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HbA1c adjusted by erythrocyte creatine is a useful glycemic control indicator in patients with hemolysis.
Koga, M, Inada, S, Shibata, M, Ijima, H, Jinnouchi, H, Ono, Y, Iwasaka, T, Tokuhiro, S, Matsumura, Y, Matsui, H, et al
Clinical biochemistry. 2019;:77-81
Abstract
OBJECTIVES HbA1c shows low in patients with hemolysis, whereas glycated albumin (GA) is not affected by hemolysis. Therefore, the GA/HbA1c ratio reflects hemolysis in diabetic patients with hemolysis. Erythrocyte creatine (EC) is an indicator of hemolysis that reflects the mean erythrocyte age. The aim of this study was to examine whether HbA1c adjusted by EC accurately reflected glycemic control in patients with hemolysis. MATERIALS AND METHODS A total of 238 individuals, consisting of 131 diabetic patients and 107 non-diabetic subjects, and consisting of 42 patients with hemolysis, and 196 subjects without hemolysis were selected for the study. HbA1c expressed in the IFCC units (iA1c) as well as in the NGSP units (A1C) were used. From the fact that EC and the GA/iA1c ratio showed a significant positive correlation, a formula for iA1c adjusted by EC (ECadj-iA1c) was created from a regression equation between EC and the GA/iA1c ratio. RESULTS Significant correlations were observed between the GA/iA1c ratio and various hemolytic indicators but not between the GA/ECadj-iA1c ratio and those hemolytic indicators. The GA/iA1c ratio in individuals with hemolysis was significantly higher than in individuals without hemolysis, while no significant differences were observed in the GA/ECadj-iA1c ratio between the groups. Further, iA1c concentrations in non-diabetic patients with hemolysis were significantly lower than in the non-diabetic subjects without hemolysis, whereas ECadj-iA1c and GA concentrations showed no significant difference between the two groups. CONCLUSIONS These results suggested that ECadj-iA1c accurately reflected glycemic control in patients with hemolysis.
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Association of metabolic syndrome and change in Unified Parkinson's Disease Rating Scale scores.
Leehey, M, Luo, S, Sharma, S, Wills, AA, Bainbridge, JL, Wong, PS, Simon, DK, Schneider, J, Zhang, Y, Pérez, A, et al
Neurology. 2017;(17):1789-1794
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Abstract
OBJECTIVE To explore the association between metabolic syndrome and the Unified Parkinson's Disease Rating Scale (UPDRS) scores and, secondarily, the Symbol Digit Modalities Test (SDMT). METHODS This is a secondary analysis of data from 1,022 of 1,741 participants of the National Institute of Neurological Disorders and Stroke Exploratory Clinical Trials in Parkinson Disease Long-Term Study 1, a randomized, placebo-controlled trial of creatine. Participants were categorized as having or not having metabolic syndrome on the basis of modified criteria from the National Cholesterol Education Program Adult Treatment Panel III. Those who had the same metabolic syndrome status at consecutive annual visits were included. The change in UPDRS and SDMT scores from randomization to 3 years was compared in participants with and without metabolic syndrome. RESULTS Participants with metabolic syndrome (n = 396) compared to those without (n = 626) were older (mean [SD] 63.9 [8.1] vs 59.9 [9.4] years; p < 0.0001), were more likely to be male (75.3% vs 57.0%; p < 0.0001), and had a higher mean uric acid level (men 5.7 [1.3] vs 5.3 [1.1] mg/dL, women 4.9 [1.3] vs 3.9 [0.9] mg/dL, p < 0.0001). Participants with metabolic syndrome experienced an additional 0.6- (0.2) unit annual increase in total UPDRS (p = 0.02) and 0.5- (0.2) unit increase in motor UPDRS (p = 0.01) scores compared with participants without metabolic syndrome. There was no difference in the change in SDMT scores. CONCLUSIONS Persons with Parkinson disease meeting modified criteria for metabolic syndrome experienced a greater increase in total UPDRS scores over time, mainly as a result of increases in motor scores, compared to those who did not. Further studies are needed to confirm this finding. CLINICALTRIALSGOV IDENTIFIER NCT00449865.
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Efficacy and safety of creatine supplementation in juvenile dermatomyositis: A randomized, double-blind, placebo-controlled crossover trial.
