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free cortisol in 24 hour urine

Indications: - evaluation of Cushing's syndrome - evaluation of Addison's disease Contraindications: - not sufficiently sensitive to assess for cortisol excess in the setting of adrenalomas [6] - not accurate during acute illness [6] Reference interval: 1) adults: 20-90 ug/day (55-248 nmol/day) - < 50 ug/24 hours (< 138 nmol/24 hours) [2] 2) children 11-20 years of age: 5-55 ug/day (14-152 nmol/day) 3) children 1-10 years of age: 2-27 ug/day (6-74 nmol/day) Increases: 1) pharmaceutical agents - cortisone acetate, danazol, hydrocortisone, oral contraceptives 2) clinical disorders - Cushing's syndrome, late pregnancy, stress Decreases: 1) pharmaceutical agents - dexamethasone, ethacrynic acid, ketoconazole, thiazides 2) clinical disorders - Addison's disease, congenital adrenal hyperplasia, hypopituitarism Methods: - radioimmunoassay (RIA) - HPLC - equilibrium dialysis/ICMA Specimen: 1) preserve with 1 g boric acid to maintain pH < 7.5 2) freeze -20 C for long-term storage Notes: - normal cortisol variations & pulsatile nature of secretion makes random specimens of limited use - 24 hour urine creatinine should be collected simultaneously to assess completeness of urine collection - renal insufficiency can impair cortisol excretion

Related

cortisol; hydrocortisone (Cortef, Solu-Cortef, Alphaderm, Cetacort, Cortenema, Nutracort)

General

24 hour urine free cortisol in timed urine

References

  1. Clinical Guide to Laboratory Tests, 3rd ed. Teitz ed., W.B. Saunders, 1995
  2. Medical Knowledge Self Assessment Program (MKSAP) 11, 17 American College of Physicians, Philadelphia 1998, 2015
  3. Clinical Chemistry, Principles, Procedures, Correlations, 2nd ed., Bishop, Duben-Engelkirk, Fody (eds), JB Lippincott, Philadelphia, 1991, pg 1826
  4. Medline Plus: Cortisol - urine http://www.nlm.nih.gov/medlineplus/ency/article/003703.htm
  5. Panel of 12 tests Laboratory Test Directory ARUP: 92100 - Panel of 8 tests Laboratory Test Directory ARUP: 97222
  6. NEJM Knowledge+ Question of the Week. May 29, 2018 https://knowledgeplus.nejm.org/question-of-week/1833/

Component-of

hypertension panel