Proline/Creatinine Ratio, 24-Hour Urine

This test checks the levels of certain substances in your urine by measuring everything your body produces over a full 24-hour period. Because these levels can rise and fall throughout the day, collecting your urine for 24 hours gives your healthcare provider more accurate results than a single sample.

Proline is an amino acid used to build proteins. This test measures urinary proline relative to creatinine, a substance used to account for urine concentration.

Your healthcare provider may order this test to see how well your kidneys are working or to measure hormones, proteins, minerals, or other substances that a routine urine test cannot measure reliably. It can help diagnose or monitor conditions such as kidney disease, high blood pressure, or hormone problems.

It may be used to investigate unusually high urinary proline levels or evaluate a possible inherited problem involving amino acid metabolism.

For this test, you will collect every drop of urine you pass during a 24-hour period. You will empty your bladder into the toilet first, then save all later urine in a special container with a lid. The container is kept cool, usually in a refrigerator, and returned to the lab when the collection is finished.

You collect all urine for a full 24-hour period according to the laboratory's instructions. The laboratory then measures proline and creatinine in the collected sample and calculates their ratio.

Your healthcare provider will give you a collection container and detailed instructions, which may include avoiding certain foods, drinks, or medicines before and during the test. Plan to stay close to a bathroom during the collection period, and tell your provider about all medicines and supplements you take.

Follow the collection instructions carefully, including the start and end times. The laboratory may ask you to refrigerate the container and bring it in promptly; fasting is generally not required.