| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Cortisol
MessagePerforming Lab: Regions
Test Code
3354
Alias/See Also
Sunquest: CORT
CPT Codes
82533
Preferred Specimen
0.2 mL Lithium Heparin Plasma (light green-top) tube
Minimum Volume
0.1 mL
Other Acceptable Specimens
Serum separator (gold-top), Red, Red/Gray
Instructions
Collection:
Blood should be collected at 8 AM and 4 PM to evaluate baseline diurnal variation.
Blood should be collected at 8 AM and 4 PM to evaluate baseline diurnal variation.
Transport Temperature
Refrgerated
Specimen Stability
Room Temperature: Not Recommended
Refrigerated: 14 Days
Frozen: 1 month
Refrigerated: 14 Days
Frozen: 1 month
Methodology
Competitive Immunoassay
Setup Schedule
Daily
Report Available
Same day.
Limitations
Circulating cortisol results from patients receiving Prednisolone or Prednisone therapy may be falsely elevated. Exercise caution with cortisol determinations for patients undergoing therapy with these and structurally related synthetic corticosteroids.
Reference Range
AM (before 10:00 am): 3.7 - 19.4 µg/dL
PM (after 5:00 pm): 2.9 - 17.3 µg/dL
PM (after 5:00 pm): 2.9 - 17.3 µg/dL
Clinical Significance
Corticosteroids are synthesized from cholesterol in the adrenal cortex, and cortisol is the main corticosteroid produced and secreted by humans. Physiological actions of cortisol include regulation of carbohydrate metabolism, electrolyte balance, water distribution and immunosuppressant and anti-inflammatory activity. Cortisol secretion is dependent on the integrity of the hypothalamic-pituitary-adrenal (HPA) axis and the steroid exerts a negative feedback on its own synthesis through this axis. Cortisol measurement is thus an important parameter in the investigation of apparent HPA dysfunction.
The circulating cortisol concentration is normally subject to a circadian rhythm, with the maximum level being reached at 8-9 a.m. and the minimum around midnight. Concentrations are usually elevated in pregnancy and in patients receiving high dose estrogen therapy. Anomalous cortisol concentrations can result from stimuli such as trauma, fear, fever, shock, hypoglycemia and depression.
In pathological states of the HPA axis, elevated or depressed values of cortisol may be found. Adrenal tumors and pituitary or ectopic adrenocorticotrophic hormone (ACTH)-producing tumors are frequently associated with cortisol over-production (Cushing’s syndrome), while adrenal insufficiency results in cortisol under-production (Addison’s disease).
The circulating cortisol concentration is normally subject to a circadian rhythm, with the maximum level being reached at 8-9 a.m. and the minimum around midnight. Concentrations are usually elevated in pregnancy and in patients receiving high dose estrogen therapy. Anomalous cortisol concentrations can result from stimuli such as trauma, fear, fever, shock, hypoglycemia and depression.
In pathological states of the HPA axis, elevated or depressed values of cortisol may be found. Adrenal tumors and pituitary or ectopic adrenocorticotrophic hormone (ACTH)-producing tumors are frequently associated with cortisol over-production (Cushing’s syndrome), while adrenal insufficiency results in cortisol under-production (Addison’s disease).
