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Monteyne AJ, Falkenhain K, Whelehan G, Neudorf H, Abdelrahman DR, Murton AJ, Wall BT, Stephens FB, Little JP. A ketone monoester drink reduces postprandial blood glucose concentrations in adults with type 2 diabetes: a randomised controlled trial. Diabetologia 2024; 67:1107-1113. [PMID: 38483543 PMCID: PMC11058041 DOI: 10.1007/s00125-024-06122-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 02/01/2024] [Indexed: 04/07/2024]
Abstract
AIMS/HYPOTHESIS The aim of the present study was to conduct a randomised, placebo-controlled, double-blind, crossover trial to determine whether pre-meal ketone monoester ingestion reduces postprandial glucose concentrations in individuals with type 2 diabetes. METHODS In this double-blind, placebo-controlled, crossover design study, ten participants with type 2 diabetes (age 59±1.7 years, 50% female, BMI 32±1 kg/m2, HbA1c 54±2 mmol/mol [7.1±0.2%]) were randomised using computer-generated random numbers. The study took place at the Nutritional Physiology Research Unit, University of Exeter, Exeter, UK. Using a dual-glucose tracer approach, we assessed glucose kinetics after the ingestion of a 0.5 g/kg body mass ketone monoester (KME) or a taste-matched non-caloric placebo before a mixed-meal tolerance test. The primary outcome measure was endogenous glucose production. Secondary outcome measures were total glucose appearance rate and exogenous glucose appearance rate, glucose disappearance rate, blood glucose, serum insulin, β-OHB and NEFA levels, and energy expenditure. RESULTS Data for all ten participants were analysed. KME ingestion increased mean ± SEM plasma beta-hydroxybutyrate from 0.3±0.03 mmol/l to a peak of 4.3±1.2 mmol/l while reducing 2 h postprandial glucose concentrations by ~18% and 4 h postprandial glucose concentrations by ~12%, predominately as a result of a 28% decrease in the 2 h rate of glucose appearance following meal ingestion (all p<0.05). The reduction in blood glucose concentrations was associated with suppressed plasma NEFA concentrations after KME ingestion, with no difference in plasma insulin concentrations between the control and KME conditions. Postprandial endogenous glucose production was unaffected by KME ingestion (mean ± SEM 0.76±0.15 and 0.88±0.10 mg kg-1 min-1 for the control and KME, respectively). No adverse effects of KME ingestion were observed. CONCLUSIONS/INTERPRETATION KME ingestion appears to delay glucose absorption in adults with type 2 diabetes, thereby reducing postprandial glucose concentrations. Future work to explore the therapeutic potential of KME supplementation in type 2 diabetes is warranted. TRIAL REGISTRATION ClinicalTrials.gov NCT05518448. FUNDING This project was supported by a Canadian Institutes of Health Research (CIHR) Project Grant (PJT-169116) and a Natural Sciences and Engineering Research Council (NSERC) Discovery Grant (RGPIN-2019-05204) awarded to JPL and an Exeter-UBCO Sports Health Science Fund Project Grant awarded to FBS and JPL.
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Affiliation(s)
- Alistair J Monteyne
- Nutritional Physiology Research Group, Department of Public Health and Sport Sciences, University of Exeter, Exeter, UK
| | - Kaja Falkenhain
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, Canada
| | - Gráinne Whelehan
- Nutritional Physiology Research Group, Department of Public Health and Sport Sciences, University of Exeter, Exeter, UK
| | - Helena Neudorf
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, Canada
| | - Doaa R Abdelrahman
- Department of Surgery, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Center on Aging, University of Texas Medical Branch, Galveston, TX, USA
| | - Andrew J Murton
- Department of Surgery, University of Texas Medical Branch, Galveston, TX, USA
- Sealy Center on Aging, University of Texas Medical Branch, Galveston, TX, USA
| | - Benjamin T Wall
- Nutritional Physiology Research Group, Department of Public Health and Sport Sciences, University of Exeter, Exeter, UK
| | - Francis B Stephens
- Nutritional Physiology Research Group, Department of Public Health and Sport Sciences, University of Exeter, Exeter, UK.
| | - Jonathan P Little
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, BC, Canada.
