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Asiriwardhana MU, Dinesh OC, Brunton JA, Bertolo RF. Dietary Methionine Enhances Portal Appearance of Guanidinoacetate and Synthesis of Creatine in Yucatan Miniature Piglets. J Nutr 2024; 154:1571-1581. [PMID: 38527737 PMCID: PMC11130667 DOI: 10.1016/j.tjnut.2024.03.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 02/27/2024] [Accepted: 03/14/2024] [Indexed: 03/27/2024] Open
Abstract
BACKGROUND Creatine plays a significant role in energy metabolism and positively impacts anaerobic energy capacity, muscle mass, and physical performance. Endogenous creatine synthesis requires guanidinoacetic acid (GAA) and methionine. GAA can be an alternative to creatine supplements and has been tested as a beneficial feed additive in the animal industry. When pigs are fed GAA with excess methionine, creatine is synthesized without feedback regulation. In contrast, when dietary methionine is limited, creatine synthesis is limited, yet, GAA does not accumulate in plasma, urine, or liver. OBJECTIVE We hypothesized that portal GAA appearance requires adequate dietary methionine. METHODS Yucatan miniature piglets (17-21 d old; n = 20) were given a 4 h duodenal infusion of complete elemental diets with supplemental GAA plus 1 of 4 methionine concentrations representing either 20%, 80%, 140%, or 200% of the dietary methionine requirement. Arterial and portal blood metabolites were measured along with blood flow to determine mass balance across the gut. [3H-methyl] methionine was infused to measure the methionine incorporation rate into creatine. RESULTS GAA balance across the gut was highest in the 200% methionine group, indicating excess dietary methionine enhanced GAA absorption. Creatine synthesis in the liver and jejunum was higher with higher concentrations of methionine, emphasizing that the transmethylation of GAA to creatine depends on sufficient dietary methionine. Hepatic GAA concentration was higher in the 20% methionine group, suggesting low dietary methionine limited GAA conversion to creatine, which led to GAA accumulation in the liver. CONCLUSIONS GAA absorption and conversion to creatine require a sufficient amount of methionine, and the supplementation strategies should accommodate this interaction.
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Affiliation(s)
| | - Olupathage C Dinesh
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Janet A Brunton
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Robert F Bertolo
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL, Canada.
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Aguiar MS, Pereira R, Koch AJ, Machado M. Psychological effect of acute creatine pre-workout supplementation induces performance improvement in resistance exercise. Res Sports Med 2024; 32:174-185. [PMID: 35726856 DOI: 10.1080/15438627.2022.2090253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 06/11/2022] [Indexed: 10/18/2022]
Abstract
The purpose of this study was to test whether believed versus actual acute creatine ingestion impacted resistance exercise performance. Fifteen men (21.9 ± 2.7 years old) completed four bouts of three sets each of squat and bench press to volitional fatigue at a 10RM load with 1-min between-sets rest interval. Thirty minutes prior to each exercise bout, they received the following treatments in a randomized order: 1) nothing (CON); 2) 0.3 g·kg-1 dextrose placebo (PLC); 3) 0.3 g·kg-1 dextrose, identified as creatine (Cr-False); 4) 0.3 g·kg 20 -1 creatine, identified as creatine (CrTrue). Between-treatments comparisons included the total repetitions completed and the rate of perceived exertion. Results revealed (p < 0.05) higher repetitions performed for all treatments versus CON for both squat and bench press. In the squat, more repetitions were performed with Cr-True (p < 0.001) and CrFalse (p < 0.001) than with either CON or PLC. Bayes Factor analyses revealed strong (PLC to Cr-True BF = 19.1) and very strong (PLC to CrFalse BF = 45.3) posterior probability favouring positive effects for both "creatine" conditions over PLC for the squat. In conclusion, in acute measures, belief versus ingestion of creatine yields similar exercise performance.