Solis, MY, Hayashi, AP, Artioli, GG, Roschel, H, Sapienza, MT, Otaduy, MC, De Sã Pinto, AL, Silva, CA, Sallum, AM, Pereira, RM, et al
Muscle & nerve. 2016;(1):58-66
Abstract
INTRODUCTION It has been suggested that creatine supplementation is safe and effective for treating idiopathic inflammatory myopathies, but no pediatric study has been conducted to date. The objective of this study was to examine the efficacy and safety of creatine supplementation in juvenile dermatomyositis (JDM) patients. METHODS In this study, JDM patients received placebo or creatine supplementation (0.1 g/kg/day) in a randomized, crossover, double-blind design. Subjects were assessed at baseline and after 12 weeks. The primary outcome was muscle function. Secondary outcomes included body composition, aerobic conditioning, health-related quality of life, and muscle phosphocreatine (PCr) content. Safety was assessed by laboratory parameters and kidney function measurements. RESULTS Creatine supplementation did not affect muscle function, intramuscular PCr content, or any other secondary outcome. Kidney function was not affected, and no side effects were reported. CONCLUSIONS Twelve weeks of creatine supplementation in JDM patients were well-tolerated and free of adverse effects, but treatment did not affect muscle function, intramuscular PCr, or any other parameter.
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Creatine ingestion augments dietary carbohydrate mediated muscle glycogen supercompensation during the initial 24 h of recovery following prolonged exhaustive exercise in humans.
Roberts, PA, Fox, J, Peirce, N, Jones, SW, Casey, A, Greenhaff, PL
Amino acids. 2016;(8):1831-42
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Abstract
Muscle glycogen availability can limit endurance exercise performance. We previously demonstrated 5 days of creatine (Cr) and carbohydrate (CHO) ingestion augmented post-exercise muscle glycogen storage compared to CHO feeding alone in healthy volunteers. Here, we aimed to characterise the time-course of this Cr-induced response under more stringent and controlled experimental conditions and identify potential mechanisms underpinning this phenomenon. Fourteen healthy, male volunteers cycled to exhaustion at 70 % VO2peak. Muscle biopsies were obtained at rest immediately post-exercise and after 1, 3 and 6 days of recovery, during which Cr or placebo supplements (20 g day(-1)) were ingested along with a prescribed high CHO diet (37.5 kcal kg body mass(-1) day(-1), >80 % calories CHO). Oral-glucose tolerance tests (oral-GTT) were performed pre-exercise and after 1, 3 and 6 days of Cr and placebo supplementation. Exercise depleted muscle glycogen content to the same extent in both treatment groups. Creatine supplementation increased muscle total-Cr, free-Cr and phosphocreatine (PCr) content above placebo following 1, 3 and 6 days of supplementation (all P < 0.05). Creatine supplementation also increased muscle glycogen content noticeably above placebo after 1 day of supplementation (P < 0.05), which was sustained thereafter. This study confirmed dietary Cr augments post-exercise muscle glycogen super-compensation, and demonstrates this occurred during the initial 24 h of post-exercise recovery (when muscle total-Cr had increased by <10 %). This marked response ensued without apparent treatment differences in muscle insulin sensitivity (oral-GTT, muscle GLUT4 mRNA), osmotic stress (muscle c-fos and HSP72 mRNA) or muscle cell volume (muscle water content) responses, such that another mechanism must be causative.
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Recreational alcohol use induces changes in the concentrations of choline-containing compounds and total creatine in the brain: a (1)H MRS study of healthy subjects.
Tunc-Skarka, N, Weber-Fahr, W, Ende, G
Magma (New York, N.Y.). 2015;(5):503-10
Abstract
OBJECTIVE It has previously been reported that even social alcohol consumption affects the magnetic resonance spectroscopy (MRS) signals of choline-containing compounds (tCho). The purpose of this study was to investigate whether the consumption of alcohol affects the concentrations of the metabolites tCho, N-acetylaspartate, creatine, or myo-inositol and/or their T 2 relaxation times. MATERIALS AND METHODS (1)H MR spectra were obtained at 3 T from a frontal white matter voxel of 25 healthy subjects with social alcohol consumption (between 0 and 25.9 g/day). Absolute brain metabolite concentrations and T 2 relaxation times of metabolites were examined via MRS measurements at different echo times. Metabolite concentrations and their T 2 relaxation times were correlated with subjects' alcohol consumption, controlling for age. RESULTS We observed positive correlations of absolute tCho and phosphocreatine and creatine (tCr) concentrations with alcohol consumption but no correlation between any metabolite T 2 relaxation time and alcohol consumption. CONCLUSIONS This study shows that even social alcohol consumption affects the concentrations of tCho and tCr in cerebral white matter. Future studies assessing brain tCho and tCr levels should control for the confounding factor alcohol consumption.
