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Physiological Reviews Jul 2000The goal of this review is to present a comprehensive survey of the many intriguing facets of creatine (Cr) and creatinine metabolism, encompassing the pathways and... (Review)
Review
The goal of this review is to present a comprehensive survey of the many intriguing facets of creatine (Cr) and creatinine metabolism, encompassing the pathways and regulation of Cr biosynthesis and degradation, species and tissue distribution of the enzymes and metabolites involved, and of the inherent implications for physiology and human pathology. Very recently, a series of new discoveries have been made that are bound to have distinguished implications for bioenergetics, physiology, human pathology, and clinical diagnosis and that suggest that deregulation of the creatine kinase (CK) system is associated with a variety of diseases. Disturbances of the CK system have been observed in muscle, brain, cardiac, and renal diseases as well as in cancer. On the other hand, Cr and Cr analogs such as cyclocreatine were found to have antitumor, antiviral, and antidiabetic effects and to protect tissues from hypoxic, ischemic, neurodegenerative, or muscle damage. Oral Cr ingestion is used in sports as an ergogenic aid, and some data suggest that Cr and creatinine may be precursors of food mutagens and uremic toxins. These findings are discussed in depth, the interrelationships are outlined, and all is put into a broader context to provide a more detailed understanding of the biological functions of Cr and of the CK system.
Topics: Animals; Creatine; Creatinine; Humans
PubMed: 10893433
DOI: 10.1152/physrev.2000.80.3.1107 -
Nephron 2017Measuring serum creatinine is cheap and commonly done in daily practice. However, interpretation of serum creatinine results is not always easy. In this review, we will... (Review)
Review
Measuring serum creatinine is cheap and commonly done in daily practice. However, interpretation of serum creatinine results is not always easy. In this review, we will briefly remind the physiological limitations of serum creatinine due notably to its tubular secretion and the influence of muscular mass or protein intake on its concentration. We mainly focus on the analytical limitations of serum creatinine, insisting on important concept such as reference intervals, standardization (and IDMS traceability), analytical interferences, analytical coefficient of variation (CV), biological CV and critical difference. Because the relationship between serum creatinine and glomerular filtration rate is hyperbolic, all these CVs will impact not only the precision of serum creatinine but still more the precision of different creatinine-based equations, especially in low or normal-low creatinine levels (or high or normal-high glomerular filtration rate range).
Topics: Biomarkers; Creatinine; Glomerular Filtration Rate; Humans; Kidney Diseases; Kidney Function Tests; Reference Values
PubMed: 28441651
DOI: 10.1159/000469669 -
American Family Physician Dec 2019Acute kidney injury is a clinical syndrome characterized by a rapid decline in glomerular filtration rate and resultant accumulation of metabolic waste products. Acute...
Acute kidney injury is a clinical syndrome characterized by a rapid decline in glomerular filtration rate and resultant accumulation of metabolic waste products. Acute kidney injury is associated with an increased risk of mortality, cardiovascular events, and progression to chronic kidney disease. Severity of acute kidney injury is classified according to urine output and elevations in creatinine level. Etiologies of acute kidney injury are categorized as prerenal, intrinsic renal, and postrenal. Accurate diagnosis of the underlying cause is key to successful management and includes a focused history and physical examination, serum and urine electrolyte measurements, and renal ultrasonography when risk factors for a postrenal cause are present (e.g., older male with prostatic hypertrophy). General management principles for acute kidney injury include determination of volume status, fluid resuscitation with isotonic crystalloid, treatment of volume overload with diuretics, discontinuation of nephrotoxic medications, and adjustment of prescribed drugs according to renal function. Additional supportive care measures may include optimizing nutritional status and glycemic control. Pharmacist-led quality-improvement programs reduce nephrotoxic exposures and rates of acute kidney injury in the hospital setting. Acute kidney injury care bundles are associated with improved in-hospital mortality rates and reduced risk of progression. Nephrology consultation should be considered when there is inadequate response to supportive treatment and for acute kidney injury without a clear cause, stage 3 or higher acute kidney injury, preexisting stage 4 or higher chronic kidney disease, renal replacement therapy, and other situations requiring subspecialist expertise.
