Gastric pH circadian rhythm in the rural Canzibe area of the Eastern Cape Province, South Africa: a preliminary pilot study

Abstract

Objective: In this study, an attempt has been made to describe the normal circadian rhythm of gastric pH in the dwellers of Canzibe. The high incidence of esophageal cancer in this region is one of the motivating factors to undertake this study. Esophageal impedance studies carried out earlier has supported this finding. Methods: Gastric pH signals were recorded in 14 healthy volunteers during a 24Hr period using Ohmega ambulatory data logger attached to a unisensor dual pH probe. Results: The gastric pH circadian rhythm for males was characterized by 2 alkaline peaks at 09H00 and 12H00 and 2 nadir points at 15H00 and 03H00, while that for females were defined by only 1 alkaline peak at 09H00 and 1nadir point at 05H00. There were great fluctuations in gastric pH within the nycthemeral in males than in femalesbut with females presenting with higher gastric pH than males (ANOVA, P<0.0001). Conclusion: The peak and nadir of the gastric pH circadian rhythm are noted at 09H00 and 05H00 respectively.

Keywords: Gastric pH; circadian rhythm; esophageal cancer; esophageal impedance