Pituitary Dysfunction Flashcards
What are the stimulatory and inhibitory factors of Growth Hormone?
Stimulatory:
Sleep, stress, Ghrelin, Protein/Arginine, Hypoglycemia
Inhibitory:
Obesity/FFA, Glucocorticoids, Leptin, Hyperglycemia
What are the signs of excess or deficiency of growth hormone?
Excess: Acromegaly
Deficiency: GH Deficiency
What are the signs of excess or deficiency of PRL?
Excess: Hypogonadism
Deficiency: Failed Lactation
What are the signs of excess or deficiency of FSH/LH?
Excess: rarely clinically evident
Deficiency: Hypogonadism
What are the signs of excess or deficiency of ACTH?
Excess: Cushing’s disease
Deficiency: Adrenal Insufficiency
What are the signs of excess or deficiency of TSH?
Excess: Hyperthyroidism
Deficiency: Hypothyroidism
What are the signs of excess or deficiency of ADH?
Excess: SIADH
Deficiency: Diabetes Insipidus
What distinguishes primary gland failure from secondary or tertiary causes?
Levels of pituitary/tropic hormones present. Low target gland or tissue function in the presence of high stimulatory hormones indicates a primary gland failure. Low target gland or tissue function in the presence of low stimulatory hormones indicates secondary or tertiary gland failure.
What dynamic test is used to detect excess GH/acromegaly and what are the diagnostic criteria?
Oral glucose test. Administration of oral glucose (75mg) should depress secretion of GH due to insulin feedback. Continued expression of GH indicates GH excess.
Old pictures for comparison of physical features, elevated IGF-1 levels over 24 hrs.
What are the treatments for GH excess/acromegaly?
Surgery
Medical therapies: somatostatin analogs, Growth Hormone Receptor Antagonist
Radiation Therapy
What are the manifestations of growth hormone deficiency?
Body composition: Inc fat, dec muscle mass and exercise capacity
Bone strength: Inc bone loss and fracture risk
Metabolic/Cardovascular: Inc cholesterol, Inc inflammatory and reactive markers (C RP)
Psychological Wellbeing: Impaired energy and mood, QoL
What are the tests for diagnosis and treatments for growth hormone deficiency?
Tests: Insulin induced hypoglycemia, Low IGF-1 level in setting of other pituitary hormone deficiency
Treatment:
GH replacement therapy.
Approved in children
Controversial in adults due to cost/benefit ratio
What are the normal PRL levels and what are physiologic, pathologic, and pharmacologic causes of hyperprolactinemia?
PRL Levels norm
What are the signs/symptoms of prolactinomas in men and women and what is the diagnostic criteria?
Men: Headache, impotence, anterior pituitary malfunction, EOM paralysis, visual field abnormalities, galactorrhea
Women: Galactorrhea, Menstrual irregularities, infertility, Impaired GnRH pulsatility
Diagnosis: PRL levels >150g/dl, Pituitary MRI
What is the etiology, presentation, and diagnostic criteria of PRL deficiency
Etiology: Severe pituitary destruction from any cause (tumors, infiltrative or infectious disease, infarction, radiation)
Presentation: Failed lactation in post-partum women, no known effect in males
Diagnosis: Low basal PRL level