Cr Supplementation Research Articles

The effect of combined supplementation of carbohydrates and creatine on anaerobic performance.

The purpose of the study was to examine the effect of creatine (Cr) supplementation on anaerobic performance when ingesting creatine and carbohydrates (CHO) together. Twenty male physical education students comprised the two experimental (CR and CRCHO) and one control (CON) groups of the study. All groups performed three 30 s anaerobic Wingate tests (AWTs) interspersed with 6 minutes of recovery. The CR group (n = 7) ingested 5 g of Cr 5 times per day for 4 days. Subjects in the CRCHO group (n = 6) ingested the same quantity but additionally after each 5 g dose of Cr consumed 500 ml of a commercially available energy drink containing 100 g of simple sugars. Over all three AWTs average mean power improved significantly compared to baseline for the CR group (5.51%) but not for the CRCHO group (3.06%). Mean power for the second AWT was improved following the acute loading for the CR group only (4.54%) and for the third AWT for both CR (8.49%) and CRCHO (5.75%) groups. Over all three AWTs a significant change was recorded in average peak power following the acute loading for the CR group (8.26%) but not for the CRCHO group (4.11%). Peak power was significantly improved following the loading only for the CR group during the third AWT (19.79%). No changes in AWT performance were recorded for the CON group after intervention. The findings of the present study suggest that ingesting creatine together with carbohydrates will not further improve performance compared to the ingestion of creatine only.

Optimization of factors influencing exopolysaccharide production by Halomonas xianhensis SUR308 under batch culture.

A moderately halophilic bacterium, Halomonas xianhensis SUR308 (GenBank Accession No. KJ933394) was isolated from multi-pond solar salterns of Odisha, India. Exopolysaccharide (EPS) production by this strain in malt extract yeast extract (MY) medium has been optimized under batch culture system. Among the different media tested, MY medium showed an EPS production of 2.55 g/L, which increased to 2.85 g/L under optimized aeration. An initial pH of 7.5 and incubation temperature of 32 °C were found to be most suitable for EPS production by the isolate under aerobic condition. An EPS production of 3.85 g/L was achieved when the growth medium was supplemented with 2.5% NaCl. Glucose was the most favourable carbon source for EPS production and maximum production (5.70 g/L) was recorded with 3% glucose. However, growth as well as production of EPS was remarkably affected when the growth medium was supplemented with hydrocarbons as sole source of carbon. Among different nitrogen sources, casein hydrolysate at 0.5% level was proved to be the best for EPS production and an initial inoculum dose of 7% (v/v) enhanced the EPS production to 7.78 g/L, while the divalent metal ions were in general toxic to growth and EPS production, EPS synthesis by SUR308 was enhanced with Cr (VI) supplementation.

Intradialytic creatine supplementation: A scientific rationale for improving the health and quality of life of dialysis patients

The CK/PCr-system, with creatine (Cr) as an energy precursor, plays a crucial role in cellular physiology. In the kidney, as in other organs and cells with high and fluctuating energy requirements, energy-charged phospho-creatine (PCr) acts as an immediate high-energy source and energy buffer, and as an intracellular energy transport vehicle. A maximally filled total Cr (Cr plus PCr) pool is a prerequisite for optimal functioning of the body and its organs, and health. Skeletal- and cardiac muscles of dialysis patients with chronic kidney disease (CKD) are depleted of Cr in parallel with the duration of dialysis. The accompanying accumulation of cellular damage seen in CKD patients lead to a deterioration of musculo-skeletal and neurological functioning and poor quality of life (QOL). Therefore, to counteract Cr depletion, it is proposed to supplement CKD patients with Cr. The anticipated benefits include previously documented improvements in the musculo-skeletal system, brain and peripheral nervous system, as well as improvements in the common comorbidities of CKD patients (see below). Thus, with a relatively simple, safe and inexpensive Cr supplementation marked improvements in quality of life (QOL) and life span are likely reached. To avoid Cr and fluid overload by oral Cr administration, we propose intradialytic Cr supplementation, whereby a relatively small amount of Cr is added to the large volume of dialysis solution to a final concentration of 1–10mM. From there, Cr enters the patient’s circulation by back diffusion during dialysis. Because of the high affinity of the Cr transporter (CRT) for Cr affinity for Cr (Vmax of CRT for Cr=20–40μM Cr), Cr is actively transported from the blood stream into the target cells and organs, including skeletal and cardiac muscle, brain, proximal tubules of kidney epithelial cells, neurons, and leukocytes and erythrocytes, which all express CRT and depend on the CK/PCr system. By this intradialytic strategy, only as much Cr is taken up by the body as is needed to fill the tissue Cr pools and no excess Cr has to be excreted, as is the case with oral Cr. Because aqueous solutions of Cr are not very stable, Cr must be added immediately before dialysis either as solid Cr powder or from a frozen Cr stock solution to the dialysate, or alternatively, Cr could become an additional component of a novel dry dialysate mixture in a cartridge device.

