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Christine Feinlebisset - One of the best experts on this subject based on the ideXlab platform.
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effects of Intragastric Administration of l tryptophan on the glycaemic response to a nutrient drink in men with type 2 diabetes impacts on gastric emptying glucoregulatory hormones and glucose absorption
Nutrition & Diabetes, 2021Co-Authors: Maryam Hajishafiee, Rachel A Elovaris, Karen L Jones, Leonie K Heilbronn, Michael Horowitz, Sally D Poppitt, Christine FeinlebissetAbstract:The rate of gastric emptying and glucoregulatory hormones are key determinants of postprandial glycaemia. Intragastric Administration of L-tryptophan slows gastric emptying and reduces the glycaemic response to a nutrient drink in lean individuals and those with obesity. We investigated whether tryptophan decreases postprandial glycaemia and slows gastric emptying in type 2 diabetes (T2D). Twelve men with T2D (age: 63 ± 2 years, HbA1c: 49.7 ± 2.5 mmol/mol, BMI: 30 ± 1 kg/m2) received, on three separate occasions, 3 g (‘Trp-3’) or 1.5 g (‘Trp-1.5’) tryptophan, or control (0.9% saline), Intragastrically, in randomised, double-blind fashion, 30 min before a mixed-nutrient drink (500 kcal, 74 g carbohydrates), containing 3 g 3-O-methyl-D-glucose (3-OMG) to assess glucose absorption. Venous blood samples were obtained at baseline, after tryptophan, and for 2 h post-drink for measurements of plasma glucose, C-peptide, glucagon and 3-OMG. Gastric emptying of the drink was quantified using two-dimensional ultrasound. Tryptophan alone stimulated C-peptide (P = 0.002) and glucagon (P = 0.04), but did not affect fasting glucose. In response to the drink, Trp-3 lowered plasma glucose from t = 15–30 min and from t = 30–45 min compared with control and Trp-1.5, respectively (both P < 0.05), with no differences in peak glucose between treatments. Gastric emptying tended to be slower after Trp-3, but not Trp-1.5, than control (P = 0.06). Plasma C-peptide, glucagon and 3-OMG increased on all days, with no major differences between treatments. In people with T2D, Intragastric Administration of 3 g tryptophan modestly slows gastric emptying, associated with a delayed rise, but not an overall lowering of, postprandial glucose.
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effects of Intragastric Administration of l tryptophan on the glycaemic response to a nutrient drink in men with type 2 diabetes impacts on gastric emptying glucoregulatory hormones and glucose absorption
Nutrition & Diabetes, 2021Co-Authors: Maryam Hajishafiee, Rachel A Elovaris, Karen L Jones, Leonie K Heilbronn, Michael Horowitz, Sally D Poppitt, Christine FeinlebissetAbstract:BACKGROUND The rate of gastric emptying and glucoregulatory hormones are key determinants of postprandial glycaemia. Intragastric Administration of L-tryptophan slows gastric emptying and reduces the glycaemic response to a nutrient drink in lean individuals and those with obesity. We investigated whether tryptophan decreases postprandial glycaemia and slows gastric emptying in type 2 diabetes (T2D). METHODS Twelve men with T2D (age: 63 ± 2 years, HbA1c: 49.7 ± 2.5 mmol/mol, BMI: 30 ± 1 kg/m2) received, on three separate occasions, 3 g ('Trp-3') or 1.5 g ('Trp-1.5') tryptophan, or control (0.9% saline), Intragastrically, in randomised, double-blind fashion, 30 min before a mixed-nutrient drink (500 kcal, 74 g carbohydrates), containing 3 g 3-O-methyl-D-glucose (3-OMG) to assess glucose absorption. Venous blood samples were obtained at baseline, after tryptophan, and for 2 h post-drink for measurements of plasma glucose, C-peptide, glucagon and 3-OMG. Gastric emptying of the drink was quantified using two-dimensional ultrasound. RESULTS Tryptophan alone stimulated C-peptide (P = 0.002) and glucagon (P = 0.04), but did not affect fasting glucose. In response to the drink, Trp-3 lowered plasma glucose from t = 15-30 min and from t = 30-45 min compared with control and Trp-1.5, respectively (both P < 0.05), with no differences in peak glucose between treatments. Gastric emptying tended to be slower after Trp-3, but not Trp-1.5, than control (P = 0.06). Plasma C-peptide, glucagon and 3-OMG increased on all days, with no major differences between treatments. CONCLUSIONS In people with T2D, Intragastric Administration of 3 g tryptophan modestly slows gastric emptying, associated with a delayed rise, but not an overall lowering of, postprandial glucose.
