Diabetes Mellitus Flashcards
(48 cards)
What is the action of insulin?
Decrease hepatic glucose output
Decrease proteolysis
Decrease lipolysis
Decrease ketogenesis
What are the clinical implications involving insulin?
Type 1 diabetes mellitus
Hypoglycaemia
Insulin Resistance
Type 2 diabetes mellitus
In which cells is GLUT-4 common in?
Myocytes (muscle)
Adipocytes (fat)
What are the main features of GLUT-4?
Highly insulin-responsive
Lies in vesicles
Recruited and enhanced by insulin
7-fold increase glucose uptake
Where does gluconeogenesis take place?
The liver
What effect does insulin have on the liver in the few state?
Amino acids taken up by the liver
Increased protein synthesis
Decreased gluconeogenesis
What are the main fuels stores of the body?
Carbohydrate
Protein
Fat
How long does it take for these stores to be depleted?
Carbohydrate- 16 hours
Protein- 15 days
Fat- 30/40 days
What is the function lipoprotein lipase?
(LPL) enzyme breaks down triglycerides that would otherwise be unable to leave the circulation
What is the action of insulin on adipocytes in the fed state?
Increases glucose uptake int the fat cell
Converts the glycerol and NEFA’s into triglycerides
Encourages lipogenesis
Inhibits glycolysis
How can insulin act quickly on the liver?
Secreted into the hepatic portal system
What is the action of insulin on adipocytes in the fasting state?
Hepatic gluconeogenesis responsible for 25% of hepatic glucose output after a 10 hour fast
Why is the brain unique?
Unable to utilise fatty acids as a fuel
What does ketone body production result from?
Low levels of insulin
When is ketone body formation abnormal?
When there are high levels of glucose
Normal in fasting state
What is hepatic glycogenolysis?
Generation of glucose from stored glycogen in the liver
What is the action of insulin on muscle in the fed state?
Uptake of glucose bu muscle cells
Used for respiration to release energy
What is the action of insulin on muscle in the fasting state?
No action
Counter regulatory hormones prevent excess uptake
Summarise what occurs in the fasted state?
Low insulin-to-glucagon ratio
[Glucose] 3.0-5.5mmol/l
Increased [NEFA]
Decreased [amino acid] when prolonged
What actions occur in the fasted state?
Increased Proteolysis Lipolysis HGO from glycogen and gluconeogenesis Muscle to use lipid Brain to use glucose, later ketones Ketogenesis when prolonged
Summarise what occurs in the fed state?
Stored insulin released then 2nd phase
High [insulin] to [glucagon] ratio
What actions occur in the fed state?
Stop HGO ↑ Glycogen ↓ gluconeogenesis ↑ protein synthesis ↓ proteolysis ↑ Lipogenesis
How is diabetes diagnosed?
Fasting glucose >7.0mmol/L
Random glucose >11.1mmol/L
What tests are used to diagnose diabetes?
Oral glucose tolerance test
HbA1c (>48mmol/mol)