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Gopalasingam N, Moeslund N, Christensen KH, Berg-Hansen K, Seefeldt J, Homilius C, Nielsen EN, Dollerup MR, Alstrup Olsen AK, Johannsen M, Boedtkjer E, Møller N, Eiskjær H, Gormsen LC, Nielsen R, Wiggers H. Enantiomer-Specific Cardiovascular Effects of the Ketone Body 3-Hydroxybutyrate. J Am Heart Assoc 2024; 13:e033628. [PMID: 38563382 DOI: 10.1161/jaha.123.033628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 02/16/2024] [Indexed: 04/04/2024]
Abstract
BACKGROUND The ketone body 3-hydroxybutyrate (3-OHB) increases cardiac output (CO) by 35% to 40% in healthy people and people with heart failure. The mechanisms underlying the effects of 3-OHB on myocardial contractility and loading conditions as well as the cardiovascular effects of its enantiomeric forms, D-3-OHB and L-3-OHB, remain undetermined. METHODS AND RESULTS Three groups of 8 pigs each underwent a randomized, crossover study. The groups received 3-hour infusions of either D/L-3-OHB (racemic mixture), 100% L-3-OHB, 100% D-3-OHB, versus an isovolumic control. The animals were monitored with pulmonary artery catheter, left ventricle pressure-volume catheter, and arterial and coronary sinus blood samples. Myocardial biopsies were evaluated with high-resolution respirometry, coronary arteries with isometric myography, and myocardial kinetics with D-[11C]3-OHB and L-[11C]3-OHB positron emission tomography. All three 3-OHB infusions increased 3-OHB levels (P<0.001). D/L-3-OHB and L-3-OHB increased CO by 2.7 L/min (P<0.003). D-3-OHB increased CO nonsignificantly (P=0.2). Circulating 3-OHB levels correlated with CO for both enantiomers (P<0.001). The CO increase was mediated through arterial elastance (afterload) reduction, whereas contractility and preload were unchanged. Ex vivo, D- and L-3-OHB dilated coronary arteries equally. The mitochondrial respiratory capacity remained unaffected. The myocardial 3-OHB extraction increased only during the D- and D/L-3-OHB infusions. D-[11C]3-OHB showed rapid cardiac uptake and metabolism, whereas L-[11C]3-OHB demonstrated much slower pharmacokinetics. CONCLUSIONS 3-OHB increased CO by reducing afterload. L-3-OHB exerted a stronger hemodynamic response than D-3-OHB due to higher circulating 3-OHB levels. There was a dissocitation between the myocardial metabolism and hemodynamic effects of the enantiomers, highlighting L-3-OHB as a potent cardiovascular agent with strong hemodynamic effects.
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Affiliation(s)
- Nigopan Gopalasingam
- Department of Cardiology Aarhus University Hospital Aarhus Denmark
- Department of Clinical Medicine Aarhus University Aarhus Denmark
- Department of Cardiology Gødstrup Hospital Herning Denmark
| | - Niels Moeslund
- Department of Clinical Medicine Aarhus University Aarhus Denmark
- Department of Heart, Lung and Vascular Surgery Aarhus University Hospital Aarhus Denmark
| | - Kristian Hylleberg Christensen
- Department of Cardiology Aarhus University Hospital Aarhus Denmark
- Department of Clinical Medicine Aarhus University Aarhus Denmark
| | - Kristoffer Berg-Hansen
- Department of Cardiology Aarhus University Hospital Aarhus Denmark
- Department of Clinical Medicine Aarhus University Aarhus Denmark
| | - Jacob Seefeldt
- Department of Cardiology Aarhus University Hospital Aarhus Denmark
- Department of Clinical Medicine Aarhus University Aarhus Denmark
| | | | - Erik Nguyen Nielsen
- Department of Nuclear Medicine and PET Aarhus University Hospital Aarhus Denmark
| | | | - Aage K Alstrup Olsen
- Department of Clinical Medicine Aarhus University Aarhus Denmark
- Department of Nuclear Medicine and PET Aarhus University Hospital Aarhus Denmark
| | - Mogens Johannsen
- Department of Forensic Medicine Aarhus University Aarhus Denmark
| | - Ebbe Boedtkjer
- Department of Biomedicine Aarhus University Aarhus Denmark
| | - Niels Møller
- Department of Endocrinology and Metabolism Aarhus University Aarhus Denmark
| | - Hans Eiskjær
- Department of Cardiology Aarhus University Hospital Aarhus Denmark
| | | | - Roni Nielsen
- Department of Cardiology Aarhus University Hospital Aarhus Denmark
| | - Henrik Wiggers
- Department of Cardiology Aarhus University Hospital Aarhus Denmark
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Robberechts R, Poffé C. Defining ketone supplementation: the evolving evidence for postexercise ketone supplementation to improve recovery and adaptation to exercise. Am J Physiol Cell Physiol 2024; 326:C143-C160. [PMID: 37982172 DOI: 10.1152/ajpcell.00485.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/14/2023] [Accepted: 11/14/2023] [Indexed: 11/21/2023]
Abstract
