Creatinine is the endproduct of creatine metabolism. Creatine is present primarily in muscle and the amount of creatinine produced is related to total skeletal muscle mass. Daily creatinine production is fairly constant except when there is massive injury to muscle. The kidneys excrete creatinine very efficiently and blood levels and daily urinary excretion of creatinine fluctuates very little in healthy normal people. Since blood and daily urine excretion of creatinine shows minimal fluctuation, creatinine excretion is useful in determining whether 24-hour urine specimens for other analytes (e.g., protein) have been completely and accurately collected.
Reference Range(s):
| ≤6 Months | 2-28 mg/dL | |
| 7-11 Months | 2-31 mg/dL | |
| 1-2 Years | 2-110 mg/dL | |
| 3-8 Years | 2-130 mg/dL | |
| 9-12 Years | 2-160 mg/dL | |
| >12 Years Male | 20-320 mg/dL | |
| >12 Years Female | 20-275 mg/dL | |
This marker is part of a test that is used to detect albuminuria by measuring albumin and creatine concentrations in a random (spot) urine sample and calculating the albumin-creatinine ratio (ACR). This test is useful for assessing kidney damage, especially at an early stage, and informing management and prognosis of chronic kidney disease (CKD).
Creatinine, Random Urine
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