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Intragastric Administration of leucine and isoleucine does not reduce the glycaemic response to or slow gastric emptying of a carbohydrate containing drink in type 2 diabetes
Diabetes Research and Clinical Practice, 2021Co-Authors: Rachel A Elovaris, Maryam Hajishafiee, Michael Horowitz, Sina S Ullrich, Penelope C E Fitzgerald, Kylie Lange, Christine FeinlebissetAbstract:Abstract Aims In healthy individuals, Intragastric Administration of the branched-chain amino acids, leucine and isoleucine, diminishes the glycaemic response to a mixed-nutrient drink, apparently by stimulating insulin and slowing gastric emptying, respectively. This study aimed to evaluate the effects of leucine and isoleucine on postprandial glycaemia and gastric emptying in type-2 diabetes mellitus (T2D). Methods 14 males with T2D received, on 3 separate occasions, in double-blind, randomised fashion, either 10 g leucine, 10 g isoleucine or control, Intragastrically 30 min before a mixed-nutrient drink (500 kcal; 74 g carbohydrates, 18 g protein, 15 g fat). Plasma glucose, insulin and glucagon were measured from 30 min pre- until 120 min post-drink. Gastric emptying of the drink was also measured. Results Leucine and isoleucine stimulated insulin, both before and after the drink (all P Conclusions In contrast to health, in T2D, leucine and isoleucine, administered Intragastrically in a dose of 10 g, do not lower the glycaemic response to a mixed-nutrient drink. This finding argues against a role for ‘preloads’ of either leucine or isoleucine in the management of T2D.
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Intragastric Administration of leucine or isoleucine lowers the blood glucose response to a mixed nutrient drink by different mechanisms in healthy lean volunteers
The American Journal of Clinical Nutrition, 2016Co-Authors: Sina S Ullrich, Michael Horowitz, Penelope C E Fitzgerald, Gudrun Schober, Robert E Steinert, Christine FeinlebissetAbstract:BACKGROUND The branched-chain amino acids leucine and isoleucine lower blood glucose after oral glucose ingestion, and the intraduodenal infusion of leucine decreases energy intake in healthy, lean men. OBJECTIVE We investigated the effects of the Intragastric Administration of leucine and isoleucine on the gastric emptying of, and blood glucose responses to, a physiologic mixed-macronutrient drink and subsequent energy intake. DESIGN In 2 separate studies, 12 healthy, lean subjects received on 3 separate occasions an Intragastric infusion of 5 g leucine (leucine-5g) or an Intragastric infusion of 10 g leucine (leucine-10g), an Intragastric infusion of 5 g isoleucine (isoleucine-5g) or an Intragastric infusion of 10 g isoleucine (isoleucine-10g), or a control. Fifteen minutes later, subjects consumed a mixed-nutrient drink (400 kcal, 56 g carbohydrates, 15 g protein, and 12 g fat), and gastric emptying (13C-acetate breath test) and blood glucose, plasma insulin, C-peptide, glucagon, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and cholecystokinin (leucine study only) were measured for 60 min. Immediately afterward, energy intake from a cold, buffet-style meal was assessed. RESULTS Compared with the control, leucine-10g decreased the blood glucose area under the curve (AUC) (P < 0.05) and tended to reduce peak blood glucose (P = 0.07), whereas effects of leucine-5g were NS. Leucine-10g, but not leucine-5g, increased plasma insulin and C-peptide AUCs (P < 0.01 for both), but neither dose affected glucagon, GLP-1, GIP, cholecystokinin, gastric emptying, or energy intake. Compared with the control, isoleucine-10g reduced the blood glucose AUC and peak blood glucose (P < 0.01), whereas effects of isoleucine-5g were NS. Neither load affected insulin, C-peptide, glucagon, GLP-1, or GIP. Isoleucine-10g, but not isoleucine-5g, slowed gastric emptying (P < 0.05), but gastric emptying was not correlated with the blood glucose AUC. Isoleucine did not affect energy intake. CONCLUSIONS In healthy subjects, both leucine and isoleucine reduced blood glucose in response to a mixed-nutrient drink but did not affect subsequent energy intake. The mechanisms underlying glucose lowering appear to differ; leucine stimulated insulin, whereas isoleucine acted insulin independently. These trials were registered at www.anzctr.org.au as 12613000899741 and 12614000837628.