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Effect of the MTHFR 677C/T polymorphism on homocysteinemia in response to creatine supplementation: a case study.
Petr, M, Steffl, M, Kohlíková, E
Physiological research. 2013;(6):721-9
Abstract
Creatine (Cr) is recommended as a dietary supplement especially for athletes but its therapeutic potential is also discussed. It is assumed that human body uses Cr for the formation of phosphocreatine, which is necessary for muscular work as a source of energy. Production of Cr in a body is closely connected to methionine cycle where guanidinoacetate (GAA) is in a final step methylated from S-adenosylmethionine (SAM). Increased availability of SAM for phosphatidylcholine (PC) and sarcosine synthesis can potentially stimulate endogenous production of betaine a thus methylation of homocysteine (HCy) to form methionine. Our subject who was methylenetetrahydrofolate reductase (MTHFR) 677TT homozygote lowered plasma HCy from 33.3 micromol/l to 17.1 micromol/l following one-month Cr supplementation (5 g/day) opposite to 677CC and CT genotypes whose HCy levels tended to increase (but still in normal ranges). We suppose that Cr supplementation stimulates pathways leading to production of sarcosine which can serve to regenerate tetrahydrofolate (THF) to form 5,10-methylene-THF. This could potentially increase MTHFR enzyme activity which may later result in increased HCy methylation. Cr supplementation significantly effects metabolism of one carbon unit and potentially lower body´s demands for methyl groups. This could be beneficial as in the case of reduced enzyme activity such as MTHFR 677C/T polymorphism.
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Long-term adefovir plus lamivudine therapy does not decrease creatinine clearance in HBeAg-negative chronic hepatitis B patients.
Manolakopoulos, S, Striki, A, Deutsch, M, Mela, M, Ketikoglou, I, Tzourmakliotis, D, Manesis, EK, Papatheodoridis, GV
Liver international : official journal of the International Association for the Study of the Liver. 2011;(10):1525-32
Abstract
BACKGROUND/AIMS: As there are concerns about potential nephrotoxicity of nucleotide analogues, we evaluated renal function parameters during long-term adefovir and lamivudine combination therapy. METHODS Forty-six HBeAg-negative patients with lamivudine-resistance treated with adefovir and lamivudine for up to 90 months were included. Renal function was assessed by estimated creatinine clearance (eC(CR) ) and compared with a matched control group of untreated inactive hepatitis B virus carriers. RESULTS Serum HBV DNA became undetectable in 39 (85%) patients after a mean of 37 ± 21 months. Three (6.5%) patients developed virological breakthrough. Adefovir resistance was detected in two patients. At the end of follow up, there was a significant decrease in mean eC(CR) (95 ± 31-83 ± 30 ml/min, P = 0.003) in the treated patients with 16% presenting aeC(CR) decrease >30%. Similar changes in eC(CR) were observed in the control group (108 ± 28-96 ± 26 ml/min, P = 0.003). In multiple regression analysis, age and baseline eC(CR) were independent predictors of eC(CR) reduction. CONCLUSIONS Adefovir and lamivudine combination therapy is not an independent factor for significant renal dysfunction in HBeAg-negative patients with lamivudine-resistance. Baseline age and creatinine clearance are the only independent predictors of worsening renal function.
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Oral glycine administration increases brain glycine/creatine ratios in men: a proton magnetic resonance spectroscopy study.
