Urine Phenylpyruvate/Creatinine Ratio
Measures urine phenylpyruvate relative to creatinine. It may help evaluate phenylalanine metabolism in people being assessed or monitored for phenylketonuria.
["An elevated result may suggest excess phenylalanine metabolism and should be interpreted with blood phenylalanine and clinical findings."]
Key facts at a glance
- LOINC
- 108509-1
- Short code
- Phenylpyruvate/Creat Msmt Ur
- Synonyms
- Phenylpyruvate/Creat Msmt Ur
- 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 phenylpyruvate, a breakdown product of phenylalanine, in urine and compares it with the amount of creatinine in the same sample. The ratio helps account for differences in urine concentration.
Why might I need this test?
It may be used in evaluating or monitoring people with phenylketonuria or suspected problems with phenylalanine metabolism. Blood phenylalanine testing is generally the primary method for monitoring, and this urine test may provide additional information.
How is the test performed?
A urine specimen is collected and analyzed in the laboratory. Phenylpyruvate and creatinine are measured, and the result may be reported as a ratio to reduce the effect of variations in urine concentration.
How do I prepare for the test?
Collect urine at the time and for the duration specified by your clinician. Do not make major changes to your protein or phenylalanine intake for testing unless your metabolic-care team instructs you to do so.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated phenylpyruvate/creatinine ratio can reflect increased phenylalanine metabolism, which may occur with phenylketonuria or inadequate dietary phenylalanine restriction. Illness, hydration status, and kidney function can affect interpretation, so the result should be considered alongside blood phenylalanine levels and medical history. A low result is generally less clinically significant.
Short name
Urine phenylpyruvate/creatinine ratio
Frequently asked questions
What does phenylpyruvate measure?
Why is creatinine included in the result?
Is this the main test for monitoring phenylketonuria?
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