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Affiliation(s)
- Matheus S Aguiar
- Laboratory of Physiology and Biokinetics, Iguaçu University (UNIG) Campus V, Itaperuna, Brazil
| | - Rafael Pereira
- Research group in Neuromuscular Physiology, Department of Biological Sciences, Universidade Estadual do Sudoeste da Bahia (UESB), Jequie, Brazil
- Integrative Physiology Research Center, Department of Biological Sciences, Universidade Estadual do Sudoeste da Bahia (UESB), Jequie, Brazil
| | - Alexander J Koch
- Exercise Physiology Laboratory, Lenoir-Rhyne University, Hickory, USA
| | - Marco Machado
- Laboratory of Physiology and Biokinetics, Iguaçu University (UNIG) Campus V, Itaperuna, Brazil
- Laboratory of Human Movement Studies, Universitary Foundation of Itaperuna (FUNITA), Itaperuna, Brazil
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Oliveira EF, Forbes SC, Borges EQ, Machado LF, Candow DG, Machado M. Association between dietary creatine and visuospatial short-term memory in older adults. Nutr Health 2023; 29:731-736. [PMID: 35603861 DOI: 10.1177/02601060221102273] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Aims: The purpose was to examine the relationship between habitual dietary creatine intake obtained in food and visuospatial short-term memory (VSSM). Methods: Forty-two participants (32 females, 10 males; > 60 yrs of age) completed a 5-day dietary recall to estimate creatine intake and performed a cognitive assessment which included a visuospatial short-term memory test (forward and reverse corsi block test) and a mini-mental state examination (MMSE). Pearson correlation coefficients were determined. Further, cohorts were derived based on the median creatine intake. Results: There was a significant correlation between the forward Corsi (r = 0.703, P < 0.001), reverse Corsi (r = 0.715, P < 0.001), and the memory sub-component of the MMSE (r = 0.406, P = 0.004). A median creatine intake of 0.382 g/day was found. Participants consuming greater than the median had a significantly higher Corsi (P = 0.005) and reverse Corsi (P < 0.001) scores compared to participants ingesting less than the median. Conclusions: Dietary creatine intake is positively associated with measures of memory in older adults. Clinical Implications: Older adults should consider food sources containing creatine (i.e. red meat, seafood) due to the positive association with visuospatial short-term memory.
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Affiliation(s)
| | - Scott C Forbes
- Department of Physical Education Studies, Brandon University, Brandon, MB, Canada
| | | | | | - Darren G Candow
- Faculty of Kinesiology and Health Studies, University of Regina, Regina, SK, Canada
| | - Marco Machado
- Universidade Iguaçu Campus V, Itaperuna, RJ, Brazil
- Itaperuna Universitary Foundation (FUNITA), Itaperuna, RJ, Brazil
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Alraddadi EA, Khojah AM, Alamri FF, Kecheck HK, Altaf WF, Khouqeer Y. Potential role of creatine as an anticonvulsant agent: evidence from preclinical studies. Front Neurosci 2023; 17:1201971. [PMID: 37456992 PMCID: PMC10339234 DOI: 10.3389/fnins.2023.1201971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 06/12/2023] [Indexed: 07/18/2023] Open
Abstract
Epilepsy is one of the most common neurological disorders affecting people of all ages representing a significant social and public health burden. Current therapeutic options for epilepsy are not effective in a significant proportion of patients suggesting a need for identifying novel targets for the development of more effective therapeutics. There is growing evidence from animal and human studies suggesting a role of impaired brain energy metabolism and mitochondrial dysfunction in the development of epilepsy. Candidate compounds with the potential to target brain energetics have promising future in the management of epilepsy and other related neurological disorders. Creatine is a naturally occurring organic compound that serves as an energy buffer and energy shuttle in tissues, such as brain and skeletal muscle, that exhibit dynamic energy requirements. In this review, applications of creatine supplements in neurological conditions in which mitochondrial dysfunction is a central component in its pathology will be discussed. Currently, limited evidence mainly from preclinical animal studies suggest anticonvulsant properties of creatine; however, the exact mechanism remain to be elucidated. Future work should involve larger clinical trials of creatine used as an add-on therapy, followed by large clinical trials of creatine as monotherapy.
