T2 L12: Diabetes Mellitus Flashcards
What are the classic symptoms of diabetes mellitus?
Thirst, tiredness, weight loss, polyuria (excessive urination), ketoacidosis, hyperglycaemic coma
What is the mechanism behind the cause of diabetes mellitus?
The autoimmune destruction of beta-cells in the islets of Langerhans in the pancreas which leaves the metabolism in the starved state because glucagon is excessive
Why does urine from uncontrolled diabetics smell like pears?
Because there is a build up of acetone in the blood that the body tries to get rid of
What are the main sources of energy in a type 1 diabetic?
Fatty acid and beta-oxidation
Why do blood glucose concentrations remain high in type 1 diabetes?
Because there is no insulin to guide the glucose into tissues
Why is fatty acid synthesis diminished with type 1 diabetes?
Because lipoprotein lipase is regulated by insulin and without it, fat cant detach from VLDL so it cant be metabolised
Ketoacidosis is part of which type of diabetes?
Type 1 only
What is ketoacidosis?
The build up of ketones in the blood
Why is excessive glucose toxic?
It causes generation of ROS, osmotic damage to cells, glycosylation (addition of carbohydrates to proteins) which changes protein function
What are the 2 blood tests used to diagnose type 1 diabetes?
Fasting blood glucose levels and glucose tolerance test
What is HbA1c and what is it used for?
It’s glycated haemoglobin. Can be used to measure glucose levels over a longer period
What are the 3 causes of type 2 diabetes?
Impaired insulin secretion, increased peripheral insulin resistance, increased hepatic glucose output
What 2 things does the body fail to respond to and why with type 2 diabetes?
- Insensitivity of target cells to insulin because of defects in receptors and cell signalling
- Impaired insulin secretin caused by amyloid deposits reducing beta-cell mass
What is peripheral resistance induced by in diabetics?
Presence of fatty acids, dysregulated adipokines from adipose tissue, defects in GLUT-4
Why are glucagon levels not as raised in type 2 diabetes?
Because there is some insulin to help regulate glucagon levels
