Type II diabetes

Question 1

What are the features of Type II diabetes mellitus?

Answer 1

Non-insulin dependent diabetes

Insulin resistance and pancreatic failure

Usually develops over 30 years of age

Most patients are overweight

Question 2

What are the two mechanisms by which type II diabetes develops?

Answer 2

Insulin resistance

Beta cell dysfunction

Question 3

Characteristics of insulin resistance

Answer 3

As insulin resistance increases, body compensates by increasing insulin secretion from beta cells in the pancreas

Rise in plasma insulin = hyperinsulinemia

Question 4

Characteristics of beta cell dysfunction

Answer 4

Resistance to insulin increases and beta cells fail to compensate fully for increase in glucose

Glucose levels begin to rise

In type II diabetes - plasma insulin falls dramatically above threshold of plasma glucose

Theory = protein important to insulin becomes modified inapropriately as excess glucose is toxic to b cells

Modified protein competes for phosphorylation by tyrosine kinase receptor

Question 5

Causes of insulin resistance

Answer 5

Weight gain - main cause

Physical inactivity - contributes to weight gain and is individual component

Genetic predisposition

Ethnicity

Some medications

Age

Sleep disturbance - people who work late shifts are prone to type II diabetes

Sleep apnoea

Question 6

Complications of type II diabetes

Answer 6

2-4 fold increase of hear attack, stroke and peripheral vascular disease

Common cause of blindness

Most common reason for dialysis

Leading cause of lower-limb amputations

Question 7

What features are beneficial to control in order to decrease complications of diabetes?

Answer 7

Blood sugar levels

Blood pressure

Question 8

What is metabolic syndrome?

Answer 8

Insulin resistance and high insulin levels have a multitude of effects apart from diabetes

Elevate blood pressure
Elevate cholesterol and triglycerides
Associated with inflammatory response
Non-alcoholic fatty liver disease

Question 9

What are the two main mechanisms of treatment of type II DM?

Answer 9

1. Increase insulin levels - promotes further weight gain, increases insulin resistance => vicious cycle but more effective
2. Improve insulin sensitivity - preferred approach

Question 10

Drugs commonly used to treat type II diabetes

Answer 10

Metmorfin - improves insulin sensitivity

Sulphonylureas - increases insulin release

Insulin injection

DDP 4 ihibitors - decrease breakdowm of GLP 1

GLP 1 agonists

Question 11

How do DDP 4 inhibitors work

Answer 11

GLP1 is an intestinal peptide that stimulates insulin release

Also inhibits glucagon secretion by alpha cells

Results in decrease in glucose concentration

The DDP 4 breaks down GLP 1

So inhibiting DDP 4 means more GLP 1 is available

Question 12

How do sulphonylureas work?

Answer 12

Inhibit the potassium ATPase in beta cells

Causes increase in intracellular potassium concentration

In return, more insulin is released

Question 13

Examples of drugs sometimes used in type II diabetes

Answer 13

Glitazones - increases insulin sensitivity

SGLT2 inhibitors expressed in PCT - increases glucose excretion in the urine

Acarbose - delays carbohydrate absorption in the gut