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Affiliation(s)
- Eman A. Alraddadi
- Department of Basic Sciences, College of Science and Health Professions, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
- King Abdullah International Medical Research Center, Jeddah, Saudi Arabia
| | - Abdulrahman M. Khojah
- Department of Basic Sciences, College of Science and Health Professions, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
| | - Faisal F. Alamri
- Department of Basic Sciences, College of Science and Health Professions, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
- King Abdullah International Medical Research Center, Jeddah, Saudi Arabia
| | - Husun K. Kecheck
- Department of Basic Sciences, College of Science and Health Professions, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
| | - Wid F. Altaf
- Department of Basic Sciences, College of Science and Health Professions, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
| | - Yousef Khouqeer
- Department of Basic Sciences, College of Science and Health Professions, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
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Selective Attention and Inhibitory Processing in Older Adults: The Impact of Dietary Creatine. AGEING INTERNATIONAL 2023. [DOI: 10.1007/s12126-023-09524-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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Machado M, Masterson TD, Oliveira EF. Could dietary creatine intake modulate overweight elderly's selective attention and inhibitory function? Nutr Health 2022:2601060221127497. [PMID: 36164669 DOI: 10.1177/02601060221127497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aims: There is evidence that both aging and increased adiposity may impact creatine levels in the brain, and brain creatine levels are important for cognition. The aim of this study was to assess correlation between dietary creatine intake and cognition in in elderly women with overweight. Methods: Twenty seven overweight women over 60 years of age who were part of a larger study participated in an Eriksen Flanker Task (EFT) to asssess cognitive performance. Additionally, diet was assessed over 5 days via daily diary nutritional recalls and the estimate of the daily amount of creatine was calculated. Results: In the EFT when incongruente stimulus were presented there was a significant diferences between those with low and high intake of creatine (-35.3 ± 5.84; p < 0.001). Similarly, reaction time to answer incongruent stimulus (r = -0.383; p = 0.004) and the percent of correct answers (r = 0.743; p < 0.001) showed weak to strong correlations with self-reported daily creatine intake. Conclusions: In conclusion, our results suggest that in elderly women with overweight that dietary intake of creatine may influence cognitive ability. Clinical Implications: Our findings support the idea that intake of dietary creatine may be an important factor for cognition in older adults.
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Affiliation(s)
- Marco Machado
- 155093Universidade Iguaçu Campus V, Itaperuna, RJ, Brazil
- Itaperuna Universitary Foundation (FUNITA), Itaperuna, RJ, Brazil
| | - Travis D Masterson
- Department of Nutritional Sciences, 52469The Pennsylvania State University, PA, USA
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ALIOMRANI M, MESRIPOUR A, MEHRJARDI AS. Creatine and Alpha-Lipoic Acid Antidepressant-Like Effect Following Cyclosporine A Administration. Turk J Pharm Sci 2022; 19:196-201. [DOI: 10.4274/tjps.galenos.2021.27217] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Antonio J, Evans C, Jiannine L, Curtis J, Wojnas K, Burgess V, Willoughby D, Hohl C, Petersen B, Flynn S, Baisley J, Parekh G, Kalman D. Pharmacokinetic Evaluation of a Single 5-Gram Bolus of Creatine Monohydrate Versus Two Other Creatine-Containing Investigational Products. Cureus 2022; 14:e24395. [PMID: 35619864 PMCID: PMC9126436 DOI: 10.7759/cureus.24395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2022] [Indexed: 11/05/2022] Open
Abstract
The purpose of this study was to determine the relative pharmacokinetics of creatine monohydrate delivered as a formula or as a pure powder (all mixed in solution). A single 5 g bolus of creatine monohydrate was ingested as CreaBev 1, CreaBev 2, or creatine monohydrate. Participants we assigned a test product and monitored in a supervised laboratory setting for ingestion and all blood draws starting 30 min post-ingestion to the 6-h mark. Standard pharmacokinetic analysis was undertaken to determine relative maximum concentration (Cmax), time to maximum concentration (Tmax), and area under the curve (AUC) for the products. Cmax data indicate that CreaBev 1 10.55±4.10, CreaBev 2 15.45±5.48, and creatine monohydrate 12.77±4.0 nmol/h/μL. The Tmax analysis demonstrated CreaBev 1 1.20±1.01, CreaBev 2 1.23±0.65, and creatine monohydrate 0.91±0.2 h. The AUC data indicate that CreaBev 1 22.90±9.17, CreaBev 2 33.92±9.52, and creatine monohydrate 29.58±11.93 nmol/h/μL. When examining the data for pharmacokinetics, the AUC and Cmax pharmacokinetics were greatest for CreaBev 2 (p<0.021 and 0.020). Within the confines of this study, CreaBev 2 produced the highest blood concentrations of creatine as compared to creatine monohydrate and CreaBev 1.
