Gastric emptying, glucose metabolism and gut hormones: Evaluation of a common preoperative carbohydrate beverage

ObjectiveTo study the gastric-emptying rate and gut hormonal response of two carbohydrate-rich beverages. A specifically designed carbohydrate-rich beverage is currently used to support the surgical patient metabolically. Fruit-based beverages may also promote recovery, due to natural antioxidant and carbohydrate content. However, gastric emptying of fluids is influenced by its nutrient composition; hence, safety of preoperative carbohydrate loading should be confirmed. Because gut hormones link carbohydrate metabolism and gastric emptying, hormonal responses were studied.MethodsIn eight volunteers, gastric emptying rates of both 400 mL of a ready-to-use beverage (A: Nutricia preOp; 50.4 g carbohydrates—mainly polysaccharides; 260 mOsm/kg) and 400 mL over-the-counter fruit-based lemonade (B: Roosvicee Original; 48 g carbohydrates—mainly fruit-associated saccharides; 805 mOsm/kg) were determined scintigraphically (using hepatate Tc-99m) according to a crossover design. Plasma glucose, insulin, C-peptide, glucagon-like peptide (GLP-1), peptide YY, total glucagon, and ghrelin were studied.ResultsGastric emptying showed no differences in residual volumes. Earlier onset in emptying for beverage A versus B was observed (trend), with significantly higher glucose, insulin, C-peptide, and glucagon responses at 15-90 min. GLP-1 was inversely related to residual volume.ConclusionFruit-based lemonade is a safe alternative for preoperative purposes. It induces a more limited glucose, insulin, and C-peptide response. Later onset in gastric emptying (B versus A: trend), lower glucagon release, and differences in beverage content and osmolarity may have contributed to those differences. Efficient emptying was reflected by early GLP-1 levels.