Exploring the therapeutic role of creatine supplementation

Potential Role of Novel Cardiovascular Biomarkers in Pediatric Patients with Chronic Kidney Disease

BACKGROUND

Cardiovascular Disease is the leading cause of death in adult and pediatric patients with Chronic Kidney Disease (CKD) and its pathogenesis involves the interaction of multiple pathways. As Inflammatory mechanisms play a critical role in the vascular disease of CKD pediatric patients, there are several biomarkers related to inflammation strongly associated with this comorbidity.

OBJECTIVE

This review provides available evidence on the link between several biomarkers and the pathophysiology of heart disease in patients with CKD.

METHODS

The data were obtained independently by the authors, who carried out a comprehensive and non-systematic search in PubMed, Cochrane, Scopus, and SciELO databases. The search terms were "Chronic Kidney Disease", "Cardiovascular Disease", "Pediatrics", "Pathophysiology", "Mineral and Bone Disorder (MBD)", "Renin Angiotensin System (RAS)", "Biomarkers", "BNP", "NTproBNP", "CK-MB", "CXCL6", "CXCL16", "Endocan-1 (ESM-1)", "FABP3", "FABP4", h-FABP", "Oncostatin- M (OSM)", "Placental Growth Factor (PlGF)" and "Troponin I".

RESULTS

The pathogenesis of CKD-mediated cardiovascular disease is linked to inflammatory biomarkers, which play a critical role in the initiation, maintenance, and progression of cardiovascular disease. There are several biomarkers associated with cardiovascular disease in pediatric patients, including BNP, NTproBNP, CK-MB, CXCL6, CXCL16, Endocan-1 (ESM-1), FABP3, FABP4, Oncostatin- M (OSM), Placental Growth Factor (PlGF), and Troponin I.

CONCLUSION

The pathogenesis of CKD-mediated cardiovascular disease is not completely understood, but it is linked to inflammatory biomarkers. Further studies are required to elucidate the pathophysiological and potential role of these novel biomarkers.

Dose-Response of Creatine Supplementation on Cognitive Function in Healthy Young Adults

To determine if creatine (Cr) supplementation could influence cognitive performance and whether any changes were related to changes in prefrontal cortex (PFC) activation during such cognitive tasks, thirty (M = 11, F = 19) participants were evenly randomized to receive supplementation with Cr (CR10:10 g/day or CR20:20 g/day) or a placebo (PLA:10 g/day) for 6 weeks. Participants completed a cognitive test battery (processing speed, episodic memory, and attention) on two separate occasions prior to and following supplementation. Functional near-infrared spectroscopy (fNIRS) was used to measure PFC oxyhemoglobin (O2Hb) during the cognitive evaluation. A two-way repeated measures ANOVA was used to determine the differences between the groups and the timepoints for the cognitive performance scores and PFC O2Hb. In addition, a one-way ANOVA of % change was used to determine pre- and post-differences between the groups. Creatine (independent of dosage) had no significant effect on the measures of cognitive performance. There was a trend for decreased relative PFC O2Hb in the CR10 group versus the PLA group in the processing speed test (p = 0.06). Overall, six weeks of Cr supplementation at a moderate or high dose does not improve cognitive performance or change PFC activation in young adults.

Potential role of creatine as an anticonvulsant agent: evidence from preclinical studies

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.

Creatine Supplementation Potentiates Exercise Protective Effects against Doxorubicin-Induced Hepatotoxicity in Mice

We tested the hypothesis that creatine supplementation may potentiate exercise’s protective effects against doxorubicin-induced hepatotoxicity. Thirty-eight Swiss mice were randomly allocated into five groups: control (C, n = 7), exercised (Ex, n = 7), treated with doxorubicin (Dox, n = 8), treated with doxorubicin and exercised (DoxEx, n = 8), and treated with doxorubicin, exercised, and supplemented with creatine (DoxExCr, n = 8). Doxorubicin was administered weekly (i.p.) for a total dose of 12 mg/kg. Creatine supplementation (2% added to the diet) and strength training (climbing stairs, 3 times a week) were performed for a total of 5 weeks. The results demonstrated that doxorubicin caused hepatotoxicity, which was evidenced by increased (p < 0.05) hepatic markers of inflammation (i.e., TNF-α and IL-6) and oxidative damage, while the redox status (GSH/GSSG) was reduced. The plasma concentrations of liver transaminases were also significantly (p < 0.05) elevated. Furthermore, doxorubicin-treated animals presented hepatic fibrosis and histopathological alterations such as cellular degeneration and the infiltration of interstitial inflammatory cells. Exercise alone partly prevented doxorubicin-induced hepatotoxicity; thus, when combined with creatine supplementation, exercise was able to attenuate inflammation and oxidative stress, morphological alterations, and fibrosis. In conclusion, creatine supplementation potentiates the protective effects of exercise against doxorubicin-induced hepatotoxicity in mice.

Creatine supplementation protects against diet-induced non-alcoholic fatty liver but exacerbates alcoholic fatty liver

AIMS

This work investigated the effects of creatine supplementation on different pathways related to the pathogenesis of non-alcoholic fatty liver disease and alcoholic liver disease.

MAIN METHODS

To induce alcoholic liver disease, male Swiss mice were divided into three groups: control, ethanol and ethanol supplemented with creatine. To induce non-alcoholic fatty liver disease, mice were divided into three groups: control, high-fat diet and high-fat diet supplemented with creatine. Each group consisted of eight animals. In both cases, creatine monohydrate was added to the diets (1 %; weight/vol).

KEY FINDINGS

Creatine supplementation prevented high-fat diet-induced non-alcoholic fatty liver disease progression, demonstrated by attenuated liver fat accumulation and liver damage. On the other hand, when combined with ethanol, creatine supplementation up-regulated key genes related to ethanol metabolism, oxidative stress, inflammation and lipid synthesis, and exacerbated ethanol-induced liver steatosis and damage, demonstrated by increased liver fat accumulation and histopathological score, as well as elevated oxidative damage markers and inflammatory mediators.

SIGNIFICANCE

Our results clearly demonstrated creatine supplementation exerts different outcomes in relation to non-alcoholic fatty liver disease and alcoholic liver disease, namely it protects against high-fat diet-induced non-alcoholic fatty liver disease but exacerbates ethanol-induced alcoholic liver disease. The exacerbating effects of the creatine and ethanol combination appear to be related to oxidative stress and inflammation-mediated up-regulation of ethanol metabolism.

Age-related metabolic and neurodegenerative changes in SAMP8 mice

The most important risk factor for the development of sporadic Alzheimer’s disease (AD) is ageing. Senescence accelerated mouse prone 8 (SAMP8) is a model of sporadic AD, with senescence accelerated resistant mouse (SAMR1) as a control. In this study, we aimed to determine the onset of senescence-induced neurodegeneration and the related potential therapeutic window using behavioral experiments, immunohistochemistry and western blotting in SAMP8 and SAMR1 mice at 3, 6 and 9 months of age. The Y-maze revealed significantly impaired working spatial memory of SAMP8 mice from the 6^th month. With ageing, increasing plasma concentrations of proinflammatory cytokines in SAMP8 mice were detected as well as significantly increased astrocytosis in the cortex and microgliosis in the brainstem. Moreover, from the 3^rd month, SAMP8 mice displayed a decreased number of neurons and neurogenesis in the hippocampus. From the 6^th month, increased pathological phosphorylation of tau protein at Thr231 and Ser214 was observed in the hippocampi of SAMP8 mice. In conclusion, changes specific for neurodegenerative processes were observed between the 3^rd and 6^th month of age in SAMP8 mice; thus, potential neuroprotective interventions could be applied between these ages.

