Effect of the osmolality of caloric and acaloric liquids on gastric myoelectrical activity in humans.

BACKGROUND: The aim was to establish the effect of the osmolality of orally consumed liquids on gastric myoelectrical activity (GMA). MATERIAL/METHODS: Twenty-five healthy volunteers (13 women, 12 men aged 29.4+/-1.4 [SE] years) underwent five examinations on separate days. After a 20-min basal electrogastrographic recording, the volunteers drank 400 ml of a) bi-distilled water, b) 0.9% NaCl, osmolality 286 mmol/kg, c) 2.9% NaCl, osmolality 827 mmol/kg, d) 5% glucose, osmolality 282 mmol/kg, energy density 209 kcal/l, or e) 15% glucose, osmolality 836 mmol/kg, 627 kcal/l. Then the registration of GMA was continued for 60 min. Gastric emptying was measured with the 13C-acetate breath test. RESULTS: Compared with distilled water, the isotonic glucose drink elicited a positive chronotropic influence on and stabilization of GMA. At the transition from isotonicity to hypertonicity, a pronounced destabilization of GMA was observed, with opposite directions of changes brought about by the presence or absence of a caloric load; bradygastria was manifested after the energy-free hypertonic NaCl solution whereas hypertonic glucose evoked a tachygastric pattern. A marked delay in gastric emptying was found with both hypertonic drinks. CONCLUSIONS: Osmolality and its interplay with chemical composition/energy density must be taken into account when choosing a test meal for an electrogastrographic examination and interpreting its results. Of the five fluids examined, isotonic glucose appeared to be the drink least disturbing to GMA.

Feasibility of a breath test with a substrate of natural 13C-abundance and isotope-selective non-dispersive infrared spectrometry: a preliminary study.

BACKGROUND AND AIMS: Isotope-selective non-dispersive infrared spectrometry (NDIRS) is a cheaper alternative to isotope ratio mass spectrometry (IRMS). We checked on the efficiency of NDIRS to perform a breath test with naturally (13)C-enriched maize starch. METHODS: Fifty-six healthy volunteers were examined. After a basal fasted sample of their expiratory air was collected, the subjects ate a test breakfast of 50 g (CF50 group, n = 9) or 100 g (CF100 group, n = 47) cornflakes with 175 g yoghurt. For 6 h thereafter, exhaled air was collected every 30 min for the NDIRS measurement of (13)CO(2) concentration. RESULTS: The time-course of the curves of (13)CO(2) concentration resembled those obtained previously with IRMS. A dose-response to the amount of ingested cornflakes was observed--the maximum postprandial net increment in (13)CO(2) was statistically significantly higher in the CF100 than CF50 group: 4.78 +/- 0.13 versus 3.12 +/- 0.17 per thousand (P < 0.001), whereas the time needed to reach the maximum did not differ after the intake of 50 g (233 +/- 13 min) or 100 g (248 +/- 9 min) cornflakes. The 5-h area-under-the-curve of cumulative (13)CO(2) net recovery (AUC(60-360)) was statistically significantly greater after ingestion of 100 g compared to 50 g cornflakes (97.6 +/- 2.2 versus 61.7 +/- 2.2 micromol, P < 0.001) and it also exhibited a stable between-subject variability. CONCLUSION: The obtained proof of technical feasibility of a breath test with the use of naturally (13)C-enriched starch and NDIRS provides background for future research on the clinical usefulness of this method for a non-invasive assessment of the pancreatic exocrine function.

[Application of the hydrogen breath test for the evaluation of oro-caecal transit time]. / Zastosowanie wodorowego testu oddechowego do pomiaru czasu pasazu zoladkowo-katniczego.

Physiological background and performance of the hydrogen breath test are described. Clinical and research applications of the hydrogen breath test for evaluation of the transport function of the small bowel are pointed out. Several factors affecting the oro-caecal transit time, such as: physiological (age, sex, menstrual cycle), usage of stimulants (coffee, alcohol, cigarette smoking), as well as pathological conditions, are discussed. An in-depth review of drug effects on the oro-caecal transit time is provided.