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Kreider RB, Jäger R, Purpura M. Bioavailability, Efficacy, Safety, and Regulatory Status of Creatine and Related Compounds: A Critical Review. Nutrients 2022; 14:nu14051035. [PMID: 35268011 PMCID: PMC8912867 DOI: 10.3390/nu14051035] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 12/12/2022] Open
Abstract
In 2011, we published a paper providing an overview about the bioavailability, efficacy, and regulatory status of creatine monohydrate (CrM), as well as other “novel forms” of creatine that were being marketed at the time. This paper concluded that no other purported form of creatine had been shown to be a more effective source of creatine than CrM, and that CrM was recognized by international regulatory authorities as safe for use in dietary supplements. Moreover, that most purported “forms” of creatine that were being marketed at the time were either less bioavailable, less effective, more expensive, and/or not sufficiently studied in terms of safety and/or efficacy. We also provided examples of several “forms” of creatine that were being marketed that were not bioavailable sources of creatine or less effective than CrM in comparative effectiveness trials. We had hoped that this paper would encourage supplement manufacturers to use CrM in dietary supplements given the overwhelming efficacy and safety profile. Alternatively, encourage them to conduct research to show their purported “form” of creatine was a bioavailable, effective, and safe source of creatine before making unsubstantiated claims of greater efficacy and/or safety than CrM. Unfortunately, unsupported misrepresentations about the effectiveness and safety of various “forms” of creatine have continued. The purpose of this critical review is to: (1) provide an overview of the physiochemical properties, bioavailability, and safety of CrM; (2) describe the data needed to substantiate claims that a “novel form” of creatine is a bioavailable, effective, and safe source of creatine; (3) examine whether other marketed sources of creatine are more effective sources of creatine than CrM; (4) provide an update about the regulatory status of CrM and other purported sources of creatine sold as dietary supplements; and (5) provide guidance regarding the type of research needed to validate that a purported “new form” of creatine is a bioavailable, effective and safe source of creatine for dietary supplements. Based on this analysis, we categorized forms of creatine that are being sold as dietary supplements as either having strong, some, or no evidence of bioavailability and safety. As will be seen, CrM continues to be the only source of creatine that has substantial evidence to support bioavailability, efficacy, and safety. Additionally, CrM is the source of creatine recommended explicitly by professional societies and organizations and approved for use in global markets as a dietary ingredient or food additive.
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Affiliation(s)
- Richard B. Kreider
- Exercise & Sport Nutrition Lab, Human Clinical Research Facility, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843, USA
- Correspondence: ; Tel.: +1-972-458-1498
| | - Ralf Jäger
- Increnovo LLC, Milwaukee, WI 53202, USA; (R.J.); (M.P.)
