Prediction of fasting gastric pH using serum biological markers

Background/Aims: Previous studies have suggested that hypochlorhydria has the potential to produce adverse effects such as the development of infections of the intestinal or respiratory tract and impaired drug absorption. This indicates the importance of obtaining a noninvasive method by which this condition may be diagnosed. The purpose of this study was to determine whether fasting gastric pH could be predicted noninvasively using serum biological markers. Methodology: One hundred thirty-two patients undergoing diagnostic upper gastrointestinal endoscopy were recruited. Serum levels of pepsinogen-I, pepsinogen -II and Helicobacter pylori antibody were analyzed and the pH of fasting gastric juice determined. Multiple linear regression analysis was used to determine the best predictors of fasting gastric pH. Results: Pepsinogen -I and the presence of Helicobacter pylori were independent predictors of fasting gastric pH, and a high coefficient of determination was obtained (R ²=0.503, root mean square error=1.45). The equation for this model was as follows: fasting gastric pH=2.97-0.026 (pepsinogen -I)+2.76 (presence of Helicobacter pylori: 0=absent, 1=present). Conclusions: The model equation offers a non-invasive method by which to identify patients at high-risk of developing complications induced by hypochlorhydria.