The researchers investigated the prevalence of acid and non-acid reflux and the air-liquid composition of the refluxate in ambulant healthy subjects and patients with gastro-esophageal reflux disease (GERD).
They reported their findings in the June issue of Gastroenterology.
24-hour ambulatory recordings were performed in 30 patients with symptomatic GERD and erosive esophagitis and in 28 controls.
Esophageal pH and impedance were used to identify acid reflux (pH drop below 4.0), minor acid reflux (pH drop above 4.0), non-acid reflux (pH drop less than 1 unit as well as liquid reflux in impedance), and gas reflux.
|Proportion of subjects with pure liquid acid reflux:|
GERD patients: 45%
The total rate of gastro-esophageal reflux episodes was found to be similar in patients and controls.
Patients with GERD had a higher proportion (45% versus 33%) and rate of acid reflux than controls (21.5/24 hours versus 13/24 hours).
One third of reflux events was non-acid in both groups.
Mixed reflux of gas and liquid was the most frequent pattern, with gas preceding liquid in 50%-80% of cases.
Pure liquid reflux was more often acid in patients with GERD than controls (45% versus 32%).
Researcher Daniel Sifrim, of the University of Leuven, Belgium, concluded on behalf of his colleagues, "Reflux of gastric contents was similarly frequent in patients with GERD and controls.
"Although there was no difference in the overall number of reflux episodes, more acidic reflux occurred in symptomatic patients with GERD, suggesting differences in gastric acid secretion or distribution."