Antidiabetics - Insulin

Question 1

What is the term given to the group of cells in the pancreas that secrete glucagon and insulin?

Answer 1

• islets of langerhans

Question 2

The islets of langerhans is the term given to the group of cells in the pancreas that secrete glucagon and insulin. Which cells specifically secrete glucagon and insulin?

Answer 2

• glucagon = alpha cells

- insulin = beta cells

Question 3

What is C-peptide?

Answer 3

• a 31 amino acid peptide
• connects insulin’s A-chain to its B-chain in the pro-insulin molecule (not active until C-peptide is removed)
• C-peptide is removed prior to release from vesicles in the beta cells

Question 4

C-peptide is a 31 amino acid peptide that connects insulin’s A-chain to its B-chain in the pro-insulin molecule (not active until C-peptide is removed). The C-peptide is removed prior to release from vesicles in the beta cells. Why is C-peptide a useful measure

Answer 4

• if insulin is low as in T1DM then so to will C-peptide

Question 5

In fasting blood what level of C-peptide would be diagnosis cut off levels for the following:

• severe insulin deficiency
• intermediate insulin secretion
• substantial endogenous insulin secretion

Answer 5

• severe insulin deficiency = <80 pmol/L
• intermediate insulin secretion = >80-<250 pmol/L
• substantial endogenous insulin secretion = >250 pmol/L

Question 6

Insulin is used to treat T1DM. Insulin can come in 3 forms (how it has been produced), what are they?

Answer 6

1 - animal (bovine (beef) or porcine (pig))
2 - human
3 - synthetic

Question 7

Insulin is used to treat T1DM. Insulin duration affects can vary. What is added to the insulin that determines its duration?

Answer 7

• protamine

- affects insulins solubility meaning it cannot be absorbed as quickly by cells

Question 8

Typically insulin is used to treat T1DM, when can it typically be used in T2DM?

1 - alternative to oral anti-hyperglycaemic
2 - as part of dual therapy
3 - as part of triple therapy
4 - when oral anti-hyperglycaemic have failed to control hyperglycaemia

Answer 8

4 - when oral anti-hyperglycaemic have failed to control hyperglycaemia

Question 9

Insulin can be given in which of the emergency services?

1 - DKA
2 - hyperosmolar hyperglycemic state
3 - peri-operative glycaemic control
4 - all of the above

Answer 9

4 - all of the above

Question 10

Why is insulin used to treat hyperkalaemia?

1 - opens K+ channels
2 - binds Na+/K+ ATPase channels
3 - increases K+ excretion in urine
4 - activates Na+ /H+ antiporter

Answer 10

4 - activates Na+ /H+ antiporter

• leads to activation of Na+/K+ ATPase leading to an influx of K+ and lowering extracellular K+

Question 11

Insulin will inhibit which 2 of the following?

1 - gluconeogenesis
2 - ketogenesis
3 - glycogen synthesis
4 - lipid and protein synthesis

Answer 11

1 - gluconeogenesis
2 - ketogenesis

Question 12

All of the following are adverse events of insulin. But what is the main adverse event of insulin treatment?

1 - hyperglycaemia
2 - hypoglycaemia
3 - lipohypertrophy
4 - weight gain

Answer 12

2 - hypoglycaemia

Question 13

Does renal impairment affect insulin efficacy?

Answer 13

• yes
• insulin clearance is reduced, so can increase the risk of hypoglycaemia

Question 14

Prescribing which of the following can result in an increase in insulin being prescribed?

1 - ACE-I
2 - loop diuretics
3 - systemic glucocorticoids
4 - SGLT-2 inhibitors

Answer 14

3 - systemic glucocorticoids

• glucocorticoids increase blood glucose, so need more insulin to combat this

Question 15

What insulin regime is depicted in the image below?

1 - twice daily insulin regime
2 - once daily insulin regime
3 - continuous insulin pump
4 - basal/bolus regime

Answer 15

4 - basal/bolus regime
- bolus = high glucose at meals
- basal = continuous low glucose

• GOLD STANDARD for T1DM management
• covers entire 24 hour period

Question 16

There is a normal physiological release of insulin following breakfast, lunch and dinner. When is the largest concentration of insulin release in these 3 meals?

Answer 16

• breakfast

Question 17

What insulin regime is depicted in the image below?

1 - twice daily insulin regime
2 - once daily insulin regime
3 - continuous insulin pump
4 - basal/bolus regime

Answer 17

• once daily insulin regime
• normally lasts aprox 18-24 hours depending on which insulin is administered
• does not mimic the physiological meal response but provides slow release

Question 18

What insulin regime is depicted in the image below?

Answer 18

• twice daily insulin regime
• not recommended in T1DM patients
• this type of insulin is a form of long and short acting

Question 19

How is insulin typically administered?

1 - oral
2 - IV
3 - SC
4 - MI

Answer 19

3 - SC
- typically SC
- can be IV in emergencies