Chapter 6: Type 1 Diabetes, Insulin & Hypoglycaemia Flashcards
Characterised by persistent hyperglycaemia, what are the two ways in which diabetes can manifest?
- Deficient insulin secretion
2. Resistance to actions of insulin
What are the 4 types of diabetes?
- Type 1
- Type 2
- Gestational
- Secondary
To which 3 conditions can diabetes be secondary?
- Pancreatic damage
- Hepatitis
- Endocrine disease
Which agency must be notified if someone has diabetes and is being treated with insulin?
DVLA
Which adverse event should drivers be particularly careful of?
Hypoglycaemia
What must diabetics always carry to ensure they are informed about their plasma glucose?
- Glucose meter
2. Test strips
Diabetics using insulin should check their plasma glucose how long before driving?
Two hours
While driving how often should diabetics using insulin test their plasma glucose?
Every two hours - more frequent if recent activity that may increase risk of hypo
While driving, plasma glucose of diabetic drivers should always be above what threshold?
5mmol/L
If plasma glucose falls slightly below 5mmol/L, what should diabetic drivers using insulin do?
Have a fast-acting carbohydrated
What are the 3 steps that diabetic drivers using insulin should take if their plasma glucose falls below 4mmol/L
- Stop driving
- Switch off the engine, remove keys and move from driver’s seat
- Consume source of sugar
How long should diabetic drivers using insulin wait before driving after stopping due to it falling below 4mmol/L?
45 minutes after it has returned to normal
Under which circumstances should diabetic drivers using insulin not drive?
If hypoglycaemia awareness has been lost
As well as insulin, which other diabetic medicines may it be necessary to inform the DVLA about? (3)
- Sulphonylureas
- Nateglinide
- Repaglinide
Which lifestyle activity can mask the signs of hypoglycaemia?
Alcohol
Is it advised for all diabetics to avoid drinking alcohol?
No, they must drink in moderation and with food
Which test is mainly used to diagnose impaired glucose control? It is useful for when patients do not have severe symptoms but glucose tolerance is impaired
Oral Glucose Tolerance Test
If symptoms are already present, should the OGTT be used to diagnose diabetes?
No
In which type of diabetes is OGTT especially useful in diagnosing?
Gestational diabetes
How is the OGTT conducted?
Plasma glucose is measured after fasting.
Patient drinks glucose drink.
Plasma glucose is measured 2 hours after
Which test is a good indicator for glycaemic control?
HbA1c
What does HbA1c measure?
The amount of glycated haemoglobin
HbA1c shows average glucose control over how long?
The last 2-3 months
Should a patient fast before their HbA1c test?
No
HbA1c is used in Type 1 and Type 2 monitoring and diagnosis of Type 2, in which situations should it not be used? (10)
- Type 1 diagnosis
- Children
- Pregnancy
- Up to 2 months post-partum
- Symptoms of diabetes less than 2 months
- High risk diabetes or critically ill
- Treatment with medication that causes hyperglyacemia
- Acute pancreatic damage
- End stage CKD
- HIV
In Type 1 Diabetes, how often should HbA1c be measured?
every 2-3months
In Type 2 Diabetes, how often should HbA1c be measured?
every 2-3months
In which patients is HbA1c monitoring invalid?
- Disturbed erythrocyte turnover
2. Lack of/abnormal haemoglobin
In patients which HbA1c monitoring is invalid, what can be used instead?
- Quality controlled blood glucose profiles
- Total glycated haemoglobin estimation
- Fructosamine estimation
What does fructosamine estimation measure?
Glycated concentration of ALL plasma proteins over 14-21 days
Can type 1 diabetes produce endogenous insulin?
No (little to none)
Why is there no insulin secretion in type 1 diabetes?
Destruction of insulin-producing pancreatic beta cells
What causes the destruction of pancreatic beta cells in type 1 diabetes?
Auto-immune basis
At what age does type 1 diabetes most commonly occur?
Before adulthood
What are the microvascular complications of diabetes? (3)
- Nephropathy
- Neuropathy
- Retinopathy
What are the macrovascular complications of diabetes? (3)
- Stroke
- Cardiovascular disease (MI)
- Peripheral arterial disease
What blood glucose reading would you expect an adult presenting with Type 1 Diabetes to have?