Metabolomics profile in acute respiratory distress syndrome by nuclear magnetic resonance spectroscopy in patients with community-acquired pneumonia

Background

Acute respiratory distress syndrome (ARDS) is a challenging clinical problem. Discovering the potential metabolic alterations underlying the ARDS is important to identify novel therapeutic target and improve the prognosis. Serum and urine metabolites can reflect systemic and local changes and could help understanding metabolic characterization of community-acquired pneumonia (CAP) with ARDS.

Methods

Clinical data of patients with suspected CAP at the First Affiliated Hospital of Wenzhou Medical University were collected from May 2020 to February 2021. Consecutive patients with CAP were enrolled and divided into two groups: CAP with and without ARDS groups. ¹H nuclear magnetic resonance-based metabolomics analyses of serum and urine samples were performed before and after treatment in CAP with ARDS (n = 43) and CAP without ARDS (n = 45) groups. Differences metabolites were identifed in CAP with ARDS. Furthermore, the receiver operating characteristic (ROC) curve was utilized to identify panels of significant metabolites for evaluating therapeutic effects on CAP with ARDS. The correlation heatmap was analyzed to further display the relationship between metabolites and clinical characteristics.

Results

A total of 20 and 42 metabolites were identified in the serum and urine samples, respectively. Serum metabolic changes were mainly involved in energy, lipid, and amino acid metabolisms, while urine metabolic changes were mainly involved in energy metabolism. Elevated levels of serum 3-hydroxybutyrate, lactate, acetone, acetoacetate, and decreased levels of serum leucine, choline, and urine creatine and creatinine were detected in CAP with ARDS relative to CAP without ARDS. Serum metabolites 3-hydroxybutyrate, acetone, acetoacetate, citrate, choline and urine metabolite 1-methylnicotinamide were identified as a potential biomarkers for assessing therapeutic effects on CAP with ARDS, and with AUCs of 0.866 and 0.795, respectively. Moreover, the ROC curve analysis revealed that combined characteristic serum and urine metabolites exhibited a better classification system for assessing therapeutic effects on CAP with ARDS, with a AUC value of 0.952. In addition, differential metabolites strongly correlated with clinical parameters in patients with CAP with ARDS.

Conclusions

Serum- and urine-based metabolomics analyses identified characteristic metabolic alterations in CAP with ARDS and might provide promising circulatory markers for evaluating therapeutic effects on CAP with ARDS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02075-w.

A Distinct Metabolite Signature in Military Personnel Exposed to Repetitive Low-Level Blasts

Military Breachers and Range Staff (MBRS) are subjected to repeated sub-concussive blasts, and they often report symptoms that are consistent with a mild traumatic brain injury (mTBI). Biomarkers of blast injury would potentially aid blast injury diagnosis, surveillance and avoidance. Our objective was to identify plasma metabolite biomarkers in military personnel that were exposed to repeated low-level or sub-concussive blast overpressure. A total of 37 military members were enrolled (18 MBRS and 19 controls), with MBRS having participated in 8–20 breaching courses per year, with a maximum exposure of 6 blasts per day. The two cohorts were similar except that the number of blast exposures were significantly higher in the MBRS, and the MBRS cohort suffered significantly more post-concussive symptoms and poorer health on assessment. Metabolomics profiling demonstrated significant differences between groups with 74% MBRS classification accuracy (CA). Feature reduction identified 6 metabolites that resulted in a MBRS CA of 98%, and included acetic acid (23.7%), formate (22.6%), creatine (14.8%), acetone (14.2%), methanol (12,7%), and glutamic acid (12.0%). All 6 metabolites were examined with individual receiver operating characteristic (ROC) curve analyses and demonstrated areas-under-the-curve (AUCs) of 0.82–0.91 (P ≤ 0.001) for MBRS status. Several parsimonious combinations of three metabolites increased accuracy of ROC curve analyses to AUCs of 1.00 (P < 0.001), while a combination of volatile organic compounds (VOCs; acetic acid, acetone and methanol) yielded an AUC of 0.98 (P < 0.001). Candidate biomarkers for chronic blast exposure were identified, and if validated in a larger cohort, may aid surveillance and care of military personnel. Future point-of-care screening could be developed that measures VOCs from breath, with definitive diagnoses confirmed with plasma metabolomics profiling.

Exercise and Creatine Supplementation to Augment the Adaptation of Exercise Training Among Breast Cancer Survivors Completing Chemotherapy: Protocol for an Open-label Randomized Controlled Trial (the THRIVE Study)

BACKGROUND

In breast cancer survivors, chemotherapy-induced muscle loss has been shown to be attenuated with structured resistance exercise. Creatine supplementation can increase bioenergetics in skeletal muscle, which helps to improve overall strength and endurance and reduce muscular fatigue. Therefore, we hypothesize that adding creatinine supplementation to exercise training will accelerate improvements in strength, endurance, and bioenergetics in breast cancer survivors.

OBJECTIVE

The primary objective is to determine the effects of combining creatine supplementation with exercise on modulating strength and physical function in breast cancer survivors by comparing these effects to those of exercise alone. The secondary objectives are to determine if creatine supplementation and exercise can increase the intramuscular storage of creatine and improve body composition by comparing this intervention to exercise alone.

METHODS

We aim to test our hypothesis by conducting an open-label randomized controlled trial of 30 breast cancer survivors who have completed chemotherapy within 6 months of enrollment. Eligible participants will be equally randomized (1:1) to either a creatine and exercise group or an exercise-only group for this 12-week intervention. Individuals who are randomized to receive creatine will be initially dosed at 20 g per day for 7 days to boost the availability of creatine systemically. Thereafter, the dose will be reduced to 5 g per day for maintenance throughout the duration of the 12-week protocol. All participants will engage in 3 center-based exercise sessions, which will involve completing 3 sets of 8 to 12 repetitions on chest press, leg press, seated row, shoulder press, leg extension, and leg curl machines. The primary outcomes will include changes in strength, body composition, and physical function in breast cancer survivors. The secondary outcomes will be intramuscular concentrations of creatine and adenosine triphosphate in the vastus lateralis, midthigh cross-sectional area, and quality of life.

RESULTS

As of October 2021, a total of 9 patients have been enrolled into the study. No unexpected adverse events have been reported.

CONCLUSIONS

Creatine is being studied as a potential agent for improving strength, endurance, and bioenergetics in breast cancer survivors following chemotherapy. The findings from our trial may have future implications for supporting breast cancer survivors in reversing the muscle loss experienced during chemotherapy and improving their physical function and quality of life.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04207359; https://clinicaltrials.gov/ct2/show/NCT04207359.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/26827.

Effects of Creatine Supplementation on Brain Function and Health

While the vast majority of research involving creatine supplementation has focused on skeletal muscle, there is a small body of accumulating research that has focused on creatine and the brain. Preliminary studies indicate that creatine supplementation (and guanidinoacetic acid; GAA) has the ability to increase brain creatine content in humans. Furthermore, creatine has shown some promise for attenuating symptoms of concussion, mild traumatic brain injury and depression but its effect on neurodegenerative diseases appears to be lacking. The purpose of this narrative review is to summarize the current body of research pertaining to creatine supplementation on total creatine and phophorylcreatine (PCr) content, explore GAA as an alternative or adjunct to creatine supplementation on brain creatine uptake, assess the impact of creatine on cognition with a focus on sleep deprivation, discuss the effects of creatine supplementation on a variety of neurological and mental health conditions, and outline recent advances on creatine supplementation as a neuroprotective supplement following traumatic brain injury or concussion.