Some Biochemical Changes of Rat Hippocampal Slices under the Long-term Creatine Intraperitoneal Supplementation

For the last few decades, aggression has been linked to various modifications in cellular metabolic pathways. It has also been shown that patients undergoing extended creatine (Cr) treatment display increased aggressiveness. However, molecular mechanisms underlying a correlation between the two phenomena have not been sufficiently identified. To gain a deeper understanding of the changes resulting from supplementation of Cr into non-aggressive animals, we compared some behavioral and biochemical characteristics of Cr-treated and originally non-aggressive individuals with those of naturally non-aggressive and naturally aggressive groups. In this paper we show that extended supplementation of creatine into non-aggressive animals modifies the number of exploratory characteristics and fear-related reactions. In addition, it also changes several biochemical properties in the hippocampus among rats, by significantly reducing the content of Ca2+ions. This could be the result of Cr's direct influence on the NMDA-receptor and its functional inhibition. In conclusion, behavioral and biochemical parameters of non-aggressive individuals display changes under extended supplementation of creatine, which could provide a significant insight into formation of aggression-related behaviors and processes.

Effects of chromium-enriched bacillus subtilis KT260179 supplementation on chicken growth performance, plasma lipid parameters, tissue chromium levels, cecal bacterial composition and breast meat quality.

BackgroundBoth chromium (Cr) and probiotic bacillus own the virtues of regulating animal metabolism and meat quality. Purpose of this study was to evaluate the efficiency of supplemental Cr and bacillus in the form of chromium-enriched Bacillus subtilis KT260179 (CEBS) on chicken growth performance, plasma lipid parameters, tissue chromium levels, cecal bacterial composition and breast meat quality.MethodsSix hundred of 1-day-old Chinese Huainan Partridge chickens were divided into four groups randomly: Control, inorganic Cr, Bacillus subtilis, and CEBS. The feed duration was 56 days.ResultsAfter 28 days of treatment, broiler feed CEBS or normal B. subtilis had higher body weights than control broiler, and after 56 days, chickens given either CEBS or B. subtilis had greater body weights than control broiler or those given inorganic Cr. Plasma total cholesterol, triglycerides, and low density lipoprotein cholesterol levels declined significantly in the CEBS group compared with the control, whereas plasma high density lipoprotein cholesterol levels increased significantly. The concentration of Cr in blood and breast muscle increased after CEBS and inorganic Cr supplementation. B. subtilis and CEBS supplementation caused a significant increase in the numbers of Lactobacillus and Bifidobacterium in the caecum, while the numbers of Escherichia coli and Salmonella decreased significantly compared to the control. Feed adding CEBS increased the lightness, redness, and yellowness of breast meat, improved the water-holding capacity, decreased the shear force and cooking loss.ConclusionsIn all, CEBS supplementation promoted body growth, improved plasma lipid parameters, increased tissue Cr concentrations, altered cecal bacterial composition and improved breast meat quality.

Effect of creatine supplementation on cognitive performance and apoptosis in a rat model of amyloid-beta-induced Alzheimer's disease.

