L8 - Diabetes Flashcards
What stimulates glucose release?
Increased blood glucose
Incretins (GLP-1, GIP)
Glucagon
Parasympathetic activity (M3)
What inhibits insulin release?
Low blood glucose
Cortisol
Sympathetic activity (alpha 2)
Role of insulin
Decreased hepatic glucose output by inhibiting gluconeogenesis and glycogenolysis
Promotes the uptake of fat
Symptoms of diabetes
Polyuria Polydipsia Weight loss Lethargy Fatigue
Random plasma glucose hyperglycaemia
Above 11mmol/L
Risk factors for type 2 diabetes
Obesity Family history Ethnicity Diet - high carbohydrate and sugar Drugs - thiazides/ thiazide like diuretics/ glucocorticoids/ Beta blockers Low birth weight
HbA1c
Percentage of glycated haemoglobin over 3 months
How is insulin given?
Subcutaneous injection in:
- upper arms
- thighs
- buttocks
- abdomen
Can be given via syringe, pen, pump or inhaler
IV insulin - emergency treatment
Insulin is a protein therefore if given as a pill orally, will be digested
Types of insulin
Bovine (cow) - 3 amino acid difference
Porcine (pig) - 1 amino acid difference
Human insulin - recombinant DNA or enzymatic modification of porcine insulin
Normal formula of insulin
100 U/ml
If obese or insulin resistant, higher doses of 300 - 500 U/ml are given
Half life on insulin
5 mins in plasma
- renal and hepatic metabolism and elimination
When should insulin be given?
15-30 mins prior to meals as has the greatest effect 2-3hr after dose
Protamine
Change hexomer formation
Fast acting insulin
Zinc
Delays absorption
Slow acting insulin
Why is the site of insulin administration rotated
Prevent lipodystrophy:
- atrophy or hypertrophy of lipids around the injection site
Insulin aspart
Onset of action - 10- 20 min
Peak - 40-50 min
Duration - 3- 5 hours
- rapid action
Soluble insulin - humulin S, actrapid
Onset of action: 30 -60 mins
Peak - 2-5 hours
Duration - 5-8 hours
- short acting
Isophane insulin
Onset of action: 1-2 hours
Peak - 4-12 hours
Duration - 18-24hours
- Intermediate acting
Insulin glargine
Onset of action: 60-90 mins
Peak: plateau between 2 - 20 hours
Duration: 20-24 hours
Long acting
Contraindications and interactions of insulin
Contraindications:
- hypoglycaemia
- lipohypertrophy
- lipoatrophy
- renal impairment (hypoglycaemia if not cleared)
Interactions:
- increased dose with steroids
- other hypoglycaemic agents
Basal bolus dosing
Bolus dose
- insulin aspart
- mimic spike in insulin after eating food
Basal dose
- insulin glargine
- mimics baseline insulin
Diabetic ketoacidosis
Causes:
Hyperglycaemia
Metabolic acidosis
Ketoneamia
What can cause diabetic ketoacidosis?
Blood glucose 11 + mmol/L and:
- infection
- trauma
- poor insulin adherence
- ADR
- ketosis