endocrinology

Question 1

how is T2DM diagnosed

Answer 1

plasma glucose or HbA1c

if symptomatic (lethargy, polyuria, polydipsia):
* fasting glucose >/= 7
* random plasma glucose >/= 11.1 (or after 75g OGTT)
* HbA1c >/= 48

IF ASYMPTOMATIC - tests must show T2DM on 2 separate occasions

Question 2

what conditions can HbA1c not be taken in

Answer 2

conditions where RBC turnover is increased
* haemolytic anaemia
* CKD
* haemoglobinopathies
* suspected gestational diabetes
* untreated iron def anaemia
* HIV
* children

Question 3

what is impaired fasting glucose (IFG)

Answer 3

fasting glucose < 7 but >/= 6.1

Question 4

what is impaired glucose tolerance

Answer 4

fasting glucose < 7 AND OGTT >/= 7.8 BUT < 11.1

Question 5

how do you calculate serum osmolality in HHS (hyperglycaemic hyperosmolar syndrome)

Answer 5

(2 x sodium) + glucose + urea

Question 6

what is HHS + what are some precipitating factors for HHS

Answer 6

emergency (typically in T2DM pts) where: hyperglycaemia → increased serum osmolality → osmotic diuresis → severe dehydration

precipitating factors:
* intercurrent illness
* dementia
* sedative drugs

Question 7

clinical features of HHS

Answer 7

• onset = days (in DKA it’s hours)
• dehydration Sx, polyuria, polydipsia
• altered level of consciousness, focal neuro deficits
• hyperviscosity of blood - which could lead to MI, stroke or peripheral artery thrombosis
• lethagy, N+V

Question 8

management of HHS

Answer 8

• 0.9% NaCl given at 0.5-1L/hour
• K levels monitored and added to fluids accordingly
  *(insulin - only given if blood glucose stops falling while giving IV fluids as it should)
• VTE prophylaxis (due to hyperviscosity)

Question 9

what is the most common cause of primary hyperparathyroidism + what do the bloods look like

Answer 9

parathyroid adenoma

Ca high, Phosphate low

PTH levels: raised/ inappropriately normal (if Ca is high, you’d expect PTH to be low but if adenoma PTH is normal)

Question 10

management of primary hyperparathyroidism

Answer 10

• definitive = total parathyroidectomy
• conservative if Ca < 0.25 above higher end of normal AND < 50 y/o AND no signs of end organ damage
• if surgery not suitable: Calcimimetics e.g. Cinacalcet - binds allosterically to Ca-sensing receptors and mimics the action of Ca on tissues

Question 11

what are the x-ray findings in hyperparathyroidism

Answer 11

due to bone resorption
* pepperpot skull
* osteitis fibrosa cystica

Question 12

clinical features of primary hyperparathyroidism

Answer 12

manifestations of HYPERCALCEMIA (stones, bones, abdominal grones, thrones and psychiatric overtones)

• polyuria, polydipsia
• depression
• constipation, anorexia, nausea
• renal stones
• bone pain/fracture
• HTN
• pancreatitis
• peptic ulceration

Question 13

lab findings and potential complications of subclinical hyperthyroidism

Answer 13

TSH: low, freeT4 normal

• AF
• osteoporosis
• increased risk of dementia
• potential impact on QOL

Question 14

what conditions can cause a lower than expected HbA1c

Answer 14

due to lower lifespan of RBCs

• sickle-cell anaemia
• hereditary spherocytosis
• G6PD deficiency
• haemodialysis
• blood donation (induces production of new RBCs so reduced lifespan)

Question 15

what conditions can cause a higher than expected HbA1c

Answer 15

• splenectomy
• folate/B12 deficiency
• iron-deficiency anaemia

Question 16

what are the most common causes of hypercalcemia

Answer 16

primary hyperparathyroidism and malignancy