Neuroprotective effect of creatine (Cr) against β-amyloid (Aβ) is reported in an in vitro study. This study investigated the effect of Cr supplementation on β-amyloid toxicity in vivo. Thirty two, male Wistar rats were divided into 4 groups. During ten weeks of study, control group went through no surgical or dietary intervention. At the 4th week of study Sham group had a hippocampal normal saline injection, while Aβ and AβCr groups had an β-amyloid injection in the hippocampus. AβCr group were fed by Cr diet during the study. After 10 weeks, Morris water maze (MWM) test was administered to measure learning ability and memory retrieval. Animals were sacrificed for TUNEL anti apoptotic assay and staining of amyloid plaques by Thioflavin-T. There was a significant retention deficit among AβCr and Aβ group while the escape latency and the distance traveled to the platform were significantly higher in AβCr group compared to Aβ group. AβCr group had same percent of TUNEL positive neurons compared to Aβ group. Cr supplementation before and after β-amyloid injection into the CA1 area of hippocampus deteriorates the learning and memory impairment of rats and it does not protect neuronal apoptosis caused by β-amyloid.

Creatine Monohydrate Supplementation Does Not Augment Fitness, Performance, or Body Composition Adaptations in Response to Four Weeks of High-Intensity Interval Training in Young Females.

High-intensity interval training (HIIT) has been shown to improve cardiorespiratory fitness, performance, body composition, and insulin sensitivity. Creatine (Cr) supplementation may augment responses to HIIT, leading to even greater physiological adaptations. The purpose of this study was to determine the effects of 4 weeks of HIIT (three sessions/week) combined with Cr supplementation in recreationally active females. Seventeen females (age = 23 ± 4 yrs; BMI = 23.4 ± 2.4) were randomly assigned to either Cr (Cr; 0.3 g・kg-1・d-1 for 5 d followed by 0.1 g・kg-1・d-1 for 23 days; n = 9) or placebo (PLA; n = 8). Before and after the intervention, VO2peak, ventilatory threshold (VT), time-trial performance, lean body mass and fat mass, and insulin sensitivity were assessed. HIIT improved VO2peak (Cr = +10.2%; PLA = +8.8%), VT (Cr = +12.7%; PLA = +9.9%), and time-trial performance (Cr = -11.5%; PLA = -11.6%) with no differences between groups (time main effects, all p < .001). There were no changes over time for fat mass (Cr = -0.3%; PLA = +4.3%), whole-body lean mass (Cr = +0.5%; PLA = -0.9%), or insulin resistance (Cr = +3.9%; PLA = +18.7%). In conclusion, HIIT is an effective way to improve cardiorespiratory fitness, VT, and time-trial performance. The addition of Cr to HIIT did not augment improvements in cardiorespiratory fitness, performance or body composition in recreationally active females.

Intermittent exercise models may be basic in research of creatine complex effects in aerobic and anaerobic performance of athletes and Cr supplementation influence

Intermittent exercise models may be basic in research of creatine complex effects in aerobic and anaerobic performance of athletes and Cr supplementation influence

Response of Heat-Stressed Commercial Broilers To Dietary Supplementation of Organic Chromium

The responses of broilers to organic chromium (Cr) fed under heat stress were investigated. About 256 day old Cobb 500 broilers were divided into four dietary groups and fed iso-caloric and iso-nitrogenous diets containing 0, 0.005, 0.010 and 0.015% organic Cr (yeast fermented) up to 35 days. Feed intake, body weight gain and feed conversion ratio (FCR) were measured. Blood samples were collected at 22 and 34 days of age to determine serum parameters. On 35 days, 2 broilers from each replicate were slaughtered to determine carcass traits. Body weight and weight gain of broilers fed Cr were significantly increased at 21 and 35 days (P<0.01). Feed intake was not affected up to 21 days but increased in Cr groups (P<0.05) from 22 to 35 days. The lowest FCR was recorded for 0.010% Cr (P<0.01). A significant decrease (P<0.01) in abdominal fat were observed in Cr group. Antibody titer against Newcastle virus was increased (P<0.01) in both 0.005 and 0.010% Cr at 22 days. Heterophyl to lymphocyte ratio was decreased (P<0.01) in 0.010 and 0.015% Cr. It was therefore concluded that 0.010% dietary organic Cr supplementation may be used to improve productive performance and immune status with a reduction in abdominal fat content of broilers under heat stress condition.