Michael Horowitz - One of the best experts on this subject based on the ideXlab platform.
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effects of Intragastric Administration of l tryptophan on the glycaemic response to a nutrient drink in men with type 2 diabetes impacts on gastric emptying glucoregulatory hormones and glucose absorption
Nutrition & Diabetes, 2021Co-Authors: Maryam Hajishafiee, Rachel A Elovaris, Karen L Jones, Leonie K Heilbronn, Michael Horowitz, Sally D Poppitt, Christine FeinlebissetAbstract:The rate of gastric emptying and glucoregulatory hormones are key determinants of postprandial glycaemia. Intragastric Administration of L-tryptophan slows gastric emptying and reduces the glycaemic response to a nutrient drink in lean individuals and those with obesity. We investigated whether tryptophan decreases postprandial glycaemia and slows gastric emptying in type 2 diabetes (T2D). Twelve men with T2D (age: 63 ± 2 years, HbA1c: 49.7 ± 2.5 mmol/mol, BMI: 30 ± 1 kg/m2) received, on three separate occasions, 3 g (‘Trp-3’) or 1.5 g (‘Trp-1.5’) tryptophan, or control (0.9% saline), Intragastrically, in randomised, double-blind fashion, 30 min before a mixed-nutrient drink (500 kcal, 74 g carbohydrates), containing 3 g 3-O-methyl-D-glucose (3-OMG) to assess glucose absorption. Venous blood samples were obtained at baseline, after tryptophan, and for 2 h post-drink for measurements of plasma glucose, C-peptide, glucagon and 3-OMG. Gastric emptying of the drink was quantified using two-dimensional ultrasound. Tryptophan alone stimulated C-peptide (P = 0.002) and glucagon (P = 0.04), but did not affect fasting glucose. In response to the drink, Trp-3 lowered plasma glucose from t = 15–30 min and from t = 30–45 min compared with control and Trp-1.5, respectively (both P < 0.05), with no differences in peak glucose between treatments. Gastric emptying tended to be slower after Trp-3, but not Trp-1.5, than control (P = 0.06). Plasma C-peptide, glucagon and 3-OMG increased on all days, with no major differences between treatments. In people with T2D, Intragastric Administration of 3 g tryptophan modestly slows gastric emptying, associated with a delayed rise, but not an overall lowering of, postprandial glucose.
