title: Upright versus supine reflux in gastroesophageal reflux disease.
abstract: BACKGROUND
  Postural measures are early recommendations in the management of heartburn, and are aimed at preventing acid reflux through an incompetent lower esophageal sphincter (LES). However, LES incompetence is found in only a minority of patients, and transient LES relaxations, primarily in the upright position, are currently recognized as the main pathophysiological abnormality in gastroesophageal reflux disease (GERD). We investigated the importance of supine acid reflux in patients with GERD.
  
  
  METHODS
  Upon review of their clinical, manometric, pH monitoring and endoscopic characteristics, 85 patients with reflux symptoms were classified into three groups: Group A (n=22), consisting of symptomatic patients without esophagitis or pathological reflux; group B (n=38), symptomatic patients with reflux but no endoscopic esophagitis; and group C (n=25), symptomatic patients with both ulcerative or complicated esophagitis and pathological reflux.
  
  
  RESULTS
  All groups were similar in age distribution. Groups B and C had a higher prevalence of hiatal hernia and reflux symptoms. Manometry revealed similar LES pressures in groups A and B, but lower LES pressure in group C (P < 0.005). In groups A and B, supine reflux, in terms of percentage of time with pH < 4, was less pronounced than upright reflux (P < 0.0001). In contrast, group C supine reflux was as pronounced as the upright reflux.
  
  
  CONCLUSIONS
  The majority of patients reflux in the upright position. Only patients with complicated esophagitis have significant bipositional acid reflux. These findings suggest that unless the patient has severe reflux disease, postural measures may not be indicated.
authors.affiliation: Gastroenterology Section, Palo Alto Veterans Affairs Health Care System, Palo Alto, CA 94304, USA.
authors.forename: R
authors.initials: R
authors.lastname: Ouatu-Lascar
authors.forename: O S
authors.initials: OS
authors.lastname: Lin
authors.forename: R C
authors.initials: RC
authors.lastname: Fitzgerald
authors.forename: G
authors.initials: G
authors.lastname: Triadafilopoulos
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005764:Gastroesophageal Reflux / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D016683:Supine Position