N-Acetyllysine/Creatinine Ratio, Urine
This urine test measures N-acetyllysine relative to creatinine, which helps account for differences in urine concentration.
["The ratio can help identify conditions that cause increased urinary excretion of N-acetyllysine."]
Key facts at a glance
- LOINC
- 79627-6
- Short code
- N-A-acetyllysine/Creat Ur-sRto
- Synonyms
- N-A-acetyllysine/Creat Ur-sRto
- Category
- liver
- 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 N-acetyllysine in urine compared with the amount of creatinine. Creatinine is used as a reference because its level in urine can vary with urine concentration.
Why might I need this test?
This test may be used to evaluate suspected inherited disorders of amino acid metabolism, including conditions that affect how the body processes lysine. It may also be ordered when symptoms suggest a metabolic condition that requires urine testing.
How is the test performed?
A urine sample is collected and tested in a laboratory. The laboratory measures N-acetyllysine and creatinine and calculates their ratio. Your care team will tell you whether a single urine sample or a timed collection is needed.
How do I prepare for the test?
Follow your care team's collection instructions exactly, including whether a first-morning or timed urine sample is required. Tell the laboratory if you are pregnant, taking medications, or have a known kidney condition.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated urine N-acetyllysine-to-creatinine ratio may indicate increased urinary excretion of N-acetyllysine, which can occur in inherited disorders of lysine metabolism, including lysinuric protein intolerance. Results must be interpreted with age, symptoms, diet, medications, kidney function, and other laboratory findings. A low or borderline result is less specific and does not by itself exclude a metabolic disorder.
Short name
Urine N-Acetyllysine/Creatinine Ratio
Frequently asked questions
Why is creatinine included in this test?
Does this test require a fasting blood sample?
What symptoms might lead to this test being ordered?
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