Effect of creatine monohydrate supplementation on learning, memory and neuromuscular coordination in female albino mice.

Research findings made over the last few years have highlighted the important role of creatine (Cr) in health and disease. However, limited information is available regarding the effect of Cr supplementation on cognation. Present study was designed to determine the effect of variable doses of Cr (1% and 3%) on selected parameters of female albino mice behaviour. Following weaning, on 20th postnatal day, female albino mice were divided into three groups on the basis of dietary supplementation. Control group were was fed with normal rodent diet, whereas treated groups received diet supplemented with 1% and 3% Creatine monohydrate (Ssniff, Germany) for 10 weeks. Morris water maze (MWM), Rota rod and open field (OF) tests were carried out at the end of diet supplementation for neurofunctional assessment in all the groups. Data analysis showed that Cr supplementation did not affect the muscular activity and during rota rod test as well as locomotor and exploratory behaviour during OF test. Results of MWM probe trial indicated that mice supplemented with 3% Cr had significantly more entries in platform area than other two treatments (p=0.03) indicating improved spatial memory. Body weight remained unaffected (p>0.05) when compared between three experimental treatments. Female mice supplemented with 3% Cr showed improved spatial memory than mice fed on 1% Cr-supplemented diet and mice on normal rodent diet.

Spectroscopic characterization of genotoxic chromium(V) peptide complexes: Oxidation of Chromium(III) triglycine, tetraglycine and pentaglycine complexes

Evidence is growing that metabolites of Cr(III) dietary supplements are partially oxidized to carcinogenic Cr(VI) and Cr(V) in vivo. Hence, we examined oxidations of Cr(III) peptide (triglycine, tetraglycine and pentaglycine) complexes to Cr(VI) and Cr(V) by PbO2 at 37°C and physiological pH values between 3.85 and 7.4. The products were characterized by EPR and UV/Vis spectroscopies and electrospray mass spectrometry. At pH3.85, the monomeric Cr(V) complexes produced were relatively unstable and degraded over min to hr under the acidic conditions. The triglycine and tetraglycine Cr(V) complexes had five-line 14N-superhyperfine-coupled EPR signals; giso, (AN) values 1.9824 (2.44×10−4cm−1) and 1.9825 (2.43×10−4cm−1), respectively. The pentaglycine Cr(V) complex had a seven-line 14N-superhyperfine-coupled EPR signal: giso=1.9844; AN=2.27×10−4cm−1. In phosphate buffer (pH7.4 and 5.85), several Cr(V) intermediates were produced, but Cr(VI) was the end product. For the triglycine, tetraglycine and pentaglycine Cr(V) complexes, the giso (AN, 10−4cm−1) values were 1.9831 (2.17), 1.9843 (2.27) and 1.9844 (2.30), respectively. A second EPR signal with unresolved superhyperfine structure was observed at giso~1.966. At 1min, the tetraglycine and pentaglycine Cr(V) complexes, had another signal at giso~1.978, which decayed relative to the other signals with time. This chemistry has relevance to: (i) certain types of DNA damage produced by Cr carcinogens; (ii) the intracellular oxidation of Cr(III) to Cr(VI); and (iii) redox recycling of Cr(III) metabolites formed from both the intracellular reduction of carcinogenic Cr(VI) and from Cr(III) supplements.

Can Creatine Supplementation Improve Body Composition and Objective Physical Function in Rheumatoid Arthritis Patients? A Randomized Controlled Trial.

