Theme C lecture 7

Question 1

What is the leading cause of death in patients with known/unknown diabetes?

Answer 1

Cardiovascular disease

*Many people with diabetes don’t know they have it

Question 2

What percentage of diabetics have hypertension?

Answer 2

70%

Question 3

Why does diabetes contribute to cardiovascular disease?

Answer 3

Elevated blood glucose damages endothelial cells. This results in weakened blood vessels and in turn cardiovascular disease.

Question 4

What causes diabetes, generally speaking?

Answer 4

Defects in insulin secretion, action, or both.

Question 5

How many people in the world suffer from diabetes?

Answer 5

366 million people globally.

Question 6

How many people suffer from diabetes in Australia?

Answer 6

2.5 - 3 million in Australia

Question 7

Interesting fact:

Answer 7

half the people with diabetes don’t even know they have it

Question 8

What are the types of complications that can arise from diabetes?

Answer 8

Microvascular: retinopathy and nephropathy

Macrovascular:
Heart disease and stroke.

Question 9

Why is it important for glucose levels to be maintained?

Answer 9

Glucose levels should be maintained in the blood to constantly supply the brain.

Question 10

How does insulin get produced?

Answer 10

biphasic secretion. It allows entry of glucose into the cell by upregulating GLUT.

It also suppresses liver glucose production.

Question 11

What stimulate change in beta cell mass?

Answer 11

beta cell mass changes in response to demand

Question 12

How does insulin regulate glucose levels in the blood?

Answer 12

1) Increase in blood glucose.
2) Increase in insulin secretion
3) Glucose is utilised by muscle, liver, adipose tissue, etc
4) Blood glucose decreases
5) negative feedback reduces insulin secretion

Question 13

What is the difference between insulin resistance and sensitivity?

Answer 13

Insulin resistance is a condition where the body does not respond to insulin signals

Insulin sensitivity is the degree to which the body responds to insulin.

The less sensitive an individual is to insulin the more resistant he is.

Question 14

What are some risk factors for diabetes?

Answer 14

Diet

Lifestyle

Low birth weight

Question 15

What did monozygotic twin experiments show about the nature of insulin resistance?

Answer 15

Between 2 twins the one with lowest birth weight have an increased insulin secretion and higher blood sugar levels.

Question 16

What period during gestation is most important in programming of metabolic dysfunction?

Answer 16

Developmental insults during late gestation may be a critical period in programming metabolic dysfunction.

Question 17

What is the “thrifty phenotype” hypothesis?

Answer 17

Fetus can adapt to suboptimal intrauterine conditions by redirecting nutrients to most vital organs (brain) at expense of other organs.

Events during critical periods may permanently program the fetus metabolism to enhance survival.

If postnatal nutrition is abundant, advantage is lost.

Question 18

What is the result of IUGR malnutrition?

Answer 18

Increase in malnutrition:

Decreases beta cell mass

Decrease in glucose uptake and increases glucose production

Decrease in insulin sensitivity

Inhibition of lipolysis

All these factors result in a decrease in pancreatic function and glucose intolerance and insulin and resistance and in turn diabetes

Question 19

What happens to insulin sensitivity during aging?

Answer 19

It decreases

Question 20

What are the steps in type 2 diabetes development?

Answer 20

1) Body less sensitive to insulin
2) beta cells compensate by increasing insulin secretion
3) Beta cells get exhausted and undergo more apoptosis causing decrease in insulin secretion
4) Sustained IFG
5) Further decline
6) Sustained type 2 diabetes

Question 21

How do pancreatic beta cells respond to increased insulin resistance?

Answer 21

Pancreatic beta cells increase insulin secretion in response to decline in insulin sensitivity until a point of beta cell exhaustion

Question 22

What does fetal programming do to the pancreas?

Answer 22

It decreases beta cell mass at birth. For this reason the exhaustion point is lower for the beta cells of these individuals

Question 23

Why is uteroplacental insufficiency the most commonly used method during research of fetal programming?

Answer 23

uteroplacental insufficiency is most commonly used in experiments because it is the leading cause of low birth weight in western countries

Question 24

How do the genders differ in glucose tolerance?

Answer 24

the fetal programming effect of glucose tolerance happens more often in males than females.

If the growth restricted females become pregnant they have impacted glucose tolerance during pregnancy.

Question 25

What was seen in IUGR and metabolic dysfunction rats?

Answer 25

Structurally:

Decrease in pancreas and muscle mass

Decrease in islet and beta cell mass by 70%

Decrease in pancreatic vascularisation

Molecular changes:

Gene and protein expression (receptors, growth, and transcription factors.)

Mitochondrial dysfunction (ATP is critical-insulin production and release.

Epigenetic changes

Question 26

What is gestational diabetes?

Answer 26

Occurs during pregnancy when body can not cope with extra demands for insulin.

Question 27

What does gestational diabetes do to offspring?

Answer 27

Increases risk of diabetes in offspring.

Increases lifetime risk of diabetes in the mother.

Gestational diabetes can influence several generations in a row

Question 28

What are some interventions that can decrease the risk associated with gestational diabetes?

Answer 28

Improved diet

Vitamin supplements

Therapeutics/Drugs

Exercise/physical activity

Question 29

How does exercise help decrease the risk caused by gestational diabetes?

Answer 29

It increases beta cell mass restored in growth restricted adult rats.