Topics: Acute Kidney Injury; Creatinine; Fluid Therapy; Glomerular Filtration Rate; Humans; Nephrology; Prognosis; Referral and Consultation; Risk Factors
PubMed: 31790176
DOI: No ID Found -
Revista Medica de Chile Mar 2018Glomerular filtration rate (GFR) is the best approximation to global renal function and its estimation is of great relevance for clinical practice. Since the measurement... (Review)
Review
Glomerular filtration rate (GFR) is the best approximation to global renal function and its estimation is of great relevance for clinical practice. Since the measurement of GFR by reference methods is complex, costly and not widely available, its routine evaluation is performed using endogenous biomarkers. Within these, creatinine is the most commonly used. It allows the estimation of GFR by means of its clearance or by formulas based on its concentration on plasma. Creatinine measurement should be performed using enzimatic methods as they confer more accurate values than Jaffe methods, especially for normal and low creatinine levels.
Topics: Biomarkers; Creatinine; Glomerular Filtration Rate; Humans; Reference Values
PubMed: 29999105
DOI: 10.4067/s0034-98872018000300344 -
Journal of Veterinary Internal Medicine Mar 2022Basal serum cortisol (BSC) ≥2 μg/dL (>55 nmol/L) has high sensitivity but low specificity for hypoadrenocorticism (HA).
BACKGROUND
Basal serum cortisol (BSC) ≥2 μg/dL (>55 nmol/L) has high sensitivity but low specificity for hypoadrenocorticism (HA).
OBJECTIVE
To determine whether the urinary corticoid:creatinine ratio (UCCR) can be used to differentiate dogs with HA from healthy dogs and those with diseases mimicking HA (DMHA).
ANIMALS
Nineteen healthy dogs, 18 dogs with DMHA, and 10 dogs with HA.
METHODS
Retrospective study. The UCCR was determined on urine samples from healthy dogs, dogs with DMHA, and dogs with HA. The diagnostic performance of the UCCR was assessed based on receiver operating characteristics (ROC) curves, calculating the area under the ROC curve.
RESULTS
The UCCR was significantly lower in dogs with HA (0.65 × 10 ; range, 0.33-1.22 × 10 ) as compared to healthy dogs (3.38 × 10 ; range, 1.11-17.32 × 10 ) and those with DMHA (10.28 × 10 ; range, 2.46-78.65 × 10 ) (P < .0001). There was no overlap between dogs with HA and dogs with DMHA. In contrast, 1 healthy dog had a UCCR value in the range of dogs with HA. The area under the ROC curve was 0.99. A UCCR cut-off value of <1.4 yielded 100% sensitivity and 97.3% specificity in diagnosing HA.
CONCLUSIONS AND CLINICAL IMPORTANCE
The UCCR seems to be a valuable and reliable screening test for HA in dogs. The greatest advantage of this test is the need for only a single urine sample.
Topics: Adrenal Insufficiency; Animals; Creatinine; Dog Diseases; Dogs; Hydrocortisone; Retrospective Studies
PubMed: 35150029
DOI: 10.1111/jvim.16358 -
Jornal Brasileiro de Nefrologia 2015
Topics: Brazil; Calibration; Creatinine; Glomerular Filtration Rate; Humans; Kidney Diseases
PubMed: 26648490
DOI: 10.5935/0101-2800.20150068 -
Pediatric Nephrology (Berlin, Germany) Jan 2019Adequacy of dialysis is a term that has been used for many years based on measurement of small solute clearance using urea and creatinine. This has been shown in some... (Review)
Review
Adequacy of dialysis is a term that has been used for many years based on measurement of small solute clearance using urea and creatinine. This has been shown in some but not all studies in adults to correlate with survival. However, small solute clearance is just one minor part of the effectiveness of dialysis and in fact 'optimum' dialysis, rather than 'adequate' dialysis is what most paediatric nephrologists would want for their patients. Additional ways to assess the success of dialysis in children would include dialysis access complications and longevity, preservation of residual kidney function, body composition, biochemical and haematological control, nutrition and growth, discomfort during the dialysis process and psychosocial adjustment including hospitalisation and school attendance. These criteria need to be balanced against a dialysis programme that has the least possible adverse effects on quality of life.
Topics: Age Factors; Blood Urea Nitrogen; Body Composition; Child; Creatinine; Humans; Kidney; Kidney Failure, Chronic; Nutritional Status; Quality of Life; Renal Dialysis; Renal Elimination; Treatment Outcome; Urea
PubMed: 29582148
DOI: 10.1007/s00467-018-3914-6 -
PloS One 2014Bed-rest experiments are designed for investigation on catabolic effects of hypokinetic conditions and/or for microgravity simulation in on-ground aerospace research....
BACKGROUND
Bed-rest experiments are designed for investigation on catabolic effects of hypokinetic conditions and/or for microgravity simulation in on-ground aerospace research. Bed-rest effects include a reduction in fat-free mass and muscle mass. Urea and creatinine are catabolites of endogenous protein and of muscular energetic metabolism which are excreted mainly by the kidney. The study investigated on urea, creatinine, and kidney function during bed-rest.
