Diabetes: overview and type 2

Question 1

What is diabetes?

Answer 1

A chronic state of hyperglycaemia caused by a lack of insulin OR a diminished effectiveness of endogenous insulin

Question 2

What does insulin do?

Answer 2

REDUCES blood glucose

Suppresses hepatic glucose output

Increases glucose intake into insulin sensitive tissues
Increases glycogen, fat and protein formation from glucose

Suppresses lipolysis and breakdown of muscles (preventing release of glucose into blood)

Uptake of K into cells

Question 3

What does glucagon do?

Answer 3

INCREASES blood glucose

Increases hepatic glucose output

Reduces peripheral glucose uptake

Stimulates peripheral release of gluconeogenic precursors, by lipolysis

Question 4

Where are glucagon and insulin made?

Answer 4

In pancreas
In islets of Langerhans

Insulin in beta cells
Glucagon in alpha cells

Question 5

Describe what happens in the fasting state? How are the muscles provided with enough fuel to work?

Answer 5

No input of glucose from food to supply the body cells

So all glucose comes from liver

• glycogen is broken down to release glucose
• gluconeogenesis, synthesis of glucose

This glucose is delivered to muscle for fuel

Question 6

What is:

• glycogen
• glucagon
• gluconeogenesis?

Answer 6

Glycogen: storage glucose

Glucagon: hormone which increases blood glucose

Gluconeogenesis: synthesis of glucose from non-carbohydrate molecules like glycerol, pyruvate

Question 7

Describe what happens in the fed state?

Answer 7

After eating food there’s a rapid rise in blood glucose

Some is used by the liver, some is stored as glycogen there

Some goes to muscles and is used straight away

Any excess glucose is stored as adipose or glycogen in muscles

Question 8

Why do you get fat when you eat too many sugary things?

Answer 8

Excess glucose in the bloodstream after eating is stored as glycogen (in muscles or liver) or as adipose tissue

Question 9

How can people die of diabetes?

Answer 9

They can get acute hyperglycaemia

If this is untreated, they can go into acute metabolic emergency, leading to organ failure, coma, death

Question 10

What types of diabetes are there?

Answer 10

Type 1
Type 2

Medication induced
Maturity onset diabetes of youth
Pancreatic diabetes
Endocrine diabetes
Malnutrition related diabetes

Question 11

What is pancreatic diabetes?

Answer 11

If someone has pancreatic failure due to cancer, pancreatitis etc.

Their pancreas will not be as efficient at making insulin and glucagon

Hence diabetes

Question 12

Clinical features of diabetes?

Answer 12

Polyuria: frequent urination

Polydypsia: frequent thirst

Weight loss

Lack of energy

Question 13

Which drugs can cause diabetes?

Answer 13

Steroids

Thiazides

Question 14

How do you diagnose diabetes?

Answer 14

Fasting glucose > 7 mmol
and
Glucose tolerance test

OR

Random glucose > 11 mmol

OR
Hba1c: levels over 48 on 2 separate occasions

Question 15

What is the glucose tolerance test?

Answer 15

Patient fasts

Then they are given glucose and blood samples are taken after to determine how quickly glucose is removed from the blood

The slower = diabetes

Question 16

What is the cause of type 1 diabetes?

Answer 16

Unknown, but it is though that a viral infection triggers it.

The antibodies created against the virus begin to attack the beta cells of pancreas

Over time they get damaged so much they stop making insulin

Question 17

Describe the progression of type 1 diabetes from normal healthy person to person with type 1 diabetes?

Answer 17

Healthy person with genetic pre-disposition to type I diabetes

Trigger, viral infection

Antibodies produced to fight virus start to attack B cells of Islets of Langerhans

This causes insulinitis: inflammation of the Islets of Langerhans, including the B cells

In time the damage to the B cells makes them stop making insulin

Pre-diabetes
Leading to diabetes

Question 18

When does ketoacidosis occur?

Answer 18

In type 1 diabetes only

When the body cells are unable to get any glucose, because it is all stuck in the blood stream

The body starts breaking down fat to use as fuel

This means ketones are released

To many ketones can be toxic: leading to ketoacidosis

Question 19

In which type of diabetes, 1 or 2 is the genetic component stronger?

Answer 19

Type 2

Question 20

What causes type 2 diabetes?

Answer 20

Insulin resistance
+
Impaired insulin secretion

Question 21

What are the risk factors for type 2 diabetes?

Answer 21

Obesity
Sedentary lifestyle
Family history
Age
Ethnicity

Question 22

Pathogenesis of type 2 diabetes?

Answer 22

High blood sugar due to diet

Body tries to counteract this by releasing more insulin

It can’t maintain this forever so B cells in IoL get damaged and can’t maintain levels of insulin

Resistance develops to insulin

Diabetes occurs

Question 23

Management of type 2 diabetes?

Answer 23

Lifestyle changes:

• reduce weight
• better diet

Metformin drug

Sulfonylurea

Question 24

How does the drug sulfonylurea work?

Answer 24

By increasing insulin release from the beta cells

Question 25

What is hyperosmolar hyperglycaemic state?

Answer 25

Very high blood glucose, occurs in type 2 diabetes

Question 26

How does metformin treat diabetes?

Answer 26

It reduces gluconeogenesis in the liver