Over the last decade, there has been a growing interest in the use of ketone supplements to improve athletic performance. These ketone supplements transiently elevate the concentrations of the ketone bodies acetoacetate (AcAc) and d-β-hydroxybutyrate (βHB) in the circulation. Early studies showed that ketone bodies can improve energetic efficiency in striated muscle compared with glucose oxidation and induce a glycogen-sparing effect during exercise. As such, most research has focused on the potential of ketone supplementation to improve athletic performance via ingestion of ketones immediately before or during exercise. However, subsequent studies generally observed no performance improvement, and particularly not under conditions that are relevant for most athletes. However, more and more studies are reporting beneficial effects when ketones are ingested after exercise. As such, the real potential of ketone supplementation may rather be in their ability to enhance postexercise recovery and training adaptations. For instance, recent studies observed that postexercise ketone supplementation (PEKS) blunts the development of overtraining symptoms, and improves sleep, muscle anabolic signaling, circulating erythropoietin levels, and skeletal muscle angiogenesis. In this review, we provide an overview of the current state-of-the-art about the impact of PEKS on aspects of exercise recovery and training adaptation, which is not only relevant for athletes but also in multiple clinical conditions. In addition, we highlight the underlying mechanisms by which PEKS may improve exercise recovery and training adaptation. This includes epigenetic effects, signaling via receptors, modulation of neurotransmitters, energy metabolism, and oxidative and anti-inflammatory pathways.
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Affiliation(s)
- Ruben Robberechts
- Exercise Physiology Research Group, Department of Movement Sciences, KU Leuven, Leuven, Belgium
| | - Chiel Poffé
- Exercise Physiology Research Group, Department of Movement Sciences, KU Leuven, Leuven, Belgium
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Falkenhain K, Oliveira BF, Islam H, Neudorf H, Cen HH, Johnson JD, Madden K, Singer J, Walsh JJ, Little JP. The effect of acute and 14-day exogenous ketone supplementation on glycemic control in adults with type 2 diabetes: two randomized controlled trials. Am J Physiol Endocrinol Metab 2024; 326:E61-E72. [PMID: 37991451 DOI: 10.1152/ajpendo.00332.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/02/2023] [Accepted: 11/17/2023] [Indexed: 11/23/2023]
Abstract
Acute ingestion of the exogenous ketone monoester supplement [(R)-3-hydroxybutyl-(R)-3-hydroxybutyrate] lowers blood glucose, suggesting therapeutic potential in individuals with impaired glucose metabolism. However, it is unknown how acute or repeated ingestion of exogenous ketones affects blood glucose control in individuals with type 2 diabetes (T2D). We conducted two randomized, counterbalanced, double-blind, placebo-controlled crossover trials to determine if 1) acute exogenous ketone monoester (0.3 g/kg body mass; N = 18) or 2) 14-day thrice daily premeal exogenous ketone monoester (15 g; N = 15) supplementation could lower blood glucose in individuals living with T2D. A single dose of the ketone monoester supplement elevated blood β-OHB to ∼2 mM. There were no differences in the primary outcomes of plasma glucose concentration (acutely) or serum fructosamine (glycemic control across 14 days) between conditions. Ketone monoester ingestion acutely increased insulin and lowered nonesterified fatty acid concentrations; plasma metabolomics confirmed a reduction in multiple free fatty acids species and select gluconeogenic amino acids. In contrast, no changes were observed in fasting metabolic outcomes following 14 days of supplementation. In the context of these randomized controlled trials, acute or repeated ketone monoester ingestion in adults with T2D did not lower blood glucose when consumed acutely in a fasted state and did not improve glycemic control following thrice daily premeal ingestion across 14 days. Future studies exploring the mechanistic basis for the (lack of) glucose-lowering effect of exogenous ketone supplementation in T2D and other populations are warranted.NEW & NOTEWORTHY Exogenous ketone supplements can acutely lower blood glucose, suggesting therapeutic potential in individuals with impaired glucose metabolism. However, the effect of exogenous ketones on glucose metabolism in adults with type 2 diabetes has not been investigated in a controlled setting. In adults with type 2 diabetes, ketone monoester ingestion did not lower blood glucose acutely in a fasted state and did not improve glycemic control across thrice daily premeal ingestion across 14 days.
