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Sample

  1. Serum of the patient is required.
  2. The urine sample may be used.
  3. For catecholamines (Epinephrine and Norepinephrine) plasma in heparin or EDTA is needed.
    • Transport this plasma on the ice and centrifuged at 4 C within 30 minutes and separate the plasma. Now freeze till the test is run.
    • Urine may be collected for 24 hours. Add 6 M HCl and Refrigerate during collection.
  4. For Cortisol, Serum is needed. Can use heparinized plasma.
    • Urine for 24 hours is collected with the addition of boric acid.
    • The serum is stable for 2 days at 2 to 8 °C.
  5. Aldosterone test can be done on plasma (heparin, EDTA or citrate). 
    • The serum can also be used.
    • Patient must be upright for 2 hours before the sample is taken.
    • Urine 24 hours is collected with boric acid and during collection is refrigerated.
  6. Estrogen can be estimated in the serum.
    • Serum needs to be freeze immediately after collection.
    • Urine 24 hours sample is collected with the addition of boric acid.

Precautions before performing the Adrenal gland tests

  1. Fasting sample is needed.
  2. Avoid exercise or physical activity.
  3. Reduce stress before performing this test.
  4. Avoid herbal medicines and any medication which interfere with the test.
  5. Avoid nuclear scan before this test.
  6. Aldosterone AM sample is higher than PM.
  7. Cortisol highest level is 8 AM  and >50% less at 8 PM.
    1. Transport the plasma on ice to the lab.
    2. Centrifuge at 4 °C.

Pathophysiology

  1. Adrenal glands consist of:
    1. Adrenal medulla.
    2. Adrenal cortex.
      1. The adrenal cortex is derived from mesoderm.
        1. These hormones maintain the homeostasis of the body.
      2. The adrenal medulla is derived from ectoderm.
  2. Adrenal Cortex secretes steroids hormones.
    1. Mineralocorticoid like aldosterone which regulates sodium and potassium.
      1. It promotes renal K+ excretion and increases water retention by increasing renal Na+ retention.
    2. Glucocorticoids like cortisol which is gluconeogenic.
      1. It regulates intermediary carbohydrate metabolism.
    3. Sex hormone like estrogen and progesterone.
  3. The adrenal medulla is neuroendocrine gland which secretes:
    1. Epinephrine.
    2. Norepinephrine.
      1. Both acts on the sympathetic nervous system.
        1. These hormones regulate the acute response of the body to external stimuli.

  1.  ACTH (Adrenocorticotropin hormone) from pituitary gland stimulates the adrenal cortex.
  2. Pituitary gland (ACTH) is stimulated by the Hypothalamic hormone (Corticotropin-releasing factor (CRH).

   

  1. Serum ACTH level has a diurnal variation:
    1.  Peak level is at 7 AM about 200 pg/ml.
    2. ACTH level decline and the lowest level is at midnight  around 100 pg/ml
  2. Cortisol secretions follow ACTH:
    1. Peak level is from 8.00 to 9.00 AM 
  3. Cortisol inhibits the secretion of ACTH from the pituitary gland and also inhibit CRH from the hypothalamus.

Normal 

Lab tests for various adrenal dysfunctions:

Adrenal Hyperfunction leads to:

  1. Excess of Cortisol causes  Cushing's syndrome.
  2. Excess of Aldosterone causes Hyperaldosteronism.
  3. Excess of Androgens causes Virilizing syndrome.

Primary Hyperadrenalism:

  1. Cortisol level is raised.
  2. ACTH level decreases.

Primary Adrenal Insufficiency (Addison's disease):

This is due to the diseases of the gland.

  1. Cortisol level is decreased.
  2. Serum sodium is low.
  3. Glucose level is decreased
  4. ACTH level is raised.
  5. Potassium, calcium and blood urea are raised

Secondary Hypoadrenalism (secondary or tertiary Adrenal insufficiency):

This is due to external factors which lead to under activity of the glands.

  1. Cortisol level is decreased
  2. ACTH levelly is low.

Cushing's syndrome: 

  1. There is no diurnal variation of ACTH and it is absent.
  2. There is an elevated level of Cortisol, Glucose, and Sodium.
  3. There is a decreased Potassium level.

Adult adrenogenital syndrome:

  1. There is an elevated level of:
    1. DHEA
    2. Urine 17- ketosteroids
    3. ACTH
  2. There is a decreased level of:
    1. Cortisol

Congenital Adrenal Hyperplasia:

  1. There is an elevated level of:
    1. ACTH
    2. Androgens level
  2. Decreased level of:
    1. Cortisol
    2. Aldosterone

Primary Hyperaldosteronism (Conn's syndrome):

  1. There is an elevated level of:
    1. Aldosterone urine and blood
    2. Serum sodium
  2. There is a decreased level of:
    1. Potassium
    2. Renin
    3. No response to aldosterone suppression test

Possible References Used

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