10 - diabetes Flashcards
How is diabetes mellitus characterised?
Persistsnt hyperglycaemia (usually >6 mmol/l)
What are some long term consequences of diabetes?
Cerebrovascular accidents (strokes), blindness (retinopathy), myocardial infarctions, kidney failure (nephropathy) and amputation (neuropathy)
Which type of complications do people with type 1 diabetes get?
Micro vascular complications (retinopathy, neuropathy and nephropathy)
What is the difference between type 1 and type 2 diabetes?
In type 1, the body does not produce enough insulin but in type 2 the body tissues can’t use insulin very well
What are two causes of persistent hypoglycaemia?
Hyperinsulinism and glycogen storage diseases
How does insulin lower blood glucose?
- stimulates tissues to take in glucose
- stimulates the liver to convert glucose to glycogen
How does the body increase blood glucose levels?
The pancreas releases glucagon which causes the liver to convert glycogen to glucose and release the glucose into the bloodstream
What happens in glycogen storage diseases?
The body is unable to efficiently convert glycogen to glucose which results in hypoglycaemic
How is insulin secreted from the beta cells in the pancreas?
- glucose enters the cell
- glucose undergoes respiration which increases ATP concentration
- High ATP concentration causes potassium channels to close which causes the potassium concentration to increase
- this causes the membrane to depolarise so calcium is moved into the cells
- increase in calcium triggers insulin exocytosis
What happens when insulin binds to it’s receptors?
- Insulin binds
- Tyrosine kinases are activated
- Signal transduction
- GLUT4 transporters are moves to the membrane
- Glucose is taken up and used by the cells
- Insulin also increases protein uptake, cell survival and proliferation
What causes type 1 diabetes?
Autoimmune destruction of beta cells of the pancreas (caused by an environmental or viral trigger)
Weak family trait
What causes type 2 diabetes?
- over nutrition, obesity, lack of exercise
- genetics
- environment
- metabolic syndrome
How is type 2 diabetes treated?
- reduced calories, carbohydrates and lipids
- increased exercise
- sulphonyureas (make beta cells secrete more insulin)
- weight loss surgery
What tests can be used to diagnose diabetes mellitus
- urine glucose test (only positive when BG is >10mmol)
- HbA1c
- blood glucose (fasting, random and oral glucose tolerance test)
How is an Oral Glucose Tolerance Test performed?
- baseline fasting blood glucose is measured
- 75g of glucose in 300ml is drunk in 5 minutes
- plasma glucose is measured every 30 minutes for two hours
- > 11 mmol /l indicates diabetes
- 7.8-11 mmol/l indicates impaired glucose tolerance
