Esophageal acid exposure analysis is divided to upright and supine.
This is based on the assumption that the supine-awake period is similar to the supine-asleep period.
Dr Ronnie Fass and colleagues from Arizona, USA determined if the principal acid-reflux characteristics of supine-awake are closer to supine-asleep or upright period.
|The frequency of acid-reflux events was higher in both upright and supine-awake periods|
|Neurogastroenterology & Motility|
Patients with heartburn underwent an upper endoscopy and pH testing.
The team instructed the patients to carefully document their upright, supine-awake and supine-asleep periods.
A total of 64 patients were enrolled into this study, of which 35 were male with a mean age of 52 years.
The research team found that the mean percentage total time of a pH less than 4 was not different between upright and the supine-awake period.
Frequency of acid-reflux events per hour, and number of sensed reflux events was not different between upright and the supine-awake period .
The team found in contrast, that the mean percentage total time of pH less than 4 was significantly higher in both upright and supine-awake periods vs supine-asleep.
In addition, the frequency of acid-reflux events and number of sensed reflux events was higher in both upright and supine-awake periods vs supine-asleep.
Dr Fass' team concluded, "The principal characteristics of the acid-reflux events in the supine-awake period are closer to the upright period than to the supine-asleep period."