Leucine-to-Creatinine Ratio, Urine
Measures the amount of leucine in urine relative to creatinine, helping evaluate urinary amino acid excretion and kidney handling of amino acids.
["This urine test can help identify abnormal loss of the amino acid leucine, which may occur with certain inherited or kidney-related conditions."]
Key facts at a glance
- LOINC
- 30053-3
- Short code
- Leucine/Creat Ur-Rto
- Synonyms
- Leucine/Creat Ur-Rto
- Category
- kidney
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test measures the amount of leucine, an amino acid, in your urine relative to the amount of creatinine. Creatinine is used to help account for how concentrated or diluted the urine sample is.
Why might I need this test?
It may be used to evaluate unusual amino acid loss in the urine, especially when symptoms suggest an inherited disorder of amino acid transport or metabolism. It may also help assess the kidneys' ability to reabsorb amino acids.
How is the test performed?
A urine sample is collected and analyzed in a laboratory. The laboratory compares the amount of urinary leucine with the amount of urinary creatinine and reports their ratio. The type of urine collection requested can vary, such as a single sample or a 24-hour collection.
How do I prepare for the test?
Follow your clinician's instructions about the type and timing of urine collection. Good hydration and normal eating are generally sufficient unless you are told otherwise. Tell the laboratory and clinician about medicines, supplements, pregnancy, or a recent urinary infection that could affect the result.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A higher-than-expected ratio may indicate increased urinary loss of leucine. This can occur with inherited amino acid transport or metabolism disorders and may also be associated with some kidney conditions. Results should be interpreted with symptoms, other urine tests, and the collection method because diet, hydration, medicines, and urine concentration can affect the ratio.
Short name
Urine leucine-to-creatinine ratio
Frequently asked questions
Is this the same as a 24-hour urine test?
Why is creatinine included in the result?
Does an abnormal result confirm a genetic disorder?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy