Characteristics of insulin secretion (normal and diabetic)

Question 1

Describe the secretion of insulin in a healthy patient?

Answer 1

A basal level of insulin will be secreted through out the day which will deal with the fasting glucose. This accounts for about 50% of the glucose secreted. Postprandial (after a meal) a top up of insulin will be released to cope with the added glucose from the meal.

Question 2

How does the secretion of insulin differ with diabetics?

Answer 2

Type 1- insulin is not secreted at all therefore you need to mechanically recreate the insulins basal level and postprandial level.
Type 2- have resistance to insulin and therefore will need drug treatment.

Question 3

What are the different types of insulin

Answer 3

Rapid acting analogues
Short acting 
Intermediate acting
Long acting analogue
Mixed

Question 4

Rapid acting insulin

Answer 4

Works within 2 hours. Should be administered 30 mins before food.
Examples include Humalog, Novorapid, Apidra

Question 5

Short acting

Answer 5

This is human insulin. It takes longer than the analogues and therefore isnt used as much.
Examples include Humalin, Actrapid, Insuman rapid.

Question 6

Intermediate acting insulin

Answer 6

Supposedly work for 12 hours- however unlikely that they actually do.
Examples include- Insulatard, Humalin I, Insuman Basal

Question 7

Long acting analogue

Answer 7

Work for up to 24 hours.

Examples include- lantus, levemir.

Question 8

Mixed insulin

Answer 8

You can get rapid acting analogue and intermediate mixture. The rapid acting analogue covers the meal times and the intermediate covers the basal.
You can also get short acting, intermediate mix. However this doesn’t have the same efficient short action as the analogue.

Question 9

Fallbacks of mixed insulin

Answer 9

The mixed insulin actually reacts with each other therefore it is not as effective. The seperate injections work better but arent tolerated as well by patients.

Question 10

Fallbacks of twice daily insulin

Answer 10

People have to eat regularly- this is ok if the patient is old and has a fixed lifestyle but it isn’t good for younger people.

Question 11

Fallbacks of insulin pumps

Answer 11

Patients have to calculate their carb intake and then calculate how much insulin to administer.

Question 12

How to work out how much insulin to give on a newly diagnosed patient.

Answer 12

Weight in kg. Give 0.3 units per kg.
Half of this should be prandial and half should be basal. The prandial can then be subdivided by three to give the three meals a day.

Question 13

Fasting blood glucose target for diabetics

Answer 13

5-7mmol

Question 14

Premeal blood glucose

Answer 14

4-7mmol

Question 15

Post meal (1-2 hours) blood glucose

Answer 15

Less than 10mmol.

Question 16

Prandial insulins

Answer 16

Rapid insulin analogues:
Onset of action (ideally) 10-15 minutes.
Peak action at 50-90 mins.

Soluble insulin
Onset is 30-60mins.
Peak action at 2-4 hours.

Question 17

Basal insulins

Answer 17

Intermediate or long acting insulins
Peak activity 4-6 hours after administering

Intermediate analogues
Longer duration of action and less peak activity (smoother curve). Should be given once or twice daily.

Question 18

When is carbohydrate counting suitable?

Answer 18

For those on mechanical pumps or multiple daily injections (MDI).

Question 19

How are carbohydrates counted?

Answer 19

1 unit of insulin to every 10g of carbohydrate.

Question 20

Insulin pumps

Answer 20

Continuous administration of short acting insulin. Deliver basal rate of insulin aswell which can be adjusted to time of day etc. Boost insulin at meal times.

Question 21

How is diabetes monitored on a daily basis?

Answer 21

Fingerprick testing.

Question 22

Target HbAC1 level

Answer 22

Less than 48mmol.

However this is quite hard in someone who has had diabetes for a long time therefore try 53mmol or 58mmol

Question 23

Factors that affect insulin action

Answer 23

Temperature
Injection site
Injection depth
Exercise.

Question 24

What is lipohypertrophy?

Answer 24

When you inject too much into the same site you get big lumps of fat forming. You can’t then use this as an injections site any longer.