The effects of repeated ingestion of high and low glucose-electrolyte solutions on gastric emptying and blood 2H2O concentration after an overnight fast.

The addition of carbohydrate to drinks designed to have a role in rehydrating the body is commonplace. The gastric emptying and fluid uptake characteristics following repeated ingestion of drinks with high and low glucose concentrations were examined in eight subjects (three male and five female). Following a 13 h fluid restriction period, the subjects ingested a volume of test solution amounting to 3 % of the initial body mass over a period of 60 min. Test drinks were 2 and 10 % glucose-electrolyte solutions with osmolalities of 189 (SD 3) and 654 (SD 3) mOsm/kg, respectively. The initial bolus of each test solution contained 10 g of (2)H(2)O. Blood samples were collected throughout drinking and for 60 min afterwards. Gastric volumes were determined via gastric aspiration at 15 min intervals for 120 min. No difference between trials in total stomach volume was observed until 30 min after the ingestion of the first bolus of test drink, but blood (2)H concentration was increased during both trials 10 min after ingestion of the first bolus. Blood (2)H concentration was greater at this time point during the 2 % glucose trial than during the 10 % glucose trial and remained higher for the duration of the trial with the exception of one time point. Urine volume at the end of the trial was greater in the 2 % glucose trial than in the 10 % glucose trial. It is concluded that the reduced overall rate of fluid uptake following ingestion of the 10 % glucose solution was due largely to a relatively slow rate of gastric emptying.