Creatinine, 24 Hour, Urine
Use
This test is useful for normalizing urinary analytes to account for the variation in urinary concentration. Creatinine is formed from the metabolism of creatine and phosphocreatine, substances primarily found in muscle, making the amount of creatinine largely dependent on muscle mass. It suggests that the renal clearance of creatinine provides an estimate of glomerular filtration rate, which is crucial in assessing kidney function.
Special Instructions
This test is not orderable individually and is available only as part of a profile. For more information, refer to TLTE4 / Leukotriene E4, 24 Hour, Urine or MCM24 / Mast Cell Mediators, 24 Hour, Urine.
Limitations
The reliability of 24-hour urinary creatinine determinations highly depends on accurately collected 24-hour specimens. Intraindividual variability can occur due to differences in muscle mass or dietary protein intake. Interference from certain drugs like Rifampicin, levodopa, and calcium dobesilate can lead to artificially altered results. Methyldopa, as tested, also causes alteration in results.
FDA ApprovedNew York Approved
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 65634-8
- 2162-6
- 13362-9
- 3167-4
- 20624-3
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
Not provided
Minimum Volume
1 mL
Collection Instructions
Specimen must be collected over a 24-hour period. Only orderable as part of a profile.
Storage Instructions
Specimens should be frozen (preferred) to ensure stability, or can be stored at room temperature for up to 14 days or refrigerated for up to 30 days.
Causes for Rejection
All specimens will be evaluated for test suitability, unsuitable specimens may be rejected.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 30 days |
| Frozen | 30 days |