title: [Perception of symptoms with minimal reductions of esophageal pH in patients with erosive and non-erosive GERD].
abstract: BACKGROUND
  Patients with gastrointestinal reflux disease GERD perceive < 5% of acid reflux episodes, independently of GERD type. The role of minimal changes on esophageal pH (1 or 2 units) on development of symptoms is unknown.
  
  
  OBJECTIVE
  To evaluate symptom perception and its relationship with minimal changes on esophageal pH in patients with erosive and non-erosive GERD (NERD).
  
  
  METHODS
  We evaluated consecutive patients with symptomatic GERD. All patients had endoscopy in the previous 8 weeks. All patients underwent 24-h esophageal pH-monitoring. Abnormal pH-metry was defined as % time of pH < 4 > 4.2. Symptom index (SI) was considered positive when > or = 50. We also calculated SI at pH 5 and pH 6. Patients with GERD were classified into three groups: 1) abnormal pH and negative SI. For statistical analysis, we used the test-Student, chi 2, and ANOVA test. P < 0.05 was considered statistically significant.
  
  
  RESULTS
  We evaluated 120 patients, 79 (66%) females and 41 (34%) males with mean age of 47.8 years (range 21-83 years). Eighty three (69%) patients had NERD and 37 (31%), erosive esophagitis (EE). Seventy two patients (87%) with NERD and 36 (97%) with erosive GERD developed symptoms during the study. NERD patients had mean of 69 reflux episodes compared with 184 of patients with EE. Perception of reflux symptoms was significantly higher in the group with EE (3.4 vs. 1.02 p < 0.0001). Among patients with NERD, 33% had abnormal pH-metry and 67%, a normal test. Of these patients, nine (16%) had normal pH test and positive SI, and 47 (83%) normal pH test and negative SI. There was no difference in symptom perception among the three groups. Patients with NERD and abnormal pH had similar SI patients with EE; 4% of patients with normal pH and negative SI at pH 4 had positive SI when calculated at pH 5, and 68% when SI was calculated at pH 6.
  
  
  CONCLUSIONS
  The majority of acid reflux episodes are not perceived and this phenomenon is independent of erosive or non-erosive GERD. Patients with erosive esophagitis had significantly higher esophageal acid exposure than patients with NERD. Minimal changes in esophageal pH (1 or 2 pH units) increases SI in patients with GERD, especially in those with normal esophageal acid exposure.
authors.affiliation: Laboratorio de Motilidad Gastrointestinal, Departamento de Gastroenterología, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Sección XVI, Tlalpan CP 14000 México, D.F.
authors.forename: José María
authors.initials: JM
authors.lastname: Remes-Troche
authors.forename: Octavio
authors.initials: O
authors.lastname: Gómez-Escudero
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Ruíz
authors.forename: Max Julio
authors.initials: MJ
authors.lastname: Schmulson
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Valdovinos Díaz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004947:Esophagus / Q000378:metabolism; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications / Q000175:diagnosis / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged