Nutrients, Vol. 18, Pages 469: The Impact of a Fat-Dominant Preload Before a Carbohydrate-Rich Meal on Glucose Homeostasis in Patients Without Diabetes After Sleeve Gastrectomy: A Proof-of-Concept, Randomised, Open-Label, Crossover Study
Nutrients doi: 10.3390/nu18030469
Authors:
Gráinne Whelehan
Louisa Y. Herring
Aikaterina Tziannou
Joseph Henson
Alice E. Thackray
David Bowrey
Jenny Abraham
Vinod Menon
Iskandar Idris
Helen Waller
David J. Stensel
David R. Webb
Thomas Yates
Melanie J. Davies
Dimitris Papamargaritis
Background/Objectives: Sleeve gastrectomy (SG) improves glycaemic control; however, it also markedly accelerates gastric emptying, which can lead to exaggerated postprandial glucose and insulin excursions and, in some cases, postprandial hyperinsulinaemic hypoglycaemia. In non-surgical populations, fat preloads can reduce postprandial glycaemia by slowing gastric emptying, but their effects after SG are unclear. Methods: Ten adults >1-year post-SG completed a randomised, open-label, crossover study involving two mixed-meal tolerance tests (MMTTs), preceded (−30 min) by either a moderate, fat-dominant preload (28 g Brazil nuts) or 100 mL water (control). Blood samples were collected over three hours to assess plasma glucose, insulin, c-peptide, and total glucagon-like peptide-1 (GLP-1). Hypoglycaemia and dumping symptoms were assessed using validated questionnaires. Nadir plasma glucose concentration was the primary outcome. Results: Nadir plasma glucose was identical between conditions (both 3.8 mmol/L; 95% CI: −0.4, 0.3, p = 0.849), and neither peak glucose nor overall postprandial glucose exposure (incremental area under the curve iAUC0–180 min) differed between the preload and water conditions. Insulin and c-peptide concentrations immediately before the MMTT were higher after the fat-dominant preload (both p < 0.001). Overall insulin and c-peptide responses during the MMTT (iAUC0–180 min) remained comparable between conditions (95% CI −225, 2665; p = 0.442 and −67,787, 70,263; 0.968), but peak values for both hormones were higher after the preload (95% CI 2.9, 79.1, p = 0.038 and 17.3, 2402.7, p = 0.040, respectively). Total GLP-1 was also elevated prior to the MMTT (95% CI 1.6, 22.8, p = 0.028), while its early and overall postprandial responses did not differ (both p > 0.05). Ratings of hypoglycaemia and dumping symptoms were similar for both study arms. Discussion: A moderate, fat-dominant preload consumed before a mixed meal did not alter nadir or overall postprandial glucose in adults without diabetes after SG. However, the preload was associated with higher peak insulin secretion, a finding that should be interpreted with caution, as the study was not powered for secondary outcomes. Given the unique gastrointestinal physiology after SG, further research is needed to determine how different nutrient compositions or timing approaches influence postprandial glucose homeostasis in this population.
Background/Objectives: Sleeve gastrectomy (SG) improves glycaemic control; however, it also markedly accelerates gastric emptying, which can lead to exaggerated postprandial glucose and insulin excursions and, in some cases, postprandial hyperinsulinaemic hypoglycaemia. In non-surgical populations, fat preloads can reduce postprandial glycaemia by slowing gastric emptying, but their effects after SG are unclear. Methods: Ten adults >1-year post-SG completed a randomised, open-label, crossover study involving two mixed-meal tolerance tests (MMTTs), preceded (−30 min) by either a moderate, fat-dominant preload (28 g Brazil nuts) or 100 mL water (control). Blood samples were collected over three hours to assess plasma glucose, insulin, c-peptide, and total glucagon-like peptide-1 (GLP-1). Hypoglycaemia and dumping symptoms were assessed using validated questionnaires. Nadir plasma glucose concentration was the primary outcome. Results: Nadir plasma glucose was identical between conditions (both 3.8 mmol/L; 95% CI: −0.4, 0.3, p = 0.849), and neither peak glucose nor overall postprandial glucose exposure (incremental area under the curve iAUC0–180 min) differed between the preload and water conditions. Insulin and c-peptide concentrations immediately before the MMTT were higher after the fat-dominant preload (both p < 0.001). Overall insulin and c-peptide responses during the MMTT (iAUC0–180 min) remained comparable between conditions (95% CI −225, 2665; p = 0.442 and −67,787, 70,263; 0.968), but peak values for both hormones were higher after the preload (95% CI 2.9, 79.1, p = 0.038 and 17.3, 2402.7, p = 0.040, respectively). Total GLP-1 was also elevated prior to the MMTT (95% CI 1.6, 22.8, p = 0.028), while its early and overall postprandial responses did not differ (both p > 0.05). Ratings of hypoglycaemia and dumping symptoms were similar for both study arms. Discussion: A moderate, fat-dominant preload consumed before a mixed meal did not alter nadir or overall postprandial glucose in adults without diabetes after SG. However, the preload was associated with higher peak insulin secretion, a finding that should be interpreted with caution, as the study was not powered for secondary outcomes. Given the unique gastrointestinal physiology after SG, further research is needed to determine how different nutrient compositions or timing approaches influence postprandial glucose homeostasis in this population. Read More