Lecture 2: Adrenal Flashcards
Describe the difference between the short-term and long-term stress response in terms of the HPA axis and the adrenal cortex.
- Short-term causes stimulation of the adrenal medulla to ↑ release of catecholamine (NE and epinephrine)
- Long-term causes stimulation of the adrenal cortex and ↑ release of mineralocorticoids and glucocorticoids
What are the effects of angiotensin II on the adrenal cortex and pituitary gland?
- Adrenal cortex: stimulates secretion of aldosterone
- Posterior pituitary: stimulates the secretion of ADH
What are the 3 mainstays of treatment in an infant in crisis due to congenital adrenal hyperplasia (21-hydroxylase deficiency)?
- Hydrocortisone (IV or IM)
- Fluids/glucose (IV)
- Management of hyperkalemia: get K+ levels ↓
Summarize the purpose of mandatory newborn screening, which 7 major classes of disorders are screened for?
- Amino acid disorders
- Endocrine disorders
- Fatty acid oxidation disorders
- Hemoglobin disorders
- Lysosomal storage disorders
- Organic acid conditions
- Others: CF, hearling loss, classic galoctosemia, congenital HD, SCID
What is the most common cause of adrenal destruction responsible for primary adrenal insufficiency (Addison disease) in the US?
Autoimmune
Which autoimmune causes of adrenal destruction are associated with neurological deterioration which may mimic multiple sclerosis?
Adrenoleukodystrophy and adrenomyeloneuropathy
What is the inheritance pattern and what is seen with familial glucocorticoid deficiency (ACTH, cortisol, and mineralocorticoid levels)?
- Autosomal recessive
- ACTH resistance due to mutations in the adrenal ACTH receptors –> isolated cortisol deficiency
- ↑ ACTH causes skin pigmentation
- Mineralocorticoid production is always normal
Which disease of adrenal dysgenesis is associated with hypogonadotropic hypogonadism, myopathy, and high-frequency hearing loss?
Congenital adrenal HYPOplasia (x-linked) = absence of adrenal cortex
What is the most common cause of impaired steroidognesis leading to primary adrenal insufficiency; what are the levels of adrenal hormones like?
- 21-hydroxylase deficiency
- Deficiency of aldosterone = salt-wasting
- Deficiency of cortisol
- Excessive androgens (virilization of females)
Nearly all patients with primary adrenal insufficiency complain of what signs/sx’s?
- Fatigue + reduced stamina + weakness + anorexia + weight loss
- Skin hyperpigmentation
What is the serum Na+, K+, glucose, and calcium like in primary adrenal insufficiency?
- Low serum Na+
- High serum K+
- Fasting HYPOglycemia
- HYPERcalcemia may be present (↓ renal filtration)
What is the confirmatory test for primary adrenal insufficiency?
- Cosyntropin (synthetic ACTH) stimulation test
- If cortisol levels do no respond after 45 mins., confirms
Which serum markers can be used to confirm autoimmun Addison disase and which is required for diagnosis of 21-hydroxylase deficiency?
- Serum antibodies to 21-hydroxylase confirm dx of autoimmune Addison disease
- ↑ serum levels of 17-OH progresterone are required for diagnosis
What is the treatment for primary adrenal insufficiency (Addison disease)?
- Glucocorticoid replacement therapy: hydrocortisone, predisone, prednisolone
- Mineralocorticoid replacement therapy: fludrocortison acetate (Na+ sparing)
- DHEA: given to some post-menopausal women (libido, done density, hormonal balance)
List 5 labs which can be ordered to help diagnose acute adrenal crisis?
- ACTH (cosyntropin) stimulation test
- Cortisol level
- Blood sugar
- Serum K+
- Serum Na+