Creatinine (24 hour urine test)

We remind you that independent interpretation of the results is unacceptable, the information provided below is for reference purposes only.

Creatinine is a laboratory test that measures the amount of creatinine excreted in urine over a 24-hour period. Creatinine is naturally produced during muscle metabolism and is almost completely eliminated by the kidneys. The test is used to evaluate kidney function, metabolic status, and to calculate creatinine clearance.

Indications

• evaluation of kidney function
• suspected chronic kidney disease
• monitoring of kidney failure
• calculation of creatinine clearance
• monitoring patients with hypertension and diabetes mellitus
• assessment of treatment effectiveness in kidney diseases
• investigation of edema or changes in urine volume
• comprehensive evaluation of metabolic disorders

Procedure

• the test is performed using a 24-hour urine collection
• the first morning urine sample should not be collected
• afterward, all urine passed during the next 24 hours must be collected in a clean container
• the final portion should be added the following morning at the same time the collection began
• after completing the collection, it is necessary to:
  • measure and record the total urine volume collected over 24 hours
  • gently mix the contents of the container
  • transfer a small amount of urine into a sterile container for delivery to the laboratory
• during the collection period, the container should be stored in a refrigerator or cool place

Interpretation of Results

• Elevated urine creatinine level:
  • may occur in individuals with high muscle mass
  • may be seen after intense physical activity
  • can sometimes be associated with increased protein intake
• Decreased urine creatinine level:
  • may indicate impaired kidney function
  • may occur with significant loss of muscle mass
  • can be present in certain chronic diseases

Clinical Significance

• helps evaluate the excretory function of the kidneys
• used to calculate creatinine clearance and estimate renal filtration
• contributes to monitoring the progression of kidney diseases
• may help identify protein and fluid-electrolyte metabolism disorders
• used in the comprehensive diagnosis of nephrological and endocrine disorders
   

Sources:

https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=creatinine_urine
https://www.mayocliniclabs.com/test-catalog/overview/610603
https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/creatinine-urine-level

IMPORTANT!

It is essential to remember that the information provided in this section is not intended for self-diagnosis or self-treatment. If you experience any symptoms or a worsening of your condition, it is crucial to consult a healthcare professional for proper diagnostic tests and treatment. Only a qualified specialist can make an accurate diagnosis and determine appropriate treatment. To ensure the most accurate and consistent evaluation of test results, it is recommended to have them conducted at the same laboratory. Different laboratories may employ varying methods and units of measurement for similar tests.