Role of Creatine Supplementation in Conditions Involving Mitochondrial Dysfunction: A Narrative Review

Creatine monohydrate (CrM) is one of the most widely used nutritional supplements among active individuals and athletes to improve high-intensity exercise performance and training adaptations. However, research suggests that CrM supplementation may also serve as a therapeutic tool in the management of some chronic and traumatic diseases. Creatine supplementation has been reported to improve high-energy phosphate availability as well as have antioxidative, neuroprotective, anti-lactatic, and calcium-homoeostatic effects. These characteristics may have a direct impact on mitochondrion's survival and health particularly during stressful conditions such as ischemia and injury. This narrative review discusses current scientific evidence for use or supplemental CrM as a therapeutic agent during conditions associated with mitochondrial dysfunction. Based on this analysis, it appears that CrM supplementation may have a role in improving cellular bioenergetics in several mitochondrial dysfunction-related diseases, ischemic conditions, and injury pathology and thereby could provide therapeutic benefit in the management of these conditions. However, larger clinical trials are needed to explore these potential therapeutic applications before definitive conclusions can be drawn.

Creatine Supplementation in Type 2 Diabetic Patients: A Systematic Review of Randomized Clinical Trials

Type 2 Diabetes Mellitus (DM) is the most common form of diabetes. The initial treatment of type 2 DM consists of the adoption of healthy lifestyle habits together with several classes of hypoglycemic agents. However, these medications are not always able to reduce the blood glucose levels in all patients. Therefore, creatine supplementation has emerged as a new putative candidate for type 2 DM treatment. This systematic review aimed to investigate the effects (benefits and harms) of creatine supplementation in patients with type 2 diabetes through a systematic review. The studies were searched in MEDLINE, EMBASE, LILACS, CENTRAL, SPORTDiscus, and CINAHL databases, without date or language restrictions. Methodological quality was assessed using the Cochrane risk-of-bias table. The certainty of the evidence was classified using the Grading of Recommendations Assessment, Development and Evaluation approach. Three randomized controlled trials (RCTs) were included (87 participants). Overall, the methodological quality was classified as unclear to a high risk of bias. Each trial compared creatine supplementation with a different control group (placebo, metformin, and glibenclamide). Creatine supplementation seems to be effective in decreasing glycemic levels and glycosylated hemoglobin concentrations compared to placebo. No difference was observed compared to metformin or glibenclamide with creatine, and all treatments were able to reduce blood glucose levels. No major adverse effects were observed. Based on the low certainty of evidence, creatine supplementation was shown to be a hypoglycemic intervention for patients with type 2 diabetes, without major adverse events reported. However, well- designed RCTs with larger sample sizes and long-term outcomes are needed to support this evidence.

The Application of Creatine Supplementation in Medical Rehabilitation

Numerous health conditions affecting the musculoskeletal, cardiopulmonary, and nervous systems can result in physical dysfunction, impaired performance, muscle weakness, and disuse-induced atrophy. Due to its well-documented anabolic potential, creatine monohydrate has been investigated as a supplemental agent to mitigate the loss of muscle mass and function in a variety of acute and chronic conditions. A review of the literature was conducted to assess the current state of knowledge regarding the effects of creatine supplementation on rehabilitation from immobilization and injury, neurodegenerative diseases, cardiopulmonary disease, and other muscular disorders. Several of the findings are encouraging, showcasing creatine's potential efficacy as a supplemental agent via preservation of muscle mass, strength, and physical function; however, the results are not consistent. For multiple diseases, only a few creatine studies with small sample sizes have been published, making it difficult to draw definitive conclusions. Rationale for discordant findings is further complicated by differences in disease pathologies, intervention protocols, creatine dosing and duration, and patient population. While creatine supplementation demonstrates promise as a therapeutic aid, more research is needed to fill gaps in knowledge within medical rehabilitation.

Elucidating the Multi-Targeted Role of Nutraceuticals: A Complementary Therapy to Starve Neurodegenerative Diseases

The mechanisms underlying multifactorial diseases are always complex and challenging. Neurodegenerative disorders (NDs) are common around the globe, posing a critical healthcare issue and financial burden to the country. However, integrative evidence implies some common shared mechanisms and pathways in NDs, which include mitochondrial dysfunction, neuroinflammation, oxidative stress, intracellular calcium overload, protein aggregates, oxidative stress (OS), and neuronal destruction in specific regions of the brain, owing to multifaceted pathologies. The co-existence of these multiple pathways often limits the advantages of available therapies. The nutraceutical-based approach has opened the doors to target these common multifaceted pathways in a slow and more physiological manner to starve the NDs. Peer-reviewed articles were searched via MEDLINE and PubMed published to date for in-depth research and database collection. Considered to be complementary therapy with current clinical management and common drug therapy, the intake of nutraceuticals is considered safe to target multiple mechanisms of action in NDs. The current review summarizes the popular nutraceuticals showing different effects (anti-inflammatory, antioxidant, neuro-protectant, mitochondrial homeostasis, neurogenesis promotion, and autophagy regulation) on vital molecular mechanisms involved in NDs, which can be considered as complementary therapy to first-line treatment. Moreover, owing to its natural source, lower toxicity, therapeutic interventions, biocompatibility, potential nutritional effects, and presence of various anti-oxidative and neuroprotective constituents, the nutraceuticals serve as an attractive option to tackle NDs.

The Potential Role of Creatine in Vascular Health

Creatine is an organic compound, consumed exogenously in the diet and synthesized endogenously via an intricate inter-organ process. Functioning in conjunction with creatine kinase, creatine has long been known for its pivotal role in cellular energy provision and energy shuttling. In addition to the abundance of evidence supporting the ergogenic benefits of creatine supplementation, recent evidence suggests a far broader application for creatine within various myopathies, neurodegenerative diseases, and other pathologies. Furthermore, creatine has been found to exhibit non-energy related properties, contributing as a possible direct and in-direct antioxidant and eliciting anti-inflammatory effects. In spite of the new clinical success of supplemental creatine, there is little scientific insight into the potential effects of creatine on cardiovascular disease (CVD), the leading cause of mortality. Taking into consideration the non-energy related actions of creatine, highlighted in this review, it can be speculated that creatine supplementation may serve as an adjuvant therapy for the management of vascular health in at-risk populations. This review, therefore, not only aims to summarize the current literature surrounding creatine and vascular health, but to also shed light onto the potential mechanisms in which creatine may be able to serve as a beneficial supplement capable of imparting vascular-protective properties and promoting vascular health.

Creatine Supplementation and Brain Health

There is a robust and compelling body of evidence supporting the ergogenic and therapeutic role of creatine supplementation in muscle. Beyond these well-described effects and mechanisms, there is literature to suggest that creatine may also be beneficial to brain health (e.g., cognitive processing, brain function, and recovery from trauma). This is a growing field of research, and the purpose of this short review is to provide an update on the effects of creatine supplementation on brain health in humans. There is a potential for creatine supplementation to improve cognitive processing, especially in conditions characterized by brain creatine deficits, which could be induced by acute stressors (e.g., exercise, sleep deprivation) or chronic, pathologic conditions (e.g., creatine synthesis enzyme deficiencies, mild traumatic brain injury, aging, Alzheimer’s disease, depression). Despite this, the optimal creatine protocol able to increase brain creatine levels is still to be determined. Similarly, supplementation studies concomitantly assessing brain creatine and cognitive function are needed. Collectively, data available are promising and future research in the area is warranted.

Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show?

Supplementing with creatine is very popular amongst athletes and exercising individuals for improving muscle mass, performance and recovery. Accumulating evidence also suggests that creatine supplementation produces a variety of beneficial effects in older and patient populations. Furthermore, evidence-based research shows that creatine supplementation is relatively well tolerated, especially at recommended dosages (i.e. 3-5 g/day or 0.1 g/kg of body mass/day). Although there are over 500 peer-refereed publications involving creatine supplementation, it is somewhat surprising that questions regarding the efficacy and safety of creatine still remain. These include, but are not limited to: 1. Does creatine lead to water retention? 2. Is creatine an anabolic steroid? 3. Does creatine cause kidney damage/renal dysfunction? 4. Does creatine cause hair loss / baldness? 5. Does creatine lead to dehydration and muscle cramping? 6. Is creatine harmful for children and adolescents? 7. Does creatine increase fat mass? 8. Is a creatine 'loading-phase' required? 9. Is creatine beneficial for older adults? 10. Is creatine only useful for resistance / power type activities? 11. Is creatine only effective for males? 12. Are other forms of creatine similar or superior to monohydrate and is creatine stable in solutions/beverages? To answer these questions, an internationally renowned team of research experts was formed to perform an evidence-based scientific evaluation of the literature regarding creatine supplementation.

Creatine in Health and Disease

Although creatine has been mostly studied as an ergogenic aid for exercise, training, and sport, several health and potential therapeutic benefits have been reported. This is because creatine plays a critical role in cellular metabolism, particularly during metabolically stressed states, and limitations in the ability to transport and/or store creatine can impair metabolism. Moreover, increasing availability of creatine in tissue may enhance cellular metabolism and thereby lessen the severity of injury and/or disease conditions, particularly when oxygen availability is compromised. This systematic review assesses the peer-reviewed scientific and medical evidence related to creatine's role in promoting general health as we age and how creatine supplementation has been used as a nutritional strategy to help individuals recover from injury and/or manage chronic disease. Additionally, it provides reasonable conclusions about the role of creatine on health and disease based on current scientific evidence. Based on this analysis, it can be concluded that creatine supplementation has several health and therapeutic benefits throughout the lifespan.

MRS suggests multi-regional inflammation and white matter axonal damage at 11 years following perinatal HIV infection

The neurological changes in children living with perinatal HIV (PHIV) on antiretroviral therapy (ART) can be studied at a metabolic level through proton magnetic resonance spectroscopy. While previous studies in children have largely focused on individual metabolite changes, investigating patterns within and across regions of interest can aid in identifying metabolic markers of HIV infection. In this study 76 children with PHIV from the Children with HIV Early AntiRetroviral (CHER) trial, 30 children who were HIV-exposed-uninfected (HEU) and 30 children who were HIV-unexposed (HU), were scanned at the age of 11.6 (sd = 0.3) years using a 3 T Skyra scanner. Metabolite concentrations were quantified within the basal ganglia (BG), midfrontal gray matter (MFGM) and peritrigonal white matter (PWM), comparing levels between HIV status groups using linear regression. Factor analysis and logistic regression were performed to identify metabolic patterns characteristic of HIV infection within and across the regions of interest. In the BG region we observed restored metabolic activity in children with PHIV and children who were HEU, despite differences being previously observed at younger ages, suggesting that treatment may effectively reduce the effects of HIV infection and exposure. Elevated MFGM choline levels in children with PHIV are indicative of inflammation. Further, we observed reduced N-acetyl-aspartate (NAA) in the PWM of children with PHIV and children who were HEU, indicating possible axonal damage. Lower levels of PWM creatine in children with PHIV suggest that this may not be a valid reference metabolite in HIV studies. Finally, factor scores for a cross-regional inflammatory factor and a PWM axonal factor, driven by PWM NAA and creatine levels, distinguished children with PHIV from children without HIV (HEU and HU) at 11 years. Therefore, the effects of perinatal HIV infection and exposure continue to be seen at 11 years despite early treatment.

The Evolving Applications of Creatine Supplementation: Could Creatine Improve Vascular Health?

Creatine is a naturally occurring compound, functioning in conjunction with creatine kinase to play a quintessential role in both cellular energy provision and intracellular energy shuttling. An extensive body of literature solidifies the plethora of ergogenic benefits gained following dietary creatine supplementation; however, recent findings have further indicated a potential therapeutic role for creatine in several pathologies such as myopathies, neurodegenerative disorders, metabolic disturbances, chronic kidney disease and inflammatory diseases. Furthermore, creatine has been found to exhibit non-energy-related properties, such as serving as a potential antioxidant and anti-inflammatory. Despite the therapeutic success of creatine supplementation in varying clinical populations, there is scarce information regarding the potential application of creatine for combatting the current leading cause of mortality, cardiovascular disease (CVD). Taking into consideration the broad ergogenic and non-energy-related actions of creatine, we hypothesize that creatine supplementation may be a potential therapeutic strategy for improving vascular health in at-risk populations such as older adults or those with CVD. With an extensive literature search, we have found only four clinical studies that have investigated the direct effect of creatine on vascular health and function. In this review, we aim to give a short background on the pleiotropic applications of creatine, and to then summarize the current literature surrounding creatine and vascular health. Furthermore, we discuss the varying mechanisms by which creatine could benefit vascular health and function, such as the impact of creatine supplementation upon inflammation and oxidative stress.

Creatine supplementation does not promote tumor growth or enhance tumor aggressiveness in Walker-256 tumor-bearing rats

OBJECTIVES

This study aimed to analyze the effect of creatine (Cr) supplementation on tumor microenvironment, evaluating the parameters of tumor aggressiveness.

METHODS

Sixteen male Wistar rats were randomly assigned to 2 groups (n = 8/group): Tumor-bearing (T) and tumor-bearing supplemented with Cr (TCr). Cr supplementation was provided in drinking water for a total of 21 d. After 11 d of Cr supplementation (TCr group) or water (T group), Walker-256 tumor cells were inoculated subcutaneously in the right flank of all rats, which kept receiving Cr supplementation (TCr group) or water (T group) for 10 more days. The total period of the experiment was 21 d.

RESULTS

Tumor weight corresponded with approximately 3.5% ± 0.9% of animal body weight in the T group. Cr supplementation did not accelerate tumor growth or increase tumor size. The histopathological analysis demonstrated the presence of nuclear pleomorphisms and atypical nuclei, with the presence of low-differentiated tumor cells, in both groups. Cr supplementation did not alter apoptosis and cell proliferation markers, nor tumor capsule thickness and viable tumor area.

CONCLUSIONS

Cr supplementation in Walker-256 tumor-bearing rats did not induce significant changes in tumor development, and did not interfere with the parameters of tumor aggressiveness, such as the level of cell differentiation and proliferation.

Enhanced mitochondrial biogenesis is associated with the ameliorative action of creatine supplementation in rat soleus and cardiac muscles

The current study focused on the effect of creatine supplementation with/without exercise on the expression of genes controlling mitochondrial biogenesis in skeletal and cardiac muscles, as well as its safety profile on the liver and kidney. A total of 40 male Wister rats were included in the present study. Two unexercised groups: The control sedentary group and the sedentary creatine-treated group (n=10) were treated daily with oral creatine (0.5 g/kg per day). Two exercised groups performed swimming exercise training 5 days/week for a period of 5 weeks; The Exercise training group, and exercise training and creatine (0.5 g/kg per day) treated group. After sacrifice, blood samples, cardiac and soleus muscles were collected for assessment of mtDNA copy number, gene expression analysis and nuclear extraction for the assay of PGC-1α. The results of the current study demonstrated that, physical activity with short-term creatine supplementation increased all factors of mitochondrial biogenesis, an effect that is devoid of any kidney or liver adverse effects. Further studies are still required to explore the potential of creatine supplementation in ameliorating mitochondrial diseases, including epilepsy, skeletal and cardiac myopathies, hepatopathies and nephropathies.

