TEST FOR STEROID HORMONES

Adrenocorticol Hormone Test

-          These tests determine levels of aldosterone and cortisol  in blood and urine.

Ø      Aldosterone, a mineralcorticoid, aid in the regulation of the amount of sodium and potassium in the blood and helps maintain fluid balance.

Ø      Cortisol, a glucocorticoid, is responsible for the  metabolism of proteins, fats, and carbohydrates, as well as glucose.

Purpose

Measurement of Aldosterone is used to diagnose hyperaldosteronism and hypoaldosteronism (occurs in low level of cortisol). In which is the excessive secretion of the adrenal glands’ hormone.

Cortisol test is act upon patients who are assumed to have faulty adrenal glands. It is known to be the finest indicator of adrenal activity.

Ø     3 Most important tests for Cushing’ syndrome investigation and Addison’s disease:

·        Urine cortisol measurement

·        Blood cortisol measurement

·        Determination of ACTH levels

      Cushing’s Syndrome – overproduction of Cortisol

      Addison's disease - underproduction of Cortisol

Precautions

·        Serum or urine is the specimen used for Adrenocorticol function tests.

·        Universal Precautions should be observed to prevent transmission of bloodborne pathogens.

·        Diurnal variation is observed in blood for cortisol level.

·        Results should be evaluated. Time of day of the blood collected must be considered.

·        If the patient’s fluid balance may already be compromised by illness the patient must undergo 24 hr urine tests.

·        Physicians will also determine if patients can stop the taking of drugs that control sodium and potassium levels and fluid balance prior to testing.

·        Sometimes performed using RIA that mark test reagents with radioactive iodide

·        The RIA results may be altered with patients who have had recent procedures using radiation or had taken radioactive drugs.

Measurement

Ø      Enzyme immunoassay is the most common method used for cortisol determination. It’s routinely done in most laboratories.

             Measurement of cortisol intermediates such as 11-dexoycortisol and 17-hydroxyprogesterone are used in conjunction with cortisol for the detection of congenital adrenal hyperplasia.

    Adrenal hyperplasia - an enzyme deficiency in the synthetic pathway of cortisol leads to low cortisol and build up of one or more steroid intermediates above the block.

Ø      While, chemiluminescent immunoassay or radioimmunoassay is the method used to determine Aldosterone levels. These require a more sensitive method than with that of the cortisol determination.

·        Blood plasma or 24 hour urine specimen is the specimen used to test for aldosterone.

·        time of drawing a blood sample significant because Levels of aldosterone peak in early morning and are at half that level by afternoon.

·        For a more reliable evaluation, 2 samples may be drawn for testing, one in early morning (8 AM) and one mid-afternoon (4 PM). 

·        Diet and posture (upright or lying down) is significant for the fluctuation of aldosterone level, a single blood sample may falsely increased or decreased their levels and may not accurately reflect hormone production.

·        Hospitalized patients should remain in an upright position or at least sitting for two hours before blood is drawn, since posture and body position affect aldosterone production.

·        Nonhospitalized patients  should arrive at the lab for atleast 2 hrs. Before the collection to maintain an upright position.

Preparation

Ø      Fasting is not required for aldosterone blood or urine tests.

Ø      The patient should maintain a normal sodium diet (approximately 3 g/day) for at least two weeks before either test.

Ø       The testing physician should decide if drugs that alter sodium, potassium, and fluid balance should be withdrawn. The test will be more accurate if these are discontinued for a period of at least two weeks before the test.

Ø       Renin inhibitors should not be taken one week before the test, unless permitted by the physician.

Ø      The patient should avoid licorice (aldosterone-like effect) for at least two weeks before the test,

Ø      Strenuous exercise and stress should be avoided because they can alter the results through an increase in aldosterone levels.

Results

Aldosterone

Reference ranges for blood plasma levels:

• Supine (lying down): 3-10 ng/dL.
• Upright (sitting for at least two hours): Female: 5-30ng/dL; Male: 6-22 ng/dL.

Reference ranges for urine:

-         2-80 micrograms/24 hr.

Disease associated with an increase level of Aldosterone:

-          Conn's disease (aldosterone-producing adrenal tumor)

-           Bartter's syndrome (overexcretion of potassium, sodium, and chloride by the kidneys resulting in low blood levels of potassium and high blood levels of aldosterone and renin)

-          secondary aldosteronism

-          in primary conditions such as congestive heart failure

-           cirrhosis of the liver

-           certain kidney diseases

-          Hyperkalemia

-          a sodium-depleted diet

-          toxemia of pregnancy

-           stress

-          Malignant hypertension.

Decreased levels of aldosterone:

-          aldosterone deficiency

-          steroid therapy

-          high-sodium diets

-          certain antihypertensive therapies

-          Addison's disease (an autoimmune disorder also involving abnormal cortisol and ACTH levels).

Cortisol

Reference ranges for blood serum levels:

• Adults (8 A.M.): 6-28 micrograms/dL; adults (4 P.M.): 2-12 mcg/dL.
• Child 1-6 years (8 A.M.): 3-21 mcg/dL; child 1-6 years (4 P.M.): 3-10 mcg/dL.
• Newborn: 1/24 mcg/dL.

Reference ranges for urine (free cortisol):

• Adult: 10-100 micrograms/24 hr.
• Adolescent: 5-55 mcg/24 hr.
• Child: 2-27 mcg/24 hr.

Increased levels of cortisol:

-          Cushing's syndrome

-          hyperthyroidism (excess thyroid activity)

-          obesity

-          ACTH-producing tumors

-          Pregnancy

-          high levels of physical or emotional stress.

Decreased levels of cortisol:

-          Addison's disease

-          conditions of hypothyroidism (reduced thyroid activity)

-           hypopituitarism (diminished pituitary activity).

Saliva Analysis

Saliva serves as the diagnostic medium to determine the biologically active fraction of steroid hormones in the bloodstream.

Why saliva?

Ø    It’s a natural filtrate of blood that’s why it’s an excellent means to measure steroids and steroids not bound by carrier proteins in the blood freely diffuse into saliva.

Ø    Only about 1-10% of the steroids in blood are in the unbound or free form, and it is this fraction that diffuses into target tissues of the body, and into saliva

Ø    The steroid hormones that have been studied most extensively in saliva include estrogens (estradiol, estrone, and estriol), progesterone, androgens (DHEA, testosterone,DHT), and cortisol.

Saliva vs. Serum Testing

Ø      Collection time is more controlled.

Ø      Collection is Non-invasive, uncomplicated, safe, stress free, and painless

Ø      Allows for multiple collections

Ø      Hormones stable in saliva at room temperature for at least 3 weeks

Ø      Less expensive than blood testing

Ø      Saliva reflects the biologically active (free) fraction of steroids in the bloodstream (unlike blood or urine which measures total levels)

Test Methods
Radioimmunoassay is the assay used for the determination of hormones in the saliva. In which, the radioactive and non-radioactive hormones compete for a fixed number of antibody binding sites to determine the concentration of the hormone present in the saliva.
Specimen Requirements

Ø      7 ml of saliva is requested.

Ø       Specimen must be either frozen or delivered within 1 day of collection.

Ø       Specimen received for atleast 3 weeks in an stable ambient temperature is still acceptable.

REFERENCES:

http://www.aeron.com/technical_information.htm

http://www.enotes.com/nursing-encyclopedia/adrenocortical-hormone-tests