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Duan BB, Xu JW, Xing T, Li JL, Zhang L, Gao F. Creatine nitrate supplementation strengthens energy status and delays glycolysis of broiler muscle via inhibition of LKB1/AMPK pathway. Poult Sci 2021; 101:101653. [PMID: 35007932 PMCID: PMC8749301 DOI: 10.1016/j.psj.2021.101653] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/18/2021] [Accepted: 11/25/2021] [Indexed: 01/10/2023] Open
Abstract
This study aimed to evaluate the effects of dietary creatine nitrate (CrN) on growth performance, meat quality, energy status, glycolysis, and related gene expression of liver kinase B1/AMP-activated protein kinase (LKB1/AMPK) pathway in Pectoralis major (PM) muscle of broilers. A total of 240 male Arbor Acres broilers (28-day-old) were randomly allocated to one of 5 dietary treatments: the basal diet (control group), and the basal diets supplemented with 600 mg/kg guanidinoacetic acid (GAA), 300, 600, or 900 mg/kg CrN (identified as GAA600, CrN300, CrN600, or CrN900, respectively). We found that dietary GAA and CrN supplementation for 14 d from d 28 to 42 did not affect broiler growth performance, carcass traits, and textural characteristics of breast muscle. GAA600, CrN600, and CrN900 treatments increased pH24h and decreased drip loss of PM muscle compared with the control (P < 0.05). The PM muscles of CrN600 and CrN900 groups showed higher glycogen concentration and lower lactic acid concentration accompanied by lower activities of phosphofructokinase (PFK), pyruvate kinase (PK), and lactate dehydrogenase (LDH) (P < 0.05). Simultaneously, GAA600 and all CrN treatments increased concentration of muscle creatine, phosphocreatine (PCr) and ATP, and decreased AMP concentration and AMP/ATP ratio (P < 0.05). Meanwhile, the concentrations of muscle creatine, PCr, and ATP were increased linearly, while muscle AMP concentration and AMP/ATP ratio were decreased linearly and quadratic as the dose of CrN increased (P < 0.05). GAA600, CrN600, and CrN900 treatments upregulated mRNA expression of CreaT in PM muscle, and CrN600 and CrN900 treatments downregulated GAMT expression in liver and PM muscle compared with the control or GAA600 groups (P < 0.05). The mRNA expression of muscle LKB1, AMPKα1, and AMPKα2 was downregulated linearly in response to the increasing CrN level (P < 0.05). Overall, CrN showed better efficacy on strengthening muscle energy status and improve meat quality than GAA at the some dose. These results indicate that CrN may be a potential replacement for GAA as a new creatine supplement.
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Affiliation(s)
- B B Duan
- College of Animal Science and Technology, Jiangsu Provincial Key Laboratory of Animal Origin Food Production and Safety Guarantee, Jiangsu Provincial Key Laboratory of Gastrointestinal Nutrition and Animal Health, Jiangsu Provincial Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - J W Xu
- College of Animal Science and Technology, Jiangsu Provincial Key Laboratory of Animal Origin Food Production and Safety Guarantee, Jiangsu Provincial Key Laboratory of Gastrointestinal Nutrition and Animal Health, Jiangsu Provincial Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - T Xing
- College of Animal Science and Technology, Jiangsu Provincial Key Laboratory of Animal Origin Food Production and Safety Guarantee, Jiangsu Provincial Key Laboratory of Gastrointestinal Nutrition and Animal Health, Jiangsu Provincial Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - J L Li
- Institute of Agricultural Products Processing, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - L Zhang
- College of Animal Science and Technology, Jiangsu Provincial Key Laboratory of Animal Origin Food Production and Safety Guarantee, Jiangsu Provincial Key Laboratory of Gastrointestinal Nutrition and Animal Health, Jiangsu Provincial Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
| | - F Gao
- College of Animal Science and Technology, Jiangsu Provincial Key Laboratory of Animal Origin Food Production and Safety Guarantee, Jiangsu Provincial Key Laboratory of Gastrointestinal Nutrition and Animal Health, Jiangsu Provincial Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