Muscular Atrophy and Sarcopenia in the Elderly: Is There a Role for Creatine Supplementation?

Sarcopenia is characterized by a loss of muscle mass, quality, and function, and negatively impacts health, functionality, and quality of life for numerous populations, particularly older adults. Creatine is an endogenously produced metabolite, which has the theoretical potential to counteract many of the morphological and metabolic parameters underpinning sarcopenia. This can occur through a range of direct and indirect mechanisms, including temporal and spatial functions that accelerate ATP regeneration during times of high energy demand, direct anabolic and anti-catabolic functions, and enhanced muscle regenerating capacity through positively impacting muscle stem cell availability. Studies conducted in older adults show little benefit of creatine supplementation alone on muscle function or mass. In contrast, creatine supplementation as an adjunct to exercise training seems to augment the muscle adaptive response to the training stimulus, potentially through increasing capacity for higher intensity exercise, and/or by enhancing post-exercise recovery and adaptation. As such, creatine may be an effective dietary strategy to combat age-related muscle atrophy and sarcopenia when used to complement the benefits of exercise training.

Examining the effects of creatine supplementation in augmenting adaptations to resistance training in patients with prostate cancer undergoing androgen deprivation therapy: a randomised, double-blind, placebo-controlled trial

INTRODUCTION

Creatine supplementation has consistently been demonstrated to augment adaptations in body composition, muscle strength and physical function in a variety of apparently healthy older adults and clinical populations. The effects of creatine supplementation and resistance training in individuals with cancer have yet to be investigated. This study aims to examine the effects of creatine supplementation in conjunction with resistance training on body composition, muscle strength and physical function in prostate cancer patients undergoing androgen deprivation therapy.

METHODS AND ANALYSIS

This is a randomised, double-blind, placebo-controlled trial designed to examine the effects of creatine supplementation in addition to resistance training in patients with prostate cancer receiving androgen deprivation therapy. Both supplement and placebo groups will receive a 12-week supervised exercise programme comprising resistance training undertaken three times per week. The primary endpoint (fat-free mass) and secondary endpoints (fat mass, per cent body fat, physical fitness, quality of life and blood biomarkers) will be assessed at baseline and immediately following the intervention.

ETHICS AND DISSEMINATION

The Human Research Ethics Committee of Edith Cowan University approved this study (ID: 22243 FAIRMAN). If the results of this trial demonstrate that creatine supplementation can augment beneficial adaptations of body composition, physical function and/or psychosocial outcomes to resistance training, this study will provide effect sizes that will inform the design of subsequent definitive randomised controlled trials. The results of this study will be published in peer-reviewed journals and presented at various national and international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12619000099123.

Effects of Creatine Supplementation on Muscle Fatigue in Rats Receiving Doxorubicin Treatment

The purpose of this study was to investigate the effects of in vivo creatine monohydrate (Cr) supplementation on doxorubicin (Dox)-induced muscle dysfunction. Male rats were fed a diet supplemented with 3% Cr or a standard chow for 2 wk. After 2 wk of feeding, animals received Dox or saline as a placebo. Five days post-injection, grip strength was measured, and muscle fatigue was analyzed ex vivo. When compared with controls, a significantly lower grip strength was observed with Dox treatment, but no significant handgrip difference was observed with Cr feeding prior to Dox treatment when compared to controls. In the isolated muscle fatigue experiments, solei (primarily type I muscle) from controls produced significantly less force than baseline at 60 s and solei from Dox treated rats produced significantly less force than baseline at 30 s; however, Cr feeding prior to Dox produced significantly less force than baseline at 60 s. In the primarily type II EDL, a decline in force production from baseline was observed at 50 s in controls and Cr + Dox and at 20 s in standard chow + Dox. Cr attenuated the increase in fatigue that accompanies Dox treatment suggesting that Cr supplementation may have use in managing Dox myotoxicity.

Creatine is a Conditionally Essential Nutrient in Chronic Kidney Disease: A Hypothesis and Narrative Literature Review

To accommodate the loss of the plethora of functions of the kidneys, patients with chronic kidney disease require many dietary adjustments, including restrictions on the intake of protein, phosphorus, sodium and potassium. Plant-based foods are increasingly recommended as these foods contain smaller amounts of saturated fatty acids, protein and absorbable phosphorus than meat, generate less acid and are rich in fibers, polyunsaturated fatty acids, magnesium and potassium. Unfortunately, these dietary recommendations cannot prevent the occurrence of many symptoms, which typically include fatigue, impaired cognition, myalgia, muscle weakness, and muscle wasting. One threat coming with the recommendation of low-protein diets in patients with non-dialysis-dependent chronic kidney disease (CKD) and with high-protein diets in patients with dialysis-dependent CKD, particularly with current recommendations towards proteins coming from plant-based sources, is that of creatine deficiency. Creatine is an essential contributor in cellular energy homeostasis, yet on a daily basis 1.6–1.7% of the total creatine pool is degraded. As the average omnivorous diet cannot fully compensate for these losses, the endogenous synthesis of creatine is required for continuous replenishment. Endogenous creatine synthesis involves two enzymatic steps, of which the first step is a metabolic function of the kidney facilitated by the enzyme arginine:glycine amidinotransferase (AGAT). Recent findings strongly suggest that the capacity of renal AGAT, and thus endogenous creatine production, progressively decreases with the increasing degree of CKD, to become absent or virtually absent in dialysis patients. We hypothesize that with increasing degree of CKD, creatine coming from meat and dairy in food increasingly becomes an essential nutrient. This phenomenon will likely be present in patients with CKD stages 3, 4 and 5, but will likely be most pronouncedly present in patients with dialysis-dependent CKD, because of the combination of lowest endogenous production of creatine and unopposed losses of creatine into the dialysate. It is likely that these increased demands for dietary creatine are not sufficiently met. The result of which, may be a creatine deficiency with important contributions to the sarcopenia, fatigue, impaired quality of life, impaired cognition, and premature mortality seen in CKD.

Creatine Supplementation Improves Phosphagen Energy Pathway During Supramaximal Effort, but Does Not Improve Anaerobic Capacity or Performance

This study aimed to investigate the effects of short-duration creatine monohydrate supplementation on anaerobic capacity (AC), anaerobic energy pathways, and time-to-exhaustion during high-intensity running. Fourteen healthy men underwent a graded exercise test (GXT) followed by a O_2max confirmation test, 5 submaximal efforts, and 4 supramaximal running bouts at 115% of V˙O_2max intensity (the first two supramaximal sessions were applied as familiarization trials) to measure the AC using two procedures; the maximum accumulated oxygen deficit (MAOD) and non-oxidative pathways energetics sum (AC_{[La-]+EPOCfast}). The investigation was conducted in a single-blind and placebo-controlled manner, with participants performing the efforts first after being supplemented with a placebo (dextrose 20 g⋅day^-1 for 5 days), and then, after a 7 day “placebo” washout period, they started the same procedure under creatine supplementation (20 g⋅day^-1 for 5 days. This order was chosen due to the prolonged washout of creatine. MAOD was not different between placebo (3.35 ± 0.65 L) and creatine conditions (3.39 ± 0.79 L; P = 0.58) and presented a negligible effect [effect size (ES) = 0.08], similar to, AC_{[La-]+EPOCfast} (placebo condition (3.66 ± 0.79 Land under creatine ingestion 3.82 ± 0.85 L; P = 0.07) presenting a small effect (ES = 0.20). The energetics from the phosphagen pathway increased significantly after creatine supplementation (1.66 ± 0.40 L) compared to the placebo condition (1.55 ± 0.42 L; P = 0.03). However, the glycolytic and oxidative pathways were not different between conditions. Furthermore, time to exhaustion did not differ between placebo (160.79 ± 37.76 s) and creatine conditions (163.64 ± 38.72; P = 0.49). Therefore, we can conclude that creatine supplementation improves the phosphagen energy contribution, but with no statistical effect on AC or time to exhaustion in supramaximal running.

