Type 1 Diabetes Flashcards
What is the aetiology of type 1 diabetes?
Autoimmune destruction of pancreatic B-cells
Islet cell antibodies present in 85-90% of patients with T1DM
Idiopathic (no known cause)
What are the main signs/symptoms of diabetes mellitus?
Thirst Polyuria Lethargy Visual disturbances Weight Loss
Urogenital Infection
Ketoacidosis (DKA) in type 1,
Hyperosmolar Hyperglycaemic state (HHS) in type
Myocardial infarction
CVA (cerebrovascular accident)
How is diabetes mellitus diagnosed?
Fasting glucose greater than or equal to 7 mmol/L
2hr post glucose greater than or equal to 11.1 mmol/L
Diagnosis can also be made if HbA1c is greater than or equal to 48 mmol/mol
How is impaired glucose tolerance diagnosed?
Fasting glucose less than 7 mmol/L
2hr post glucose greater than or equal to 7.8 mmol/L
How is impaired fasting glycaemia diagnosed?
Fasting glucose between 6.1 and 7 mmol/L
2hr post glucose less than 7.8 mmol/L
What are the main quality of life issues related to diabetes?
Daily activities (e.g. driving or work)
Emotions (around 50% of people with diabetes have depression)
Financial
Leisure
Relationships
Physical health
Polypharmacy
What are the main aims of diabetes therapy?
Relieve signs and symptoms of the disease
Prevent or slow the progression of long term complications
Fasting blood glucose between 4-7 mmol/L
2hr post glucose less than 8.5 mmol/L
No glucose in the urine
HbA1c between 48-58 mmol/mol, aim for 53 mmol/mol
What are the main sources of insulin?
Bovine
- Prepared from a process of recrystallisation
- Differs from human insulin by 3 amino acids
Porcine
- Not linked to antibody formation
- Differs from human insulin by 1 amino acid
Human
- Produced by enzymatic modification of porcine insulin
- Biosynthesis methods including E-coli or Yeast
What are the most common indications for insulin use?
Type 1 diabetes
Poorly controlled type 2 diabetes
- either symptomatic or asymptomatic
Intercurrent illness
- Pre and post op
- Infection
- MI
- Steroid therapy
Pregnancy
What is the onset, peak and duration of action of Zinc Suspension Insulin?
Onset: 3 hours
Peak: 6-14 hours
Duration: 24-28 hours
What is the onset, peak and duration of action of Long acting insulin analogues?
Onset: 1-2 hours
Peak: No peak
Duration: 24 hours
What is the onset, peak and duration of action of Isophane insulin?
Onset: 1 hour
Peak: 2-12 hours
Duration: 24 hours
What is the main problem with isophane insulin?
Risk of nocturnal hypos
What is the onset, peak and duration of action of Fast acting insulin analogues?
Onset: 5-10 minutes
Peak: 4-5 hours
Duration: 4-5 hours
What is the onset, peak and duration of action of Soluble insulin?
Onset: 30-60 minutes
Peak: 1-5 hours
Duration: 7-8 hours
When should rapid acting insulin analogues be given?
Directly before or after food
When should soluble insulin be given?
30 minutes before food
What is the onset, peak and duration of action of Biphasic analogues?
Onset: 5-10 minutes
Peak: 1-2 hours and 6-8 hours
Duration: 12-24 hours
What is the onset, peak and duration of action of Biphasic Insulin?
Onset: 30-60 minutes
Peak: 1-12 hours
Duration: 14-24 hours
Describe the twice daily insulin regimen
Use of biphasic analogue mix
Short acting component controls the rise in glucose after breaking and evening meal
Long acting component maintains control over lunch through to early evening and then from late evening to the next morning
Usually given in a 2/3 and 1/3 ratio
Snacks needed between meals to prevent hypos
Describe the Basal-Bolus insulin regimen
Use of short acting insulin just before each meal and then a long acting insulin traditionally given at bedtime (but can be given at any time of the day as long as it is at the same time)
Allows greater flexibility
Patients can adjust their short acting insulin according to their blood glucose level, exercise and carbohydrate intake (CHO counting: DAFNE)
How should insulin doses be adjusted?
