Impedance-pH reflux patterns can differentiate non-erosive reflux disease from functional heartburn patients.
BACKGROUND
Symptom association is important to distinguish non-erosive reflux disease [NERD; abnormal oesophageal acid exposure time (AET) and/or positive symptom association] from functional heartburn (FH; normal AET and negative symptom association). Asymptomatic patients during reflux monitoring are challenging as symptom association cannot be assessed.


OBJECTIVE
To evaluate whether impedance-pH reflux patterns are useful to differentiate NERD from FH.


METHODS
Endoscopy-negative reflux patients underwent impedance-pH off-therapy. Oesophageal AET, characteristics of reflux episodes and symptom association probability (SAP) were measured. Twenty patients asymptomatic during the first test repeated a second examination.


RESULTS
Of 329 patients, 130 (40%) were pH-POS, 120 (36%) pH-NEG/SAP+ (hypersensitive oesophagus = HO) and 79 (24%) pH-NEG/SAP- (FH). Total and acid reflux episodes were significantly higher (p < 0.01) in pH-POS compared to pH-NEG/SAP+, pH-NEG/SAP- and healthy volunteers (HVs). Patients pH-NEG/SAP+ had a significantly increased number of weakly acidic reflux episodes compared to pH-POS, pH-NEG/SAP- and HVs (p < 0.01). The rate of proximal reflux episodes in pH-POS (50%) and pH-NEG/SAP+ (47%) was higher (p < 0.01) than in pH-NEG/SAP- (33%) and HVs (33%). Measuring AET, number of reflux episodes and percentage of proximal reflux events permits to identify FH in 70% of cases and HO in 80% of cases who repeated the examination.


CONCLUSIONS
In patients with normal AET and SAP+, increased number of weakly acidic reflux and higher rate of proximal reflux are the main discriminant features. There is large overlap between FH and HVs. These differences can be of help in diagnosing patients with normal oesophageal acid exposure who fail to have symptoms during MII-pH testing.
Division of Gastroenterology, Department of Internal Medicine, University of Genoa, Genoa, Italy. edoardo.savarino@unige.it
Edoardo
E
Savarino
Patrizia
P
Zentilin
Radu
R
Tutuian
Daniel
D
Pohl
Lorenzo
L
Gemignani
Alberto
A
Malesci
Vincenzo
V
Savarino
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D017097:Electric Impedance; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D006356:Heartburn / Q000175:diagnosis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D055815:Young Adult