Diabetes tutorial Flashcards
OGTT
oral glucose tolerance test
diabetes mellitus
-under utilization of glucose by tissue
-Overproduction of glucose by the liver
= increase in plasma glucose and yet starvation of tissues
-There is a dysfunction in insulin signals
Symptoms of diabetes
-elevated blood glucose levels (hyperglycaemia). normal = 5mM, which exceeds the glucose renal threshold of around 10mM, meaning glucose can enter the urine = high osomotic effcet= water difuuses into the urine
-leads to polydysia(dehydration)
-weight loss
-acidosis= decrease in blood PH due to elevated of plasma ketone bodies (ketosis)
insulin deficiency
-reduces glucose uptake into cells except the liver
In liver cells:- inhibits glycolysis and glucose synthesis- promotes gluconeogenesis and glycogen breakdown
Type 1 diabetes
-see early in life
-Insulin production (B-cells of the pancreas) is defective.
-B cells fail to develop OR are destroyed due to autoimmune disease (embryonic or later) OR viral infection
type 2 diabetes
- adult onset form of diabetes: milder
-Insulin production by B-cells is normal
defect in: response of cells to insulin
how do we use a Oral glucose tolerance test to test for diabetes?
-Occurs after a overnight fast to get basal levels of glucose
-The individual then takes glucose over a short time period and the plasma glucose is measured over 2-3 hours
- blood insulin levels can also be measured
what would be defined as normal results
- resting glucose level- less than 6mmol/L before the test
-does not exceed renal threshold
-less than 7.8mmol/L two hours after the test
What would be defined as impaired glucose tolerance(pre-diabetic state)
-6-7mmol/L before the test
-does/does not exceed renal threshold
-7.9-11 mmol/L two hours after the test
What would be defined as a diabetic response?
-blood glucose more than 7mmol/L before the test
-exceeds renal threshold
-more than 11mmol/L two hours after the test
How do you convert mg/100mL to mmol/L in glucose
-mmol/L = (mg/100mL × 10) ÷ 180
-This is because:
1 mg/100mL = 10 mg/L
Molar mass of glucose ≈ 180 g/mo
explain the method in which we use radioactive assay data to measure insulin concentration in the blood
urpose: Measures tiny amounts of hormones (e.g. insulin).
Why used? Very sensitive and accurate — detects low hormone levels.
How it works:
Radioactive insulin + sample insulin compete to bind to antibodies.
More real insulin = less radioactive insulin binds.
CPM (Counts Per Minute):
Measures radioactivity.
High CPM = Low insulin.
Low CPM = High insulin.
Standard Curve:
Plot insulin concentration vs average CPM.
Used to determine unknown insulin levels.
How do we use the insulin standard curve to calculate blood insulin levels
Look at the CPM (counts per minute) from your sample.
Use the standard curve to find the insulin concentration that matches that CPM.
If the sample was diluted, multiply the insulin value by the dilution factor.
This gives you the true insulin concentration in the original sample.
Why you do this
CPM tells you how much radioactive insulin was bound.
The standard curve links CPM to known insulin levels.
Dilution affects how much insulin is measured, so you need to adjust for it.
see final slide for the graph of glucose concentration and insulin combined and try and do all theses practices
