Endocrine - Diabetes

Question 1

What does insulin do?

Answer 1

lowers blood glucose concentrations

Question 2

What does glucagon do?

Answer 2

Increase blood glucose concentrations

Question 3

What does somatostatin do?

Answer 3

acts as a paracrine hormone to inhibit both insulin & glucagon

Question 4

Explain the process of glucose homeostatis

Answer 4

Low blood glucose level (<4 mmol/l)

a-cells release glucagon, which stimulates glycogen breakdown & gluconeogenesis

after a meal = high glucose levels >5 mmol/l

b-cells release insulin, which stimulates glucose reuptake by peripheral tissues

Question 5

Explain the different roles of insulin

Answer 5

Stimulates the liver = reduced gluconeogenesis, increased glycogen synthesis & storage

Muscle tissue - increased protein & glycogen synthesis, transportation of glucose into muscle cells

Adipose tissue: promotes triglyceride storage, increases glucose transport into fat cells

Question 6

What is type 1 diabetes?

Answer 6

Wherethe body’s immune system attacks and destroys the cells that produce insulin.

Typically juvenile onset. Insulin dependent

Question 7

What is type 2 diabetes?

Answer 7

Where the body doesn’t produce enough insulin, or the body’s cells don’t react to insulin. Typically middle age onset. Insulin independent.

Question 8

Explain osmotic diuresis with normal - low glucose levels

Answer 8

Normal or low levels of glucose in the blood stream

Therefore glucose and water are reabsorbed from the renal tubule

Question 9

Explain osmotic diuresis with high glucose levels

Answer 9

High levels of glucose in the tubule.

Reabsorption mechanisms are saturated.

Osmotic gradient draws water into tubule leading to diuresis

This increase urine (polyuria)

Question 10

What happens in DKA?

Answer 10

The patient isn’t producing insulin or isn’t injecting insulin - this leads to no movement of glucose into cells and the …is rich in glucose -> the patient is Hyperglycaemic

So the body metabolises fatty acids as an energy source instead, the body cant use glucose in the bloods stream (the glucose needs to move into the cell and without this mechanism, the body needs to use fatty acids).

However a byproduct of that energy source is the production of ketones. However ketones in the blood stream can cause pH to become acidotic, i.e. keto-acidosis.

Question 10

Explain the risk factors of having diabetes & HTN

Answer 10

CVD: the risk factors would naturally include highly pressurised blood overloading the heart as well as a blood supply that is saturated with glucose, which could be damaging to the blood vessels.

Kidneys: (similar): if you have highly pressurised blood blasting through the glomerulus, this can impair the integrity of the filter, which can lead to CKD & the high glucose can be damaging

Neuro: peripheral vasculature (similar)

Question 11

Explain how to consider treatment for HTN with diabetes

Answer 11

When thinking about treating, need to look at blood pressure, and dependent on this, may need to provide pharmacological management. If BP is between 135 - 150, need to look at risk factors and diabetes is one of those risk factors. If someone has 1+, you would need to treat.

Unless exception to the rule (see slide)
- T1Dm with 2+ metabolic syndromes (treat at a lower BP level)
- Albumin -> a big molecule/compound. If found in the urine, it shows ‘the sieve’ (the glomerulus) is impaired and this is inappropriately passing through.

Question 12

Explain statin provision in diabetes

Answer 12

-> dependent on if they are T1 or T2

-> primary dependent on risk, lifestyle interventions or provision of a statin (aspirin is no longer primary prevention - this comes in once someone has had an event)

T1 = consider statins for all

T2 = calculate CVD risk score. If >10% risk, start atorvastatin 20 mg od

Question 13

Explain the details of rapid acting insulin with examples

Answer 13

Rapid acting insulin analogues

Quick onset (10-20mins), short duration (3-5hrs)

Can inject shortly before, or after meal if necessary

Hypoglycaemia less common (compared to short acting)
Apidra (Insulin glulisine)
Humalog (Insulin lispro)
Novorapid (Insulin aspart)

Question 14

Explain the details of short acting insulin with examples

Answer 14

Soluble insulin

Onset of action 30-60mins (give 15-30mins pre-meals)

Often used in diabetic emergencies (greater chance of hypogylcaemia than rapid acting)

Peak action 2-4hrs

Duration of action up to 8hrs

Actrapid
Humulin S
Hypurin Porcine Neutral
Insuman Rapid

Question 15

Explain the details of intermediate acting insulin with examples

Answer 15

Isophane insulin (suspension of insulin with protamine)

Onset 2 hours, peak 8 hours, duration 24 hours

Humulin I
Hypurin Bovine Isophane
Hypurin Porcine Isophane
Insulatard
Insuman Basal

Question 16

Explain the details of long acting insulin with examples

Answer 16

Slower onset, long duration (16-35hrs)

Given once or twice daily

Long acting human insulin analogues

Lantus / Semglee / Abasaglar (Insulin glargine)
Levemir (Insulin detemir)
Tresiba (Insulin degludec)

Question 17

Explain the details of biphasic insulin with examples

Answer 17

Pre-mixed suspension of rapid/short-acting insulin with intermediate insulin

Mixed release profile – initial peak & prolonged duration of action

Novomix 30 (Insulin aspart, insulin aspart protamine)
Humalog Mix 25 or Mix 50 (Insulin lispro, insulin lispro protamine)
Humulin M3 (soluble insulin, isophane insulin)
Insuman Comb 15, 25 or 50 (soluble insulin, isophane insulin)

Combination product so needs an expression of strength as multiple preparations exist

Number refers to % rapid acting/short acting insulin (i.e., 30 = 30 units of rapid acting in 100units/ml)

Question 18

What is metformin

Answer 18

Biguanide (metformin)
Metformin has no effect on insulin release but acts by increasing peripheral glucose uptake and inhibits gluconeogenesis.

Activation of the energy regulating enzyme AMP-kinase in the liver and skeletal muscle is thought to be a principal mechanism of action.

This drug additionally reduces LDL and VLDL lipoproteins.

Metformin is the drug of choice in overweight patients when dietary measures have proved ineffective as it promotes weight loss.