Type 2 Diabetes Mellitus Flashcards
What is type 2 diabetes mellitus?
“A condition in which the combination of insulin resistance and beta-cell failure result in hyperglycaemia”
- Body makes insulin but tissues don’t respond to it (reason not fully understood)
- INSULIN RESISTNACE
- obesity and genetic risk factors of T2DM
- Body makes excess insulin to try to move the glucose out of blood
- Eventually puts strain on beta cells (overworked)- beta cell damage
- Insulin starts to go down (depending on time of diagnosis, insulin levels will vary)
What is the fasting glucose level that shows impaired fasting glucose (pre-diabetes)?
patient doesn’t eat/ drink for 8 Hrs
6 mmol/L ≤ fasting glucose levels ≤ 7 mmol/L
(6-7 mmol/L is pre-diabetes)
(less than 6 is normal)
(more than 7 is diabetes)
What is the reading of an oral glucose tolerance test for impaired glucose tolerance (pre-diabetes)?
Give glucose & take blood samples at time intervals
7.7 mmol/L ≤ 2-hr glucose (OGTT) ≤ 11mmol/L
(7.7-11 is prediabetes)
(less than 7.7 is normal)
(more than 11 is diabetes)
What is the HbA1c level for pre diabetes or non-diabetic hyperglycaemia?
glycated hemoglobin (hemoglobin attached glucose)- glucose level for the part 3 months
42 mmol/L ≤ HbA1c ≤ 48mmol/L
(42-48 is prediabetes)
(less than 42 is normal)
(more than 48 is diabetes)
What is needed for the diagnosis of type 2 diabetes?
(1 positive test + symptoms or 2 positive tests)
Usually:
First line test for diagnosis is HbA1c.
1x HbA1c >=48mmol/L with symptoms
Or
2x HbA1c >=48 mmol/mol if aysymptomatic
What can occur from a long duration of T2DM?
In long-duration type 2 diabetes, beta-cell failure may progress to complete insulin deficiency
=Hyperglycaemia
important not to stop giving insulin as at risk of ketoacidosis
What effect does T2DM have on insulin release?
- Normally we encounter a “first phase insulin release” which is an immediate/ spike release
- This is lost in T2DM
How does the liver react to the reduced insulin levels seen after T2DM?
Hepatic glucose production is increased due to both a reduction in insulin action and increase in glucagon action
“excessive glucagon-mediated glucose output” (but reduced clearance of glucose- still not being removed from circulation”
What is the relationship b/t insulin secretion and insulin sensitivity?
As insulin secretion decreases, the insulin sensitivity increases
What is the random glucose (non-fasting glucose) level for diabetes?
(Can be done at any time)
levels greater than or equal to 11.1 mmol/L + symptoms
What consequences do other body tissues face from T2DM?
Skeletal muscle:
- Reduced glucose uptake
- Impaired glycogen synthesis
Adipocytes:
- Reduced glucose uptake
- Increased lipolysis
- Reduced lipogenesis
Liver:
- Increase in hepatic glucose production
- Increased lipogenesis
Is diabetes monogenic or polygenic?
Type I and II (most common types) are polygenic: not born with the diabetes but high risk and may develop later depending on other factors
MODY diabetes is monogenic: you are born with the single gene mutation and it is always going to develop into diabetes
What are other associations seen with T2DM?
- Obesity
- Perturbations/ abnormalities in gut microbiota (inflammation causes various signaling metabolic pathways)
- Intra-uterine growth retardation
What are the presentations of T2DM?
Hyperglycaemia
Overweight
Dyslipidaemia
Fewer osmotic symptoms
With complications
Insulin resistance
Later insulin deficiency
What are the risk factors of T2DM?
- Age
- PCOS
- high BMI
- Family History
- Ethnicity
- Inactivity