Over 11mmol/L
What BMI would you expect an adult presenting with Type 1 Diabetes to have?
Less than 25kg/m2
How old would you expect an adult presenting with Type 1 Diabetes to be?
Less than 50
As well as hyperglycaemia, low BMI, and younger than 50, what other characteristics do adults presenting with T1DM have? (3)
- Rapid weight loss
- Ketosis
- (Family) history of autoimmune disease
Increasingly used in T2DM, what is the mainstay of treatment for T1DM?
Insulin
Using insulin regimens, what are the 3 aims of treating T1DM?
- Achieve blood glucose control
- Reduce frequency of hypoglycaemic episodes
- Minimise the risk of microvascular and macrovascular complications
What is the target HbA1c for T1DM?
Less than 48mmol/mol
How often must T1DM patients monitor their blood glucose daily?
at least 4 times daily - before each meal and before bed
What is the target fasting blood glucose for T1DM patients?
5-7mmol/L
What is the target random blood glucose for T1DM patients?
4-7mmol/L
What is the target blood glucose for T1DM patients after eating?
5-9mmol/L
As well as controlling blood glucose with insulin, which other cardiovascular risk factors must be actively managed in patients with diabetes?
- Hypertension
2. Blood lipids
Unlicensed, which oral antidiabetic can be used alongside insulin in the management of T1DM?
Metformin
Unlicensed, in which patients can Metformin be used alongside insulin in the management of T1DM?
BMI over 25 (over 23 S. Asian)
What are the advantages of usince Metformin alongside insulin (unlicensed) in T1DM?
- Improve blood glucose
2. Minimise insulin dose
Which other healthcare professional should be involved in manageing patients with diabetes to ensure they control their weight, lower cardiovascular risk and understand the hyperglycaemia effects of food?
Dietician
What type of training must T1DM patients receive in order to tailor their insulin dose throughout the day?
Carbohydrate-counting training
Can insulin be initiated by the GP?
No, specilist initiation and management
What are the 3 main insulin REGIMENS?
- Multiple daily BASAL-BOLUS regimens
- Mixed (BIPHASIC) regimens
- Continuous subcutaneous insulin infusion
A basal insulin injection is…
Long acting
A bolus insulin injection is…
Short acting
What does a mixed (biphasic) regimen injection contain?
Short acting + intermediate acting
What is the first line recommended insulin regimen for patients with T1DM?
Basal-bolus
Give 2 examples of long acting insulin injections
- Insulin detemir
2. Insulin glargine
Are non basal-bolus insulin regimens recommended for patients newly diagnosed with T1DM? Examples: biphasic, basal-only, bolus-only
NO
When should rapid acting insulin be administered?
Before meals
What is the second line insulin regimen for patients with T1DM?
Biphasic
Which insulin regimen should patients with disabling hyperglyceamia or high HbA1c above 69 mmol/mol be given? Specialist initiation only
Continuous subcutaneous insulin infusion
What can persistent poor glucose control be due to?
- Adherence issues
- Poor injection technique
- Injection site issues
- Poor blood-glucose monitoring skills
- Lifestyle (diet/exercise/alcohol)
- Psychological issues
- Organic disease
Give 5 examples of organic disease that may cause poor glucose control
- Renal disease
- Thyroid disorder
- Coeliac disease
- Addison’s disease
- Gastroparesis
Under which circumstances might a patient require increased insulin? (3)
- Infection
- Stress
- Accidental/Surgical trauma
Under which circumstances might a patient require decreased insulin? (3)
- Physical activity
- Intercurrent illness
- Reduced food intake
- Impaired renal function
- Endocrine disorders
What are the early symptoms of hypoglycaemia? (8)
- Palour
- Tingling lips
- Sweating
- Palpitations
- Fatigue
- Hunger
- Shaking/Trembling
- Irritable
What are the symptoms of more advanced hypoglycaemia? (8)
- Weakness
- Blurred vision
- Difficulty concentrating
- Slurred speech
- Confusion
- Sleepiness
- Seizures
- Coma
What is an invetiable adverse effect of insulin?
