Week 9 - Endocrine Flashcards
What is the mechanism of action of Metformin?
Suppresses hepatic gluconeogenesis.
Increases peripheral sensitisation to insulin, increasing skeletal muscle and adipose glucose uptake and sensitisation
increases AMPK
inhibits G6Pase and PEPCK
Give an example of a sulphonyurea
Glibeclamide
Glipizide
What does pioglitazone do?
glitazone
Increases transcription of insulin sensitising genes. increased GLUT 4
Name some GLP-1
Liraglutide
exenatide
What is hirsutism?
Excess hair growth in a male pattern due to increased androgens or increased skin sensitivity to androgens
e.g. PCOS, corticosteroids, metformin, spironolactone
What screening tests would you use to investigate for cushings?
24 hour urine free cortisol
Overnight dexamethasone suppression test
Late night salivary cortisol
What investigations would you do to test for adrenal insufficiency?
Suspicious biochemistry - increased K, decreased Na, hypoglycaemic
Short synACTHen test
ACTH levels
Renin aldosterone levels (R inc, Aldo dec)
What is Kallmann’s syndrome?
Isolated gonadotrophin deficiency (LH and FSH)
May have anosmia or hyposmia
Micropenis ± cryptochidism
deafness, renal genesis, cleft lip/palate
Give some examples of primary gonadal failure. (low T)
Klinfelters, cryptorchidism, seminiferous tubules failure, adult leydig cell failure
What is hypogonadotrophic hypogonadism?
A form of hypogonadism due to a problem with the pituitary or hypothalamus. E.g. Kallmann’s
What is SIADH?
Excess ADH or inappropriate ADH for serum osmolality
Hyponatraemia with inappropriately low plasma osmolality
What is thyrotoxicosis?
Syndrome resulting from excessive free T3 and T4
What is T1DM?
A metabolic disorder of multiple aetiology characterised by chronic hyperglycaemia with disturbances of carbohydrate, fat and protein metabolism due to deficits in insulin secretion, action or both
What is the diagnostic criteria for T1DM?
One abnormal test value and symptomatic OR
Two abnormal tea values and asymptomatic
What tests would you perform to differentiate between types of DM?
Ketones +/- bicarbonate
C-peptide level
Autoantibodies
What is the Whipples triad?
- Sx consistent with hypoglycaemia
- Low plasma glucose concentration
- Relief of Sx after plasma glucose level raised
What is T2DM?
Chronic progressive metabolic disorder characterised by hyperglycaemia, insulin resistance and relative impairment of insulin deficiency
What is the pathophysiology for T2DM?
Risk factors Insulin resistance Hyperinsulinemia Exhausted Beta cells Hyperglycaemia
What is the MoA of metformin?
Supresses hepatic gluconeogenesis. increases glucose uptake in skeletal muscles and adipose, inhibits PEPCK and. G6Pase.
What is PCO?
Gonadotrophs, Androgens, insulin resistance
Characterised by irregular or no periods, acne, obesity and hirsutism.
Presents in adolescence
What is hypogonadism?
Reduced functional activity of the gonads, testes or ovaries that may diminish production of sex hormones
How could you manage pancreatic diabetes?
SU +/- insulin
What considerations must you take in prescribing diabetes drugs in Renal disease?
Stop metformin when eGFR <30ml/min/1.73m2
Caution with SU - increased risk of hypo
Possible dose reduction in DPP-4 and GLP-1
Canagliflozin for renal protection
What are some causes of primary amenorrhoea?
Never had a period
Congenital absence of Uterus, cervix or vagina - Rokitansky syndrome or androgen insensitivity syndrome
Chromosomal abnormality - Turners syndrome
What are some causes of secondary amenorrhoea?
Haven’t had a period in 6 months
Uterine - Ashermas syndrome
Ovarian - PCOS, Premature ovarian failure
Pituitary - Prolactinoma, pituitary tumour
Hypothalamic - Stress, weight loss, opiates
How could you manage Hirsutism?
Topical inhibitors - Elfornithine
Adrenal androgen suppression - corticosteroids
5 Alpha reductase inhibitors - Finasteride
Insulin sensitiser - metformin
Adrenal receptor antagonist - Spironolactone
What are some causes of primary gonadal failure?
Adult lending cell failure.
Seminiferous tubule failure
Klinfelters
Cryptochidism
How would you establish there is a cortisol excess?
Dexamethasone suppression test, 24 hour urinary free cortisol, late night salivary cortisol
then establish the source of the excess
What diseases are associated with mutation to teh RET protooncogene?
Familial medullary thyroid cancer
Multiple endocrine neoplasia type 2 and 3 (pheochromocytoma)
Hirschsprungs
How might a patient with Graves disease present?
Exophthalmos, Goitre, Pretibial myxoedema (deposits of mucin under the skin, very specific to graves), Thyroid acropathy
What are some rules if you are on steroids?
Do not stop suddenly Wear identification If get sick contact Dr immediately Inform all people who treat you that you are on steroids Reduce dose gradually if want to stop
What are the different patterns on nuclear imaging in thyrotoxicosis?
Diffuse uptake - Graves
Irregular uptake - Toxic multinodular goitre
Hot nodule - Toxic adenoma
Reduced uptake - thyroiditis
When is radio iodide contraindicated?
Lactaion, pregnancy, active thyroid eye disease
What are some contra-indications to metformin?
eGFR <30, metabolic acidosis, chronic heart failure, MI, DKA
