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Threonine/Creatinine Ratio, 24-Hour Urine

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

Measures threonine excretion relative to creatinine in urine collected over 24 hours to help evaluate amino acid handling and nutritional status.

Quick summary

["This test compares urinary threonine with creatinine to provide context when interpreting threonine excretion."]

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

Key facts at a glance

LOINC
44413-3
Short code
Threonine/Creat 24h Ur
Synonyms
Threonine/Creat 24h 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 the amount of threonine, an essential amino acid, in urine relative to the amount of creatinine. The ratio is commonly used to help interpret threonine excretion and may be part of an evaluation of nutrition or amino acid metabolism.

Why might I need this test?

Your clinician may order this test to investigate unusual amino acid levels, monitor nutritional status, or assess how your body handles threonine. It may be interpreted alongside diet, supplement use, kidney function, and other laboratory results.

How is the test performed?

You collect all urine for a full 24-hour period in the container provided by the laboratory. The lab then measures threonine and creatinine and calculates their ratio.

How do I prepare for the test?

Follow the laboratory's collection instructions and record the start and end times. Keep the container refrigerated if directed, and tell your clinician about vitamin, amino acid, or protein supplements because they may affect the results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

24-Hour Urine Threonine-to-Creatinine Ratio

Frequently asked questions

Why is creatinine included in this test?
Creatinine provides a reference for comparing urinary threonine with another substance that is normally excreted. This can make the threonine result more useful than an unadjusted urine measurement alone.
What does a high threonine-to-creatinine ratio mean?
It may indicate increased threonine excretion or relatively lower creatinine excretion. Diet, supplements, kidney function, and collection completeness must also be considered.
What happens if urine collection is missed?
Missing urine or collecting for less than 24 hours can make the result inaccurate or uninterpretable. Ask the laboratory whether the collection should be repeated.
  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