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Test Code Epic LAB568 Cortisol, Free, Random, Urine

Additional Codes

SUNQUEST: CRANUM

MAYO: CRANR


Ordering Guidance


The preferred screening test for Cushing syndrome is a measurement of free cortisol in a 24-hour urine collection by liquid chromatography tandem mass spectrometry (LC-MS/MS); order CORTU / Cortisol, Free, 24 Hour, Urine.

 

The optimal specimen type for evaluation of primary adrenal insufficiency and hypopituitarism is serum; order CORT / Cortisol, Serum.



Specimen Required


Supplies: Urine tube, 10 mL (T068)

Collection Container/Tube: Clean, plastic urine container with no metal cap or glued insert

Submission Container/Tube: Plastic, 10-mL urine tube or clean, plastic aliquot container with no metal cap or glued insert

Specimen Volume: 10 mL

Collection Instructions: Collect a random urine specimen.


Secondary ID

609741

Useful For

Investigating suspected hypercortisolism when a 24-hour collection is prohibitive (ie, pediatric patients)

Profile Information

Test ID Reporting Name Available Separately Always Performed
CRAN Cortisol, Random, U No Yes
CRETR Creatinine, Random, U Yes, (order RCTUR ) Yes

Method Name

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

CRETR: Enzymatic Colorimetric Assay

Reporting Name

Cortisol, Free, Random, U

Specimen Type

Urine

Specimen Minimum Volume

3 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 14 days
  Frozen  28 days
  Ambient  7 days

Reject Due To

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

Reference Values

Males

0-2 years: 3.0-120 mcg/g creatinine

3-8 years: 2.2-89 mcg/g creatinine

9-12 years: 1.4-56 mcg/g creatinine

13-17 years: 1.0-42 mcg/g creatinine

≥18 years: 1.0-119 mcg/g creatinine

 

Females

0-2 years: 3.0-120 mcg/g creatinine

3-8 years: 2.2-89 mcg/g creatinine

9-12 years: 1.4-56 mcg/g creatinine

13-17 years: 1.0-42 mcg/g creatinine

≥18 years: 0.7-85 mcg/g creatinine

 

Use the conversion factors below to convert each analyte from mcg/g creatinine to nmol/mol creatinine.

 

Conversion factor

Cortisol: mcg/g creatinine x 312=nmol/mol creatinine

 

Cortisol molecular weight=362.5

Creatinine molecular weight=113.12

Method Description

Isotopically labeled cortisol and cortisone are added to the sample as internal standards. Cortisol, cortisone, and coinciding internal standards are extracted from the specimens using online turbulent flow chromatography, which is followed by liquid chromatography tandem mass spectrometry analysis.(Unpublished Mayo method)

 

Creatinine:

The enzymatic method is based on the determination of sarcosine from creatinine with the aid of creatininase, creatinase, and sarcosine oxidase. The liberated hydrogen peroxide is measured via a modified Trinder reaction using a colorimetric indicator. Optimization of the buffer system and the colorimetric indicator enables the creatinine concentration to be quantified both precisely and specifically.(Package insert: Creatinine plus ver 2. Roche Diagnostics; V15.0, 03/2019)

Day(s) Performed

Monday through Friday

Report Available

2 to 6 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

82530

82570

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CRANR Cortisol, Free, Random, U 44309-3

 

Result ID Test Result Name Result LOINC Value
10328 Cortisol/Creatinine Ratio 11155-9
CRETR Creatinine, Random, U 2161-8