Endocrine Flashcards
Cushing’s disease: electrolyte disturbances
Hypernatraemia
Hypokalaemia
Metabolic alkalosis
“al-K-low-sis”
Most common cause of primary hyperparathyroidism?
Solitary parathyroid adenoma
Why can you get ‘inappropriately normal PTH levels’ with hypercalcaemia?
Hypercalcaemia should feedback and cause low PTH levels (low PTH = low calcium, high PTH = high calcium).
If calcium is high, PTH should be low, therefore if PTH is actually normal, this actually means it is ‘inappropriately high’.
The high calcium is not feeding back to the parathyroid to reduce PTH.
Non-functioning pituitary adenomas can cause WHAT hormone abnormalities on tests?
Decreased levels of FLATPIG
- FSH
- LH
- ACTH
- TSH
- Prolactin
- IGF-1
- GH
What is sick euthyroid syndrome?
Low T3/T4, normal TSH, during acute illness
Congenital adrenal hyperplasia is a deficiency of WHAT enzyme?
What is the function of the enzyme?
What is the result of a deficiency of this enzyme?
21-hydroxylase enzyme
Converts progesterone to aldosterone + cortisol, ∴ deficiency = reduction in both
21-hydroxylase is NOT needed to convert progesterone into testosterone though, so excess progesterone becomes testosterone instead of cortisol + aldosterone (∴ virilising females)
What are the electrolyte + sugar disturbances in CAH?
Hyponatraemia (no aldosterone = no Na reabsorption)
Hyperkalaemia (no aldosterone = no K+ excretion)
Hypoglycaemia (no cortisol)
TSH receptor stimulating antibodies (TSHR-Ab) are diagnostic of what?
Grave’s disease
Low dose dex: no cortisol suppression
High dose dex: suppression of cortisol + ACTH
What is the underlying cause?
Cushing’s disease (i.e. pituitary secreting excessive amounts of ACTH)
Which hormones are reduced following stress (e.g. surgery)?
- Insulin
- Testosterone
- Oestrogen
Hypothyroidism + goitre + anti-TPO = ?
Hashimoto’s thyroiditis
Mechanism of action of orlistat
Pancreatic lipase inhibitor, ∴ reducing digestion of fat
What should pregnant women taking levothyroxine do?
Increase their levothyroxine by ~50%