Rheumatoid cachexia (muscle wasting) in rheumatoid arthritis (RA) patients contributes to substantial reductions in strength and impaired physical function. The objective of this randomized controlled trial was to investigate the effectiveness of oral creatine (Cr) supplementation in increasing lean mass and improving strength and physical function in RA patients. In a double-blind design, 40 RA patients were randomized to either 12 weeks' supplementation of Cr or placebo. Body composition (dual x-ray absorptiometry and bioelectrical impedance spectroscopy [BIS]), strength, and objectively assessed physical function were measured at baseline, day 6, week 12, and week 24. Data analysis was performed by analysis of covariance. Cr supplementation increased appendicular lean mass (ALM; a surrogate measure of muscle mass) by mean ± SE 0.52 ± 0.13 kg (P = 0.004 versus placebo), and total LM by 0.60 ± 0.37 kg (P = 0.158). The change in LM concurred with the gain in intracellular water (0.64 ± 0.22 liters; P = 0.035) measured by BIS. Despite increasing ALM, Cr supplementation, relative to placebo, failed to improve isometric knee extensor strength (P = 0.408), handgrip strength (P = 0.833), or objectively assessed physical function (P = 0.335-0.764). In patients with RA, Cr supplementation increased muscle mass, but not strength or objective physical function. No treatment-related adverse effects were reported, suggesting that Cr supplementation may offer a safe and acceptable adjunct treatment for attenuating muscle loss; this treatment may be beneficial for patients experiencing severe rheumatoid cachexia.

Effects of Five Weeks of Resistance Training and Relatively-Dosed Creatine Monohydrate Supplementation on Body Composition and Muscle Strength, and Whole-Body Creatine Metabolism in Resistance-Trained Males

Background: Creatine (Cr) supplementation has been established as an ergogenic aid in most individuals during anaerobic exercise. However, discrepancies exist in the data when using absolute dosing. Objective: The effects of five weeks of resistance training with relatively-dosed Cr followed by four weeks of resistance training after ceasing supplementation were determined. Methods: Resistance-trained men, 19 (CR = 9, PL = 10), ingested Cr or placebo for five weeks with resistance training. Participants ingested 0.3 g/kg lean body mass/day for one week, 0.075 g/kg lean body mass/day for four weeks, with a four-week wash out. Five muscle samples, six blood samples, and nine urine samples were collected. Separate two-way ANOVAs for each criterion variable were used employing an alpha level of ≤ 0.05. Results: A group x time interaction for increased total body mass for CR Day 1 and 64 (p = 0.03) and total lean mass for CR Day 1 and 64 (p = 0.01). Group x time interactions occurred for Cr supplementation increasing serum Cr at Day 4, 8, and 22 (p = 0.03), urinary Cr at Day 4 (p = 0.01), and total muscle Cr at Day 8 (p < 0.001), 22 (p = 0.003), and 36 (p < 0.001). No significant differences occurred for serum (p = 0.14) or urine (p = 0.15) creatinine. Conclusion: Elevated levels of urinary Cr demonstrate dosing could be reduced. Keywords: Urine, creatinine, resistance training, muscle strength, serum

Effects of Creatine Supplementation on Athletic Performance and Body Composition after Complex Training