Start on a low dose
Patients who are CHO counting should start with 1 unit per 10g of CHO
Regular blood glucose monitoring
Adjust by 2 units every 2-3 days
Once patient on high doses (>40 units) adjust by 10%
What factors can influence insulin intake?
Injection site - absorbs more readily from abdomen, then arms,leg and buttocks
Body weight - insulin requirments drop as people lose weight
Illness - BG levels may rise during illness
Climate - absorb insulin more readily in hot weather
Drug interactions
Needle length
- all patients should use 4-5mm needs to prevent injecting IM
What patient monitoring is usually required for diabetics?
Blood pressure monitoring
HbA1c 6.5-7.5% (provides indication of BG control over the last 3 months)
Blood glucose levels
Lipid profile
Foot care and eye care
What prophylactic treatment is normally prescribed for diabetics?
ACEi
Aspirin
Lipid-regulating drugs (e.g. statins)
What is Diabetic Ketoacidosis?
Moderate-to-high blood glucose levels together with water and electrolyte depletion
Why does Diabetic Ketoacidosis occur?
When hyperglycaemia is sustained, osmotic diuresis occurs which results in water and electrolyte excretion
What are the signs and symptoms of Diabetic Ketoacidosis?
Hyperglycaemia Thirst Polyuria Fatigue Blurred vision Fruity breath (ketone breath) Difficultly breathing Nausea and vomiting Stomach pains Loss of appetite
How is DKA normally managed?
Fluid replacement: 0.9% saline
Insulin: continuous IV infusion and monitor blood glucose levels
Electrolyes: potassium (K) supplementation started once elevated potassium levels begin to drop and good urine outflow - serum potassium levels may be initially high in acidosis.
How should diabetics who are unwell/undergoing surgery be treated?
10% Glucose
Soluble Insulin 50units/50ml (syringe driver adjusted to BG levels)
What are the signs and symptoms of hypoglycaemia?
Anxiety Blurred Vision Confusion Hunger Numbness Sweating Tingling Tremor
Give examples of drugs that may increase hypoglycaemic effects
ACEi Alcohol Beta-blockers Salicylates Sulphonamides
Give examples of drugs that may increase hyperglycaemic effects
Atypical antipsychotics Beta-antagonists Beta-blockers Ciclosporin Corticosteroids Diuretics Oestrogen Phenytoin Protease inhibitors
Give examples of conditions that may lead to loss of blood glucose control
Fever
Trauma
Infection
Surgery
- Patients receiving oral antidiabetic agents who undergo elective surgery are switched to insulin from the day before the intervention and continued on insulin until they start to eat and drink
Stress
What are the ‘sick day rules’ for type 1 diabetics?
Keep taking your insulin Keep testing blood glucose levels Drinks lots of sugar-free drinks Check for ketones Keep eating even if just snacks (e.g. ice cream, biscuits, toast, tea, milky drinks etc)
If ketones normal but blood glucose high, give 1-6 units extra insulin per meal time dose (depending on how high blood glucose is).
If ketones are high give 10-20% of daily insulin dose every 2 hours (depending on how high ketones are)
What are the proportions of insulin to be given with basul-bolus regimen?
2/3 Fast acting (total daily dose), 1/3 Long acting (total daily dose)
What are the proportions of insulin to be given with twice daily regimen?
2/3 given with breakfast, 1/3 given evening meal
Patient education for patients with diabetes
Dietician for carb couting education (DAFNE)?
Blood Glucose Monitoring
Check feet and eyes regularly
Ensure they attend regular clinics
Alert prescriber of any changes in weight
Sick day rules
Rotate injection site (check technique and needle length)
Do not reuse needles
Lifestyle (exercise, diet)
Educate about the condition and why treatment is important
