Diabetes Flashcards
What are the 5 actions of insulin?
Glucose:
1. Dec HGO
2. Inc muscle uptake
Protein:
3. Dec preoteolysis
Fat:
4. Dec lipolysis
5. Dec ketogenesis
What are GLUT-4 proteins?
Glucose transporter protein
- high in myocytes and adipocytes
- highly insulin-responsive —> GLUT-4 vesicles fuse
with plasma membrane
- inc glucose intake x7
How does insulin act on myocytes? (4)
- Inc glucose uptake
Dec gluconeogenesis:
2. Dec amino acid production (protein breakdown)
3. Dec uptake of oxygen
4. Inc protein synthesis (dec amino acids)
Which hormones act on myocytes during hypoglycaemia? (2)
- Glucagon —> dec glucose uptake
- GH —> dec glucose uptake
—> inc protein breakdown to amino acids - IGF-1 —> inc protein breakdown to amino acids
- inc gluconeogenesis
How does insulin act on hepatocytes? (4)
Dec HPO:
1. Dec gluconeogenesis
2. Inc protein synthesis (dec amino acids)
3. Dec ketogenesis
4. Inc glycogenesis
Which hormones act on hepatocytes during hypoglycaemia? (2)
- Glucagon —> inc gluconeogenesis
—> inc protein breakdown to amino acids
—> inc ketogenesis
—> inc glycogenolysis - Cortisol —> inc gluconeogenesis
- inc HPO
How does insulin act on adipocytes? (4)
Inc lipid stores:
1. Inc LPL (lipoprotein lipase) —> more triglyceride
breakdown in capillaries —> inc lipid intake
2. Inc triglyceride formation in cells
3. Inc glucose uptake
4. Dec triglyceride breakdown in cells —> dec lipid exit
Which hormones act on adipocytes during hypoglycaemia? (2)
- GH —> inc triglyceride breakdown in cells
- Cortisol —> inc triglyceride breakdown
- inc glycerol and NEFA out for gluconeogenesis +
ketogenesis
Where is insulin secreted to and why?
Hepatic portal system
- act on liver very quickly
Where is insulin injected in diabetics and why?
Adipose tissue —> slow absorption —> gradual rise in blood glucose
Which organ is glucose essential for and why?
Brain
- main energy source (+ partially ketone bodies)
- fatty acids can’t cross blood brain barrier
How does diabetes affect ketone body production?
Dec insulin response —> dec glucose uptake —> inc ketone body production for brain
- see high sugar + high ketones in blood (unusual)
What are the main differences between the fasted vs fed state?
Fasted:
- blood —> low insulin : glucagon
—> [glucose] 3.0-5.5 mmol/L
—> [NEFA] inc
—> [amino acid] inc (prolongued fasting)
- myocytes —> inc proteinolysis
—> uses lipids (β-ox)
- hepatocytes - inc HPO
—> inc gluconeogenesis
—> inc glycogenolysis
—> inc ketogenesis
- adipocytes —> inc lipolysis
Fed:
- blood —> high insulin : glucagon
- 1st and 2nd phase insulin release
- myocytes —> dec proteinolysis
—> inc protein synthesis
- hepatocytes - dec HPO
—> dec gluconeogenesis
—> inc glycogenesis
- adipocytes —> inc lipogenesis
How is diabetes diagnosed? (7)
2 positive tests/ 1 positive tests + symptoms
- Fasting glucose >6.9 mmol/L
- Random glucose >11.1 mmol/L
- Oral glucose tolerance test
- take fasting glucose
- give 75g glucose load
- take blood glucose after 2 hours
- HbA1c >48 mmol/mol
T1DM:
5. Antibodies —> GAD
—> IA2
6. C-peptide
7. Blood ketones
What is T1DM?
Autoimmune condition —> insulin deficiency