Creatinine is a chemical waste product produced by muscle metabolism. When your kidneys are functioning normally, they filter creatinine and other waste products out of your blood. These waste products are removed from your body through urination.
Sara A. Love, Jesse C. Seegmiller, Julie Kloss, Fred S. Urine drug testing is commonly performed in both clinical and forensic arenas for screening, monitoring and compliance purposes.
We sought to determine if urine creatinine concentrations in monitoring program participants were ificantly different from hospital in-patients and out-patients undergoing urine drug testing. We retrospectively reviewed urine creatinine submitted in June through December for all specimens undergoing urine drug testing. In the two groups subject to on-demand sampling time pressures, median creatinine concentrations were ificantly lower in the R vs.
What is a dilute specimen?
The frequency at which some populations are drug tested may be higher than others; e. For these reasons a person who has ingested or has been exposed to an illegal substance may be inclined to adulterate their urine sample to avoid the consequences of a positive urine drug test result. Many efforts have explored urine sample adulteration and have highlighted the many different approaches in which this may occur 4—8.
One of the most common routes of adulteration is through dilution of the urine. This can be achieved by adding water directly to the sample after urine collection or by consuming large volumes of water prior to voiding.
In an attempt to correct for dilutional effects in specimens, efforts focusing on urine laboratory measurements of osmolality 910specific gravity 9—12and creatinine 9—12 have shown utility in this screen. In an observation was made on creatinine levels in normal urines where it was found to be surprisingly uniform amongst samples In current times it is well known that muscle mass, diet, renal function and other factors may ificantly alter the creatinine levels in urine. Biochemically creatinine is produced in vivo as a non-enzymatic breakdown products of creatine, phosphoryl creatine and phosphoryl creatinine Creatinine The daily creatine turnover is 1.
This creatine turnover rate is known to be relatively constant in normal individuals 16and since the creatinine drugs are proportional to creatine excretion this marker serves a quite reasonable purpose for its employment as a day-to-day marker of urine volume.
Urinary creatinine has become one of the most commonly used endogenous markers in present time for volume adjustment ratios in clinical and toxicology testing. Urine drug testing is commonly performed in both clinical and forensic settings, including random screening, scheduled monitoring and forensic testing.
What is a dilute specimen?
Participants in drug monitoring programs routinely undergo on-demand and scheduled screen, as required by either their care provider, in pain or recovery management, or program director in legal settings. Given the serious consequences of positive urine drug testcareful interpretation of specimen validity and identification of drug dilution and adulteration attempts are critical for Creatinine acting on urine drug test. Based on our experience in all three settings, random screening, scheduled monitoring and forensic testing, we sought to determine if any of the different participant groups that were providing urine for drug testing would have ificantly different urine creatinine concentrations.
Primarily, we sought to determine if the recovery group was ificantly different than our other urine drug testing groups. We retrospectively reviewed all creatinine concentrations, without related patient or additional specimen information, measured during any drug drug screen performed between June and December at the Hennepin County Medical Center toxicology laboratory. All specimens during the study time frame were processed during routine testing, according to the laboratory's clinical and forensic procedures.
This including specimen validity testing; any specimen which failed validity testing at that time would not have reported and therefore would not be included within the current study. Data and statistical analysis was performed using R r-project. Statistical ificance was defined at P values below 0. In a given month each group submitted between and 1, specimens, with an overall mean of per group per month. Figure 1 shows a box and whisker minimum to maximum plot of the creatinine screen by group. No Creatinine individual comparisons between creatinine concentration were ificantly different.
An internet search provides many mechanisms for how to beat a drug test and the scientific literature 1222—24 has long described the effects of the seat temptsand strategies to identify them to avoid false-negative. To combat these adulteration Creatinine it is a recommended, or mandated screen that urine drug testing rely on specimen validity tests to identify possible manipulation of submitted urine specimens 12 Unique to our study was the ability to compare creatinine concentration, as a drug of specimen dilution and possible adulteration, across different sample populations that included random screening, scheduled monitoring and forensic testing groups.
We did observe differences in the recovery group; however, this does not necessarily indicate manipulation on the part of the participants. A study by Chaturvedi et al.
The median creatinine concentration was ificantly lower for the recovery group, which could be due to multiple factors. One possible explanation of this difference could be due to differences in specimen collection timing.
The participants in our groups were Creatinine urine drug testing under different time-constrained sample collection conditions. The group with the most demanding time pressure to produce a urine sample was for those undergoing monitoring in our recovery group. This increased screen pressure is due to the drug system in place for this group, which limits the allowable time between notification and collection later that day. Prior to collection these and participants in other groups are known to have a beverage to ensure a urine sample for on-demand sampling.
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This is most similar between our two most time restricted groups, deated as our recovery and legal participants. An alternate explanation for the observed difference in median creatinine concentration could due be differences in the screen of the groups. It is well documented in the drug 13—1626 that many factors can influence creatinine Creatinine such as time of day, age, race and gender. One of the limitations of the current study is these factors cannot be directly assessed from the specific samples included in this analysis, as other specimen details including time of collection and participant demographics were not compiled here.
In the absence of demographic and specimen timing, given the other specimen collection conditions were the same across screens, the ificantly lower concentration of creatinine for the recovery group cannot be fully explained as either attempted dilution efforts by participants or simply by inter-individual variation between those groups.
The recovery group was found to have ificantly different median creatinine concentrations, while important, does not give Creatinine, case managers or the courts any clarity on the intent of individual participants within the group. Close observation of individual participant's and monitoring for trends drug repeated suspiciously low concentration samples is warranted to best detect if participants are trying to alter their test .
We would like to thank the technical staff of the toxicology laboratory at Hennepin County Medical Center for their hard work and dedication in measuring urine creatinine concentrations in the studied specimens. ConeE. Journal of Analytical Toxicology32— BushD. Forensic Science International, — Google Scholar.
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