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Leucine-to-Creatinine Ratio, Urine

Published: August 9, 2026Updated: August 16, 2026

This urine test measures leucine relative to creatinine, helping account for differences in urine concentration.

Quick summary

["The result shows how much leucine is being excreted in the urine relative to creatinine."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
22693-6
Short code
Leucine/Creat Ur-sRto
Synonyms
Leucine/Creat Ur-sRto
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 the amino acid leucine in urine compared with the amount of creatinine. Creatinine is used as a marker of urine concentration.

Why might I need this test?

A clinician may order this test when there is concern about increased loss of amino acids in the urine, possible impaired kidney handling of leucine, or an inherited metabolic condition.

How is the test performed?

A urine sample is collected and analyzed in the laboratory. The laboratory compares the amount of leucine with the amount of creatinine in the same sample and calculates the ratio.

How do I prepare for the test?

Follow the collection instructions provided by the laboratory, which may request a spot urine or a timed collection such as a 24-hour collection. Fasting is usually not required unless your clinician specifically says otherwise.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine Leucine/Creatinine Ratio

Frequently asked questions

Does this test measure a vitamin?
No. Leucine is an essential amino acid, a building block of protein, rather than a vitamin.
Why is creatinine included in the result?
Creatinine helps show how concentrated the urine is. Including it makes the leucine measurement less dependent on variations in urine volume.
Does an abnormal result confirm a specific disease?
No. An abnormal ratio may suggest several kidney or metabolic conditions and is usually interpreted alongside other laboratory findings and clinical information.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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