Protein ingestion acutely inhibits insulin-stimulated muscle carnitine uptake in healthy young men
BACKGROUND: Increasing skeletal muscle carnitine content represents an appealing intervention in conditions of perturbed lipid metabolism such as obesity and type 2 diabetes but requires chronic L-carnitine feeding on a daily basis in a high-carbohydrate beverage. OBJECTIVE: We investigated wheth...
| Main Authors: | , , , |
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| Format: | Article |
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American Society for Nutrition
2016
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| Online Access: | https://eprints.nottingham.ac.uk/35102/ |
| _version_ | 1848795003303755776 |
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| author | Shannon, Chris E. Nixon, Aline Victoria Greenhaff, Paul L. Stephens, Francis B. |
| author_facet | Shannon, Chris E. Nixon, Aline Victoria Greenhaff, Paul L. Stephens, Francis B. |
| author_sort | Shannon, Chris E. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | BACKGROUND:
Increasing skeletal muscle carnitine content represents an appealing intervention in conditions of perturbed lipid metabolism such as obesity and type 2 diabetes but requires chronic L-carnitine feeding on a daily basis in a high-carbohydrate beverage.
OBJECTIVE:
We investigated whether whey protein ingestion could reduce the carbohydrate load required to stimulate insulin-mediated muscle carnitine accretion.
DESIGN:
Seven healthy men [mean ± SD age: 24 ± 5 y; body mass index (in kg/m(2)): 23 ± 3] ingested 80 g carbohydrate, 40 g carbohydrate + 40 g protein, or control (flavored water) beverages 60 min after the ingestion of 4.5 g L-carnitine tartrate (3 g L-carnitine; 0.1% (2)[H]3-L-carnitine). Serum insulin concentration, net forearm carnitine balance (NCB; arterialized-venous and venous plasma carnitine difference × brachial artery flow), and carnitine disappearance (Rd) and appearance (Ra) rates were determined at 20-min intervals for 180 min.
RESULTS:
Serum insulin and plasma flow areas under the curve (AUCs) were similarly elevated by carbohydrate [4.5 ± 0.8 U/L · min (P < 0.01) and 0.5 ± 0.6 L (P < 0.05), respectively] and carbohydrate+protein [3.8 ± 0.6 U/L · min (P < 0.01) and 0.4 ± 0.6 L (P = 0.05), respectively] consumption, respectively, compared with the control visit (0.04 ± 0.1 U/L · min and -0.5 ± 0.2 L). Plasma carnitine AUC was greater after carbohydrate+protein consumption (3.5 ± 0.5 mmol/L · min) than after control and carbohydrate visits [2.1 ± 0.2 mmol/L · min (P < 0.05) and 1.9 ± 0.3 mmol/L · min (P < 0.01), respectively]. NCB AUC with carbohydrate (4.1 ± 3.1 μmol) was greater than during control and carbohydrate-protein visits (-8.6 ± 3.0 and -14.6 ± 6.4 μmol, respectively; P < 0.05), as was Rd AUC after carbohydrate (35.7 ± 25.2 μmol) compared with control and carbohydrate consumption [19.7 ± 15.5 μmol (P = 0.07) and 14.8 ± 9.6 μmol (P < 0.05), respectively].
