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Proline/Creatinine Ratio, 24-Hour Urine

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

Measures urine proline relative to creatinine collected over 24 hours to help assess collagen metabolism and the body’s handling of proline.

Quick summary

["This test helps evaluate collagen turnover and may identify increased proline loss in urine."]

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

Key facts at a glance

LOINC
56973-1
Short code
Proline/Creat 24h Ur-Rto
Synonyms
Proline/Creat 24h Ur-Rto
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 proline and creatinine in urine collected for 24 hours. Proline is an amino acid that is especially abundant in collagen, while creatinine helps account for differences in urine concentration.

Why might I need this test?

Your clinician may order it to evaluate collagen breakdown, investigate a suspected problem with proline metabolism, or assess certain bone and connective-tissue conditions.

How is the test performed?

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

How do I prepare for the test?

Follow the laboratory’s instructions for the exact start and end times, and collect every urine sample during that period. Normal fluid intake is usually appropriate, but ask your clinician whether any dietary or activity restrictions are needed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An elevated ratio may occur when collagen is being broken down more rapidly, such as with some bone disorders, fractures, or connective-tissue conditions. It may also reflect an inherited problem in proline metabolism or reduced kidney clearance. Results must be interpreted alongside kidney function, medications, diet, and the completeness of the urine collection.

Short name

24-Hour Urine Proline/Creatinine Ratio

Frequently asked questions

Why is creatinine included in this test?
Creatinine is used to help adjust the urine proline measurement for variations in urine concentration. The ratio can therefore be more useful than the proline result alone.
How is a 24-hour urine collection done?
Usually, you empty your bladder at the specified start time, discard that sample, and then collect all urine for the next 24 hours. The final sample is included, and the container is labeled and returned according to the laboratory’s instructions.
What can cause an abnormal result?
Abnormal results may reflect increased collagen turnover, impaired proline metabolism, kidney function changes, or incomplete urine collection. Your clinician will interpret the result in the context of your health and other laboratory tests.
  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