Hippurate/Creatinine Ratio, 24-Hour Urine
Measures hippurate relative to creatinine in a 24-hour urine collection to evaluate how well the liver conjugates the amino acid glycine.
["This urine ratio can help assess liver function, especially when a glycine-conjugation disorder is suspected."]
Key facts at a glance
- LOINC
- 49903-8
- Short code
- Hippurate/Creat 24h Ur-sRto
- Synonyms
- Hippurate/Creat 24h Ur-sRto
- Category
- kidney
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 3.5
- Ref high
- 7.2
- 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?
Hippurate is a compound formed when the liver attaches glycine to another substance, particularly benzoate. This test measures urinary hippurate compared with urinary creatinine in urine collected for 24 hours. The ratio helps account for differences in urine concentration.
Why might I need this test?
This test may be used to evaluate liver function or investigate suspected defects in glycine conjugation. It is sometimes performed in people with unexplained neurological symptoms, developmental concerns, or episodes of illness triggered by infection, fasting, or certain medications.
How is the test performed?
You collect all urine produced during a full 24-hour period in a labeled container provided by the laboratory. The laboratory measures hippurate and creatinine in the collection and calculates their ratio.
How do I prepare for the test?
Follow the laboratory's instructions for the 24-hour collection, including the starting and ending times. Avoid accidentally including urine from before the collection begins or after it ends. The laboratory may advise refrigeration and may provide special instructions for the collection day.
Reference range
NCBI: Uric Acid Male 3.5-7.2 mg/dL; Female 2.5-6.8 mg/dLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A low hippurate-to-creatinine ratio may indicate reduced liver capacity to conjugate glycine, including in some inherited glycine-conjugation disorders. Interpretation can also be affected by urine collection errors, kidney function, hydration, illness, and medication or supplement use, so results should be reviewed with the ordering clinician.
Short name
24-Hour Urine Hippurate/Creatinine Ratio
Frequently asked questions
What does the hippurate-to-creatinine ratio show?
Why is a 24-hour urine collection required?
What if I miss part of the urine collection?
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 17, 2026. · Read our editorial policy