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Order Code COCOU Cortisol/Cortisone, Free, 24 Hour, Urine

Reporting Name

Cortisol/Cortisone, Free, U

Useful For

Screening test for Cushing syndrome (hypercortisolism)

 

Assisting in diagnosing acquired or inherited abnormalities of 11-beta-hydroxy steroid dehydrogenase (cortisol to cortisone ratio)

 

Diagnosis of pseudo-hyperaldosteronism due to excessive licorice consumption

 

This test has limited usefulness in the evaluation of adrenal insufficiency.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Urine


Necessary Information


24-Hour volume (in milliliters) is required.



Specimen Required


Supplies: Urine Tubes, 10-mL (T068)

Submission Container/Tube: Plastic, urine tube (T068)

Specimen Volume: 5 mL

Collection Instructions:

1. Add 10 g of boric acid as preservative at start of collection.

2. Collect urine for a full 24 hours (required) and record the total volume.

Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.


Specimen Minimum Volume

3 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 14 days
  Frozen  28 days
  Ambient  72 hours

Reference Values

CORTISOL

0-2 years: not established

3-8 years: 1.4-20 mcg/24 h

9-12 years: 2.6-37 mcg/24 h

13-17 years: 4.0-56 mcg/24 h

≥18 years: 3.5-45 mcg/24 h

 

CORTISONE

0-2 years: not established

3-8 years: 5.5-41 mcg/24 h

9-12 years: 9.9-73 mcg/24 h

13-17 years: 15-108 mcg/24 h

≥18 years: 17-129 mcg/24 h

 

Use the factors below to convert each analyte from mcg/24 h to nmol/24 h:

 

Conversion factors

Cortisol: mcg/24 hours x 2.76=nmol/24 h (molecular weight=362.5)

Cortisone: mcg/24 hours x 2.78=nmol/24 h (molecular weight=360)

 

For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html

Day(s) Performed

Monday through Friday

CPT Code Information

82530-Cortisol; free

82542

Method Description

The cortisol and cortisone are extracted from the resulting supernatant by an online extraction utilizing high throughput liquid chromatography. This is followed by conventional liquid chromatography and analysis on a tandem mass spectrometer equipped with a heated nebulizer ion source. Deuterated cortisol (d4-cortisol, d7-cortisone) is added to a 0.1 mL sample as an internal standard. Cortisol, Cortisone and d4-cortisol are extracted from the specimens using online turbulent flow high-performance liquid chromatography extraction.(Unpublished Mayo method)

Reject Due To

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Method Name

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Urine Preservative Collection Options

Note: The addition of preservative or application of temperature controls must occur at the start of the collection.

Ambient (no additive)

No

Refrigerate (no additive)

OK

Frozen (no additive)

OK

50% Acetic Acid

OK

Boric Acid

Preferred

Diazolidinyl Urea

No

6M Hydrochloric Acid

No

6M Nitric Acid

No

Sodium Carbonate

No

Thymol

No

Toluene

No