PRESENTATIONS OF HYPOPITUITARISM

This depends on the hormones which are deficient. GH deficiency causes growth disorder and abnor­mal body structure. Gonadotrophin deficiency causes infertility, men­strual and sexual dysfunction and loss of secondary sexual characteristics in men. TSH and ACTH deficiency cause growth retarda­tion, hypothyroidism, adrenal insufficiency. Mineralo­corticoid action is retained. PRL(prolactin) deficiency causes failure of lacta­tion. If Posterior pituitary is also involved there is poly­uria, polyd’Rsia due to vasopressin deficiency.

Lab investigations for Hypopituitarism

• There are low levels of trophic hormones and low level of target hormones also e.g. Iow ACTH with low corti­sol, low FSH with low testosterone, estradiol, proges­terone, low level of TSH with low T₃₁ T₄, low levels of GH with low IGF (insulin like growth factors).
• Provocative tests are done to assess pituitary reserve.

Hypopituitarism Risk Factors

• Infections
• Infiltrative diseases
• Irradiation
• Lymphocytic hypophysitis
• Postoperative
• Pregnancy and delivery
• Trauma
• Tumors
• Vascular aneurysms

Assessment history of pituitary function,

• Pregnancy-related hemorrhage or hypotension
• Gonadal dysfunction
• Empty sella
• Craniofacial abnormalities
• Pituitary or hypothalamic lesions
• Inflammatory or granulomatous disease
• Head trauma or head surgery
• Cranial radiation

Hypopituitarism Physical Exam

• •Pituitary failure secondary to tumors:
  • ACTH: Hypotension, anorexia, pallor, weight loss
  • Gonadotropins: Delayed puberty
  • TSH: Weight gain, hair loss, dry skin, bradycardia, hoarseness, hypotension
  • GH: Decreased muscle mass and strength, increased visceral fat, growth retardation
• •Visual field defects
• •Children:
  • Congenital malformations and syndromes, especially malformations of the head and genitalia
  • Growth retardation and delayed puberty

Hypopituitarism Differential Diagnosis

• Primary hypothyroidism
• Primary hypogonadism
• Kallmann syndrome
• Hypothalamic insufficiency
• Constitutional short stature
• Chronic liver disease
• Addison disease, primary adrenal insufficiency

Treatment of Hypopituitarism

• Generalized condition caused by partial or total failure of anterior pituitary gland’s hormones: adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), growth hormone (GH), and prolactin.
• Less commonly, the posterior pituitary gland’s hormones can be affected: AVP/ADH and oxytocin.
• Hormone replacement therapy like glucocorti­coids, thyroid hormone, sex steroids, growth hormone, vasopressin are given.
• Shortages of ACTH, TSH, and ADH can be life-threatening.
• Synonym(s): Empty sella syndrome; Hypopituitarism; Pituitary cachexia; Simmonds syndrome; Panhypopituitarism; as a consequence of blood loss during pregnancy, Sheehan syndrome
• System(s) affected: Cardiovascular; Endocrine/Metabolic; GI; Musculoskeletal; Nervous; Reproductive; Skin/Exocrine
• Treatment of ACTH, TSH, LH, and FSH deficiencies similar to the treatment of primary hormone deficiencies of their respective target organ:
• ACTH deficiency results in cortisol deficiency:
  • Treatment consists of administration of glucocorticoid hormones (hydrocortisone, dexamethasone, or prednisone) to mimic normal pattern of cortisol secretion; mineralocorticoid replacement is rarely necessary.
  • Dosages and administration schedule vary according to age and sex.
  • Hypoprolactinemia has no treatment.
  • LH and FSH deficiency: Treatment depends on gender and whether fertility is desired.
• Men: Testerone replacement if fertility not desired; gonadotropins for fertility
  • Recombinant human GH (for treating short stature in children and for treating selected adult patients)
  • TSH deficiency: Goal of treatment is normal free T₄ value. Treat with levothyroxine.
• Women: Estrogen–progesterone (and possibly testosterone) replacement, or pulsatile gonadotropins for fertility
  • Infectious disease: Antibiotics as appropriate
• Inflammatory or granulomatous disease: Specific treatment
• Adrenal insufficiency should be excluded before thyroid hormone replacement is initiated; otherwise, thyroid hormone replacement could precipitate adrenal crisis
• Replacement of hormones secreted by target glands