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DISORDERS OF THE ADRENOCORTICAL HORMONES Dr. Ayisha Qureshi MBBS, Mphil Hypoadrenalism- ADDISON’S DISEASE ADDISON’S DISEASE DEFINITION: Addison’s disease results from the inability of the adrenal cortices to produce the adrenal hormones & this is most frequently caused by the primary atrophy of adrenal cortex. CAUSES: 1.Autoimmune disorder 2.Tuberculous destruction of the glands 3.Cancer 4.Secondary to impaired pituitary gland function leading to insufficient ACTH production. Signs & Symptoms Mineralocorticoid deficiency Glucocorticoid deficiency • Greatly decreased renal sodium reabsorption • Increased loss of Na, Cl & water in the urine • Decreased ECF/ hypovolemia • Hyponatremia • Hyperkalemia • Mild Acidosis • Increased RBC conc. Due to decreased ECF • Decreased CO • Shock • Death • Patient cannot maintain normal blood glucose levels as no gluconeogenesis b/w meals • Nausea, vomiting, fever, hypotension • All metabolisms effected • Patient highly susceptible to the deteriorating effects of stress. • Even mild infections can lead to death Signs & Symptoms • Extreme melanin pigmentation of the mucous membranes & skin. • Usually deposited in blotches • Cause is increased ACTH secretion as well as increased MSH secretion WHAT IS POMC & MSH? Proopiomelanocortin (POMC) is a preprohormone which when cleaved causes the formation of: • MSH (melanocyte stimulating hormone) which causes darkening of the skin by stimulating formation of melanin & dispersing it to the epidermis • Beta Lipoprotein • Beta endorphin & few others (ACTH also has 1/30 as much activity of MSH & so its hypersecretion also causes Hyperpigmentation of the skin.) TREATMENT • A person with complete destruction of the adrenal may die within a few days to 2 weeks b/c of weakness & circulatory shock. • However, if small quantities of mineralo & glucocorticoids are administered daily, they can live for years. Hyperadrenalism- Cushing’s Syndrome DEFINITION: Hypersecretion by the adrenal cortex causes a complex cascade of hormone effects called Cushing’s syndrome. CAUSES: • Exogenous - Factitious - Iatrogenic • ACTH-Dependant - Pituitary adenoma - Ectopic ACTH syndrome • ACTH-Independant - Adrenal adenoma - Adrenal carcinoma When Cushing’s syndrome is secondary to excess secretion of ACTH by the anterior pituitary, it is called CUSHING’S DISEASE. Signs & Symptoms • Truncal Obesity • Supraclavicular & dorsal fat pad • Buffalo hump • Moon Facies • Purple striae due to decreased collagen proteins • Thin skin • Capillary fragility & easy bruising • Hirsuitism • Diabetes Mellitus also called Adrenal Diabetes • Thin extremities and severe muscle weakness due to increased protein catabolism • Infections due to suppressed immune system with impaired wound healing • Osteoporosis • Hypertension Diagnosis & Treatment DIAGNOSIS: • Very challenging • Diagnose excess Cortisol (24 hour urine cortisol & midnight salivary cortisol level) • Dexamethasone suppression test TREATMENT: • Removal of the cause: Surgery of the adrenal tumour OR pituitary tumour • Drugs that block steroidogenesis.e.g. Ketaconazole • Drugs that inhibit ACTH secretion.e.g. Serotonin antagonists • Partial or total adrenalectomy PRIMARY ALDOSTERONISM (CONN’S SYNDROME) DEFINITION: Occasionally, a small tumor of the zona glomerulosa cells occurs & secretes large amounts of aldosterone; the resulting condition is called “Primary aldosteronism” or “ Conn’s disease”. CAUSES: • Small tumour of Zona Glomerulosa cells that secretes large amounts of Aldosterone. • Sometimes even hyperplastic adrenal cortices secrete aldosterone instead of cortisol. Signs & Symptoms • Severe hypokalemia causing muscle paralysis • Increased blood and ECF volume • Slight increase in Na conc. • Hypertension Usually, diagnosed by decreased plasma renin and increased aldosterone concentration. ADRENOGENITAL SYNDROME A syndrome that is caused by occasional adrenocortical tumour that secretes excessive quantities of androgens. Signs & Symptoms • - In Females: Virile characteristics Growth of a beard Deeper voice Occasionally baldness Masculine distribution of hair on the body Deposition of proteins in a masculine manner • In Males: - In prepubertal male, a virilizing adrenal tumour causes same characteristics as in the female plus rapid development of the male sex organs - In adult male, the virilising characteristics are often masked by the virilising effects of Testosterone - Diagnosis is made by the presence of excess 17-ketosteroids in the urine.