METHODS
Twenty healthy young men underwent a 7-day adaptation period (day-6 to day-0) and a 35-day bed-rest experiment (day1 to day35) during normocaloric diet. Urine were collected from day-3 to day0 (baseline) and from day1 to day35. Blood samples and anthropometrical data were collected at day0 (baseline) and bed-rest days 7, 14, 21, 28, and 35.
RESULTS
Bed-rest reduced plasma volume, weight, fat-free mass, and muscle mass (P<0.001). During bed-rest there was a transient increase in plasma and urinary urea, a decrease in plasma creatinine, and no change in urinary creatinine. The overall integral of changes from day0 to day35 was on average +101.7 mg/dL for plasma urea (95%CI = +43.4/+159.9), +82.2 g/24 h for urinary urea (95%CI = +55.8/+108.7), -2.5 mg/dL for plasma creatinine (95%CI = -3.1/-1.9). Bed-rest reduced plasma cistatyn C also, which was used as mass-independent marker of glomerular filtration rate (-13.1%, P<0.05). Correlations with final reduction in fat-free mass and muscle mass were significant for the overall integral of changes in urinary urea from day0 to day35 (R = 0.706, P<0.001) and for early changes in urinary urea and plasma urea from day0 to day7 (R = 0.566, P = 0.009 and R = 0.715, P<0.001, respectively).
CONCLUSIONS
Study results shows that urea is a marker of catabolic conditions secondary to hypokinetic conditions.
Topics: Adiposity; Anthropometry; Bed Rest; Creatinine; Diet; Erythrocyte Indices; Humans; Male; Urea; Young Adult
PubMed: 25265226
DOI: 10.1371/journal.pone.0108805 -
Annales de Biologie Clinique 2010Serum creatinine is certainly one of the most prescribed biological parameters. In this review article, we remind some historical data regarding creatinine. Different... (Review)
Review
Serum creatinine is certainly one of the most prescribed biological parameters. In this review article, we remind some historical data regarding creatinine. Different methodologies to measure creatinine in blood and urine are deeply described. We also discuss the physiological reason for its use as a glomerular filtration rate marker. However, analytical and physiological limitations are described and discussed. Creatinine clearance usefulness is finally largely discussed.
Topics: Biomarkers; Creatinine; Glomerular Filtration Rate; Humans; Reproducibility of Results
PubMed: 20870575
DOI: 10.1684/abc.2010.0479 -
Journal of Cancer Research and... 2021The role of ascorbic acid in cancer therapy is mainly due to its structural similarity with glucose. When supplemented intravenously in high dose, ascorbic acid can get... (Clinical Trial)
Clinical Trial
BACKGROUND
The role of ascorbic acid in cancer therapy is mainly due to its structural similarity with glucose. When supplemented intravenously in high dose, ascorbic acid can get into the cancer cells and induce apoptosis by causing mitochondrial damage.
AIM
The aim was to study the efficacy of high-dose intravenous (IV) ascorbic acid as monotherapy in cancer patients following ketogenic diet and its role in improving the quality of life.
RESULTS
C-reactive protein (CRP) and erythrocyte sedimentation rates (ESRs) were considered as parameters to determine the efficacy of the treatment, and substantial decrease in both the levels was observed within 1-week treatment. CRP levels declined from 3.1946 ± 3.2508 mg/L to 1.0606 ± 0.6706 mg/L (P = 2.27E-10), whereas ESR levels declined from 64.1333 ± 38.8253 mm/h to 31.6 ± 16.5520 mm/h (P = 0.0041). A decline in these parameters shows the association of ascorbic acid in reducing the inflammatory response in cancer. The renal effect of ascorbic acid was also studied by analyzing the creatinine level pre- and postascorbic acid treatment sessions, and it raised from 0.8526 ± 0.22904 to 1.1666 ± 0.2894 mg/dL (P = 1.18E-14). This showed the renal impact of ascorbic acid.
CONCLUSION
The study highlighted the clinical benefit of IV ascorbic acid in the reduction of inflammatory response in cancer patients. The renal adverse events associated with ascorbic acid alarm the use with caution and therapeutic drug monitoring for ascorbic acid.
Topics: Adult; Ascorbic Acid; Creatinine; Diet, Ketogenic; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Humans; Infusions, Intravenous; Kidney; Male; Middle Aged; Neoplasms; Quality of Life; Renal Elimination; Treatment Outcome
PubMed: 34916403
DOI: 10.4103/jcrt.JCRT_973_19