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HelpTest Code COCOU Cortisol/Cortisone, Free, 24 Hour, Urine
Reporting Name
Cortisol/Cortisone, Free, UPerforming Laboratory
Mayo Clinic Laboratories in Rochester
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.
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
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 Type
UrineSpecimen Minimum Volume
3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 14 days | |
| Frozen | 28 days | ||
| Ambient | 72 hours |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.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
Interpretation
Most patients with Cushing syndrome have increased 24-hour urinary excretion of cortisol and/or cortisone. Further studies, including suppression or stimulation tests, measurement of serum corticotropin (adrenocorticotropic hormone) concentrations, and imaging are usually necessary to confirm the diagnosis and determine the etiology.
Values in the normal range may occur in patients with mild Cushing syndrome or with periodic hormonogenesis. In these cases, continuing follow-up and repeat testing are necessary to confirm the diagnosis.
Patients with Cushing syndrome due to intake of synthetic glucocorticoids should have both suppressed cortisol and cortisone. In these circumstances a synthetic glucocorticoid screen might be ordered (call 800-533-1710).
Suppressed cortisol and cortisone values may also be observed in primary adrenal insufficiency and hypopituitarism. However, random urine specimens are not useful for evaluation of hypocorticalism. Further, many normal individuals also may exhibit a very low 24-hour urinary cortisol excretion with considerable overlap with the values observed in pathological hypocorticalism. Therefore, without other tests, 24-hour urinary cortisol measurements cannot be relied upon for the diagnosis of hypocorticalism.
Patients with 11-beta hydroxy steroid dehydrogenase deficiency may have cortisone to cortisol ratios <1, whereas a ratio of 2:1 to 3:1 is seen in normal patients. Excessive licorice consumption and use of carbenoxolone, a synthetic derivative of glycyrrhizinic acid used to treat gastroesophageal reflux disease, also may suppress the ratio to <1.
Day(s) Performed
Monday through Friday
Report Available
2 to 6 daysTest 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-Cortisol; free
82542
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| COCOU | Cortisol/Cortisone, Free, U | 101319-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 8546 | Cortisol, U | 14158-0 |
| 10327 | Cortisone, U | 14044-2 |
| TM93 | Collection Duration (h) | 13362-9 |
| VL47 | Volume (mL) | 3167-4 |