Insulin

Question 1

What is diabetes?

Answer 1

A condition in which the body either does not produce enough or does not properly respond to insulin - a hormone produced in the pancreas

Question 2

What is insulin?

Answer 2

Low molecular weight protein produced and stored by the beta cells of the pancreas

• The pancreas produces 25-50 units per day and also produces it in response to High Blood Glucose Levels

Question 3

What is the aim of insulin?

Answer 3

The aim is to conserve fuel by facilitating uptake and storage of glucose, amino acids and fats after a meal

Question 4

How does insulin facilitate glucose use?

Answer 4

• Increasing uptake of glucose
• Increasing liver glycogen
• Decreasing glycogen breakdown by liver
• Increasing synthesis of fatty acids
• Inhibiting breakdown of fatty acids into ketone bodies
• Promoting incorporation of amino acids into protein

Question 5

What happens if the insulin is deficient?

Answer 5

It releases stored glycogen and fat for energy production

Question 6

How is insulin produced?

Answer 6

• Synthesised as a precursor (preproinsulin) by the beta cells of the pancreas
• Undergoes proteolytic cleavage to form proinsulin, the insulin
• Secreted by beta cells of the pancreas at a steady basal rate and in response to high blood sugar levels

Question 7

What is Insulin: MOA ?

Answer 7

• Insulin binds to its receptor
• Occupied receptors aggregate into clusters and are then internalised into cells via vesicles
• Insulin then exerts its effects via a number of pathways : one of which results in the translocation of GLUT-4 receptors to the plasma membrane

This allows increased glucose uptake by the cell

Question 8

How can insulin be used for clinical use?

Answer 8

• Clinical use can be either bovine origin or recombinant human insulin
• Insulin, being a protein is destroyed by enzymes in the Gastrointestinal Tract, and should be given parenterally

Pulmonary absorption if possible

Question 9

Ultra Short Acting insulin?

Answer 9

(Onset 1/4 hour, duration 4-6 hours)

• Insulin Lispro, analogue (Humalog)
• Insulin Aspart, analogue (Novorapid)
• Insulin Glulisine, analogue (Apidra)

Question 10

Short Acting insulin?

Answer 10

(Onset 1/2 hour, duration 4-8 hours)

• Neutral, human (Actrapid, Humulin R)
• Neutral, bovine (Hypurin Neutral)

Question 11

Intermediate Acting insulin?

Answer 11

(Onset 1-2 hours, duration 8-16 hours)

-Non mixed isophane insulin, human (Protophane, Humulin NPH)
- Non mixed isophane insulin, bovine (Hypurin, Isophane)

Question 12

Long Acting Insulin?

Answer 12

(Onset 1-4 hours, duration 18-24 hours)

• Insulin glargine, analogue (Lantus)
• Insulin Detemir, analogue (Levemir)

Question 13

Mixed insulin?

Answer 13

• Novomix 30 (30% rapid, 70% intermediate)
• Humalog mix 25 (25% rapid, 75% intermediate)
• Humalog mix 50 (50% rapid, 50% intermediate)
• Mixtard 30/70, mixtard 50/50 and Humulin 30/70

Question 14

What is Hypoglycaemia?

Answer 14

It is a side effect of insulin
- Causes sweating, hunger, faintness, palpitations, tremor, headache, visual disturbances, altered mood

Question 15

What is hypoglycaemia?

Answer 15

• Low blood glucose levels
• Excessive dose
• delayed/insufficient food intake
• increased physical activity

Question 16

What drugs increase blood glucose?

Answer 16

• Corticosteroids : not fludrocortisone
• Adrenaline
• Beta 2 agonists (High dose, e.g. IV salbutamol)
• Antipsychotics : clozapine, haloperidol, olanzapine, paliperidone, quetiapine, risperidone

Question 17

What drugs decrease blood glucose?

Answer 17

• Alcohol
• Aspirin (analgesic doses)
• Trimethoprim with Sulfamethoxazole

Question 18

What are basal bolus injections?

Answer 18

• most commonly used regime and recommended from diagnosis
• give the intermediate or long acting insulin as the basal component
• give the short ot ultra acting insulin as the boulus component

Question 19

What is the insulin dosing for T2DM?

Answer 19

Usually start with a small notch dose of intermediate to long acting insulin and increase from there
- Lantus and Protophane often used

Often continue with Oral Hypoglycemics with insulin
- causes less weight gain than with insulin treatment alone