Kaufman, MJ, Prescot, AP, Ongur, D, Evins, AE, Barros, TL, Medeiros, CL, Covell, J, Wang, L, Fava, M, Renshaw, PF
Psychiatry research. 2009;(2):143-9
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Abstract
Oral high-dose glycine administration has been used as an adjuvant treatment for schizophrenia to enhance glutamate neurotransmission and mitigate glutamate system hypofunction thought to contribute to the disorder. Prior studies in schizophrenia subjects documented clinical improvements after 2 weeks of oral glycine administration, suggesting that brain glycine levels are sufficiently elevated to evoke a clinical response within that time frame. However, no human study has reported on brain glycine changes induced by its administration. We utilized a noninvasive proton magnetic resonance spectroscopy ((1)H-MRS) technique termed echo time-averaged (TEAV) (1)H-MRS, which permits noninvasive quantification of brain glycine in vivo, to determine whether 2 weeks of oral glycine administration (peak dose of 0.8 g/kg/day) increased brain glycine/creatine (Gly/Cr) ratios in 11 healthy adult men. In scans obtained 17 h after the last glycine dose, brain (Gly/Cr) ratios were significantly increased. The data indicate that it is possible to measure brain glycine changes with proton spectroscopy. Developing a more comprehensive understanding of human brain glycine dynamics may lead to optimized use of glycine site agonists and glycine transporter inhibitors to treat schizophrenia, and possibly to treat other disorders associated with glutamate system dysfunction.
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Creatine supplementation improves muscular performance in older women.
Gotshalk, LA, Kraemer, WJ, Mendonca, MA, Vingren, JL, Kenny, AM, Spiering, BA, Hatfield, DL, Fragala, MS, Volek, JS
European journal of applied physiology. 2008;(2):223-31
Abstract
Muscle power and strength decrease with age leading to reduced independence and increased health risk from falls. Creatine supplementation can increase muscle power and strength. The purpose of this study was to examine the effects of 7 days of creatine supplementation on body composition, muscular strength, and lower-body motor functional performance in older women. Thirty 58-71 year old women performed three test sessions (T1-T3) each separated by one week. Each session consisted of one repetition maximum tests for bench press and leg press, and isometric hand-grip, tandem gait, upper-body ergometer, and lower-body ergometer tests. Following T2, subjects were assigned to a creatine monohydrate (0.3 g kg body mass(-1) for 7 days) (CR: 63.31 +/- 1.22 year, 160.00 +/- 1.58 cm, 67.11 +/- 4.38 kg) or a placebo (PL: 62.98 +/- 1.11 year, 162.25 +/- 2.09 cm, 67.84 +/- 3.90 kg) supplementation group. CR significantly (P < 0.05) increased bench press (1.7 +/- 0.4 kg), leg press (5.2 +/- 1.8 kg), body mass (0.49 +/- 0.04 kg) and fat free mass (0.52 +/- 0.05) and decreased completion time on the functional tandem gait tests from T2-T3. No significant changes were found for PL on any of the measured variables. No adverse side-effects were reported by either group. Short-term creatine supplementation resulted in an increase in strength, power, and lower-body motor functional performance in older women without any adverse side effects.
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Creatine supplementation does not improve cognitive function in young adults.
Rawson, ES, Lieberman, HR, Walsh, TM, Zuber, SM, Harhart, JM, Matthews, TC
Physiology & behavior. 2008;(1-2):130-4
Abstract
Creatine supplementation has been reported to improve certain aspects of cognitive and psychomotor function in older individuals and in young subjects following 24 and 36 h of sleep deprivation. However, the effects of creatine supplementation on cognitive processing and psychomotor performance in non-sleep deprived young adults have not been assessed with a comprehensive battery of neurocognitive tests. The primary objective of this study was to examine the effects of creatine supplementation on cognitive processing and psychomotor performance in young adults. Twenty-two subjects (21+/-2 yr) ingested creatine (0.03 g/kg/day) or placebo for 6 weeks in a double-blind placebo-controlled fashion. Subjects completed a battery of neurocognitive tests pre- and post-supplementation, including: simple reaction time (RT), code substitution (CS), code substitution delayed (CSD), logical reasoning symbolic (LRS), mathematical processing (MP), running memory (RM), and Sternberg memory recall (MR). There were no significant effects of group, no significant effects of time, and no significant group by time interactions for RT, CS, CSD, LRS, MP, RM, and MR (all p>0.05), indicating that there were no differences between creatine and placebo supplemented groups at any time. These results suggest that six weeks of creatine supplementation (0.03/g/kg/day) does not improve cognitive processing in non-sleep deprived young adults. Potentially, creatine supplementation only improves cognitive processing and psychomotor performance in individuals who have impaired cognitive processing abilities.