Pituitary Dysfunction

Question 1

What stimulates the release of growth hormone?

Answer 1

Sleep 
Puberty
Glucagon
Hypoglycemia
Stress
High levels of amino acids
Alpha-adrenergic agonists

Question 2

What suppresses the release of growth hormone?

Answer 2

Aging
Somatostatin
Hyperglycemia
Free fatty acids

Question 3

Disorders in the HPA axis can be either central or peripheral. What does this mean?

Answer 3

Central disorders arise from problems in the hypothalamus or pituitary, while peripheral disorders arise from the target organ.

Question 4

Describe the process of dynamic pituitary testing.

Answer 4

You use the natural stimulus for a hormone to induce secretion. If the natural stimulus does not elicit the expected response, then you know that hormone is somehow affected.

Question 5

What organ secretes IGF-1?

Answer 5

The liver (in response to GH)

Question 6

What is the best screening test for acromegaly?

Answer 6

IGF-1 levels

Question 7

What three categories of treatment can help treat acromegaly?

Answer 7

• Surgical excision of the GH-secreting tumor
• Radiation therapy of the GH-secreting tumor
• Somatostatin analogues or GH antagonists

Question 8

What happens to GH over the lifespan?

Answer 8

Its levels decrease by about 14% per decade.

Question 9

Use of GH in those with adult-onset growth hormone deficiency has ________________.

Answer 9

not been shown to decrease fracture risk or improve longevity

Question 10

_______________ tests can be used to test for GH reserves, but it is not done often because of its intrinsic danger.

Answer 10

Insulin-induced hypoglycemia

Question 11

_______________ are more common in women and present with infertility and menstrual irregularities.

Answer 11

Prolactinomas

Question 12

_______________ is used in all those with prolactinomas, except for in pregnant women who receive bromocriptine because of its favorable pregnancy safety profile.

Answer 12

Cabergoline

Question 13

What can cause low prolactin levels?

Answer 13

Use of dopamine agonists or infiltrative neoplasms

Question 14

Cushing’s disease can be either ____________ or _____________.

Answer 14

ATCH-dependent (75% of cases) or ACTH-independent (25%)

Question 15

The nadir of cortisol usually occurs at _________, while the peak occurs at __________.

Answer 15

~midnight; ~8:00 AM

Question 16

When should you test someone’s cortisol to test for Cushing’s syndrome?

Answer 16

Midnight (you have them chew a cotton ball and send it in)

Question 17

What can cause adrenal insufficiency?

Answer 17

• Opioids
• Surgical removal of the pituitary
• Use of exogenous steroids (that then suppress the HPA axis)

Question 18

When should you test cortisol levels for suspicion of adrenal insufficiency?

Answer 18

~8:00 AM

Question 19

Most _____________ adenomas are silent because their secreted product is dysfunctional.

Answer 19

gonadotrope

Question 20

What is apoplexy?

Answer 20

Sudden hemorrhage of the pituitary gland that leads to headache, ophthalmoplegia, and altered mental status

Question 21

ADH is primarily released by _________________.

Answer 21

hyperosmolar states

Question 22

_______________ occurs in about 20% of hospitalized patients.

Answer 22

SIADH

Question 23

Two endocrine disorders can cause SIADH: _______________.

Answer 23

hypothyroidism and hypocortisolism

Question 24

To fit the criteria for SIADH, people must have what two lab values?

Answer 24

Na less than 135 mEq/L and serum osmolarity less than 275 mEq/L

Question 25

Which side of the pituitary is bigger?

Answer 25

The anterior side

Question 26

Describe the nomenclature of primary, secondary, and tertiary in endocrine disorders.

Answer 26

Primary: target organ fails to respond to pituitary hormone
Secondary: pituitary fails to respond to hypothalamic hormone
Tertiary: hypothalamus fails to produce hormone

Question 27

After administering glucose, levels of ____________ should be low.

Answer 27

growth hormone

Question 28

Prolactin levels greater than _____________ are indicative of prolactinoma.

Answer 28

150 ng/mL

Question 29

Low TSH and low T4 indicates _________.

Answer 29

central hypothyroidism

Question 30

Thinking of the anterior pituitary, what is one reason it’s important for kids to get sleep?

Answer 30

Growth hormone secretion peaks during sleep

Question 31

Excess FSH/LH is _______________.

Answer 31

rarely clinically evident

Question 32

___________-adenomas are detected in over 80% of cases of acromegaly.

Answer 32

Macro

Question 33

What can cause prolactinemia?

Answer 33

Use of D2 antagonists
Primary hypothyroidism
Suckling
Stalk interruption (from a mass)
Estrogen use
TCAs
Prolactinomas

Question 34

Which layers of the adrenal cortex does ACTH act on?

Answer 34

All three

Question 35

ADH deficiency is common in _____________.

Answer 35

metastatic cancer

Question 36

Hypopituitarism presents with ________-kalemia.

Answer 36

hyper (due to loss of aldosterone from the deficient ACTH)