Complex training takes advantage of the phenomenon known as postactivation potentiation (PAP), which is an acute enhancement of jump performance following the heavy resistance exercise (HRE). Numerous of researches have shown fatigue mask the PAP effect in the early stage of recovery and the PAP is an individualized phenomenon. Creatine (Cr) supplementation plays an important role in short term energy metabolism of skeletal muscle. PURPOSE: To examine the effects of Cr supplementation on athletic performance and body composition after 4 weeks of complex training with optimal individual PAP time. METHOD: Thirty two explosive athletes conducted the tests of body composition, counter movement jump (CMJ), 30 m sprint and 1-repetition maximal (1 RM) half squat strength. A matched pair design was used to assign the subjects into creatine group (Cr gr.) or placebo group (Pla gr.) by their maximal muscular strength. Subjects consumed 5 g of Cr or methyl cellulose (Pla gr.) plus 5 g of glucose 4 times per day for 6 days. The 1 RM half squat strength was test again after the supplementation to calculate the weight of HRE in complex training. Meanwhile, subjects ingested 2 g of Cr (or methyl cellulose) plus 2 g of glucose per day till the end of study. Thereafter, complex training (6 sets, 5 RM of half squat and 8 jumps, with optimal individual PAP time for rest) was executed 3 times per week for 4 weeks. Body composition and athletic performance were tested after the training periods. RESULTS: After 4 weeks of training, time for 30 m sprint (Cr gr.: 4.31 ± 0.20 vs. 4.13 ± 0.17 s; Pla gr.: 4.26 ± 0.20 vs. 4.18 ± 0.15 s, p < .05) and 1 RM half squat strength (Cr gr.: 128.43 ±13.75 vs. 180.31 ±17.83 kg; Pla gr.: 127.18 ±17.50 vs. 165.31 ±14.19 kg, p < .05) were significantly improved in both groups. And the strength in Cr gr. was significantly higher than in Pla gr. There were no significant difference in height and peak power of CMJ, body mass, and body fat. CONCLUSION: Cr supplementation improved maximum muscle strength, but no effect on other athletic performance and body composition after 4 weeks of complex training with optimal individual PAP time for rest. Supported by Ministry of Science and Technology, Taiwan. (Grant No: MOST 102-2410-H-179-002)

The effects of creatine supplementation on striatal neural progenitor cells depend on developmental stage.

Transplantation of neural progenitor cells (NPCs) is a promising experimental therapy for Huntington's disease (HD). The variables responsible for the success of this approach, including selection of the optimal developmental stage of the grafted cells, are however largely unknown. Supporting cellular energy metabolism by creatine (Cr) supplementation is a clinically translatable method for improving cell transplantation strategies. The present study aims at investigating differences between early (E14) and late (E18) developmental stages of rat striatal NPCs in vitro. NPCs were isolated from E14 and E18 embryos and cultured for 7days with or without Cr [5mM]. Chronic treatment significantly increased the percentage of GABA-immunoreactive neurons as compared to untreated controls, both in the E14 (170.4±4.7%) and the E18 groups (129.3±9.3%). This effect was greater in E14 cultures (p<0.05). Similarly, short-term treatment for 24h resulted in increased induction (p<0.05) of the GABA-ergic phenotype in E14 (163.0±10.4%), compared to E18 cultures (133.3±9.5%). Total neuronal cell numbers and general viability were not affected by Cr (p>0.05). Protective effects of Cr against a metabolic insult were equal in E14 and E18 NPCs (p>0.05). Cr exposure promoted morphological differentiation of GABA-ergic neurons, including neurite length in both groups (p<0.05), but the number of branching points was increased only in the E18 group (p<0.05). Our results demonstrate that the role of Cr as a GABA-ergic differentiation factor depends on the developmental stage of striatal NPCs, while Cr-mediated neuroprotection is not significantly influenced. These findings have potential implications for optimizing future cell replacement strategies in HD.

The effects of creatine supplementation on thermoregulation and physical (cognitive) performance: a review and future prospects.

Creatine (Cr) is produced endogenously in the liver or obtained exogenously from foods, such as meat and fish. In the human body, 95% of Cr is located in the cytoplasm of skeletal muscle either in a phosphorylated (PCr) or free form (Cr). PCr is essential for the immediate rephosphorylation of adenosine diphosphate to adenosine triphosphate. PCr is rapidly degraded at the onset of maximal exercise at a rate that results in muscle PCr reservoirs being substantially depleted. A well-established strategy followed to increase muscle total Cr content is to increase exogenous intake by supplementation with chemically pure synthetic Cr. Most Cr supplementation regimens typically follow a well-established loading protocol of 20gday(-1) of Cr for approximately 5-7days, followed by a maintenance dose at between 2 and 5gday(-1) for the duration of interest, although more recent studies tend to utilize a 0.3-gkg(-1)day(-1) supplementation regimen. Some studies have also investigated long-term supplementation of up to 1year. Uptake of Cr is enhanced when taken together with carbohydrate and protein and/or while undertaking exercise. Cr supplementation has been shown to augment muscle total Cr content and enhance anaerobic performance; however, there is also some evidence of indirect benefits to aerobic endurance exercise through enhanced thermoregulation. While there is an abundance of data supporting the ergogenic effects of Cr supplementation in a variety of different applications, some individuals do not respond, the efficacy of which is dependent on a number of factors, such as dose, age, muscle fiber type, and diet, although further work in this field is warranted. Cr is increasingly being used in the management of some clinical conditions to enhance muscle mass and strength. The application of Cr in studies of health and disease has widened recently with encouraging results in studies involving sleep deprivation and cognitive performance.