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effects of Intragastric Administration of l tryptophan on the glycaemic response to a nutrient drink in men with type 2 diabetes impacts on gastric emptying glucoregulatory hormones and glucose absorption
Nutrition & Diabetes, 2021Co-Authors: Maryam Hajishafiee, Rachel A Elovaris, Karen L Jones, Leonie K Heilbronn, Michael Horowitz, Sally D Poppitt, Christine FeinlebissetAbstract:BACKGROUND The rate of gastric emptying and glucoregulatory hormones are key determinants of postprandial glycaemia. Intragastric Administration of L-tryptophan slows gastric emptying and reduces the glycaemic response to a nutrient drink in lean individuals and those with obesity. We investigated whether tryptophan decreases postprandial glycaemia and slows gastric emptying in type 2 diabetes (T2D). METHODS Twelve men with T2D (age: 63 ± 2 years, HbA1c: 49.7 ± 2.5 mmol/mol, BMI: 30 ± 1 kg/m2) received, on three separate occasions, 3 g ('Trp-3') or 1.5 g ('Trp-1.5') tryptophan, or control (0.9% saline), Intragastrically, in randomised, double-blind fashion, 30 min before a mixed-nutrient drink (500 kcal, 74 g carbohydrates), containing 3 g 3-O-methyl-D-glucose (3-OMG) to assess glucose absorption. Venous blood samples were obtained at baseline, after tryptophan, and for 2 h post-drink for measurements of plasma glucose, C-peptide, glucagon and 3-OMG. Gastric emptying of the drink was quantified using two-dimensional ultrasound. RESULTS Tryptophan alone stimulated C-peptide (P = 0.002) and glucagon (P = 0.04), but did not affect fasting glucose. In response to the drink, Trp-3 lowered plasma glucose from t = 15-30 min and from t = 30-45 min compared with control and Trp-1.5, respectively (both P < 0.05), with no differences in peak glucose between treatments. Gastric emptying tended to be slower after Trp-3, but not Trp-1.5, than control (P = 0.06). Plasma C-peptide, glucagon and 3-OMG increased on all days, with no major differences between treatments. CONCLUSIONS In people with T2D, Intragastric Administration of 3 g tryptophan modestly slows gastric emptying, associated with a delayed rise, but not an overall lowering of, postprandial glucose.
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Intragastric Administration of leucine and isoleucine does not reduce the glycaemic response to or slow gastric emptying of a carbohydrate containing drink in type 2 diabetes
Diabetes Research and Clinical Practice, 2021Co-Authors: Rachel A Elovaris, Maryam Hajishafiee, Michael Horowitz, Sina S Ullrich, Penelope C E Fitzgerald, Kylie Lange, Christine FeinlebissetAbstract:Abstract Aims In healthy individuals, Intragastric Administration of the branched-chain amino acids, leucine and isoleucine, diminishes the glycaemic response to a mixed-nutrient drink, apparently by stimulating insulin and slowing gastric emptying, respectively. This study aimed to evaluate the effects of leucine and isoleucine on postprandial glycaemia and gastric emptying in type-2 diabetes mellitus (T2D). Methods 14 males with T2D received, on 3 separate occasions, in double-blind, randomised fashion, either 10 g leucine, 10 g isoleucine or control, Intragastrically 30 min before a mixed-nutrient drink (500 kcal; 74 g carbohydrates, 18 g protein, 15 g fat). Plasma glucose, insulin and glucagon were measured from 30 min pre- until 120 min post-drink. Gastric emptying of the drink was also measured. Results Leucine and isoleucine stimulated insulin, both before and after the drink (all P Conclusions In contrast to health, in T2D, leucine and isoleucine, administered Intragastrically in a dose of 10 g, do not lower the glycaemic response to a mixed-nutrient drink. This finding argues against a role for ‘preloads’ of either leucine or isoleucine in the management of T2D.
