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Proline/Hydroxyproline/Creatinine, Urine — Ratio

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

A urine test that measures proline and hydroxyproline relative to creatinine, providing information about collagen breakdown and bone turnover.

Quick summary

["This ratio can help evaluate collagen and bone turnover, but results must be interpreted with other clinical findings."]

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

Key facts at a glance

LOINC
79611-0
Short code
Prolyl-OH-proline/Creat Ur-sRto
Synonyms
Prolyl-OH-proline/Creat Ur-sRto
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 proline and hydroxyproline in urine and compares them with urine creatinine. Hydroxyproline is released when collagen is broken down, so the ratio may provide information about collagen and bone turnover.

Why might I need this test?

A clinician may order this test when evaluating disorders involving bone remodeling, such as Paget disease, osteoporosis, osteomalacia, or conditions affecting collagen metabolism. It is usually considered alongside symptoms, examination findings, and other laboratory tests.

How is the test performed?

Proline, hydroxyproline, and creatinine are measured in a urine sample, and the reported ratio is calculated from these results. Creatinine is included as a reference because urine concentration can vary from one collection to another.

How do I prepare for the test?

Follow the laboratory's urine-collection instructions exactly. If a 24-hour collection is requested, collect all urine for the stated period, record the start and finish times, and keep the container refrigerated if instructed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An elevated ratio may indicate increased collagen breakdown or altered bone turnover. This can occur with Paget disease, bone disorders, or certain connective-tissue and metabolic conditions. A single abnormal result does not establish a diagnosis and should be interpreted by the ordering clinician.

Short name

Urine proline and hydroxyproline-to-creatinine ratio

Frequently asked questions

What does hydroxyproline measure?
Hydroxyproline is an amino acid released during collagen breakdown. Its measurement can help assess collagen turnover and, in some clinical settings, bone remodeling.
Why is creatinine included?
Creatinine is used to account for how concentrated or dilute the urine is. This helps make the calculated ratio more comparable between urine samples.
Does an abnormal result confirm a bone disease?
No. The ratio may support an evaluation for a bone or connective-tissue disorder, but symptoms, examination findings, and other tests are needed to determine the cause.
  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