Diabetes Flashcards
What is insulinoma?
Insulin producing tumour in pancreas
causes hypoglycaemia
What are the main causes of hypoglycaemia?
Insulinoma Hypoadrenalism Alcohol Severe liver failure Insulin or suphonylureas (Gliclazides)
Insulin is secreted by what cells in the pancreas?
Beta cells
Glucogon is secreted by what cells in the pancreas?
Alpha cells
Where does glucose homeostasis predominantly occur?
Liver
What is glucose stored as in the liver?
Glycogen
When is glucose stored and released in the liver?
Stored during absorptive state
Released post absorptive state (Between meals)
What does insulin suppress?
Gluconeogenesis and facilitated uptake of glucose for storage as glycogen
What is the ratio of insulin and glucagon in the fed state?
High insulin
Low glucagon
What is the ratio of insulin and glucagon in the fasting state?
Insulin low
Glucagon high
How does insulin decrease blood glucose?
Increases glucose absorption into cells and out of plasma
How does glucagon raise blood glucose?
Increases breakdown of glycogen to glucose in liver and upregulating gluconeogenesis
What percentage of patients are type 1 diabetics?
10%
What type of hypersensitivity reaction is type 1 diabetes?
Type 4 - one’s own T cells attacks beta cells of pancreas
What genes have been identified in some Type 1 diabetics?
HLA DR3 and DR4 on Chr 6
Type 1 DM symptoms
Glycosuria (glucose in urine) Polyuria (increased urine) Polydipsia (thirst) Weight loss Polyphagia (hunger)
Why do type 1 diabetics present with weight loss?
Lipolysis and breaking down of protein as adipose tissue and muscle try to produce their own energy
Why does DKA occur?
Lipolysis causes fatty acids to be broken down into acetic acid and beta hydroxybutyric acid in liver.
These ketone bodies are acids and cause metabolic acidosis.
Body compensates - Kussmaul’s breathing
Acidosis and low insulin causes hyperkalaemia
How does DKA cause hyperkalaemia?
Insulin normally stimulates Na+/Ka+ ATPase which enables K+ to enter cells.
Acidosis and large concentration of H+ outside the cell drive H+ into cell, therefore driving K+ out of cell.
Percentage of T2DM in population
90%
What happens to beta cells in T2DM?
Over time higher than normal insulin levels cause beta cell hyperplasia to try and normalise glucose levels
Amylin produced which builds up in beta cells causing damage and insulin then falls
Can T2DM develop DKA?
No - they have normal insulin levels
What is HHS?
Hyperosmolar Hyperglycaemia State
High glucose leads to extreme hyperosmolarity and dehydration causing cells to shrivel
Get mild acidosis
Ways to diagnosis diabetes?
Random blood glucose
High fasting glucose
Oral glucose tolerance test (2 hours after glucose load)
HBA1C
What is HbA1C?
Proportion of Hb in RBC which has glucose attached to it
Long term consequences of diabetes?
Damage to microvasculature (Retinopathy, nephropathy)
Atherosclerosis
Neuropathy
Leg ulcers