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Intragastric Administration of leucine or isoleucine lowers the blood glucose response to a mixed nutrient drink by different mechanisms in healthy lean volunteers
The American Journal of Clinical Nutrition, 2016Co-Authors: Sina S Ullrich, Michael Horowitz, Penelope C E Fitzgerald, Gudrun Schober, Robert E Steinert, Christine FeinlebissetAbstract:BACKGROUND The branched-chain amino acids leucine and isoleucine lower blood glucose after oral glucose ingestion, and the intraduodenal infusion of leucine decreases energy intake in healthy, lean men. OBJECTIVE We investigated the effects of the Intragastric Administration of leucine and isoleucine on the gastric emptying of, and blood glucose responses to, a physiologic mixed-macronutrient drink and subsequent energy intake. DESIGN In 2 separate studies, 12 healthy, lean subjects received on 3 separate occasions an Intragastric infusion of 5 g leucine (leucine-5g) or an Intragastric infusion of 10 g leucine (leucine-10g), an Intragastric infusion of 5 g isoleucine (isoleucine-5g) or an Intragastric infusion of 10 g isoleucine (isoleucine-10g), or a control. Fifteen minutes later, subjects consumed a mixed-nutrient drink (400 kcal, 56 g carbohydrates, 15 g protein, and 12 g fat), and gastric emptying (13C-acetate breath test) and blood glucose, plasma insulin, C-peptide, glucagon, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and cholecystokinin (leucine study only) were measured for 60 min. Immediately afterward, energy intake from a cold, buffet-style meal was assessed. RESULTS Compared with the control, leucine-10g decreased the blood glucose area under the curve (AUC) (P < 0.05) and tended to reduce peak blood glucose (P = 0.07), whereas effects of leucine-5g were NS. Leucine-10g, but not leucine-5g, increased plasma insulin and C-peptide AUCs (P < 0.01 for both), but neither dose affected glucagon, GLP-1, GIP, cholecystokinin, gastric emptying, or energy intake. Compared with the control, isoleucine-10g reduced the blood glucose AUC and peak blood glucose (P < 0.01), whereas effects of isoleucine-5g were NS. Neither load affected insulin, C-peptide, glucagon, GLP-1, or GIP. Isoleucine-10g, but not isoleucine-5g, slowed gastric emptying (P < 0.05), but gastric emptying was not correlated with the blood glucose AUC. Isoleucine did not affect energy intake. CONCLUSIONS In healthy subjects, both leucine and isoleucine reduced blood glucose in response to a mixed-nutrient drink but did not affect subsequent energy intake. The mechanisms underlying glucose lowering appear to differ; leucine stimulated insulin, whereas isoleucine acted insulin independently. These trials were registered at www.anzctr.org.au as 12613000899741 and 12614000837628.
Maryam Hajishafiee - One of the best experts on this subject based on the ideXlab platform.
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effects of Intragastric Administration of l tryptophan on the glycaemic response to a nutrient drink in men with type 2 diabetes impacts on gastric emptying glucoregulatory hormones and glucose absorption
Nutrition & Diabetes, 2021Co-Authors: Maryam Hajishafiee, Rachel A Elovaris, Karen L Jones, Leonie K Heilbronn, Michael Horowitz, Sally D Poppitt, Christine FeinlebissetAbstract:The rate of gastric emptying and glucoregulatory hormones are key determinants of postprandial glycaemia. Intragastric Administration of L-tryptophan slows gastric emptying and reduces the glycaemic response to a nutrient drink in lean individuals and those with obesity. We investigated whether tryptophan decreases postprandial glycaemia and slows gastric emptying in type 2 diabetes (T2D). Twelve men with T2D (age: 63 ± 2 years, HbA1c: 49.7 ± 2.5 mmol/mol, BMI: 30 ± 1 kg/m2) received, on three separate occasions, 3 g (‘Trp-3’) or 1.5 g (‘Trp-1.5’) tryptophan, or control (0.9% saline), Intragastrically, in randomised, double-blind fashion, 30 min before a mixed-nutrient drink (500 kcal, 74 g carbohydrates), containing 3 g 3-O-methyl-D-glucose (3-OMG) to assess glucose absorption. Venous blood samples were obtained at baseline, after tryptophan, and for 2 h post-drink for measurements of plasma glucose, C-peptide, glucagon and 3-OMG. Gastric emptying of the drink was quantified using two-dimensional ultrasound. Tryptophan alone stimulated C-peptide (P = 0.002) and glucagon (P = 0.04), but did not affect fasting glucose. In response to the drink, Trp-3 lowered plasma glucose from t = 15–30 min and from t = 30–45 min compared with control and Trp-1.5, respectively (both P < 0.05), with no differences in peak glucose between treatments. Gastric emptying tended to be slower after Trp-3, but not Trp-1.5, than control (P = 0.06). Plasma C-peptide, glucagon and 3-OMG increased on all days, with no major differences between treatments. In people with T2D, Intragastric Administration of 3 g tryptophan modestly slows gastric emptying, associated with a delayed rise, but not an overall lowering of, postprandial glucose.