Are Chromium (Cr) Supplements Efficacious for Glycemic Control in Type 2 Diabetes (T2DM)?

Chromium (Cr)‐containing dietary supplements are claimed to improve glycemic control in T2DM. We conducted a systematic literature search of randomized clinical trials (RCT) of adults with T2DM to document changes in glycemic control from pre‐ to post‐supplementation with Cr. The search included studies from 1/1991–1/2014 with the following terms: blood glucose, blood sugar, glucose metabolism disorders, or metabolic syndrome; randomized clinical trial, systematic review or meta‐analysis; trials with adults (&gt;18yr.); T2DM defined by self‐report, clinical diagnosis or biochemical determination of elevated fasting plasma glucose [FPG ] or hemoglobin A1c [HbA1c];with and without concurrent treatment with hypoglycemic agents; and RCT design having a placebo or comparator control along with the Cr dietary supplement. Exclusions were studies in children, or solely in patients with T1DM; presence of unstable chronic disease and/or acute conditions; studies of combination therapies without a separate Cr supplement; observational, non‐randomized or un‐blinded studies; and those not reporting results pre vs. post‐supplementation. We defined elevated FPG as &gt;126 mg/dL, or elevatedHbA1c as &gt; 6.5%, and treatment goals as FPG ≤ 130 mg/dL, or ≤7.0% HbA1c, and a clinically substantial decrease as ≥0.5% HbA1c (or 60 mg/dL, a criterion based on reduction achieved by successful drug therapy; no similar criterion was available for a single FPG). A total of 20 RCT (22 arms) were identified. Many different doses and forms of Cr were used. 16 of 20 RCT continued hypoglycemic medications and lifestyle modifications during Cr supplementation, which confounded the interpretation of the cause of changes during supplementation. Many studies failed to show decreases compared to controls and in others decreases were small. Glycemic treatment goals were reached after Cr supplementation in 5/20studies using the mean FPG criterion, 3/14 using HgA1c, and 1/14 using both FPG and HgA1c. Mean HbA1c declined by ≥0.5% in 5/14 RCT, but in 4/5 of those with a drop concurrent hypoglycemic medications were also administered. Neither dose nor duration of Cr supplementation appeared to be associated with effectiveness. Also, we discovered that many of the RCT had features that threatened their quality, including heterogeneous study populations, small study size, high drop‐out rates, and short study duration. Moreover, in many studies the advantages of randomization for causal inference were lost due to high dropout rates and analyses solely of completers (per protocol analysis) rather than by intent to treat. The low strength of the evidence to date makes it unlikely that Cr supplements are efficacious for glycemic control. Future meta‐analyses should be selective and use similar inclusion criteria, similar forms of Cr, and include only high quality studies to provide scientifically sound recommendations.Support or Funding InformationFunding: Office of Dietary Supplements, National Institutes of Health.

Synergy between tobramycin and trivalent chromium ion in electrochemical control of Pseudomonas aeruginosa

