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

Objective: To 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. Methods: In 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-99(m)) according to a crossover design. Plasma glucose, insulin, C-peptide, glucagon-like peptide (GLP-1), peptide YY, total glucagon, and ghrelin were studied. Results: Gastric 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. Conclusion: Fruit-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. (C) 2011 Elsevier Inc. All rights reserved.