Carbohydrate Intolerance and Exercise

Question 1

pancreatic islets of langerhans
- what do they do
- what cells are the 2 hormones secreted from

Answer 1

• rapid release of insulin and glucagon into the portal vein
• Insulin by β-cells of pancreatic islets, Glucagon by α-cells

Question 2

how are insulin and glucagon antagonistic

Answer 2

insulin is secreted in response to elevated blood glucose to reduce it, and glucagon in response to low blood glucose to elevate it

Question 3

healthy fasting blood glucose levels

Answer 3

Fasting blood glucose test 4-6 mmol/L

Question 4

diabetic signs
- Fasting blood glucose test
- Random blood glucose test
- Glucose in urine
- Oral Glucose Tolerance Test
- Glycated haemoglobin (HbA1c)
- Symptoms
- Autoantibodies against the pancreas in the blood which mainly destroy beta cells
- Disease management

Answer 4

○ > 7.0 mmol/L
○ > 10 mmol/L (even if had big sugary meal)
○ Present
○ Impaired glucose clearance (give 75g glucose drink, see what clearance is like)
○ > 10% (reflects last 3-month glucose - chronic)
○ Thirst, sweating, fatigue
○ present therefore Type-1
○ medication, diet, exercise

Question 5

what is type 1 and 2 diabetes

Answer 5

• Type 2 Diabetes: Impaired Sensitivity of cells to Insulin
• Type 1 Diabetes: Impaired Insulin Secretion as the Immune system (T-cells and b-cells) attacks the pancreas destroying b-cells

Question 6

5 long term complications of diebetes

Answer 6

• Diabetic Retinopathy - Leading cause of blindness in adults
• Diabetic Nephropathy - Leading cause of end-stage renal disease
• Diabetic Neuropathy - Leading cause of non-traumatic lower extremity amputation
• Stroke - 2-4 fold increase in CV mortality and stroke
• Cardiovascular Disease - 8/10 individuals with diabetes die from CV events

Question 7

benefits of exercise for people with diabetes

Answer 7

• Preserved beta cell function
• Lower insulin requirements, improved insulin sensitivity and glucose clearance
• Lower risk of adverse CV events
• Improved blood lipid profile (HDL:LDL)
• Increased physical fitness and function
• Improved endothelial function (FMD)
• Reduced diabetic complications/lower mortality rate
• Improved psychological well being
• Improved glycaemic control (more evidence in type 2 than 1)

Question 8

how is blood glucose increased and decreased

Answer 8

• increased by glycogenolysis and gluconeogenesis in the liver driven by epinephrine
• decreased by glucose uptake by working muscles

Question 9

what happens to blood glucose at start of exercise and during prolonged

Answer 9

• initially rapid increased as epinephrine stimulation outweighs muscle uptake
• prolonged exercise reduces it because liver glycogen depletes

Question 10

why do insulin taking diabetics have to be carefully when injecting before exercise

Answer 10

injections reduced prior because this insulin will continue to reduce blood glucose so will drop too low