lecture 38 - diabetes

Question 1

What are symptoms of diabetes mellitus?

Answer 1

Weight loss, fatigue, thirst, increased urination, glucose in urine

Question 2

What are the main diagnostic biochemical signs of diabetes?

Answer 2

Hyperglycaemia accompanied by glucosuria. and in advanced cases, hyperketonaemia and ketonuria

Question 3

What type of diabetes is Insulin Dependent Diabetes mellitus (IDDM)?

Answer 3

Type 1

Question 4

What type of diabetes is Non-Insulin Dependent Diabetes mellitus (NIDDM)?

Answer 4

Type 2

Question 5

What defect is present in those with IDDM/Type 1 diabetes?

Answer 5

Autoimmune destruction of pancreatic beta-cells so that no insulin is produced

Question 6

What defect is present in those with NIDDM/Type 2 diabetes?

Answer 6

Resistance to action of insulin and defective insulin secretion

Question 7

What is the normal range of blood glucose levels?

Answer 7

3-7 mmol/L

Question 8

What are the main target tissues of insulin?

Answer 8

Liver, muscle and adipose tissue

Question 9

What is the overall effect of insulin?

Answer 9

Promote cellular uptake and storage of metabolic fuels and prevent their mobilisation

Question 10

What type of metabolism is present in those with untreated type 1 diabetes?

Answer 10

Catabolic - the breakdown of fuel stores and tissues

Question 11

How is glycogen storage impacted by a lack of insulin?

Answer 11

Glycogen storage is normally activated by insulin, so this is impaired. Instead glycogen stores tend to be broken down

Question 12

What is the impact of a lack of insulin on glycogen mobilisation?

Answer 12

There is a net mobilisation to provide fuel

Question 13

What happens to the rate of gluconeogenesis when there is no insulin?

Answer 13

Increased rate - glucose is synthesised from amino acids and glycerol

Question 14

What is the impact of low insulin on TAG stores in adipose tissue?

Answer 14

Unrestrained release of fatty acids followed by increased fatty acid oxidation and ketone body production in the liver.

Question 15

What is the impact of low insulin on TAG clearance from plasma?

Answer 15

Impaired, because of lack of activation of lipoprotein lipase

Question 16

Why does diabetes cause the loss of water and electrolytes (dehydration)?

Answer 16

Glucosuria causes osmotic diuresis where salt and water and not reabsorbed into the body.

Question 17

Why does a lack of insulin causes acidosis?

Answer 17

because ketone bodies, which are acidic, are produced in response to the unrestrained release of fatty acids from adipose tissue

Question 18

What are the key long-term complications of diabetes?

Answer 18

Retinopathy, nephropathy, neuropathy, cardiovascular disease, peripheral vascular disease.