Creatine supplementation in Walker-256 tumor-bearing rats prevents skeletal muscle atrophy by attenuating systemic inflammation and protein degradation signaling

PURPOSE

The aim of this study was to investigate the effects of creatine supplementation on muscle wasting in Walker-256 tumor-bearing rats.

METHODS

Wistar rats were randomly assigned into three groups (n = 10/group): control (C), tumor bearing (T), and tumor bearing supplemented with creatine (TCr). Creatine was provided in drinking water for a total of 21 days. After 11 days of supplementation, tumor cells were implanted subcutaneously into T and TCr groups. The animals' weight, food and water intake were evaluated along the experimental protocol. After 10 days of tumor implantation (21 total), animals were euthanized for inflammatory state and skeletal muscle cross-sectional area measurements. Skeletal muscle components of ubiquitin-proteasome pathways were also evaluated using real-time PCR and immunoblotting.

RESULTS

The results showed that creatine supplementation protected tumor-bearing rats against body weight loss and skeletal muscle atrophy. Creatine intake promoted lower levels of plasma TNF-α and IL-6 and smaller spleen morphology changes such as reduced size of white pulp and lymphoid follicle compared to tumor-bearing rats. In addition, creatine prevented increased levels of skeletal muscle Atrogin-1 and MuRF-1, key regulators of muscle atrophy.

CONCLUSION

Creatine supplementation prevents skeletal muscle atrophy by attenuating tumor-induced pro-inflammatory environment, a condition that minimizes Atrogin-1 and MuRF-1-dependent proteolysis.

Supplements with purported effects on muscle mass and strength

PURPOSE

Several supplements are purported to promote muscle hypertrophy and strength gains in healthy subjects, or to prevent muscle wasting in atrophying situations (e.g., ageing or disuse periods). However, their effectiveness remains unclear.

METHODS

This review summarizes the available evidence on the beneficial impacts of several popular supplements on muscle mass or strength.

RESULTS

Among the supplements tested, nitrate and caffeine returned sufficient evidence supporting their acute beneficial effects on muscle strength, whereas the long-term consumption of creatine, protein and polyunsaturated fatty acids seems to consistently increase or preserve muscle mass and strength (evidence level A). On the other hand, mixed or unclear evidence was found for several popular supplements including branched-chain amino acids, adenosine triphosphate, citrulline, β-Hydroxy-β-methylbutyrate, minerals, most vitamins, phosphatidic acid or arginine (evidence level B), weak or scarce evidence was found for conjugated linoleic acid, glutamine, resveratrol, tribulus terrestris or ursolic acid (evidence level C), and no evidence was found for other supplements such as ornithine or α-ketoglutarate (evidence D). Of note, although most supplements appear to be safe when consumed at typical doses, some adverse events have been reported for some of them (e.g., caffeine, vitamins, α-ketoglutarate, tribulus terrestris, arginine) after large intakes, and there is insufficient evidence to determine the safety of many frequently used supplements (e.g., ornithine, conjugated linoleic acid, ursolic acid).

CONCLUSION

 In summary, despite their popularity, there is little evidence supporting the use of most supplements, and some of them have been even proven ineffective or potentially associated with adverse effects.

The potential therapeutic effects of creatine supplementation on body composition and muscle function in cancer

Low muscle mass in individuals with cancer has a profound impact on quality of life and independence and is associated with greater treatment toxicity and poorer prognosis. Exercise interventions are regularly being investigated as a means to ameliorate treatment-related adverse effects, and nutritional/supplementation strategies to augment adaptations to exercise are highly valuable. Creatine (Cr) is a naturally-occurring substance in the human body that plays a critical role in energy provision during muscle contraction. Given the beneficial effects of Cr supplementation on lean body mass, strength, and physical function in a variety of clinical populations, there is therapeutic potential in individuals with cancer at heightened risk for muscle loss. Here, we provide an overview of Cr physiology, summarize the evidence on the use of Cr supplementation in various aging/clinical populations, explore mechanisms of action, and provide perspectives on the potential therapeutic role of Cr in the exercise oncology setting.

Beyond muscle: the effects of creatine supplementation on brain creatine, cognitive processing, and traumatic brain injury

The ergogenic and therapeutic effects of increasing muscle creatine by supplementation are well-recognized. It appears that similar benefits to brain function and cognitive processing may also be achieved with creatine supplementation, however research in this area is more limited, and important knowledge gaps remain. The purpose of this review is to provide a comprehensive overview of the current state of knowledge about the influence of creatine supplementation on brain function in healthy individuals. It appears that brain creatine is responsive to supplementation, however higher, or more prolonged dosing strategies than those typically used to increase muscle creatine, may be required to elicit an increase in brain creatine. The optimal dosing strategy to induce this response, is currently unknown, and there is an urgent need for studies investigating this. When considering the influence of supplementation strategies on cognitive processes, it appears that creatine is most likely to exert an influence in situations whereby cognitive processes are stressed, e.g. during sleep deprivation, experimental hypoxia, or during the performance of more complex, and thus more cognitively demanding tasks. Evidence exists indicating that increased brain creatine may be effective at reducing the severity of, or enhancing recovery from mild traumatic brain injury, however, only limited data in humans are available to verify this hypothesis, thus representing an exciting area for further research.

Pharmacological targeting of exercise adaptations in skeletal muscle: Benefits and pitfalls

Exercise exerts significant effects on the prevention and treatment of many diseases. However, even though some of the key regulators of training adaptation in skeletal muscle have been identified, this biological program is still poorly understood. Accordingly, exercise-based pharmacological interventions for many muscle wasting diseases and also for pathologies that are triggered by a sedentary lifestyle remain scarce. The most efficacious compounds that induce muscle hypertrophy or endurance are hampered by severe side effects and are classified as doping. In contrast, dietary supplements with a higher safety margin exert milder outcomes. In recent years, the design of pharmacological agents that activate the training program, so-called "exercise mimetics", has been proposed, although the feasibility of such an approach is highly debated. In this review, the most recent insights into key regulatory factors and therapeutic approaches aimed at leveraging exercise adaptations are discussed.

Oral creatine supplementation attenuates muscle loss caused by limb immobilization: a systematic review

Abstract Introduction: Recent studies have pointing creatine supplementation as a promising therapeutic alterna- tive in several diseases, especially myopathies and neurodegenerative disorder. Objective: elucidate the role of creatine supplementation on deleterious effect caused by limb immobilization in humans and rats. Methods: Analyzed articles were searched by three online databases, PubMed, SportDicus e Scielo. After a review and analysis, the studies were included in this review articles on effect of creatine supplementation on skeletal muscle in humans and rat, before, during and after a period of limb immobilization. Results: Studies analyzed demonstrated positive points in use of creatine supplementation as a therapeutic tool to mitigating the deleterious effects of limb immobilization, in humans and rat. Conclusion: The dataset of this literature review allows us to conclude that creatine supplementation may reduce muscle loss and/or assist in the recovery of muscle atrophy caused by immobilization and disuse in rats and humans. Also, we note that further research with better methodological rigor is needed to clarify the mechanisms by which creatine support the recovery of muscle atrophy. Moreover, these effects are positive and promising in the field of muscle rehabilitation, especially after member’s immobilization.