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Affiliation(s)
- Kaja Falkenhain
- Faculty of Health and Social Development, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Barbara F Oliveira
- Faculty of Health and Social Development, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Hashim Islam
- Faculty of Health and Social Development, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Helena Neudorf
- Faculty of Health and Social Development, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Haoning H Cen
- Department of Cellular & Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - James D Johnson
- Department of Cellular & Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kenneth Madden
- Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Joel Singer
- Faculty of Medicine, School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jeremy J Walsh
- Department of Kinesiology, Faculty of Science, McMaster University, Hamilton, Ontario, Canada
| | - Jonathan P Little
- Faculty of Health and Social Development, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
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Svart M, Nielsen MM, Rittig N, Hansen M, Møller N, Gravholt CH. Oral 3-hydroxybuturate ingestion acutely lowers circulating testosterone concentrations in healthy young males. Scand J Med Sci Sports 2023; 33:1976-1983. [PMID: 37377131 DOI: 10.1111/sms.14441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/14/2023] [Accepted: 06/19/2023] [Indexed: 06/29/2023]
Abstract
Ketone bodies, such as 3-hydroxybutyrate (3-OHB), have been frequently used by endurance athletes, such as cyclists, to enhance performance and recovery and are recognized for their health benefits and therapeutic effects for decades. Testosterone is a potent regulator of red blood cell production. Evidence suggests that ketone bodies can increase the production of erythropoietin, which stimulates red blood cell production. Therefore, we investigated whether an acute increase in 3-OHB levels affects testosterone levels in healthy young men. We studied six healthy, young male participants who fasted overnight and were tested twice: (i) after drinking 37.5 g of Na-D/L-3-OHB dissolved in 500 mL of distilled water (KET), and (ii) after drinking 500 mL of placebo saline water (0.9% NaCl) (CTR). During the KET trial, 3-OHB levels increased to approximately 2.5 mM. Testosterone levels decreased significantly by 20% during KET compared to 3% during CTR. A simultaneous increase in luteinizing hormone was observed in KET. We observed no changes in other adrenal androgens, such as androstenedione and 11-keto androgens. In conclusion, an acute increase in 3-OHB levels decreases testosterone levels. Concomitantly, an increase in luteinizing hormone was observed. This suggests that 3-OHB may counteract some of the beneficial effects of endurance training. Further studies, involving larger sample sizes and performance outcomes, are required to fully understand this phenomenon.
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Affiliation(s)
- Mads Svart
- Department of Endocrinology, Aarhus University Hospital, Aarhus N, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark
- Steno Diabetes Center Aarhus, Aahus University Hospital, Aarhus N, Denmark
| | - Mette Mølby Nielsen
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus N, Denmark
| | - Nikolaj Rittig
- Department of Endocrinology, Aarhus University Hospital, Aarhus N, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark
- Steno Diabetes Center Aarhus, Aahus University Hospital, Aarhus N, Denmark
| | - Mette Hansen
- Department of Public Health, Section of Sport Science, Aarhus University, Aarhus N, Denmark
| | - Niels Møller
- Department of Endocrinology, Aarhus University Hospital, Aarhus N, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark
| | - Claus H Gravholt
- Department of Endocrinology, Aarhus University Hospital, Aarhus N, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark
- Department of Molecular Medicine, Aarhus University Hospital, Aarhus N, Denmark
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Margolis LM, Pasiakos SM, Howard EE. High-fat ketogenic diets and ketone monoester supplements differentially affect substrate metabolism during aerobic exercise. Am J Physiol Cell Physiol 2023; 325:C1144-C1153. [PMID: 37721006 PMCID: PMC10635661 DOI: 10.1152/ajpcell.00359.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/07/2023] [Accepted: 09/07/2023] [Indexed: 09/19/2023]
Abstract
Chronically adhering to high-fat ketogenic diets or consuming ketone monoester supplements elicits ketosis. Resulting changes in substrate metabolism appear to be drastically different between ketogenic diets and ketone supplements. Consuming a ketogenic diet increases fatty acid oxidation with concomitant decreases in endogenous carbohydrate oxidation. Increased fat oxidation eventually results in an accumulation of circulating ketone bodies, which are metabolites of fatty acids that serve as an alternative source of fuel. Conversely, consuming ketone monoester supplements rapidly increases circulating ketone body concentrations that typically exceed those achieved by adhering to ketogenic diets. Rapid increases in ketone body concentrations with ketone monoester supplementation elicit a negative feedback inhibition that reduces fatty acid mobilization during aerobic exercise. Supplement-derived ketosis appears to have minimal impact on sparing of muscle glycogen or minimizing of carbohydrate oxidation during aerobic exercise. This review will discuss the substrate metabolic and associated aerobic performance responses to ketogenic diets and ketone supplements.
