Creatinine excretion: variability and relationships to diet and body size.
01 Jun 1962-Journal of Laboratory and Clinical Medicine (J Lab Clin Med)-Vol. 59, Iss: 6, pp 945-955
TL;DR: By serial daily creatinine analyses over long experimental periods on a metabolic ward, "timing" artifact in 24 hour collections was minimized; this is an important source of error if single 24 hour or random samples are used.
Abstract: In general, rates of addition of creatine to and loss of creatinine from the precursor pool depend upon the dietary intake and synthesis of creatine and the conversions of phosphoryl creatine and creatine to creatinine. Meat in a usual diet can appreciably expand the pool because of the slow turnovers of the precursors. Thus, 24 hour urinary creatinine contains a component from that day's turnover of stored creatine ingested previously. During this study, ingestion of creatine and creatinine free, but adequate protein diets, adjusted pool size toward supply and demand and lowered creatinine excretion as much as 30 per cent. For any population, correlation coefficients between estimates of body size or metabolically effective tissue and urinary creatinine depend in part on the expansion of the precursor pool. By serial daily creatinine analyses over long experimental periods on a metabolic ward, "timing" artifact in 24 hour collections was minimized; this is an important source of error if single 24 hour or random samples are used.
Citations
More filters
TL;DR: The fundamental principles of physiology, metabolism, and analytical chemistry that are necessary to correctly interpret the serum creatinine concentration are reviewed and applied to important clinical circumstances, including aging, pregnancy, diabetes mellitus, drug administration, and acute and chronic renal failure.
Abstract: The serum creatinine concentration is widely interpreted as a measure of the glomerular filtration rate (GFR) and is used as an index of renal function in clinical practice. Glomerular filtration of creatinine, however, is only one of the variables that determines its concentration in serum. Alterations in renal handling and metabolism of creatinine and methodological interferences in its measurement may have a profound impact on the serum concentration of creatinine. We review the fundamental principles of physiology, metabolism, and analytical chemistry that are necessary to correctly interpret the serum creatinine concentration. These principles are then applied to important clinical circumstances, including aging, pregnancy, diabetes mellitus, drug administration, and acute and chronic renal failure. Despite numerous limitations, serum creatinine remains a useful clinical tool, but more accurate measures of renal function are frequently necessary.
1,550 citations
Cites background or methods from "Creatinine excretion: variability a..."
...A similar effect was described by Bleiler and Schedl (Figure 3) (56)....
[...]
...of the diet reduces creatinine excretion by 10-30% (56, 66, 67)....
[...]
...nine in meat may account for 15-30% of daily creatinine excretion (56, 66, 67)....
[...]
...Evidence suggests that reductions in dietary protein mediate small decreases (by 5-15%) in the size of the creatine pool; such decreases appear to reflect reduced availability of the creatine precursors arginine and glycine (44,56)....
[...]
TL;DR: This review summarizes the physical bases and assumptions, describes applications, and discusses the theoretical and practical limitations of currently available indirect methods of estimating fat-free mass and percent body fat.
Abstract: Renewed interest in the assessment of human body composition has stimulated the need for a balanced understanding of available methodologies of estimating fat-free mass and percent body fat. This review summarizes the physical bases and assumptions, describes applications, and discusses the theoretical and practical limitations of currently available indirect methods. Although standard methods are discussed, recent modifications and adaptations are emphasized.
1,111 citations
TL;DR: While creatinine excretion may serve as a useful approximation of muscle mass in carefully selected subjects, there remains a need for accurate and practical indices of Muscle mass for use in the individuals in whom the method cannot be reliably applied.
Abstract: Measuring muscle mass is an important component of the nutritional assessment examination and a suggested index of this body space is the 24-h urinary excretion of creatinine. The method originated from studies in a variety of animal species in whom early workers found a parallelism between total body creatine and urinary excretion of creatinine. Assuming that nearly all creatine was within muscle tissue, that muscle creatine content remained constant and that creatinine was excreted at a uniform rate, an obvious "corollary" was that urinary creatinine was proportional to muscle mass. The so-called "creatinine equivalence" (kg muscle mass/g urinary creatinine) ranged experimentally from 17 to 22. One of the limiting factors in firmly establishing this constant and its associated variability was (and is) the lack of another totally acceptable noninvasive technique of measuring muscle mass to which the creatinine method could (or would) be compared. An improved understanding of creatine metabolism and a variety of clinical studies in recent years has tended to support the general validity of this approach. However, specific conditions have also been established in which the method becomes either inaccurate or invalid. While creatinine excretion may serve as a useful approximation of muscle mass in carefully selected subjects, there remains a need for accurate and practical indices of muscle mass for use in the individuals in whom the method cannot be reliably applied.