NMR-based metabolomic analysis for the effects of creatine supplementation on mouse myoblast cell line C2C12

Creatine (Cr) supplementation has drawn much attention from researchers owing to its widespread efficacy in sports, and more recently, in therapeutic fields. However, the underlying molecular mechanisms remain elusive. Here, we performed nuclear magnetic resonance-based metabolomic analysis to address the metabolic profile of aqueous extracts from the mouse myoblast cell line C2C12 exposed to 2 mM Cr for 24 h (the Cr-treated group). Results showed that Cr supplementation facilitated the proliferation of C2C12 myoblasts. Both pattern recognition and hierarchical cluster analyses demonstrated that the metabolic profiles of the Cr-treated and control groups were distinctly different. We identified 13 characteristic metabolites significantly responsible for the discrimination of metabolic profiles between the two groups, through orthogonal projection to latent structures discriminant analysis and independent samples t-test. We further verified the discrimination performances of these metabolites by conducting univariate receiver operating characteristic curve analysis. Compared with the control group, the Cr-treated group exhibited increased levels of Cr, phosphocreatine (PCr), glutathione (GSH), and glucose, but decreased levels of leucine, valine, isoleucine, phenylalanine, methionine, choline, O-phosphocholine, sn-glycero-3-phosphocholine, and glycerol. Our results demonstrated that Cr supplementation upregulated PCr and glucose, promoted trichloroacetic acid cycle anaplerotic flux and GSH-mediated antioxidant capacity, and stabilized lipid membranes through suppressing glycerophospholipid metabolism. Our work provides new clues to the molecular mechanisms underlying the pleiotropic effects of Cr in muscle cells.

Effect of age, diet, and tissue type on PCr response to creatine supplementation

Creatine/phosphorylcreatine (PCr) responses to creatine supplementation may be modulated by age, diet, and tissue, but studies assessing this possibility are lacking. Therefore we aimed to determine whether PCr responses vary as a function of age, diet, and tissue. Fifteen children, 17 omnivorous and 14 vegetarian adults, and 18 elderly individuals ("elderly") participated in this study. Participants were given placebo and subsequently creatine (0.3 g·kg^-1·day^-1) for 7 days in a single-blind fashion. PCr was measured through phosphorus magnetic resonance spectroscopy (³¹P-MRS) in muscle and brain. Creatine supplementation increased muscle PCr in children (P < 0.0003) and elderly (P < 0.001), whereas the increase in omnivores did not reach statistically significant difference (P = 0.3348). Elderly had greater PCr increases than children and omnivores (P < 0.0001 for both), whereas children experienced greater PCr increases than omnivores (P = 0.0022). In relation to diet, vegetarians (P < 0.0001), but not omnivores, had significant increases in muscle PCr content. Brain PCr content was not affected by creatine supplementation in any group, and delta changes in brain PCr (-0.7 to +3.9%) were inferior to those in muscle PCr content (+10.3 to +27.6%; P < 0.0001 for all comparisons). PCr responses to a standardized creatine protocol (0.3 g·kg^-1·day^-1 for 7 days) may be affected by age, diet, and tissue. Whereas creatine supplementation was able to increase muscle PCr in all groups, although to different extents, brain PCr was shown to be unresponsive overall. These findings demonstrate the need to tailor creatine protocols to optimize creatine/PCr accumulation both in muscle and in brain, enabling a better appreciation of the pleiotropic properties of creatine.NEW & NOTEWORTHY A standardized creatine supplementation protocol (0.3 g·kg^-1·day^-1 for 7 days) effectively increased muscle, but not brain, phosphorylcreatine. Older participants responded better than younger participants whereas vegetarians responded better than omnivores. Responses to supplementation are thus dependent on age, tissue, and diet. This suggests that a single "universal" protocol, originally designed for increasing muscle creatine in young individuals, may lead to heterogeneous muscle responses in different populations or even no responses in tissues other than skeletal muscle.

Renal dysfunction in early adulthood following birth asphyxia in male spiny mice, and its amelioration by maternal creatine supplementation during pregnancy

BACKGROUND

Acute kidney injury affects ~70% of asphyxiated newborns, and increases their risk of developing chronic kidney disease later in life. Acute kidney injury is driven by renal oxygen deprivation during asphyxia, thus we hypothesized that creatine administered antenatally would protect the kidney from the long-term effects of birth asphyxia.

METHODS

Pregnant spiny mice were fed standard chow or chow supplemented with 5% creatine from 20-d gestation (midgestation). One day prior to term (37-d gestation), pups were delivered by caesarean or subjected to intrauterine asphyxia. Litters were allocated to one of two time-points. Kidneys were collected at 1 mo of age to estimate nephron number (stereology). Renal function (excretory profile and glomerular filtration rate) was measured at 3 mo of age, and kidneys then collected for assessment of glomerulosclerosis.

RESULTS

Compared with controls, at 1 mo of age male (but not female) birth-asphyxia offspring had 20% fewer nephrons (P < 0.05). At 3 mo of age male birth-asphyxia offspring had 31% lower glomerular filtration rate (P < 0.05) and greater glomerular collagen IV content (P < 0.01). Antenatal creatine prevented these renal injuries arising from birth asphyxia.

CONCLUSION

Maternal creatine supplementation during pregnancy may be an effective prophylactic to prevent birth asphyxia induced acute kidney injury and the emergence of chronic kidney disease.

Potential for use of creatine supplementation following mild traumatic brain injury

There is significant overlap between the neuropathology of mild traumatic brain injury (mTBI) and the cellular role of creatine, as well as evidence of neural creatine alterations after mTBI. Creatine supplementation has not been researched in mTBI, but shows some potential as a neuroprotective when administered prior to or after TBI. Consistent with creatine’s cellular role, supplementation reduced neuronal damage, protected against the effects of cellular energy crisis and improved cognitive and somatic symptoms. A variety of factors influencing the efficacy of creatine supplementation are highlighted, as well as avenues for future research into the potential of supplementation as an intervention for mTBI. In particular, the slow neural uptake of creatine may mean that greater effects are achieved by pre-emptive supplementation in at-risk groups.

Impact of creatine supplementation in combination with resistance training on lean mass in the elderly

BACKGROUND

Human ageing is a process characterized by loss of muscle mass, strength, and bone mass. We aimed to examine the efficacy of low-dose creatine supplementation associated with resistance training on lean mass, strength, and bone mass in the elderly.

METHODS

This was a 12-week, parallel-group, double-blind, randomized, placebo-controlled trial. The individuals were randomly allocated into one of the following groups: placebo plus resistance training (PL + RT) and creatine supplementation plus resistance training (CR + RT) . The participants were assessed at baseline and after 12 weeks. The primary outcomes were lean mass and strength, assessed by dual energy X-ray absorptiometry (DXA) and ten-repetition maximal tests (10 RM), respectively. Secondary outcomes included the lumbar spine, right and left femoral neck, both femur and whole body bone mineral density (BMD), and whole body bone mineral content (BMC), assessed by DXA.

