Mechanisms and consequences of hypoglycaemia, and pharmacology of insulin treatment options in type 1 diabetes Flashcards
What are the key features of type 1 diabetes mellitus?
- Autoimmune condition (β-cell damage) with genetic component
- Profound insulin deficiency
What are the key features of type 2 diabetes mellitus?
- 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
Do T1DM or T2DM require insulin?
T1DM
Eventually T2DM will need insulin
Which type of diabetes is once-daily basal insulin used in?
Only type 2
Which type of diabetes is twice-daily mix insulin used in?
Both
Which type of diabetes is basal-bolus therapy used in?
Mostly in type 1
Sometimes in type 2
What are the advantages of basal insulin in type 2 diabetes?
- 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
What are the disadvantages of basal insulin in type 2 diabetes?
- Doesn’t cover meals
- Best used with long-acting insulin analogues which are considered expensive
What are the advantages of pre-mixed insulin?
- Both basal and prandial (meal) components in a single insulin preparation
- Can cover insulin requirements through most of the day
What are the disadvantages of pre-mixed insulin?
- 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)
Which is considered the best treatment for T1DM?
Intensive basal-bolus insulin therapy
What HbA1c levels do many people start insulin at?
levels of ≥9%
What is level 1 hypoglycaemia?
- Alert value
- Plasma glucose <3.9 mmol/l (70 mg/dl) and no symptoms
What is level 2 hypoglycaemia?
- Serious biochemical
- Plasma glucose <3.0 mmol/l (55 mg/dl)
What is non severe hypoglycaemia?
Patient has symptoms but can self-treat and cognitive function is mildly impaired
What is level 3 hypoglycaemia?
Patient has impaired cognitive function sufficient to require external help to recover (severe)
What effect does hypoglycaemia have on the brain?
Cognitive dysfunction, blackouts, seizures, comas, psychological effects
What effect does hypoglycaemia have on the heart?
Increased risk of myocardial ischaemia, cardiac arrhythmias
What effect does hypoglycaemia have on the musculoskeletal system?
Falls, accidents, driving accidents, fractures, dislocations
What effect does hypoglycaemia have on the circulation?
Inflammation, blood coagulation abnormalities, haemodynamic changes, endothelial dysfunction
What are the autonomic symptoms of hypoglycaemia?
*Trembling
*Palpitations
*Sweating
*Anxiety
*Hunger
What are the neuroglycopenic symptoms of hypoglycaemia?
*Difficulty concentrating
*Confusion
*Weakness
*Drowsiness, dizziness
*Vision changes
*Difficulty speaking
What are non-specific symptoms of hypoglycaemia?
*Nausea
*Headache
What is the second symptom of hypoglycaemia?
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
What is the third symptom of hypoglycaemia?
Response to treatment with carbohydrate
What are causes of hypoglycaemia?
- 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
What risk factors should screening be based on for severe hypoglycaemia?
- 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
What are the steps to treat hypoglycaemia?
- Recognise symptoms so they can be treated as soon as they occur
- Confirm the need for treatment if possible (blood glucose <3.9 mmol/l is the alert value)
- Treat with 15g fast-acting carbohydrate to relieve symptoms
- Retest in 15 minutes to ensure blood glucose >4.0 mmol/l and re-treat (see above) if needed
- Eat a long-acting carbohydrate to prevent recurrence of symptoms
