The effects of the recommended dose of creatine monohydrate on kidney function

Creatine supplementation enhances anti-tumor immunity by promoting adenosine triphosphate production in macrophages

Creatine is an indispensable organic compound utilized in physiological environments; however, its role in immunity is still poorly understood. Here, we show that creatine supplementation enhances anti-tumor immunity through the functional upregulation of macrophages by increasing adenosine triphosphate (ATP) production. Creatine supplementation significantly suppressed B16-F10-originated tumor growth in mice compared with the control treatment. Under these conditions, intratumor macrophages polarized towards the M1 phenotype rather than the M2 phenotype, and there was an increase in tumor antigen-specific CD8+ T cells in the mice. The cytokine production and antigen-presenting activity in the macrophages were enhanced by creatine supplementation, resulting in a substantial increase in tumor antigen-specific CD8+ T cells. ATP upregulation was achieved through the cytosolic phosphocreatine (PCr) system via extracellular creatine uptake, rather than through glycolysis and mitochondrial oxidative phosphorylation in the macrophages. Blockade of the creatine transporter (CrT) failed to upregulate ATP and enhance the immunological activity of macrophages in creatine supplementation, which also impaired CD8+ T cell activity. Consequently, CrT blockade failed to suppress tumor growth in the creatine-supplemented mice. Thus, creatine is an important nutrient that promotes macrophage function by increasing ATP levels, ultimately contributing to enhanced anti-tumor immunity orchestrated by CD8+ T cells.

Effect of creatine supplementation on kidney stones recurrence in an athlete: a case report

INTRODUCTION

Several studies examined the effects of creatine monohydrate supplementation on renal function, but no previous study has investigated its effects on kidney stones in humans.

OBSERVATION

A renal ultrasound in a healthy young athlete (without a known renal morphological anomaly, normal kidney function, normal phospholipid and uric acid data) revealed a kidney stone of 11 mm in the lower right calyx. Extracorporeal shock wave lithotripsy was applied in order to break the down stone. Twentyone days later, a follow-up renal ultrasound showed the absence of stones in the kidney. One week later, the athlete started creatine monohydrate supplementation for two months. Fourteen months after stopping creatine monohydrate supplementation, a third renal ultrasound confirmed the absence of stones in the kidney.

CONCLUSION

Two months of creatine monohydrate supplementation in an athlete with a history of kidney stones could not be associated with kidney stone recurrence in the long run.

Nutritional and Non-Nutritional Strategies in Bodybuilding: Impact on Kidney Function

Bodybuilders routinely engage in many dietary and other practices purported to be harmful to kidney health. The development of acute kidney injury, focal segmental glomerular sclerosis (FSGS) and nephrocalcinosis may be particular risks. There is little evidence that high-protein diets and moderate creatine supplementation pose risks to individuals with normal kidney function though long-term high protein intake in those with underlying impairment of kidney function is inadvisable. The links between anabolic androgenic steroid use and FSGS are stronger, and there are undoubted dangers of nephrocalcinosis in those taking high doses of vitamins A, D and E. Dehydrating practices, including diuretic misuse, and NSAID use also carry potential risks. It is difficult to predict the effects of multiple practices carried out in concert. Investigations into subclinical kidney damage associated with these practices have rarely been undertaken. Future research is warranted to identify the clinical and subclinical harm associated with individual practices and combinations to enable appropriate and timely advice.

Effects of Creatine Supplementation on Histopathological and Biochemical Parameters in the Kidney and Pancreas of Streptozotocin-Induced Diabetic Rats

Diabetes mellitus (DM) is a worldwide health concern, and projections state that cases will reach 578 million by 2030. Adjuvant therapies that can help the standard treatment and mitigate DM effects are necessary, especially those using nutritional supplements to improve glycemic control. Previous studies suggest creatine supplementation as a possible adjuvant therapy for DM, but they lack the evaluation of potential morphological parameters alterations and tissue injury caused by this compound. The present study aimed to elucidate clinical, histomorphometric, and histopathological consequences and the cellular oxidative alterations of creatine supplementation in streptozotocin (STZ)-induced type 1 DM rats. We could estimate whether the findings are due to DM or the supplementation from a factorial experimental design. Although creatine supplementation attenuated some biochemical parameters, the morphological analyses of pancreatic and renal tissues made clear that the supplementation did not improve the STZ-induced DM1 injuries. Moreover, creatine-supplemented non-diabetic animals were diagnosed with pancreatitis and showed renal tubular necrosis. Therefore, even in the absence of clinical symptoms and unaltered biochemical parameters, creatine supplementation as adjuvant therapy for DM should be carefully evaluated.

Dietary creatine and kidney function in adult population: NHANES 2017-2018

Consuming more creatine may be associated with an increased risk of renal dysfunction, yet this link remains poorly addressed at the population level. Using 2017-2018 NHANES data, the current study found that the odds ratio for having failing kidneys in 2,955 U.S adults consuming ≥2.0 g/day of dietary creatine compared to low-intake counterparts (<1.0 g/day) was 0.74 (95% CI from 0.39 to 1.38), indicating no significant association between dietary creatine intake and kidney dysfunction.