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Affiliation(s)
- Lee M Margolis
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
| | - Stefan M Pasiakos
- Office of Dietary Supplements, U.S. Department of Health and Human Services, National Institutes of Health, Bethesda, Maryland, United States
| | - Emily E Howard
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts, United States
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Yu Q, Falkenhain K, Little JP, Wong KK, Nie J, Shi Q, Kong Z. Effects of ketone supplements on blood β-hydroxybutyrate, glucose and insulin: A systematic review and three-level meta-analysis. Complement Ther Clin Pract 2023; 52:101774. [PMID: 37327753 DOI: 10.1016/j.ctcp.2023.101774] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/08/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Effects of ketone supplements as well as relevant dose-response relationships and time effects on blood β-hydroxybutyrate (BHB), glucose and insulin are controversial. OBJECTIVE This study aimed to summarize the existing evidence and synthesize the results, and demonstrate underlying dose-response relationships as well as sustained time effects. METHODS Medline, Web of Science, Embase, and Cochrane Central Register of Controlled Trials were searched for relevant randomized crossover/parallel studies published until 25th November 2022. Three-level meta-analysis compared the acute effects of exogenous ketone supplementation and placebo in regulating blood parameters, with Hedge's g used as measure of effect size. Effects of potential moderators were explored through multilevel regression models. Dose-response and time-effect models were established via fractional polynomial regression. RESULTS The meta-analysis with 327 data points from 30 studies (408 participants) indicated that exogenous ketones led to a significant increase in blood BHB (Hedge's g = 1.4994, 95% CI [1.2648, 1.7340]), reduction in glucose (Hedge's g = -0.3796, 95% CI [-0.4550, -0.3041]), and elevation in insulin of non-athlete healthy population (Hedge's g = 0.1214, 95%CI [0.0582, 0.3011]), as well as insignificant change in insulin of obesity and prediabetes. Nonlinear dose-response relationship between ketone dosage and blood parameter change was observed in some time intervals for BHB (30-60 min; >120 min) and insulin (30-60 min; 90-120 min), with linear relationship observed for glucose (>120 min). Nonlinear associations between time and blood parameter change were found in BHB (>550 mg/kg) and glucose (450-550 mg/kg), with linear relationship observed in BHB (≤250 mg/kg) and insulin (350-550 mg/kg). CONCLUSION Dose-response relationships and sustained time effects were observed in BHB, glucose and insulin following ketone supplementation. Glucose-lowering effect without increasing insulin load among population of obesity and prediabetes was of remarkable clinical implication. REGISTRY AND REGISTRY NUMBER PROSPERO (CRD42022360620).
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Affiliation(s)
- Qian Yu
- Faculty of Education, University of Macau, Macao, China
| | - Kaja Falkenhain
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Jonathan P Little
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Ka Kit Wong
- Faculty of Education, University of Macau, Macao, China
| | - Jinlei Nie
- Faculty of Health Sciences and Sports, Macao Polytechnic University, Macao, China
| | - Qingde Shi
- Faculty of Health Sciences and Sports, Macao Polytechnic University, Macao, China
| | - Zhaowei Kong
- Faculty of Education, University of Macau, Macao, China.