812 citations
TL;DR: A 42-year-old woman with a mild sensorineural hearing loss bilaterally, and a family history of renal disease, a diagnosis of hereditary nephritis was made and she entered the feasibility phase of the Modification of Diet in Renal Disease (MDRD) Study.
Abstract: Patient 1. A 42-year-old woman first was evaluated at the New England Medical Center after an episode of dysuria that resolved following treatment with an antibiotic. Her weight was 55.5 kg and the blood pressure was 150/100 mm Hg. Urinalysis disclosed 3+ protein, 5—15 red blood cells/high-power field, occasional granular casts, and oval fat bodies. A 24-hour urine sample contained 3.9 g protein and 820 mg creatinine. Serum creatinine was I. I mg/dl and creatinine clearance was 52 mI/mm. Because of the laboratory abnormalities, a mild sensorineural hearing loss bilaterally, and a family history of renal disease, a diagnosis of hereditary nephritis was made. Hypertension was treated with hydrochlorothiazide, During the next 3 years, her blood pressure was usually in the range of 130/95 mm Hg, but occasional values were as high as 180/110 mm Hg. Urinary protein excretion declined to 0.64 glday. She complained of nocturia but otherwise was asymptomatic. At age 45 years, her blood pressure was 160/85 mm Hg and serum creatinine was 2.2 mg/dI. Propranolol, 20 mg twice daily, was added to her regimen, and a 40 g protein diet was prescribed. During the next 4 years, her hypertension was treated with hydrochlorothiazide, 50 mg/day; atenolol, 50 mg/day; and captopril, 25 mg/day; her blood pressure was usually in the range of 130—140/80—90 mm Hg. Body weight and serum albumin concentration remained stable. Serum creatinine ranged from 2.2 to 2.5 mg/dl. At age 49 years, she entered the feasibility phase of the Modification of Diet in Renal Disease (MDRD) Study. She was randomly assigned to follow a very low protein diet (16 g/day, equivalent to 0.28 g of protein/kg ideal body weight/day) supplemented with 12 g/day of an
561 citations
Additional excerpts
...Figure 4, from studies by Bleiler and Schedl [65], shows the decline in renal creatinine excretion and serum creatinine following elimination of meat from the diet and the substitution of a creatine-free protein formula (casein)....
[...]
TL;DR: Mean serum creatinine values are higher in men, non-Hispanic blacks, and older persons and are lower in Mexican-Americans, and it is not clear to what extent the variability by sex, age, and age reflects normal physiological differences rather than the presence of kidney disease.
Abstract: This report describes the distribution of serum creatinine levels by sex, age, and ethnic group in a representative sample of the US population. Serum creatinine level was evaluated in the third National Health and Nutrition Examination Survey (NHANES III) in 18,723 participants aged 12 years and older who were examined between 1988 and 1994. Differences in mean serum creatinine levels were compared for subgroups defined by sex, age, and ethnicity (non-Hispanic white, non-Hispanic black, and Mexican-American). The mean serum creatinine value was 0.96 mg/dL for women in the United States and 1.16 mg/dL for men. Overall mean creatinine levels were highest in non-Hispanic blacks (women, 1.01 mg/dL; men, 1.25 mg/dL), lower in non-Hispanic whites (women, 0.97 mg/dL; men, 1.16 mg/dL), and lowest in Mexican-Americans (women, 0.86 mg/dL; men, 1.07 mg/dL). Mean serum creatinine levels increased with age among both men and women in all three ethnic groups, with total US mean levels ranging from 0.88 to 1.10 mg/dL in women and 1.00 to 1.29 mg/dL in men. The highest mean creatinine level was seen in non-Hispanic black men aged 60+ years. In the total US population, creatinine levels of 1.5 mg/dL or greater were seen in 9.74% of men and 1.78% of women. Overall, among the US noninstitutionalized population, 10.9 million people are estimated to have creatinine values of 1.5 mg/dL or greater, 3.0 million have values of 1.7 mg/dL or greater, and 0.8 million have serum creatinine levels of 2.0 mg/dL or greater. Mean serum creatinine values are higher in men, non-Hispanic blacks, and older persons and are lower in Mexican-Americans. In the absence of information on glomerular filtration rate (GFR) or lean body mass, it is not clear to what extent the variability by sex, ethnicity, and age reflects normal physiological differences rather than the presence of kidney disease. Until this information is known, the use of a single cutpoint to define elevated serum creatinine values may be misleading.
