Cortisol, urinary free

Alphabetical Test listing

Cortisol, urinary free-13493

  
Cortisol, urinary free
  
13493
  
LAB13493
  
CFU
  
Urinary free cortisol
  

The diagnosis of Cushing syndrome (CS) requires evidence of cortisol hypersecretion.

  
Urine, 24 hr
  
100 mL aliquot of a 24 hour urine collection
  
10 mL aliquot of a 24 hour urine collection
  
  
  1. Measure and record the total volume of the 24 collection
  2. Mix well
  3. Transfer a 100 mL aliquot to a Screw cap plastic container (sterile)
  
  

24 hr urine collection container with Boric acid

24 hr urine collection container with HCl

  
  • Total volume
  

Ambient (preferred) - 14 days

Refrigerated - 14 days

Frozen - 14 days

Freeze/thaw cycles - stable x 3

  
LabCorp Burlington (004432): R-LC
  
Mo - Fr
  
3 - 7 days
  

Liquid chromatography tandem mass spectrometry (LC/MS-MS)

  

Age

Male (µg/24h)

Female (µg/24h)

0 d - 1 yr

not established

not established

2 – 5 yrs

2 – 16

2 – 16

6 – 11 yrs

4 – 28

4 – 24

12 yrs

4 – 36

4 – 36

13 - 17 yrs

6 – 45

6 – 42

18 - 80 yrs

5 – 64

6 – 42

> 80 yrs

3 – 49

3 – 49

  

While serum cortisol levels fluctuate unpredictably and are strongly dependent on concurrent cortisol-binding globulin (CBG) levels, a 24-hour urine specimen integrates the cortisol production for an entire day and is not affected by CBG. Urinary cortisol reflects the portion of serum-free cortisol filtered by the kidney, and correlates well with cortisol secretion rate. The most common causes of CS are pituitary adenoma (65% to 70%), adrenal tumor (15% to 20%), and ectopic CS (10% to 15%).

  
82530
  
Result 11040-3
  
03/29/2019
  
06/14/2019
  
02/19/2021