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Falkenhain K, Islam H, Little JP. Exogenous ketone supplementation: an emerging tool for physiologists with potential as a metabolic therapy. Exp Physiol 2023; 108:177-187. [PMID: 36533967 PMCID: PMC10103874 DOI: 10.1113/ep090430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022]
Abstract
NEW FINDINGS What is the topic of this review? The integrative physiological response to exogenous ketone supplementation. What advances does it highlight? The physiological effects and therapeutic potential of exogenous ketones on metabolic health, cardiovascular function, cognitive processing, and modulation of inflammatory pathways and immune function. Also highlighted are current challenges and future directions of the field. ABSTRACT Exogenous oral ketone supplements, primarily in form of ketone salts or esters, have emerged as a useful research tool for manipulating metabolism with potential therapeutic application targeting various aspects of several common chronic diseases. Recent literature has investigated the effects of exogenously induced ketosis on metabolic health, cardiovascular function, cognitive processing, and modulation of inflammatory pathways and immune function. This narrative review provides an overview of the integrative physiological effects of exogenous ketone supplementation and highlights current challenges and future research directions. Much of the existing research on therapeutic applications - particularly mechanistic studies - has involved pre-clinical rodent and/or cellular models, requiring further validation in human clinical studies. Existing human studies report that exogenous ketones can lower blood glucose and improve some aspects of cognitive function, highlighting the potential therapeutic application of exogenous ketones for type 2 diabetes and neurological diseases. There is also support for the ability of exogenous ketosis to improve cardiac metabolism in rodent models of heart failure with supporting human studies emerging; long-terms effects of exogenous ketone supplementation on the human cardiovascular system and lipid profiles are needed. An important avenue for future work is provided by research accelerating technologies that enable continuous ketone monitoring and/or the development of more palatable ketone mixtures that optimize plasma ketone kinetics to enable sustained ketosis. Lastly, research exploring the physiological interactions between exogenous ketones and varying metabolic states (e.g., exercise, fasting, metabolic disease) should yield important insights that can be used to maximize the health benefits of exogenous ketosis.
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Affiliation(s)
- Kaja Falkenhain
- School of Health and Exercise SciencesUniversity of British Columbia OkanaganKelownaBritish ColumbiaCanada
| | - Hashim Islam
- School of Health and Exercise SciencesUniversity of British Columbia OkanaganKelownaBritish ColumbiaCanada
| | - Jonathan P. Little
- School of Health and Exercise SciencesUniversity of British Columbia OkanaganKelownaBritish ColumbiaCanada
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Falkenhain K, Daraei A, Forbes SC, Little JP. Effects of Exogenous Ketone Supplementation on Blood Glucose: A Systematic Review and Meta-analysis. Adv Nutr 2022; 13:1697-1714. [PMID: 35380602 PMCID: PMC9526861 DOI: 10.1093/advances/nmac036] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 03/04/2022] [Accepted: 04/01/2022] [Indexed: 01/28/2023] Open
Abstract
Recently developed ketone (monoester or salt) supplements acutely elevate blood β-hydroxybutyrate (BHB) exogenously without prolonged periods of fasting or carbohydrate restriction. Previous (small-scale) studies have found a blood glucose-lowering effect of exogenous ketones. This study aimed to systematically review available evidence and conduct meta-analyses of studies reporting on exogenous ketones and blood glucose. We searched 6 electronic databases on 13 December 2021 for randomized and nonrandomized trials of any length that reported on the use of exogenous ketones. We calculated raw mean differences (MDs) in blood BHB and glucose in 2 main analyses: 1) after compared with before acute ingestion of exogenous ketones and 2) following acute ingestion of exogenous ketones compared with a comparator supplement. We pooled effect sizes using random-effects models and performed prespecified subgroup analyses to examine the effect of potential explanatory factors, including study population, exercise, blood BHB, and supplement type, dosing, and timing. Risk of bias was examined using Cochrane's risk-of-bias tools. Studies that could not be meta-analyzed were summarized narratively. Forty-three trials including 586 participants are summarized in this review. Following ingestion, exogenous ketones increased blood BHB (MD = 1.73 mM; 95% CI: 1.26, 2.21 mM; P < 0.001) and decreased mean blood glucose (MD = -0.54 mM; 95% CI: -0.68, -0.40 mM; P < 0.001). Similarly, when compared with placebo, blood BHB increased (MD = 1.98 mM; 95% CI: 1.52, 2.45 mM; P < 0.001) and blood glucose decreased (MD = -0.47 mM; 95% CI: -0.57, -0.36 mM; P < 0.001). Across both analyses, significantly greater effects were seen with ketone monoesters compared with salts (P < 0.001). The available evidence indicates that acute ingestion of exogenous ketones leads to increased blood BHB and decreased blood glucose. Limited evidence on prolonged ketone supplementation was found.