Hypoglycaemia
When can impaired hypoglycaemia awareness occur? (2)
- Ability to recognise symptoms is lost
2. Symptoms are blunted / no longer present
Which questionnaire can be used to assess hypoglycaemia awareness?
Gold/Clarke score
What may reduce warning signs of hypoglyacemia?
Increased frequency of hypoglycaemia episodes
Impaired awareness of symptoms at which plasma glucose reading is considered significant?
less than 3mmol/L
Which class of drug can blunt awareness of hypoglycaemia by reducing the warning sign: tremor?
Beta blockers
Provided by the GP or community pharmacy, which container is used when disposing of insulin pens and needles?
Yellow sharps bin
How is the yellow sharps bin full of insulin pens and needles disposed of?
Taken from the patient by the local authority
What are the two functions of insulin?
- Increase glucose uptake by adipose tissue and muscles
2. Suppress hepatic glucose release
Which insulin regimen best mimics the normal profile of the body releasing endogenous insulin?
Basal-bolus
Insulins from which source are no longer initiated in patients with diabetes?
Animals
How common is insulin allergy?
Rare
Through which route is insulin usually administered?
Subcutaneous
With plenty of subcutaneous fat, to which areas of the body is insulin injected? (3)
- Abdomen
- Outer thighs
- Buttocks
Which factors can change rate of absorption? (6)
- Local tissue reactions
- Injection site
- Depth of injection
- Changes in insulin sensitivity
- Blood flow
- Amount injected
What can increase the amount of blood flow at the injection site?
Exercise
Causing erratic absorption of insulin, what can occur if injections are repeatedly administered to the same site?
Lipohypertrophy
What does short-acting insulin replicate?
The insulin released by the body in response to a meal
What are the 3 short-acting insulins?
- Insulin glulisine
- Insulin aspart
- Insulin lispro
How long does short-acting insulin take to act?
15mins
How long before meals should short-acting insulin be administered
Immediately
Why should post-meal injections be avoided? (2)
- Poorer glucose control
2. Hypoglycemia
What is the intermediate-acting insulin called?
Isophane insulin
What does intermediate-acting insulin mimic?
Endogenous basal insulin continuously secreted in response to glucose production by liver
How long does intermediate-acting insulin take to work?
1-2hours
How long does intermediate-acting insulin last?
11-24hours
What are the 2 regimen options for intermediate-acting insulins?
- One or more daily injections of intermediate insulin + short-acting insulins at meal times
- Mixed (biphasic) insulin injections
What are the 3 long-acting insulins?
- Insulin detemir
- Insulin glargine
- Insulin degludec
Which long-acting insulin can be administered either once or twice daily? The other two can only be administered once daily
Insulin detemir
Mimimicing endogenous insulin, what is the duration of action of long-acting insulin?
36 hours
How long does it take for long-acting insulin to reach steady state?
2-4 days
What is the NHS improvement important safety alert regarding insulin devices?
Risk of severe harm and death due to withdrawing insulin from pen devices - Insulin should not be extracted from pen devices
What is the recommended plasma glucose level in children with T1DM most of the time?
Between 4 and 10mmol/L
When prescribing and dispensing insulin, which word should NOT be abbreviated?
“unit”
When handing out insulin to a patient, what must you do?
Show them the contained to confirm the expected version is dispensed
What is the initial treatment of hypoglycaemia?
10-20g glucose by mouth
After the initial treatment of hypoglycaemia, what can be given to prevent levels falling again?
A carbohydrate snack
When is hypoglycaemia an emergency?
If it cause unconsciousness
In hypoglycaemia, if sugar cannot be given by mouth, what can be administered by injection?
Glucagon - increases the plasma-glucose concentration by mobilising glucagon stored in the liver
True of false: Glucagon can be issued to close relatives of patients taking insulin to treat hypoglyacemia
TRUE
In hypoglycaemia, what is the alternative treatment to glucagon?
Glucose 20% IV Infusion into a large vein
In hyperglycaemia, glucose 20% can be administered as an alternative to glucagon. Why can’t glucose 50% be given? (2)
- High risk of extravasation
2. Difficult to administer
Glucagon is not appropriate for use in chronic hypoglycaemia. Which drug can be administered by mouth to treat hypoglycaemia due to excess endogenous insulin secretion ?
Diazoxide
