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
Not provided.
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
Creatinine
Analyte
LOINC Codes
- 65634-8 - Creatinine 24H UR pnl 24h Ur
- 2162-6 - Creat 24h Ur-mRate
- 13362-9 - Specimen collect Time Ur
- 3167-4 - Specimen vol 24h Ur
- 20624-3 - Creat 24h Ur-mCnc
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 |