Creatinine, 24 Hour, Urine
Use
Calculation of creatinine clearance, a measure of renal function, when used in conjunction with serum creatinine. Creatinine is produced mainly by muscle metabolism, minimally affected day-to-day, freely filtered by the glomeruli, and partly secreted by renal tubules; renal clearance of creatinine estimates glomerular filtration rate. Reference values (mg per 24 hours) are provided for males ≥18 years (930–2955 mg/24 hours) and females ≥18 years (603–1783 mg/24 hours); not established for patients under 18 years.
Special Instructions
Not provided.
Limitations
Accuracy depends on correctly collected 24‑hour specimen. Intra‑individual variability may occur from differences in muscle mass or dietary protein intake. Acute changes in filtration prior to steady state can alter urinary creatinine excretion. Dietary intake of cooked meat may contribute to urinary creatinine levels.
FDA ApprovedNew York Approved
Methodology
Other
Biomarkers
Creatinine
Analyte
LOINC Codes
- 65634-8 - Creatinine 24H UR pnl 24h Ur
- 20624-3 - Creat 24h Ur-mCnc
- 2162-6 - Creat 24h Ur-mRate
- 13362-9 - Specimen collect Time Ur
- 3167-4 - Specimen vol 24h Ur
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
4 mL
Minimum Volume
1 mL
Container
24‑hour graduated urine container with no metal cap or glued insert; plastic aliquot tube (Sarstedt 5 mL Aliquot Tube T914)
Collection Instructions
Collect urine for 24 hours. Refrigerate specimen within 4 hours of completion. No preservative required; if used, must be added within 4 hours.
Causes for Rejection
All specimens evaluated for suitability; improper collection affects reliability
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 30 days |
| Frozen | 30 days |