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effects of Intragastric Administration of l tryptophan on the glycaemic response to a nutrient drink in men with type 2 diabetes impacts on gastric emptying glucoregulatory hormones and glucose absorption
Nutrition & Diabetes, 2021Co-Authors: Maryam Hajishafiee, Rachel A Elovaris, Karen L Jones, Leonie K Heilbronn, Michael Horowitz, Sally D Poppitt, Christine FeinlebissetAbstract:BACKGROUND The rate of gastric emptying and glucoregulatory hormones are key determinants of postprandial glycaemia. Intragastric Administration of L-tryptophan slows gastric emptying and reduces the glycaemic response to a nutrient drink in lean individuals and those with obesity. We investigated whether tryptophan decreases postprandial glycaemia and slows gastric emptying in type 2 diabetes (T2D). METHODS Twelve men with T2D (age: 63 ± 2 years, HbA1c: 49.7 ± 2.5 mmol/mol, BMI: 30 ± 1 kg/m2) received, on three separate occasions, 3 g ('Trp-3') or 1.5 g ('Trp-1.5') tryptophan, or control (0.9% saline), Intragastrically, in randomised, double-blind fashion, 30 min before a mixed-nutrient drink (500 kcal, 74 g carbohydrates), containing 3 g 3-O-methyl-D-glucose (3-OMG) to assess glucose absorption. Venous blood samples were obtained at baseline, after tryptophan, and for 2 h post-drink for measurements of plasma glucose, C-peptide, glucagon and 3-OMG. Gastric emptying of the drink was quantified using two-dimensional ultrasound. RESULTS Tryptophan alone stimulated C-peptide (P = 0.002) and glucagon (P = 0.04), but did not affect fasting glucose. In response to the drink, Trp-3 lowered plasma glucose from t = 15-30 min and from t = 30-45 min compared with control and Trp-1.5, respectively (both P < 0.05), with no differences in peak glucose between treatments. Gastric emptying tended to be slower after Trp-3, but not Trp-1.5, than control (P = 0.06). Plasma C-peptide, glucagon and 3-OMG increased on all days, with no major differences between treatments. CONCLUSIONS In people with T2D, Intragastric Administration of 3 g tryptophan modestly slows gastric emptying, associated with a delayed rise, but not an overall lowering of, postprandial glucose.
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Intragastric Administration of leucine and isoleucine does not reduce the glycaemic response to or slow gastric emptying of a carbohydrate containing drink in type 2 diabetes
Diabetes Research and Clinical Practice, 2021Co-Authors: Rachel A Elovaris, Maryam Hajishafiee, Michael Horowitz, Sina S Ullrich, Penelope C E Fitzgerald, Kylie Lange, Christine FeinlebissetAbstract:Abstract Aims In healthy individuals, Intragastric Administration of the branched-chain amino acids, leucine and isoleucine, diminishes the glycaemic response to a mixed-nutrient drink, apparently by stimulating insulin and slowing gastric emptying, respectively. This study aimed to evaluate the effects of leucine and isoleucine on postprandial glycaemia and gastric emptying in type-2 diabetes mellitus (T2D). Methods 14 males with T2D received, on 3 separate occasions, in double-blind, randomised fashion, either 10 g leucine, 10 g isoleucine or control, Intragastrically 30 min before a mixed-nutrient drink (500 kcal; 74 g carbohydrates, 18 g protein, 15 g fat). Plasma glucose, insulin and glucagon were measured from 30 min pre- until 120 min post-drink. Gastric emptying of the drink was also measured. Results Leucine and isoleucine stimulated insulin, both before and after the drink (all P Conclusions In contrast to health, in T2D, leucine and isoleucine, administered Intragastrically in a dose of 10 g, do not lower the glycaemic response to a mixed-nutrient drink. This finding argues against a role for ‘preloads’ of either leucine or isoleucine in the management of T2D.
Rachel A Elovaris - One of the best experts on this subject based on the ideXlab platform.