We recently demonstrated that the effectiveness of tobramycin (Tob), an aminoglycoside, against antibiotic-tolerant persister cells of Pseudomonas aeruginosa can be enhanced by electrochemical factors generated from direct currents (DC). Supplementation of Ni(II), Cr(III) and Fe(II) during carbon-mediated DC treatment revealed that these metal cations promote killing of persister cells in the presence of tobramycin, which led to our hypothesis that specific interactions between Tob and some metal ions contribute to the synergistic killing of persister cells. In this study, the interactions between selected metal cations and Tob were investigated using 1H-13C HSQC NMR. Increase in the concentration of Cr(III) (in the form of [CrCl2(H2O)4]+) in solutions containing Tob was found to shift the HSQC NMR peaks of Tob to new positions, suggesting the formation of a Cr(III)-Tob complex. Crystal field effects and electrochemical properties of the complex were further studied using UV–visible spectroscopy and cyclic voltammetry, which led to the finding that the Cr(III)-Tob complex has increased affinity with negatively charged nucleic acids. These findings are helpful for understanding the mechanism of electrochemical control of bacterial cells and for developing more effective antimicrobial therapies based on aminoglycosides and electrochemical species released from various metallic biomaterials. Statement of SignificanceMedical device associated infections present a major challenge to healthcare and the quality of life of affected individuals. This problem is further exacerbated by the emergence of multidrug resistant pathogens. Thus, alternative methods for microbial control are urgently needed. Recently, we reported synergy between tobramycin and low-level electrochemical currents generated using stainless steel electrodes in killing bacterial persister cells, a dormant population with high-level intrinsic tolerance to antibiotics. In this article, we describe how electrically-induced interaction between aminoglycosides and certain metal cations enhance the potency of tobramycin in bacterial killing. The findings will help design new methods for controlling infections through electrochemical disruption of cellular function and associated drug resistance.

Structural correlates of the creatine transporter function regulation: the undiscovered country.

Creatine (Cr) and phosphocreatine constitute an energy shuttle that links ATP production in mitochondria to subcellular locations of ATP consumption. Cells in tissues that are reliant on this energy shuttle, such as myocytes and neurons, appear to have very limited ability to synthesize creatine. Therefore, these cells depend on Cr uptake across the cell membrane by a specialized creatine transporter (CrT solute carrier SLC6A8) in order to maintain intracellular creatine levels. Cr supplementation has been shown to have a beneficial effect in numerous in vitro and in vivo models, particularly in cases of oxidative stress, and is also widely used by athletes as a performance enhancement nutraceutical. Intracellular creatine content is maintained within narrow limits. However, the physiological and cellular mechanisms that mediate Cr transport during health and disease (such as cardiac failure) are not understood. In this narrative mini-review, we summarize the last three decades of research on CrT structure, function and regulation.

Alleviation of thermoregulatory responses of Baladi Does by chromium and Selenium-E supplementation in subtropical areas.

This experiment was conducted to study the effect of the treating Baladi female goats with chromium and selenium-E during estrous cycle, pregnancy and postpartum periods to alleviate thermoregulatory responses of animals under hot conditions in Egypt to improve their performance throughout these stages. It has been used in this research 72 mature Baladi does (36 animal / season) with an average age of 2-3 years and an average body weight of 25 Kg, the experiment lasted for two seasons (mild and hot). Animals were divided randomly into three similar groups, the 1st group was kept without any treatments (control), the 2nd group was supplemented by chromium (chromium chloride, Cr). The 3rd group was injected intramuscularly twice a week with 2ml viteselen®, contained 0.5 mg selenium and 10.7 IU vitamin E (Se-E). Animals were kept in semi-open pens during the experimental period and allowed to graze for five hours daily at least. Thermoregulatory responses of the animal were estimated in terms of rectal temperature (RT), skin temperature (ST) and respiratory rate (RR). Results showed significant decrease in RT during the estrous cycle due to Cr and Se-E treatments. Also, Selenium-E injection showed lower ST during most of the different stages of estrous cycle. Under hot season, each of chromium and selenium-E reduced ST during estrous cycle while this effect was only due to Se-E for RR without chromium .Both Cr and Se-E treatments decreased RT and ST throughout different stages of pregnancy, except at late pregnancy of Se-E group. Under hot season conditions, does injected with Se-E were the lowest in RR during the mid and late pregnancy compared with other groups. While Cr group did not reveal significant effect on RR. During postpartum period Cr and Se-E supplementation under hot condition showed significant decrease in RT and ST. Both treatments decreased (P<0.05) RR during the postpartum period, only Se-E exhibited this decline under hot season.