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Affiliation(s)
| | - Ali Daraei
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Scott C Forbes
- Department of Physical Education Studies, Faculty of Education, Brandon University, Brandon, Manitoba, Canada
| | - Jonathan P Little
- School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
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10
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Soto‐Mota A, Norwitz NG, Evans RD, Clarke K. Exogenous
d
‐β‐hydroxybutyrate lowers blood glucose in part by decreasing the availability of L‐alanine for gluconeogenesis. Endocrinol Diabetes Metab 2022; 5:e00300. [PMID: 34787952 PMCID: PMC8754249 DOI: 10.1002/edm2.300] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 09/08/2021] [Accepted: 09/11/2021] [Indexed: 12/28/2022] Open
Abstract
Background Interventions that induce ketosis simultaneously lower blood glucose and the explanation for this phenomenon is unknown. Additionally, the glucose‐lowering effect of acute ketosis is greater in people with type 2 diabetes (T2D). On the contrary, L‐alanine is a gluconeogenic substrate secreted by skeletal muscle at higher levels in people with T2D and infusing of ketones lower circulating L‐alanine blood levels. In this study, we sought to determine whether supplementation with L‐alanine would attenuate the glucose‐lowering effect of exogenous ketosis using a ketone ester (KE). Methods This crossover study involved 10 healthy human volunteers who fasted for 24 h prior to the ingestion of 25 g of d‐β‐hydroxybutyrate (βHB) in the form of a KE drink (ΔG®) on two separate visits. During one of the visits, participants additionally ingested 2 g of L‐alanine to see whether L‐alanine supplementation would attenuate the glucose‐lowering effect of the KE drink. Blood L‐alanine, L‐glutamine, glucose, βHB, free fatty acids (FFA), lactate and C‐peptide were measured for 120 min after ingestion of the KE, with or without L‐alanine. Findings The KE drinks elevated blood βHB concentrations from negligible levels to 4.52 ± 1.23 mmol/L, lowered glucose from 4.97 ± SD 0.39 to 3.77 ± SD 0.40 mmol/L, and lowered and L‐alanine from 0.56 ± SD 0.88 to 0.41 ± SD 0.91 mmol/L. L‐alanine in the KE drink elevated blood L‐Alanine by 0.68 ± SD 0.15 mmol/L, but had no significant effect on blood βHB, L‐glutamine, FFA, lactate, nor C‐peptide concentrations. By contrast, L‐alanine supplementation significantly attenuated the ketosis‐induced drop in glucose from 28% ± SD 8% to 16% ± SD 7% (p < .01). Conclusions The glucose‐lowering effect of acutely elevated βHB is partially due to βHB decreasing L‐alanine availability as a substrate for gluconeogenesis.
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Affiliation(s)
- Adrian Soto‐Mota
- Department of Physiology, Anatomy and Genetics University of Oxford Oxford UK
| | - Nicholas G. Norwitz
- Department of Physiology, Anatomy and Genetics University of Oxford Oxford UK
| | - Rhys D. Evans
- Department of Physiology, Anatomy and Genetics University of Oxford Oxford UK
| | - Kieran Clarke
- Department of Physiology, Anatomy and Genetics University of Oxford Oxford UK
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Evans M, McClure TS, Koutnik AP, Egan B. Exogenous Ketone Supplements in Athletic Contexts: Past, Present, and Future. Sports Med 2022; 52:25-67. [PMID: 36214993 DOI: 10.1007/s40279-022-01756-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2022] [Indexed: 12/15/2022]
Abstract
The ketone bodies acetoacetate (AcAc) and β-hydroxybutyrate (βHB) have pleiotropic effects in multiple organs including brain, heart, and skeletal muscle by serving as an alternative substrate for energy provision, and by modulating inflammation, oxidative stress, catabolic processes, and gene expression. Of particular relevance to athletes are the metabolic actions of ketone bodies to alter substrate utilisation through attenuating glucose utilisation in peripheral tissues, anti-lipolytic effects on adipose tissue, and attenuation of proteolysis in skeletal muscle. There has been long-standing interest in the development of ingestible forms of ketone bodies that has recently resulted in the commercial availability of exogenous ketone supplements (EKS). These supplements in the form of ketone salts and ketone esters, in addition to ketogenic compounds such as 1,3-butanediol and medium chain triglycerides, facilitate an acute transient increase in circulating AcAc and βHB concentrations, which has been termed 'acute nutritional ketosis' or 'intermittent exogenous ketosis'. Some studies have suggested beneficial effects of EKS to endurance performance, recovery, and overreaching, although many studies have failed to observe benefits of acute nutritional ketosis on performance or recovery. The present review explores the rationale and historical development of EKS, the mechanistic basis for their proposed effects, both positive and negative, and evidence to date for their effects on exercise performance and recovery outcomes before concluding with a discussion of methodological considerations and future directions in this field.
