Mechanisms and consequences of hypoglycaemia, and pharmacology of insulin treatment options in type 1 diabetes

Question 1

What are the key features of type 1 diabetes mellitus?

Answer 1

• Autoimmune condition (β-cell damage) with genetic component
• Profound insulin deficiency

Question 2

What are the key features of type 2 diabetes mellitus?

Answer 2

• Insulin resistance
• Impaired insulin secretion and β-cell damage but initially continued insulin secretion progressive
• Excessive hepatic glucose output
• Increased counter-regulatory hormones including glucagon

Question 3

Do T1DM or T2DM require insulin?

Answer 3

T1DM
Eventually T2DM will need insulin

Question 4

Which type of diabetes is once-daily basal insulin used in?

Answer 4

Only type 2

Question 5

Which type of diabetes is twice-daily mix insulin used in?

Answer 5

Both

Question 6

Which type of diabetes is basal-bolus therapy used in?

Answer 6

Mostly in type 1
Sometimes in type 2

Question 7

What are the advantages of basal insulin in type 2 diabetes?

Answer 7

• Simple for the patient, adjusts insulin themselves, based on fasting glucose measurements
• Carries on with oral therapy, combination therapy is common
• Less risk of hypoglycaemia at night

Question 8

What are the disadvantages of basal insulin in type 2 diabetes?

Answer 8

• Doesn’t cover meals
• Best used with long-acting insulin analogues which are considered expensive

Question 9

What are the advantages of pre-mixed insulin?

Answer 9

• Both basal and prandial (meal) components in a single insulin preparation
• Can cover insulin requirements through most of the day

Question 10

What are the disadvantages of pre-mixed insulin?

Answer 10

• Not physiological
• Requires consistent meal and exercise pattern
• Cannot separately titrate individual insulin components
• Increased risk for nocturnal hypoglycaemia
• Increased risk for fasting hyperglycaemia if basal component does not last long enough
• Often requires accepting higher HbA1c goal of <7.5% or ≤8% (<58 or ≤64 mmol/mol)

Question 11

Which is considered the best treatment for T1DM?

Answer 11

Intensive basal-bolus insulin therapy

Question 12

What HbA1c levels do many people start insulin at?

Answer 12

levels of ≥9%

Question 13

What is level 1 hypoglycaemia?

Answer 13

• Alert value
• Plasma glucose <3.9 mmol/l (70 mg/dl) and no symptoms

Question 14

What is level 2 hypoglycaemia?

Answer 14

• Serious biochemical
• Plasma glucose <3.0 mmol/l (55 mg/dl)

Question 15

What is non severe hypoglycaemia?

Answer 15

Patient has symptoms but can self-treat and cognitive function is mildly impaired

Question 16

What is level 3 hypoglycaemia?

Answer 16

Patient has impaired cognitive function sufficient to require external help to recover (severe)

Question 17

What effect does hypoglycaemia have on the brain?

Answer 17

Cognitive dysfunction, blackouts, seizures, comas, psychological effects

Question 18

What effect does hypoglycaemia have on the heart?

Answer 18

Increased risk of myocardial ischaemia, cardiac arrhythmias

Question 19

What effect does hypoglycaemia have on the musculoskeletal system?

Answer 19

Falls, accidents, driving accidents, fractures, dislocations

Question 20

What effect does hypoglycaemia have on the circulation?

Answer 20

Inflammation, blood coagulation abnormalities, haemodynamic changes, endothelial dysfunction

Question 21

What are the autonomic symptoms of hypoglycaemia?

Answer 21

*Trembling
*Palpitations
*Sweating
*Anxiety
*Hunger

Question 22

What are the neuroglycopenic symptoms of hypoglycaemia?

Answer 22

*Difficulty concentrating
*Confusion
*Weakness
*Drowsiness, dizziness
*Vision changes
*Difficulty speaking

Question 23

What are non-specific symptoms of hypoglycaemia?

Answer 23

*Nausea
*Headache

Question 24

What is the second symptom of hypoglycaemia?

Answer 24

Low blood glucose (<3.9 mmol/l) (70 mg/dl)
patients with poor glycaemic control with an elevated HbA1c may experience symptoms of hypoglycaemia at levels >3.9 mmol/l

Question 25

What is the third symptom of hypoglycaemia?

Answer 25

Response to treatment with carbohydrate

Question 26

What are causes of hypoglycaemia?

Answer 26

• Long duration of diabetes
• Tight glycaemic control with repeated episodes of non severe hypoglycaemia
• Increasing age
• Use of drugs (prescribed, alcohol)
• Sleeping
• Increased physical activity

Question 27

What risk factors should screening be based on for severe hypoglycaemia?

Answer 27

• Low HbA1c: high pre-treatment HbA1c in T2DM
• Long duration of diabetes
• A history of previous hypoglycaemia
• Impaired awareness of hypoglycaemia (IAH)
• Recent episodes of severe hypoglycaemia
• Daily insulin dosage >0.85 U/kg/day
• Physically active (e.g. athlete)
• Impaired renal and/or liver function

Question 28

What are the steps to treat hypoglycaemia?

Answer 28

1. Recognise symptoms so they can be treated as soon as they occur
2. Confirm the need for treatment if possible (blood glucose <3.9 mmol/l is the alert value)
3. Treat with 15g fast-acting carbohydrate to relieve symptoms
4. Retest in 15 minutes to ensure blood glucose >4.0 mmol/l and re-treat (see above) if needed
5. Eat a long-acting carbohydrate to prevent recurrence of symptoms