RESULTS

The CR + RT group had superior gains in lean mass when compared with the PL + RT group (P = 0.02). Changes in the 10 RM tests in bench press and leg press exercises, body composition, BMD, and BMC of all assessed sites did not significantly differ between the groups (P > 0.05).

CONCLUSIONS

Twelve weeks of low-dose creatine supplementation associated with resistance training resulted in increases in lean mass in the elderly.

Creatine supplementation and glycemic control: a systematic review

The focus of this review is the effects of creatine supplementation with or without exercise on glucose metabolism. A comprehensive examination of the past 16 years of study within the field provided a distillation of key data. Both in animal and human studies, creatine supplementation together with exercise training demonstrated greater beneficial effects on glucose metabolism; creatine supplementation itself demonstrated positive results in only a few of the studies. In the animal studies, the effects of creatine supplementation on glucose metabolism were even more distinct, and caution is needed in extrapolating these data to different species, especially to humans. Regarding human studies, considering the samples characteristics, the findings cannot be extrapolated to patients who have poorer glycemic control, are older, are on a different pharmacological treatment (e.g., exogenous insulin therapy) or are physically inactive. Thus, creatine supplementation is a possible nutritional therapy adjuvant with hypoglycemic effects, particularly when used in conjunction with exercise.

Creatine supplementation in the aging population: effects on skeletal muscle, bone and brain

This narrative review aims to summarize the recent findings on the adjuvant application of creatine supplementation in the management of age-related deficits in skeletal muscle, bone and brain metabolism in older individuals. Most studies suggest that creatine supplementation can improve lean mass and muscle function in older populations. Importantly, creatine in conjunction with resistance training can result in greater adaptations in skeletal muscle than training alone. The beneficial effect of creatine upon lean mass and muscle function appears to be applicable to older individuals regardless of sex, fitness or health status, although studies with very old (>90 years old) and severely frail individuals remain scarce. Furthermore, there is evidence that creatine may affect the bone remodeling process; however, the effects of creatine on bone accretion are inconsistent. Additional human clinical trials are needed using larger sample sizes, longer durations of resistance training (>52 weeks), and further evaluation of bone mineral, bone geometry and microarchitecture properties. Finally, a number of studies suggest that creatine supplementation improves cognitive processing under resting and various stressed conditions. However, few data are available on older adults, and the findings are discordant. Future studies should focus on older adults and possibly frail elders or those who have already experienced an age-associated cognitive decline.

Creatine for women: a review of the relationship between creatine and the reproductive cycle and female-specific benefits of creatine therapy

The creatine/phosphocreatine/creatine kinase circuit is instrumental in regulating high-energy phosphate metabolism, and the maintenance of cellular energy turnover. The mechanisms by which creatine is able to buffer and regulate cellular energy balance, maintain acid-base balance, and reduce the effects of oxidative stress have led to a large number of studies into the use of creatine supplementation in exercise performance and to treat diseases associated with cellular energy depletion. Some of these studies have identified sex-specific responses to creatine supplementation, as such; there is the perception, that females might be less receptive to the benefits of creatine supplementation and therapy, compared to males. This review will describe the differences in male and female physique and physiology that may account for such differences, and discuss the apparent endocrine modulation of creatine metabolism in females. Hormone-driven changes to endogenous creatine synthesis, creatine transport and creatine kinase expression suggest that significant changes in this cellular energy circuit occur during specific stages of a female's reproductive life, including pregnancy and menopause. Recent studies suggest that creatine supplementation may be highly beneficial for women under certain conditions, such as depression. A greater understanding of these pathways, and the consequences of alterations to creatine bioavailability in females are needed to ensure that creatine is used to full advantage as a dietary supplement to optimize and enhance health outcomes for women.

Creatine supplementation decreases plasma lipid peroxidation markers and enhances anaerobic performance in rats

OBJECTIVE

The study was to investigate the effects of creatine (Cr) supplementation on oxidative stress markers and anaerobic performance in rats.

METHODS

Sixty-four rats (Wistar) were divided into two groups: C, anaerobic exercised group (n = 32) and Cr, anaerobic exercised group supplemented with creatine (n = 32). Cr supplementation consisted of the addition of 2% Cr monohydrate to the diet. After 28 days, the rats performed acute exercise (6 × 30 seconds of vertical jumps in the water with 30 seconds rest and 50% of total body weight load attached in the back). The animals were euthanized before (pre) and at 0, 2, and 6 hours (n = 8) after acute exercise.

RESULTS

Acute exercise induced an increase in plasma malondialdehyde (MDA) and advanced oxidation protein products (AOPP), as well as increased total lipid hydroperoxides and AOPP in gastrocnemius muscle. Cr supplementation inhibited the formation of MDA and lipid hydroperoxides in plasma. However, the antioxidant action of Cr was observed only against AOPP in gastrocnemius muscle. Cr supplementation also increased (P < 0.05) anaerobic performance compared to the C group.

CONCLUSION

Cr supplementation is able to inhibit the increase in plasma lipid peroxidation markers induced by high-intensity and short-duration exercise in rats; equivalent actions, however, were not observed fully in muscle tissue.

Creatine supplementation as a possible new therapeutic approach for fatty liver disease: early findings

Over the last few years, consistent data have demonstrated that creatine (Cr) supplementation prevents the accumulation of fat in rat liver as well as the progression of fatty liver disease in different situations. Studies have demonstrated that Cr is effective and prevents fatty liver in high-fat and choline-deficient diets and in hepatoma cells in vitro. Because Cr synthesis is responsible for a considerable consumption of hepatic methyl groups, studies have tested the idea that Cr supplementation could modulate phospholipid formation and VLDL secretion. Studies have also demonstrated Cr is able to modulate the expression of key genes related to fatty acid oxidation in hepatocyte cell culture and in rat liver. However, to date, the mechanism by which Cr exerts protective effects against fatty liver is poorly understood. Therefore, the present review aims to summarize the studies involving the therapeutic use of Cr supplementation on fatty liver disease and to explore the mechanisms involved in one-carbon and fatty acid metabolism for the preventive effects of Cr supplementation on fat liver accumulation. Although a small number of studies have been conducted to date, we consider Cr as a new and promising therapeutic strategy to control fat accumulation in the liver as well as the progression of fatty liver disease.

Effects of long-term low-dose dietary creatine supplementation in older women

OBJECTIVE

We aimed to investigate the effects of a one-year low-dose creatine supplementation trial on bone health, lean mass, and muscle function in older postmenopausal women.

METHODS

A double-blind, randomized, parallel-group, placebo controlled trial was conducted between November 2011 and November 2013 in Sao Paulo, Brazil. Postmenopausal osteopenic women were randomly allocated (1:1) into creatine (n=56; 1g/d) or placebo group (n=53; dextrose at same dose). At baseline and after one year of intervention, we assessed parameters of bone health, body composition, and muscle function. Blood parameters were also assessed before and after the intervention and adverse events were recorded throughout the trial. Possible differences in dietary intake were assessed by three 24-h dietary recalls.

RESULTS

Bone mineral density at lumbar spine, femoral neck, total femur, and whole body did not differ within- or between-groups. No significant changes in body weight, BMI, absolute and relative body fat, and body lean mass were observed. Muscle function, as assessed by timed-up-and-go and timed-stands tests, were not significantly changed within- or between-groups. Safety laboratory parameters remained unaltered.

CONCLUSION

A one-year low-dose creatine supplementation (1g/d) was free of adverse effects, but did not affect bone health parameters, lean mass, or muscle function in older women. Further studies with longer follow-up periods and higher doses of creatine supplementation are warranted. (Registered at clinicaltrials.gov as NCT01472393).