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effects of Intragastric Administration of l tryptophan on the glycaemic response to a nutrient drink in men with type 2 diabetes impacts on gastric emptying glucoregulatory hormones and glucose absorption
Nutrition & Diabetes, 2021Co-Authors: Maryam Hajishafiee, Rachel A Elovaris, Karen L Jones, Leonie K Heilbronn, Michael Horowitz, Sally D Poppitt, Christine FeinlebissetAbstract:The rate of gastric emptying and glucoregulatory hormones are key determinants of postprandial glycaemia. Intragastric Administration of L-tryptophan slows gastric emptying and reduces the glycaemic response to a nutrient drink in lean individuals and those with obesity. We investigated whether tryptophan decreases postprandial glycaemia and slows gastric emptying in type 2 diabetes (T2D). Twelve men with T2D (age: 63 ± 2 years, HbA1c: 49.7 ± 2.5 mmol/mol, BMI: 30 ± 1 kg/m2) received, on three separate occasions, 3 g (‘Trp-3’) or 1.5 g (‘Trp-1.5’) tryptophan, or control (0.9% saline), Intragastrically, in randomised, double-blind fashion, 30 min before a mixed-nutrient drink (500 kcal, 74 g carbohydrates), containing 3 g 3-O-methyl-D-glucose (3-OMG) to assess glucose absorption. Venous blood samples were obtained at baseline, after tryptophan, and for 2 h post-drink for measurements of plasma glucose, C-peptide, glucagon and 3-OMG. Gastric emptying of the drink was quantified using two-dimensional ultrasound. Tryptophan alone stimulated C-peptide (P = 0.002) and glucagon (P = 0.04), but did not affect fasting glucose. In response to the drink, Trp-3 lowered plasma glucose from t = 15–30 min and from t = 30–45 min compared with control and Trp-1.5, respectively (both P < 0.05), with no differences in peak glucose between treatments. Gastric emptying tended to be slower after Trp-3, but not Trp-1.5, than control (P = 0.06). Plasma C-peptide, glucagon and 3-OMG increased on all days, with no major differences between treatments. In people with T2D, Intragastric Administration of 3 g tryptophan modestly slows gastric emptying, associated with a delayed rise, but not an overall lowering of, postprandial glucose.
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effects of Intragastric Administration of l tryptophan on the glycaemic response to a nutrient drink in men with type 2 diabetes impacts on gastric emptying glucoregulatory hormones and glucose absorption
Nutrition & Diabetes, 2021Co-Authors: Maryam Hajishafiee, Rachel A Elovaris, Karen L Jones, Leonie K Heilbronn, Michael Horowitz, Sally D Poppitt, Christine FeinlebissetAbstract:BACKGROUND The rate of gastric emptying and glucoregulatory hormones are key determinants of postprandial glycaemia. Intragastric Administration of L-tryptophan slows gastric emptying and reduces the glycaemic response to a nutrient drink in lean individuals and those with obesity. We investigated whether tryptophan decreases postprandial glycaemia and slows gastric emptying in type 2 diabetes (T2D). METHODS Twelve men with T2D (age: 63 ± 2 years, HbA1c: 49.7 ± 2.5 mmol/mol, BMI: 30 ± 1 kg/m2) received, on three separate occasions, 3 g ('Trp-3') or 1.5 g ('Trp-1.5') tryptophan, or control (0.9% saline), Intragastrically, in randomised, double-blind fashion, 30 min before a mixed-nutrient drink (500 kcal, 74 g carbohydrates), containing 3 g 3-O-methyl-D-glucose (3-OMG) to assess glucose absorption. Venous blood samples were obtained at baseline, after tryptophan, and for 2 h post-drink for measurements of plasma glucose, C-peptide, glucagon and 3-OMG. Gastric emptying of the drink was quantified using two-dimensional ultrasound. RESULTS Tryptophan alone stimulated C-peptide (P = 0.002) and glucagon (P = 0.04), but did not affect fasting glucose. In response to the drink, Trp-3 lowered plasma glucose from t = 15-30 min and from t = 30-45 min compared with control and Trp-1.5, respectively (both P < 0.05), with no differences in peak glucose between treatments. Gastric emptying tended to be slower after Trp-3, but not Trp-1.5, than control (P = 0.06). Plasma C-peptide, glucagon and 3-OMG increased on all days, with no major differences between treatments. CONCLUSIONS In people with T2D, Intragastric Administration of 3 g tryptophan modestly slows gastric emptying, associated with a delayed rise, but not an overall lowering of, postprandial glucose.
