Effect of Oral Creatine Supplementation on Random Urine Creatinine, pH, and Specific Gravity Measurements

Ropero‐Miller, Jeri D.; Paget-Wilkes, Helen; Doering, Paul L.; Goldberger, Bruce A.

doi:10.1093/clinchem/46.2.295

Cited by 18 publications

(8 citation statements)

References 4 publications

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“…Analysis of 24‐h urine specimens revealed no significant change of Crn values. These results were supported by those from Ropero‐Miller et al, who examined the effects of oral Cr ingestion on urinary Crn, pH, and specific gravity values 11 . Urine samples were collected for 14 days (2 days before, 10 days during, and 2 days after supplementation).…”

Section: Discussionsupporting

confidence: 61%

The effect of creatine ingestion on urinary creatinine concentration: Does supplementation mask a heavy dilution?

Franz

Skopp

Mußhoff

2021

Drug Testing and Analysis

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A high volume of fluid can strongly reduce a drug's concentration in urine. Therefore, to detect diluted samples, the concentration of creatinine in urine is determined during testing drugs of abuse. If the concentration is below 20 mg creatinine/dl urine, the urine sample is usually rejected for drug testing. It should be examined whether creatine or creatinine ingestion can mask urine dilution by increasing the creatinine concentration. A total of 18 subjects drank 1.3 L of water and 0.2 L of orange juice on each of the three testing days: (1) without creatine, (2) with 20 g of creatine, and (3) with 20 g of creatine following incubation for 4 days in orange juice at room temperature; an acidic environment should promote conversion of creatine to creatinine. The lowest creatinine concentrations in urine were observed on average 2 h after fluid intake. At that time, ingestion of fluid without creatine, with creatine, and with creatine(ine)‐orange juice mixture resulted in mean values of 11.6, 22.5, and 28.3 mg creatinine/dl urine, respectively. It can be concluded that ingestion of creatine or creatinine can increase the concentration of creatinine in urine and thus mask dilution of a sample. The conversion of creatine in orange juice further increases availability of creatinine as it is obvious from urine creatinine concentration. Therefore, creatine ingestion during drug testing will give rise to negative results due to matrix adulteration. In a case of suspected creatine supplementation, the creatine content of the sample should be determined in addition to creatinine.

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Section: Discussionsupporting

confidence: 61%

The effect of creatine ingestion on urinary creatinine concentration: Does supplementation mask a heavy dilution?

Franz

Skopp

Mußhoff

2021

Drug Testing and Analysis

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“…Although some reports have suggested an increase in urinary creatinine following creatine supplementation, as yet that has not been clearly established. For example, both Poortmans et al and Ropero‐Miller et al have found little or no increase in urinary creatinine following short‐term creatine supplementation. Even long‐term supplementation was found to have little effect on urinary creatinine levels .…”

Section: Discussionmentioning

confidence: 99%

Comparison of Creatinine and Specific Gravity for Hydration Corrections on Measurement of the Tobacco-Specific Nitrosamine 4-(Methylnitrosamino)-1-(3-Pyridyl)-1-Butanol (NNAL) in Urine

Yang

Wong

Bunker

et al. 2014

J. Clin. Lab. Anal.

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“…Creatinine concentrations and the corresponding uncertainty about the concentrations in human urine are well documented for large (tens of thousands) numbers of individuals. , A large, detailed data set published by Barr et al provides information on the creatinine variation with ethnicity/age and the uncertainty about those values for 22,245 subjects. Activities such as ingesting dietary (creatine) supplements , and the consumption of meat , potentially affect creatinine concentrations in urine. For specific activities such as meat consumption to impact the interpretation of diurnal trends in substances ratioed to creatinine requires that subpopulations of the municipality (e.g., illicit drug consumers) disproportionately engage in activities that alter creatinine concentrations in urine.…”

Section: Introductionmentioning

confidence: 99%

Normalized Diurnal and Between-Day Trends in Illicit and Legal Drug Loads that Account for Changes in Population

Brewer

Ort

Banta‐Green

et al. 2012

Environ. Sci. Technol.

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Drug concentrations in composite municipal wastewater samples and census-based estimates of population are used to derive daily loads of illicit substances that are indexed to population. However, such estimates do not provide information on the diurnal trends of substance excretion nor can they account for changes in population. To address these limitations, a series of 1 h composites created by sampling wastewater influent at 6 min intervals was collected over four consecutive days at a single wastewater treatment plant. Creatinine (a urinary indicator), caffeine, methamphetamine, benzoylecgonine (BZE), and cocaine were analyzed by liquid chromatography/tandem mass spectrometry (LC-MS/MS). Diurnal trends and between-day trends were substance specific and related to the number of estimated doses and excretory half-life. Normalization to creatinine yielded trends in substances that differed significantly from non-normalized trends by accounting for changes in population within the municipality studied. Increases in normalized substance excretion observed during early morning hours originate from individuals among the resident population of the municipality due to the absence of commuters.

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Effect of Oral Creatine Supplementation on Random Urine Creatinine, pH, and Specific Gravity Measurements

Cited by 18 publications

References 4 publications

The effect of creatine ingestion on urinary creatinine concentration: Does supplementation mask a heavy dilution?

The effect of creatine ingestion on urinary creatinine concentration: Does supplementation mask a heavy dilution?

Comparison of Creatinine and Specific Gravity for Hydration Corrections on Measurement of the Tobacco-Specific Nitrosamine 4-(Methylnitrosamino)-1-(3-Pyridyl)-1-Butanol (NNAL) in Urine

Normalized Diurnal and Between-Day Trends in Illicit and Legal Drug Loads that Account for Changes in Population

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