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FCBGC
91673
glucocorticoids should have suppressed cortisol. In these circumstances a synthetic glucocorticoid screen
might be ordered (SGSU/81035 Synthetic Glucocorticoid Screen, Urine). Suppressed cortisol values may
also be observed in primary adrenal insufficiency and hypopituitarism. The optimal specimen type for
evaluation of primary adrenal insufficiency and hypopituitarism is serum (CORT/8545 Cortisol, Serum).
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
> or =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
> or =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 413=nmol/mol creatinine
Cortisol molecular weight=362.5
Creatinine molecular weight=149.59
Clinical References: 1. Findling JW, Raff H: Diagnosis and differential diagnosis of Cushing's
syndrome. Endocrinol Metab Clin North Am 2001;30:729-747 2. Boscaro M, Barzon L, Fallo F, Sonino
N: Cushing's syndrome. Lancet 2001;357:783-791 3. Taylor RL, Machacek D, Singh RJ: Validation of a
high-throughput liquid chromatography-tandem mass spectrometry method for urinary cortisol and
cortisone. Clin Chem 2002;48:1511-1519
Cortisol, Free, Serum
Reference Values:
Corticosteroid Binding Globulin (CBG)* (mg/dL)
Age Range
Newborns 0-3w 1.6-2.5
Infants 4w-11m 2.2-8.3
Females 12m-8y 4.3-10
Males 12m-9y 4.3-10
Older Children and Adults 2.3-3.9
Estrogen Therapy and Pregnancy >6.0
Free Cortisol, Serum (ug/dL)
Age Range
Prepubertal Females 8:00 AM 0-9y 0.1-1.2
Prepubertal Males 8:00 AM 0-10y 0.1-1.2
Adults 8:00 AM 0.2-1.8
Percent Free Cortisol, Serum (%)
Age Range
Prepubertal Females 8:00 AM 0-9y 0.8-3.4
Prepubertal Males 8:00 AM 0-10y 0.8-3.4
Adults 8:00 AM 2.3-9.5
Current as of January 4, 2013 7:15 pm CST 800-533-1710 or 507-266-5700 or MayoMedicalLaboratories.com Page 525