Diabetes Flashcards
Where is insulin released from?
Beta cells from the pancreas
Describe how GLUT4 translocates
- Insulin binds to receptor and starts signalling cascade
- GLUT4 moves towards plasma membrane and binds
- GLUT4 transporters expose to the outside of the cell
- Glucose can work itself into the cell
When we have a lot of insulin and glucose, what happens to hepatic glucose release?
It is suppressed as we do not need it
What happens to insulin during feeding?
Increasing to promote cellular glucose uptake
What happens to insulin during fasting?
Insulin levels decrease to allow hepatic glucose production and FA release
What happens to insulin during exercise?
Insulin levels decrease to allow hepatic glucose production and FA release
Where is glucagon released from?
Alpha cells from the pancreas
What does glucagon do?
Stimulates hepatic glucose production to increase blood glucose levels
What happens to glucagon during feeding?
Nil to minimal affect
What happens to glucagon during fasting?
Small sustained released
What happens to glucagon during exercise?
Released later in exercise when blood glucose is low
What are two catecholamines and what do they do?
-Epinephrine and Norepinephrine (fight or flight)
-Stimulate glycogenolysis in the liver and muscle
(breakdown of glycogen to glucose)
What happens to catecholamines during feeding?
Nil to minimal
What happens to catecholamines during fasting?
Low levels
What happens to catecholamines during exercise?
Steadily increase with intensity
What is a brief overview of type 1 diabetes?
Bodies own destruction of beta cells, antibodies produced by the body
What are some metabolic abnormalities of type 1 diabetes?
- Unrestrained hepatic glucose production
- Glycosuria/ dehydration
- Increased lipolysis, ketone production, FA in the blood
- Increased proteolysis, muscle wastage
- Loss of hypoglycaemic glucagon release (can’t bring blood sugar levels back up)
What are typical signs of type 1 diabetes?
- Young, former illness
- Incredibly fatigued, tired, moody
- Drinking lots of water
- Weight loss
- Unwell
- Vision loss
What is a brief overview of type 2 diabetes?
- Disease of insulin resistance, or not enough insulin production
- Hyperglycaemia
What are some metabolic abnormalities of type 2 diabetes?
- Hyperglycaemia, increased hepatic glucose, hyperinsulemia
- Increased lipolysis
- Loss of pancreatic sensitivity to high blood glucose
True or false, gaining 5kg or more from the age of 18 increases risk of T2D by 2-3 fold?
True, particularly if weight is stored around abdomen.
-Obviously not if it’s 5kg of pure cold hard lean muscle
What is the first mechanism of obesity to insulin resistance and explain.
Adipose tissue and inflammation
- Pro-inflammation of cytokines causing a disruption in insulin signalling
- IL-6, CRP, TNF, leptin
What do cytokines do to the body?
Cause blood and immune abnormalities and pro-thrombotic states
-Increase clotting, levels of activated leukocytes, growth factors, blood viscosity, coagulation, heart attack, stroke
What direct and indirect affect do pro-inflammatory cytokines have?
Direct: cytokine interference with insulin signalling
Indirect: communication between insulin and body tissues
-Insulin resistance and glucose uptake decreases causing more glucose in blood
What is the second mechanism of obesity to insulin resistance and explain.
Intracellular lipid accumulation
- Fatty acid stored in the adipose tissue then released in the blood stream
- Interferes with insulin signalling in the muscle and prevents GLUT4 translocation to the surface
- Ceramide production
True or false, exercise can increase insulin sensitivity up to 48 hours post exercise?
False! Up to 72 hours ;)
What happens to mitochondria in a person that does exercise, and does not exercise regarding diabetes.
- Does not exercise = mitochondria density declines due to no use
- Does exercise = mitochondria density increases due to use
- Increase in mitochondria means more space for glucose to be turned over
Explain how stress relate to insulin resistance
Chronic stress = increased sympathetic nervous system activity = catecholamine production = glucose release = more demand
True or false, insulin resistance causes hyperglycemia
True
True or false, alpha cells begin to decline due to toxicity of glucose in the blood
False, beta cells decline
-Alpha cells T1D
What is gestational diabetes?
Diabetes that occur during pregnancy
- Glucose tolerance and sensitivity may decrease by 50-70% during birth
- Key enzymes for lipid and glucose metabolism reduced
What can GD result in for the baby and mother?
- High birth weight
- Pre-eclampsia
- Early birth, C section
- Babies with high BGT
- Diabetes for both
What are normal blood glucose levels for:
Fasting:
Random:
Glucose tolerance testing:
Fasting: <6mmol/L
Random: <7.8mmol/L
Glucose tolerance testing: 7.8mmol/L
What are insulin problem glucose levels for:
Fasting:
Random:
Glucose tolerance testing:
Fasting: 6.1-6.9mmol/L
Random: 7.8-10.9mmol/L
Glucose tolerance testing: 7.8-10.9mmol/L
What are diabetes glucose levels for:
Fasting:
Random:
Glucose tolerance testing:
Fasting: >7mmol/L
Random: >11mmol/L
Glucose tolerance testing: >11mmol/L
How is GD screened?
- 50g glucose, check 1-hour post
- Healthy should be between 3.5-7.8mmol/L
What are classic symptoms of diabetes?
- Polyuria: excessive urination
- Polydipsia: excessive thirst
- Polyphagia: excessive hunger
- Unexplained weight loss (type 1)
What is HbA1? and normal levels
- Glycosylated haemoglobin, glucose bound to haemoglobin, blood marker for recent 120 days
- <7% is normal, <6% may cause hypoglycaemia
What are some typical drug management recommendations?
- Dipeptidyl peptidase-4 inhibitors - commonly end in ‘liptin’ and slow degradation of incretin hormones.
- Insulin
What is the recommended treatment pattern for someone with diabetes?
- Weight loss and exercise
- Drugs to increase insulin sensitivity - advance to drugs that increase insulin levels - then exogenous insulin
What effects does diabetes have on exercise?
- Typically none
- Might have an increased workload/ decreased aerobic capacity due to excessive weight
What are exercise recommendations for someone with diabetes?
- 150-250 minutes of moderate activity
- CDD4 recommendations
What are the 4 main ways to reduce the likelihood of diabetes?
- Exercise
- Diet
- Tobacco cessation
- Stress coping
