Hypopituitarism Flashcards
What does hypopituitarism imply?
Diminished production of one or more anterior pituitary hormones.
What are the genetic defects that can cause hypopituitarism?
- Hypophysiotropic hormone gene defects
- Pituitary hormone gene defects
- Pituitary hormone receptor genetic defects
List some congenital embryopathic defects associated with hypopituitarism.
- Anencephaly
- Pituitary aplasia
What are some acquired defects that can lead to hypopituitarism?
- Tumors (pituitary adenomas, craniopharyngiomas, metastatic tumors)
- Irradiation
- Trauma (surgery, external blunt trauma)
- Vascular disorders (Pituitary apoplexy, Sheehan’s syndrome, Vasculitis)
- Inflammatory/infiltrative diseases (Sarcoidosis, Tuberculosis, syphilis)
- Metabolic disorders (Hemochromatosis, Amyloidosis)
What are the clinical manifestations of hypopituitarism dependent on?
Which hormones are lost and the extent of the hormone deficiency.
What does GH deficiency cause in children?
Growth disorders.
What are the effects of gonadotropin deficiency in women?
- Menstrual disorders
- Infertility
What are the effects of gonadotropin deficiency in men?
- Decreased sexual function
- Infertility
- Loss of secondary sexual characteristics
When do TSH and ACTH deficiencies usually develop?
Later in the course of pituitary failure.
What does TSH deficiency cause in children?
Growth retardation and features of hypothyroidism.
What does ACTH deficiency lead to?
Secondary adrenal insufficiency with hypocortisolism.
What does PRL deficiency cause?
Failure of lactation.
What symptoms reflect loss of vasopressin secretion?
Polyuria and polydipsia.
How is biochemical diagnosis of pituitary insufficiency made?
Demonstrating low levels of trophic hormones in the setting of low target hormone levels.
What does low free thyroxine with a low or inappropriately normal TSH level suggest?
Secondary hypothyroidism.
What does a low testosterone level without elevation of gonadotropins suggest?
Hypogonadotropic hypogonadism.
What are some provocative tests used to assess GH reserve?
- Insulin-induced hypoglycemia
- Arginine
- L-dopa
- Growth hormone–releasing hormone (GHRH)
- Growth hormone–releasing peptides (GHRPs)
What does CRH administration induce?
ACTH release.
What should be performed cautiously during insulin-induced hypoglycemia?
Assessing ACTH reserve in patients with suspected adrenal insufficiency.
What is the primary treatment for hypopituitarism?
Hormone replacement therapy.
What hormones are usually included in hormone replacement therapy for hypopituitarism?
- Glucocorticoids
- Thyroid hormone
- Sex steroids
- Growth hormone
- Vasopressin
What is the hormone replacement for ACTH deficit?
Hydrocortisone (10–20 mg A.M.; 5–10 mg P.M.)
What is the hormone replacement for TSH deficit?
L-Thyroxine (0.075–0.15 mg daily)
What is the hormone replacement for FSH/LH deficit in males?
Testosterone enanthate (200 mg IM every 2 weeks)
What is the hormone replacement for FSH/LH deficit in females?
- Conjugated estrogen (0.65–1.25 mg qd for 25 days)
- Progesterone (5–10 mg qd) on days 16–25
What is the hormone replacement for GH deficiency in adults?
Somatotropin (0.1–1.25 mg SC qd)
What is the hormone replacement for GH deficiency in children?
Somatotropin [0.02–0.05 (mg/kg per day)]
What is the hormone replacement for vasopressin deficiency?
Intranasal desmopressin (5–20 g twice daily)
