Diabetes And Hypoglycaemia Flashcards
How are blood glucose levels maintained?
Dietary carbohydrates
Glycogenolysis
Gluconeogenesis
What is the effect of increased insulin?
Decreased liver production of glucose
Liver nutrients uptake
Increase peripheral uptake + decrease peripheral catabolism
What occurs to the insulin levels in the fasting state?
Insulin levels decrease to try increase glucose production
How does decreased insulin increase glucose production in the fasting state?
Increase liver gluconeogenesis
Decrease peripheral uptake
Increase proteolysis and lipolysis
Why is it important to maintain plasma glucose level?
Enough to fuel the body.
Brain and erythrocytes require a continuous supply of glucose
How is high plasma glucose level regulated in the body?
- High blood sugar levels are detected by beta cells in the pancreas
- Beta cells release insulin into the blood stream
- Insulin stimulates glucosereuptake from the blood into tissues
- Insulin also stimulates glycogen formation in the liver
How is low plasma glucose concerntration maintained?
- Low blood sugar is detected by alpha pancreatic cells
- Glucagon released from alpha cells
- Glucagon breaks down glycogen in the liver
- Increases blood glucose level
What is the role of insulin in the liver?
Decrease Gluconeogenesis
Increase glycogen synthesis
Increase lipogenesis
What is the role insulin the striated muscle?
Increase glucose uptake
Increase glycogen synthesis
Protein synthesis
What is the role of insulin in adipose tissue?
Increase glucose reputake
Increase lipogenesis
Decrease lipolysis
What is the role of epinephrine in controlling blood glucose concerntration?
Mobilises fuels in acute stress
Stimulates glycogenolysis
Stimulates fatty acid release
What is the role of cortisol in controlling plasma glucose concerntration?
Changes long term
Stimulates glyconeogenesis And amino acid mobilisation
What is the role of growth hormone in controlling plasma glucose concerntration?
Inhibits insulin action
Stimulates lipolysis
What is diabetes mellitus?
A metabolic disorder charecterised by chronic hypoglycemia
And often associated with abnormalities of lipid and protein metabolism
What are the 4 types of diabetes patients can be classified into?
Type 1
Type 2
Secondary
Gestational
What is type 1 diabetes?
Deficiency in insulin secretion
Sudden onset (days/weeks)
In young children or young adults.
Appearance of symptoms may be proceeded by a “pre diabetic” period of several months
What is type 2 diabetes?
Insulin secretion is retained but there is target organ resistance to its actions
Slow onset (months/years)
Patients middle aged/elderly
What is secondary diabetes?
Chronic pancreatitis
Pancreatic surgery
Secretion of antagonists
What is gestational diabetes?
Occurs for the first time in pregnancy
What causes type 1 diabetes?
Autoimmune destruction of B cells
Due to interaction between genetic and environmental factors
- strong link with HLA genes on chromosome 6
What is the pathogenisis of type 1 diabetes?
- Auto antigens form on insulin producing beta cells and circulate in the blood stream and lymphatics
- Processing and presentation of auto antigens by antigen presenting cells (T lymphocytes)
- Activation of
- macrophages
- autoantigen specific cytotoxic T cells
- B lymphocytes to product islet cell auto antibodies + antiGADs antibodies
Most commonly detected antibody associated with type 1 is islet cell antibody
- Destruction of beta cells with decreased insulin secretion