Standardization of Electrode Positioning and Composition of Meals for Long-Term Intragastric pH Metry in Man

Abstract

In these prospective studies the influence of two different intragastric positions of electrodes and of four different compositions of standardized meals on 24-hour ambulatory pH recording were compared intraindividually in healthy male subjects. Simultaneous pH monitoring in 12 subjects demonstrated a more pronounced postprandial pH elevation in the fundus body compared to the antral area. The intraindividual comparison of an identical diet given on two different days to 10 subjects revealed nearly identical pH profiles. Variations of carbohydrate, protein and fat content of isocaloric meals given in a randomized order did not significantly alter 24-hour intragastric pH profiles. It is concluded from these data that positioning of the pH electrode in the fundus body area is superior to an antral position. 24-hour ambulatory intragastric pH monitoring in man is well reproducible. A strict standardization of the composition of meals is mandatory only for scientific investigations.

Development of anin vitrosystem simulating bucco-gastric digestion to assess the physical and chemical changes of food

“…The composition of an isocaloric diet does not seem to change gastric pH profiles significantly as compared with a balanced diet (Londong et al, 1990). In this way, the gastric pH profile obtained in the present study with bread could be applied to ordinary meals.…”

NSAIDs: take with food or after fasting?

“…The type of meals and the consequent changes in patterns of gastric acidity are also not straightforward [24] . Variations in the content of carbohydrate, protein and fat of isocaloric meals do not have marked effects, [24] although there is a small decrease in gastric acidity in response to an isocaloric fat‐containing meal compared with that of a balanced diet [25] .…”

“…The type of meals and the consequent changes in patterns of gastric acidity are also not straightforward [24] . Variations in the content of carbohydrate, protein and fat of isocaloric meals do not have marked effects, [24] although there is a small decrease in gastric acidity in response to an isocaloric fat‐containing meal compared with that of a balanced diet [25] . In general, following a standardised meal after a fast there is buffering of gastric acid approaching a pH of 6 and a return to below pre‐fast levels within 2 h. Thus taking a NSAID before, during and after a meal is likely to have different effects on the gastric mucosa and the composition of the meal is likely to be important.…”

Simultaneous Comparison of 24-Hour Intragastric pH Recording Using Glass and Antimony Electrodes in Man

“…Positioning of the tips of the electrodes was controlled by fluoroscopy in order to guarantee position in the fundus corpus (Polydoros 100, Siemens, Erlangen, FRG). This position seems to be superior to antral positioning [16]. The data sampling period started at 07.45 h. During day time the subjects received a standardized diet with breakfast at 08.15 h, lunch at 13.00 h, and dinner at 19.00 h. The diet consisted of 334 g of carbohydrate, 78 g of fat and 94 g of protein (2,500 kcal).…”

“…The data sampling period started at 07.45 h. During day time the subjects received a standardized diet with breakfast at 08.15 h, lunch at 13.00 h, and dinner at 19.00 h. The diet consisted of 334 g of carbohydrate, 78 g of fat and 94 g of protein (2,500 kcal). Coffee for breakfast and mineral water for lunch and dinner were standardized [16], Extraordinary physical ac tivities and sunbathing were prohibited, because sweating causes differences in skin electrolyte compo sition and therefore might influence pH recordings. The subjects spent the night at home; they had to go to bed at 23.00 h. The next morning the experiment was terminated at 06.45 h by removing the electrodes and recalibrating them at 37 °C using buffers of pH 7 and 1.…”