Chapter 3 - Pathophysiology Flashcards
Define diabetes
A heterogeneous metabolic disorder characterized by the presence of hyperglycaemia due to defective, insulin, secretion, insulin, action, or both
Group of metabolic disorders, characterized by abnormalities in the metabolism of carb, protein, and fat
Conversion % of each macro to glucose
Carbs 90-100%
Protein 58%
Fat <10%
Glycogenolyis vs gluconeogenesis
Glycogenolyis = glycogen breakdown
Gluconeogenesis = new synthesis of glucose
The 2 principal storage fuels and what they are stored as
Glucose and free fatty acids, stored intracellularly as glycogen and triglycerides
Amount of glycogen the body stores and where
75g glycogen in the liver
300-500g glycogen in muscle tissues
Fuels for the brain vs heart/liver/muscle
The brain is glucose in an insulin dependent way but can use ketones.
The other vital organs can use either glucose with free fatty acids directly. Insulin is required for transport and storage
Why do we check c-peptide?
C-peptide is stored and co-secreted with insulin, thus measuring C-peptide helps distinguish between endogenous and exogenous insulin production when evaluating hypoglycaemia
Glucose levels of ? Stimulate insulin synthesis
> 3.9mmol/L
How is insulin released in response to eating?
Biphasic pattern
1.) large burst in the first 30min
2.) slower release over the next 1-2 hours
Secretion pathway of insulin
Beta cells -> portal Venus system -> liver
liver removes 50% and then rest of the insulin continues to systemic circulation
5 functions of insulin
1.) glucose into cells to be used for fuel
2.) allows circulating FFAs to be stored as TG in fat cells
3.) conversion of glucose to glycogen
4.) storage of AA as protein in muscle
5.) glycogen to be store in muscle and liver
What are the incretin hormones that stimulate insulin release
Glucose-dependent insulinotropic polypeptide (GIP)
Glucagon like peptide 1 (GLP-1)
From stomach, small and large intestine