Safety issues and harmful pharmacological interactions of nutritional supplements in Duchenne muscular dystrophy: considerations for Standard of Care and emerging virus outbreaks

At the moment, little treatment options are available for Duchenne muscular dystrophy (DMD). The absence of the dystrophin protein leads to a complex cascade of pathogenic events in myofibres, including chronic inflammation and oxidative stress as well as altered metabolism. The attention towards dietary supplements in DMD is rapidly increasing, with the aim to counteract pathology-related alteration in nutrient intake, the consequences of catabolic distress or to enhance the immunological response of patients as nowadays for the COVID-19 pandemic emergency. By definition, supplements do not exert therapeutic actions, although a great confusion may arise in daily life by the improper distinction between supplements and therapeutic compounds. For most supplements, little research has been done and little evidence is available concerning their effects in DMD as well as their preventing actions against infections. Often these are not prescribed by clinicians and patients/caregivers do not discuss the use with their clinical team. Then, little is known about the real extent of supplement use in DMD patients. It is mistakenly assumed that, since compounds are of natural origin, if a supplement is not effective, it will also do no harm. However, supplements can have serious side effects and also have harmful interactions, in terms of reducing efficacy or leading to toxicity, with other therapies. It is therefore pivotal to shed light on this unclear scenario for the sake of patients. This review discusses the supplements mostly used by DMD patients, focusing on their potential toxicity, due to a variety of mechanisms including pharmacodynamic or pharmacokinetic interactions and contaminations, as well as on reports of adverse events. This overview underlines the need for caution in uncontrolled use of dietary supplements in fragile populations such as DMD patients. A culture of appropriate use has to be implemented between clinicians and patients' groups.

Risk of Adverse Outcomes in Females Taking Oral Creatine Monohydrate: A Systematic Review and Meta-Analysis

Creatine Monohydrate (CrM) is a dietary supplement routinely used as an ergogenic aid for sport and training, and as a potential therapeutic aid to augment different disease processes. Despite its increased use in recent years, studies reporting potential adverse outcomes of CrM have been mostly derived from male or mixed sex populations. A systematic search was conducted, which included female participants on CrM, where adverse outcomes were reported, with meta-analysis performed where appropriate. Six hundred and fifty-six studies were identified where creatine supplementation was the primary intervention; fifty-eight were female only studies (9%). Twenty-nine studies monitored for adverse outcomes, with 951 participants. There were no deaths or serious adverse outcomes reported. There were no significant differences in total adverse events, (risk ratio (RR) 1.24 (95% CI 0.51, 2.98)), gastrointestinal events, (RR 1.09 (95% CI 0.53, 2.24)), or weight gain, (mean difference (MD) 1.24 kg pre-intervention, (95% CI -0.34, 2.82)) to 1.37 kg post-intervention (95% CI -0.50, 3.23)), in CrM supplemented females, when stratified by dosing regimen and subject to meta-analysis. No statistically significant difference was reported in measures of renal or hepatic function. In conclusion, mortality and serious adverse events are not associated with CrM supplementation in females. Nor does the use of creatine supplementation increase the risk of total adverse outcomes, weight gain or renal and hepatic complications in females. However, all future studies of creatine supplementation in females should consider surveillance and comprehensive reporting of adverse outcomes to better inform participants and health professionals involved in future trials.

Effect of creatine supplementation during resistance training on lean tissue mass and muscular strength in older adults: a meta-analysis

The loss of muscle mass and strength with aging results in significant functional impairment. Creatine supplementation has been used in combination with resistance training as a strategy for increasing lean tissue mass and muscle strength in older adults, but results across studies are equivocal. We conducted a systematic review and meta-analysis of randomized controlled trials of creatine supplementation during resistance training in older adults with lean tissue mass, chest press strength, and leg press strength as outcomes by searching PubMed and SPORTDiscus databases. Twenty-two studies were included in our meta-analysis with 721 participants (both men and women; with a mean age of 57–70 years across studies) randomized to creatine supplementation or placebo during resistance training 2–3 days/week for 7–52 weeks. Creatine supplementation resulted in greater increases in lean tissue mass (mean difference =1.37 kg [95% CI =0.97–1.76]; p<0.00001), chest press strength (standardized mean difference [SMD] =0.35 [0.16–0.53]; p=0.0002), and leg press strength (SMD =0.24 [0.05–0.43]; p=0.01). A number of mechanisms exist by which creatine may increase lean tissue mass and muscular strength. These are included in a narrative review in the discussion section of this article. In summary, creatine supplementation increases lean tissue mass and upper and lower body muscular strength during resistance training of older adults, but potential mechanisms by which creatine exerts these positive effects have yet to be evaluated extensively.

Acute kidney injury associated with androgenic steroids and nutritional supplements in bodybuilders(†)

Four bodybuilders who injected anabolic steroids and ingested commercial protein (78–104 g/day) and creatine (15 g/day) products presented with serum creatinine levels between 229.84 and 335.92 µmol/L (2.6–3.8 mg/dL). Renal biopsies revealed acute tubular necrosis. Four weeks after discontinuing injections and supplements, serum creatinine was in the normal range and estimated glomerular filtration rate > 1.00 mL/s (60 mL/min), including two patients with biopsies showing >30% interstitial fibrosis and tubular atrophy. The findings highlight a risk for acute and potentially chronic kidney injury among young men abusing anabolic steroids and using excessive amounts of nutritional supplements.