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Intragastric Administration of leucine and isoleucine does not reduce the glycaemic response to or slow gastric emptying of a carbohydrate containing drink in type 2 diabetes
Diabetes Research and Clinical Practice, 2021Co-Authors: Rachel A Elovaris, Maryam Hajishafiee, Michael Horowitz, Sina S Ullrich, Penelope C E Fitzgerald, Kylie Lange, Christine FeinlebissetAbstract:Abstract Aims In healthy individuals, Intragastric Administration of the branched-chain amino acids, leucine and isoleucine, diminishes the glycaemic response to a mixed-nutrient drink, apparently by stimulating insulin and slowing gastric emptying, respectively. This study aimed to evaluate the effects of leucine and isoleucine on postprandial glycaemia and gastric emptying in type-2 diabetes mellitus (T2D). Methods 14 males with T2D received, on 3 separate occasions, in double-blind, randomised fashion, either 10 g leucine, 10 g isoleucine or control, Intragastrically 30 min before a mixed-nutrient drink (500 kcal; 74 g carbohydrates, 18 g protein, 15 g fat). Plasma glucose, insulin and glucagon were measured from 30 min pre- until 120 min post-drink. Gastric emptying of the drink was also measured. Results Leucine and isoleucine stimulated insulin, both before and after the drink (all P Conclusions In contrast to health, in T2D, leucine and isoleucine, administered Intragastrically in a dose of 10 g, do not lower the glycaemic response to a mixed-nutrient drink. This finding argues against a role for ‘preloads’ of either leucine or isoleucine in the management of T2D.
Liegang Liu - One of the best experts on this subject based on the ideXlab platform.
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in vitro characterization and in vivo evaluation of nanostructured lipid curcumin carriers for Intragastric Administration
International Journal of Nanomedicine, 2012Co-Authors: Min Fang, Yilin Jin, Wei Bao, Hui Gao, Di Wang, Xia Wang, Ping Yao, Liegang LiuAbstract:BACKGROUND Curcumin has a variety of pharmacological effects. However, poor water solubility and low oral bioavailability limit its clinical utility. A delivery system for nanostructured lipid carriers has been reported to be a promising approach to enhancing the oral absorption of curcumin. The aim of the present study was to investigate the pharmacokinetics, tissue distribution, and relative bioavailability of curcumin in rats after a single Intragastric dose of a nanostructured lipid curcumin carrier formulation. METHODS Nanostructured lipid curcumin carriers were prepared using the ethanol dripping method and characterized in terms of the particle size, polydispersity index, zeta potential, differential scanning calorimetry, drug-loading capacity, encapsulation efficiency, and in vitro release. The pharmacokinetics and tissue distribution of nanostructured lipid curcumin carriers and curcumin suspension were compared after Intragastric Administration. RESULTS Nanostructured lipid curcumin carriers showed a significantly higher peak plasma concentration (564.94 ± 14.98 ng/mL versus 279.43 ± 7.21 ng/mL, P < 0.01), a shorter time taken to reach peak plasma concentration (0.5 ± 0.01 hour versus 1.0 ± 0.12 hour, P < 0.01), and a greater AUC(0-∞) (820.36 ± 25.11 mg × hour/L versus 344.11 ± 10.01 mg × hour/L, P < 0.05) compared with curcumin suspension. In the tissue distribution studies, curcumin could be detected in the spleen, heart, liver, kidneys, lungs, and brain. Following Intragastric Administration of the nanostructured lipid curcumin carrier formulation, tissue concentrations of curcumin also increased, especially in the brain. The nanostructured lipid curcumin carrier formulation improved the ability of curcumin to cross the blood-brain barrier, with an 11.93-fold increase in the area under the curve achieved in the brain when compared with curcumin suspension. CONCLUSION The nanostructured lipid carrier formulation significantly improved the oral bioavailability of curcumin and represents a promising method for its oral delivery.