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Vestergaard ET, Zubanovic NB, Rittig N, Møller N, Kuhre RE, Holst JJ, Rehfeld JF, Thomsen HH. Acute ketosis inhibits appetite and decreases plasma concentrations of acyl ghrelin in healthy young men. Diabetes Obes Metab 2021; 23:1834-1842. [PMID: 33852195 DOI: 10.1111/dom.14402] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/31/2021] [Accepted: 04/08/2021] [Indexed: 12/27/2022]
Abstract
AIM To investigate the acute effect of ketone ester (KE) ingestion on appetite and plasma concentrations of acyl ghrelin (AG), unacylated ghrelin (UAG) and glucagon-like peptide-1 (GLP-1) secretion, and to compare responses with those elicited by isocaloric glucose (GLU) administration. METHODS We examined 10 healthy young men on three separate occasions using a placebo (PBO)-controlled crossover design. A KE versus taste-matched isovolumetric and isocaloric 50% GLU and taste-matched isovolumetric PBO vehicle was orally administered. Our main outcome measures were plasma concentrations of AG, UAG, glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 along with appetite sensation scores assessed by visual analogue scale. RESULTS KE ingestion resulted in an average peak beta-hydroxybutyrate concentration of 5.5 mM. AG and UAG were lowered by approximately 25% following both KE and GLU intake compared with PBO. In the case of AG, the differences were -52.1 (-79.4, -24.8) for KE and -48.4 (-75.4, -21.5) pg/mL for GLU intake (P < .01). Concentrations of AG remained lower with KE but returned to baseline and were comparable with PBO levels after GLU intake. GLP-1, GIP, gastrin and cholecystokinin were not affected by KE ingestion. CONCLUSION Our results suggest that the suppressive effects on appetite sensation scores associated with hyperketonaemia are more probable to be mediated through reduced ghrelin concentrations than by increased activity of cholecystokinin, gastrin, GIP or GLP-1.
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Affiliation(s)
- Esben Thyssen Vestergaard
- Department of Paediatrics, Regional Hospital Randers, Randers, Denmark
- Steno Diabetes Center Aarhus (SDCA), Aarhus, Denmark
| | - Natasa Brkovic Zubanovic
- Department of Internal Medicine, Clinic for Diabetes and Endocrinology, Viborg Regional Hospital, Viborg, Denmark
- Department and Laboratory of Internal Medicine and Endocrinology, MEA, Aarhus University Hospital, Aarhus, Denmark
| | - Nikolaj Rittig
- Steno Diabetes Center Aarhus (SDCA), Aarhus, Denmark
- Department and Laboratory of Internal Medicine and Endocrinology, MEA, Aarhus University Hospital, Aarhus, Denmark
| | - Niels Møller
- Department and Laboratory of Internal Medicine and Endocrinology, MEA, Aarhus University Hospital, Aarhus, Denmark
| | - Rune Ehrenreich Kuhre
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Obesity Pharmacology, Novo Nordisk, Måløv, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens F Rehfeld
- Department of Clinical Biochemistry (KB3011), Rigshospitalet, Copenhagen, Denmark
| | - Henrik Holm Thomsen
- Department of Internal Medicine, Clinic for Diabetes and Endocrinology, Viborg Regional Hospital, Viborg, Denmark
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