Diabetes Pathogenesis

Question 1

How does Type 1 diabetes develop?

Answer 1

Autoimmune condition in which lymphocyte infiltration of Islets of Langerhans causes insulitis, destroying B cells and compromising the ability to absorb Glc from blood.

Question 2

Describe the aetiology of Type 1 Diabetes?

Answer 2

A combination of genetics and environmental factors.

Human leukocyte Antigens (HLA) + chemicals or viral infection

Question 3

Describe the aetiology of Type 2 Diabetes?

Answer 3

A combination of insulin resistance due to visceral fat and genetic inability to secrete high levels of insulin

Question 4

What causes insulin resistance in Type 2?

Answer 4

Visceral fat mass

• > Free FAs in the blood
• > FAs clog Insulin receptors
• > Reduced insulin sensitivity

Question 5

Explain the genetic aspect of Type 2 diabetes?

Answer 5

Most peoples genes are capable of upscaling insulin production to match insulin resistance.

In some people a number of genes are ‘defective variants’ which code for Poor B cell ‘high end’ insulin secretion.

Essentially they can’t produce enough insulin to match the new insulin resistance

Question 6

If visceral fat triggers Type 2 diabetes, how come some slim people get it?

Answer 6

They’re genes are so poor for insulin production that even a small amount of fat triggers diabetes

Question 7

Explain the aetiology of MODY?

Answer 7

Autosomal dominant genetic syndrome.
A single gene leads to impaired B-cell function.
Either Glucokinase or Transcription Factor mutations.

Question 8

What can cause secondary DM?

Answer 8

• Drugs e.g. CCS
• Pancreatic Destruction/removal
• Genetic syndromes
• Endocrine disorders e.g. cushings, acromegaly or pheochromocytoma

Question 9

What is the aetiology of Gestational diabetes?

Answer 9

Insulin resistance brought on by 2nd/3rd trimester of pregnancy.

Its associated with a family history of Type 2 DM

Patient’s are commonly overweight and inactive