treatment with CPAP. Follow-up was obtained in 181 patients (89%). Of these 181 patients, 165 (91%) were still using CPAP and 16 (9%) were not, forming the treatment and control groups, respectively. The patients compliant with CPAP had a significant improvement in nGER score, from a mean of 3.38 before CPAP treatment to 1.75 after treatment (48% improvement; P<.001), while patients not using CPAP (control subjects) showed no improvement (mean, 3.56 to 3.44; P =.55). There was a strong correlation between CPAP pressure and improvement in nGER score (correlation, r = 0.70; P<.001), with patients with higher CPAP pressures demonstrating a greater improvement in nGER score.
  
  
  CONCLUSIONS
  Nocturnal GER is common in patients with OSA. Treatment with nasal CPAP decreases the frequency of nGER symptoms by 48%. Higher nasal CPAP pressures are associated with greater improvement in nGER.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Bryan T
authors.initials: BT
authors.lastname: Green
authors.forename: William A
authors.initials: WA
authors.lastname: Broughton
authors.forename: J Barry
authors.initials: JB
authors.lastname: O'Connor
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D005764:Gastroesophageal Reflux / Q000150:complications* / Q000175:diagnosis / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000175:diagnosis / Q000628:therapy*; D011795:Surveys and Questionnaires; D013689:Telephone; D016896:Treatment Outcome