5.4.5: Diabetes

Question 1

What is diabetes mellitus

Answer 1

A condition in which the body is no longer able to produce sufficient insulin to control its blood glucose concentration.

Question 2

What happens after a meal rich in sugars and carbohydrates if someone with diabetes mellitus?
What happens after exercise or fasting?

Answer 2

• Prolonged very high concentrations of glucose (hyperglycemia).
• Concentrations can drop too low (hypoglycemia)

Question 3

What is type 1 diabetes known as?

Answer 3

Insulin dependent diabetes, or juvenile-onset diabetes as it usually starts in childhood.

Question 4

What is type 1 diabetes thought to be the result of?

Answer 4

• An autoimmune response in which the body’s immune system attacks and destroys the beta cells.
• May also arise from a viral attack.

Question 5

What happens in a healthy person when glucose is absorbed into the blood?

Answer 5

• Any excess is converted into glycogen in the liver and muscles.
• This glycogen can be used to release glucose when blood glucose concentrations fall.

Question 6

What happens in a type 1 diabetic when glucose is absorbed into the blood?

Answer 6

• A person with type 1 diabetes is no longer able to synthesise sufficient insulin and cannot store excess glucose as glycogen.
• Excess glucose in the blood is not removed quickly, leaving a prolonged period of high concentration.

Question 7

What happens in a Type 1 diabetic when blood glucose concentration falls.

Answer 7

• There is no store of glycogen that can be used to release glucose.
• Blood glucose concentration falls too low.
• This is when a diabetic can suffer a ‘hypo’- a period of hypoglycemia.

Question 8

What is type 2 diabetes known as?

Answer 8

• Non-insulin dependent diabetes.

- A Type 2 diabetic can produce insulin, but not enough.

Question 9

As a person ages, their responsiveness to insulin declines. Why this is

Answer 9

-The specific receptors on the surface of the muscle and liver cells become less responsive and the cells lose their ability to respond to the insulin in the blood.

Question 10

Describe the blood glucose concentration in a Type 1 diabetic.

Answer 10

Almost permanently raised.

Question 11

What is the result of a blood glucose concentration that is almost permanently raised?

Answer 11

Damage to major organs circulation.

Question 12

What can bring on an early onset of type 2 diabetes?

Answer 12

• Obesity
• Lack of regular exercise
• A diet high on sugars, particularly refined sugars
• Being of Asian or Afro-Caribbean origin
• Family history

Question 13

How is Type 1 diabetes usually treated?

Answer 13

• Insulin injections
• The blood glucose concentrations must be monitored and the correct dose of insulin administered to keep the glucose concentration fairly stable.

Question 14

What are the alternatives to insulin injections?

Answer 14

• Insulin pump therapy
• Islet cell transplantation
• A complete pancreas transplant.

Question 15

Describe insulin pump therapy.

Answer 15

A small device constantly pumps insulin at a controlled rate into the bloodstream through a needle that is permanently inserted under the skin.

Question 16

Describe islet cell transplantation.

Answer 16

Healthy beta cells from the pancreas of a deceased donor are implanted into the pancreas of someone with Type 1 diabetes.

Question 17

How can stem cells be used to treat Type 1 diabetes?

Answer 17

• Stem cells could be used to new islets of Langerhans in the pancreas.
• Stem cells are not yet differentiated and can be induced to develop into a variety of cell types.

Question 18

What is the most common source of stem cells?

Answer 18

Bone marrow and the placenta

Question 19

Scientists have found precursor cells in the pancreas of adult mice. These cells are capable of developing into a variety of cell types and may be true stem cells. If similar cells can be found in the human pancreas, what would this mean for treatments for diabetes?

Answer 19

• They could be used to produce new beta cells in patients with Type 1 diabetes.
• This would give the patient freedom from daily insulin injections.

Question 20

How is Type 2 diabetes treated?

Answer 20

• By a change in lifestyle.
• Advised to lose weight
• Exercise regularly
• Monitor diet, taking care to match carbohydrate intake and use.
• May be supplemented with medication that reduces the amount of glucose the liver releases into the bloodstream or that boosts the amount of insulin released from the pancreas.

Question 21

What treatments can be used in severe cases of Type 2 diabetes?

Answer 21

The treatment may include insulin injections or the use of other drugs that slow down the absorption of glucose from the digestive system.

Question 22

Where did we used to get insulin for the treatment of diabetes?

Answer 22

• Extracted from the pancreas of animals.

- Usually pigs as this matches human insulin more closely.

Question 23

More recently, where do we get insulin for the treatment of diabetes?

Answer 23

-Insulin produced by Escherichia coli bacteria that have undergone genetic modification to manufacture human insulin.

Question 24

What is the advantage of using insulin from genetically modified bacteria?

Answer 24

• Exact copy of human insulin so faster and more effective.
• Less chance of developing tolerance to the insulin.
• Less of a chance of rejection due to an immune response.
• Lower risk of infection
• Cheaper to manufacture insulin rather than extracting it from animals.
• Manufacture process is more adaptable to demand.
• Some people are less likely to have moral objections to using the insulin produced from bacteria than to using insulin extracted from animals.