Endocrinology

Question 1

Which hormone binds to an intracellular receptor?

Answer 1

Steroid hormones are lipid soluble and have intracellular receptors
All hormones from the adrenal glands are steroid hormones
All hormones from the anterior pituitary are peptide hormones

Question 2

Ultra Short acting insulin

Answer 2

Onset <15min, peak at 1hr, duration 4-5 hrs
Insulin aspart = novorapid
Insulin lispro = humalog

Question 3

Short acting insulin

Answer 3

Onset 30min, peak effect 2-3 hours, duration 6-8 hours

E.g. Actrapid

Question 4

Long acting insulin

Answer 4

Onset 1-2.5 hours
peak effect 4-12 hours
Duration 16 - 24 hrs
= Isophane (e.g. protaphane)

Question 5

Longer acting insulin

Answer 5

Insulin determine (e.g. Levemir)
Onset 1-2 hours
Peak effect 6 - 8 hours 
Duration 12-24 hours
Fatty acid side chain which allow it to be 98% albumin bound, which prolongs duration of action 

Insulin glargine (e.g. Lantus)
Onset 1-2 hours
No peak effect
Duration 24 hours
Toujeo (concentrates glargine) - duration 36 hours

Insulin Degludec (e.g. Ryzodeg)
Duration > 40 hours

Question 6

Teriparatide: MOA and indications

Answer 6

Is a PTH analogue used for treatment of osteoporosis
Results in increased osteoblast activity
Can only use for 18mnths - increased risk of osteosarcoma

Question 7

Definition of macroalbuminuria in diabetic nephropathy

Answer 7

Men: urine ACR >25mg/mmol + AER >300mg/24hrs
Women: urine ACR >35mg/mmol + AER >300mg/24hrs

AER = albumin excretion rate

Question 8

Conn’s

Answer 8

Aldosterone hypersecretion
Symptoms: hypernatremia, hypokalemia, HTN
Diagnosis:
1. Plasma aldosterone-to-renin ratio (elevated = positive result)
Confirm
1. 3 days oral saline loading - urinary aldosterone secretion then measured
2. Plasma aldosterone after IV NaCl loading
3. 3 days PO fludrocortisone secretion
4. Captopril challenge

Question 9

Aldosterone

Answer 9

Mineralocorticoid
Principal site of action = distal and collecting tubules of the kidney - promotes Na retention and enhances K elimination

Secretion increased by

1. RAAS
2. Direct stimulation of adrenal context by increased in serum K

Question 10

Drugs that stimulate renin secretion

Answer 10

Create false negative in an aldosterone:renin ratio result
Spironolactone
ACEi
ARBs
Diuretics
Dihydropyridine Calcium Channel antagonist

Question 11

Drugs that suppress renin levels

Answer 11

Create false positive in an aldosterone:renin ratio result
Alpha-methyldopa
Beta-blockers
Clonidine
Diclofenac
Diuretics (inc Spironolactobe)

Question 12

Drugs that don’t interfere in interpretation of an aldosterone:renin ratio result

Answer 12

Verapamil
Hydralazine
Prazosin

Question 13

MEN type 1

Answer 13

3P’s
Parathyroid - hyperparathyroid due to parathyroid hyperplasia
Pituitary 
Pancreas e.g. insulinoma, gastrinoma 
Also thyroid and adrenal

MEN 1 gene
Most common presentation- hypercalcaemia

Question 14

MEN type IIa

Answer 14

2P’s
Parathyroid 
Phaeochromocytoma
Medullary thyroid cancer
RET oncogene

Question 15

MEN type IIb

Answer 15

1P
Phaeochromocytoma

Marfoid body habitus
Neuromas
Medullary thyroid cancer
RET oncogene

Question 16

Main site of action of SGLT2 inhibitors?

Answer 16

Early proximal convoluted tubule