CONCLUSIONS:
The insulin-mediated increase in forearm carnitine balance with carbohydrate consumption was acutely blunted by a carbohydrate+protein beverage, which suggests that carbohydrate+protein could inhibit chronic muscle carnitine accumulation. |
| first_indexed | 2025-11-14T19:25:10Z |
| format | Article |
| id | nottingham-35102 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:25:10Z |
| publishDate | 2016 |
| publisher | American Society for Nutrition |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-351022020-05-04T20:04:45Z https://eprints.nottingham.ac.uk/35102/ Protein ingestion acutely inhibits insulin-stimulated muscle carnitine uptake in healthy young men Shannon, Chris E. Nixon, Aline Victoria Greenhaff, Paul L. Stephens, Francis B. BACKGROUND: Increasing skeletal muscle carnitine content represents an appealing intervention in conditions of perturbed lipid metabolism such as obesity and type 2 diabetes but requires chronic L-carnitine feeding on a daily basis in a high-carbohydrate beverage. OBJECTIVE: We investigated whether whey protein ingestion could reduce the carbohydrate load required to stimulate insulin-mediated muscle carnitine accretion. DESIGN: Seven healthy men [mean ± SD age: 24 ± 5 y; body mass index (in kg/m(2)): 23 ± 3] ingested 80 g carbohydrate, 40 g carbohydrate + 40 g protein, or control (flavored water) beverages 60 min after the ingestion of 4.5 g L-carnitine tartrate (3 g L-carnitine; 0.1% (2)[H]3-L-carnitine). Serum insulin concentration, net forearm carnitine balance (NCB; arterialized-venous and venous plasma carnitine difference × brachial artery flow), and carnitine disappearance (Rd) and appearance (Ra) rates were determined at 20-min intervals for 180 min. RESULTS: Serum insulin and plasma flow areas under the curve (AUCs) were similarly elevated by carbohydrate [4.5 ± 0.8 U/L · min (P < 0.01) and 0.5 ± 0.6 L (P < 0.05), respectively] and carbohydrate+protein [3.8 ± 0.6 U/L · min (P < 0.01) and 0.4 ± 0.6 L (P = 0.05), respectively] consumption, respectively, compared with the control visit (0.04 ± 0.1 U/L · min and -0.5 ± 0.2 L). Plasma carnitine AUC was greater after carbohydrate+protein consumption (3.5 ± 0.5 mmol/L · min) than after control and carbohydrate visits [2.1 ± 0.2 mmol/L · min (P < 0.05) and 1.9 ± 0.3 mmol/L · min (P < 0.01), respectively]. NCB AUC with carbohydrate (4.1 ± 3.1 μmol) was greater than during control and carbohydrate-protein visits (-8.6 ± 3.0 and -14.6 ± 6.4 μmol, respectively; P < 0.05), as was Rd AUC after carbohydrate (35.7 ± 25.2 μmol) compared with control and carbohydrate consumption [19.7 ± 15.5 μmol (P = 0.07) and 14.8 ± 9.6 μmol (P < 0.05), respectively]. CONCLUSIONS: The insulin-mediated increase in forearm carnitine balance with carbohydrate consumption was acutely blunted by a carbohydrate+protein beverage, which suggests that carbohydrate+protein could inhibit chronic muscle carnitine accumulation. American Society for Nutrition 2016-01 Article PeerReviewed Shannon, Chris E., Nixon, Aline Victoria, Greenhaff, Paul L. and Stephens, Francis B. (2016) Protein ingestion acutely inhibits insulin-stimulated muscle carnitine uptake in healthy young men. American Journal of Clinical Nutrition, 103 (1). pp. 276-282. ISSN 1938-3207 doubly labeled water energy requirement resting energy expenditure short bowel syndrome total energy expenditure http://ajcn.nutrition.org/content/103/1/276.long doi:10.3945/ajcn.115.119826 doi:10.3945/ajcn.115.119826 |
| spellingShingle | doubly labeled water energy requirement resting energy expenditure short bowel syndrome total energy expenditure Shannon, Chris E. Nixon, Aline Victoria Greenhaff, Paul L. Stephens, Francis B. Protein ingestion acutely inhibits insulin-stimulated muscle carnitine uptake in healthy young men |
| title | Protein ingestion acutely inhibits insulin-stimulated muscle carnitine uptake in healthy young men |
| title_full | Protein ingestion acutely inhibits insulin-stimulated muscle carnitine uptake in healthy young men |
| title_fullStr | Protein ingestion acutely inhibits insulin-stimulated muscle carnitine uptake in healthy young men |
| title_full_unstemmed | Protein ingestion acutely inhibits insulin-stimulated muscle carnitine uptake in healthy young men |
| title_short | Protein ingestion acutely inhibits insulin-stimulated muscle carnitine uptake in healthy young men |
| title_sort | protein ingestion acutely inhibits insulin-stimulated muscle carnitine uptake in healthy young men |
| topic | doubly labeled water energy requirement resting energy expenditure short bowel syndrome total energy expenditure |
| url | https://eprints.nottingham.ac.uk/35102/ https://eprints.nottingham.ac.uk/35102/ https://eprints.nottingham.ac.uk/35102/ |