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Ostojic SM, Stajer V, Vranes M, Ostojic J. Searching for a better formulation to enhance muscle bioenergetics: A randomized controlled trial of creatine nitrate plus creatinine vs. creatine nitrate vs. creatine monohydrate in healthy men. Food Sci Nutr 2019; 7:3766-3773. [PMID: 31763026 PMCID: PMC6848817 DOI: 10.1002/fsn3.1237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 09/05/2019] [Accepted: 09/14/2019] [Indexed: 11/18/2022] Open
Abstract
A novel creatine blend (creatine nitrate mixed with creatinine, CN-CRN) has been anecdotally suggested to be superior to traditional creatine formulations for bioavailability and performance. However, does CN-CRN supremely affects creatine levels in the blood and skeletal muscle of healthy humans remain currently unknown. This randomized, controlled, double-blind, crossover trial evaluated the acute effects of single-dose CN-CRN on serum creatine levels, and 5-days intervention with CN-CRN on skeletal muscle creatine and safety biomarkers in healthy men. Ten healthy young men (23.6 ± 2.9 years) were allocated to receive either CN-CRN (3 grams of creatine nitrate mixed with 3 grams of creatinine), pure creatine nitrate (3 grams, CN), or regular creatine monohydrate (3 grams, CRM) by oral administration. We found that CN-CRN resulted in a more powerful rise in serum creatine levels comparing to either CN or CRM after a single-dose intervention, as evaluated with the area under the concentration-time curve calculation (701.1 ± 62.1 (µmol/L) × min versus 622.7 ± 62.9 (µmol/L) × min versus 466.3 ± 47.9 (µmol/L) × min; p < .001). The peak serum creatine levels at 60-min sampling interval were significantly higher in CN-CRN group (183.7 ± 15.5 µmol/L), as compared to CN group (163.8 ± 12.9 µmol/L) and CRM group (118.6 ± 12.9 µmol/L) (p < .001). This was accompanied by a significantly superior increase in muscle creatine levels after CN-CRN administration at 5-days follow-up, as compared to CN and CRM, respectively (9.6% versus 8.0% versus 2.1%; p = .01). While 2 out of 10 participants were found to be nonresponsive to CN intervention (20.0%) (e.g., no amplification in muscle creatine levels found at 5-days follow-up), and 3 participants out of 10 were nonresponsive in CRM trial (30%), no nonresponders were found after CN-CRN administration, with individual upswing in total muscle creatine varied in this group from 2.0% (lowest increment) to 16.8% (highest increment). Supplemental CN-CRN significantly decreased estimated glomerular filtration rate (eGFR) at 5-days follow-up, as compared to other interventions (p = .004), with the average reduction was 14.8 ± 7.7% (95% confidence interval; from 9.3 to 20.3). Nevertheless, no single participant experienced a clinically relevant reduction in eGFR (< 60 ml/min/1.73 m2) throughout the course of the trial. Liver enzymes remained in reference ranges throughout the study, with no participant experienced high liver blood tests (e.g., AST > 40 units per L or ALT >56 units per L). Besides, no participant reported any major side effects during the trial, while the odors of CN-CRN and CN formulations were considered somewhat unpleasant in 8 out of 10 participants (80.0%). Our results suggest that CN-CRN is a preferred and relatively safe alternative to traditional creatine formulations for improved creatine bioavailability in the blood and skeletal muscle after single-dose and 5-days interventions.
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Affiliation(s)
- Sergej M. Ostojic
- Applied Bioenergetics LabFaculty of Sport and PEUniversity of Novi SadNovi SadSerbia
- Faculty of Health SciencesUniversity of PecsPecsHungary
| | - Valdemar Stajer
- Applied Bioenergetics LabFaculty of Sport and PEUniversity of Novi SadNovi SadSerbia
| | - Milan Vranes
- Faculty of SciencesUniversity of Novi SadNovi SadSerbia
| | - Jelena Ostojic
- Faculty of Health SciencesUniversity of Southern DenmarkOdenseDenmark
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