560 citations
References
More filters
Book•
31 Dec 1951
TL;DR: This book is certainly one of the best that embraces the whole subject of surgery and it presents a thoroughly readable, sound picture of the essentials of surgery.
Abstract: Edited by R. M. HANDFIELD-JONES, M.C., M.S., F.R.C.S., and SIR ARTHUR E. PRRITT, K.C.M.G., C.B.E., M.Ch., F.R.C.S. 4th Edition. Pp. xv + I263, with 641 illustrations, many in colour. Edinburgh: E. & S. 'Livingstone. 195I. 55s. 'What surgery book shall I buy?' asks the student. Many practitioners cannot afford the time or money for volumes on the subdivisions that surgery has now split into. This book is certainly one of the best that embraces the whole subject. Beautifully produced and illustrated, it is easily read and its principles are thoroughly sound. Mr. Holmes Sellors has taken over the chapter on Chest Surgery, and Mr. J. F. Simpson those on Oto-Pharyngo-Laryngology. A tree planted only 13 years ago has little dead wood, but a certain amount of pruning would be apt. Pictures of thermos flasks to deliver saline seem hardly worth,their place, while the senior editor's crusade on infections of the hands needs some less painful first aid treatment of injuries than immersion in tincture of iodine for five minutes. The old long incisions for suppurative tenosynovitis of the hand are still figured, but penicillin irrigations are mentioned only in a final paragraph. The old word 'extension' is sporadically used for traction; being also the opposite of flexion, it causes confusion and might well be dropped. The advice given on treatment of an early case of congenital talipes equino-varus would give as poor a grasp of the child's foot as of Denis Browne's method of treatment. Manipulations are to be left to a capable nurse or masseuse correcting the deformity by numbers ' for a few seconds ... at least three times a week.' This would do nothing but postpone proper treatment until a time when its best chance has been lost. Similarly, it is by no means generally agreed that every colostomy patient should irrigate and so spend 45 minutes each morning in attention to his bowel; or that radiotherapy for squamous-celled carcinoma of the anus should be reserved for inoperable cases. As a final protest, surely Halsted deserves correct spelling. But these are small criticisms. The balance of the book is good and it presents a thoroughly readable, sound picture of the essentials of surgery. It is commended to all students.
1,222 citations
1,101 citations
TL;DR: The transfer of methyl groups from methionine to choline and creatine has been demonstrated by the isolation of deuteriocholine and deuteriocreatine from the tissues, and of deutriocreatinine from urine, or rats fed methionines containg a deuterio-methionine as mentioned in this paper.
Abstract: The transfer of methyl groups from methionine to choline and creatine has been demonstrated by the isolation of deuteriocholine and deuteriocreatine from the tissues, and of deutriocreatinine from the urine, or rats fed methionine containg a deuteriomethyl group. It was found from the deuterium ocntents of the isolated compounds that at the end of a given experimental period, each of the isolated compounds had derived approximately the same percentage of methyl groups from the deuteriomethionine of the diet. All the deuterium in the isolated choline was shown to be in the methyl grops. The concentraion of deuterium in the methyl gorups of the choline and creatine from the tissues as well as of the urinary creatinine rose to 85 per cent of that of the deuterio-methionine fed over a period of 14 weeks, strongly indicating that there was no other precursor of methyl groups in the diet employed.
The transfer of methyl groups from choline to creatime has been demonstrated by the isolation of deuteriocreatime from the tissues and of deuteriocreattnine from the urine of rats maintained on a diet containing deuteriocholine and homocystine.
Thus direct proof has been afforded to substantiate the hypothesis previously presentd that methionine may be a precursor of choline in so far as the methyl groups are concerned. The significance of these findings with regard to the prevention of fatty infiltraton of the liver and to the prevention of hemorrhagic kidneys resulting from a choline-deficient diet has been pointed out. The data support the hypothesis that the body is incapable of generationg methyl groups for certain methlations and that methyl groups must be supplied in the diet in a biologically labile from such as occurs in methionine and choline.
183 citations
TL;DR: It was conclusively proved by Bloch, Schoenheimer, and Rittenberg by isotope tracer evidence that creatinine was the only normal urinary constituent containing any significant amount of body creatine nitrogen.
Abstract: Shaffer (1), Myers and Fine (2), and Hahn and Meyer (3) adduced evidence that muscle creatine is the precursor of urinary creatinine. This was questioned by Chanutin and Kinard (4) but was conclusively proved by Bloch, Schoenheimer, and Rittenberg (5, 6) by isotope tracer evidence, which also showed that creatinine was the only normal urinary constituent containing any significant amount of body creatine nitrogen (1).
147 citations
131 citations