11. Effects of Acute and Chronic Hyperglycaemia

Question 1

What are normal glucose levels before meals?

Answer 1

4-5.9 mmol/L

Question 2

What are normal glucose levels 2hr after meals?

Answer 2

Under 7.8mmol/L

Question 3

What glucose levels are considered diabetic in a fasting state?

Answer 3

> 7.1mmol/L

Question 4

What glucose levels are considered diabetic 2 hrs after a meal?

Answer 4

> 11.1mmol/L

Question 5

What are the symptoms of acute hyperglycaemia?

Answer 5

Glycosuria
Dehydrating osmotic diuresis (polyuria, polydipsia, hypokalemia, hyponatraemia)
Polyphagia (increased appetite)
Metabolism of protein and fat (weight loss and protein deficiency)

Question 6

What is a resulting marker for an episode of acute hyperglycaemia?

Answer 6

Leave increased HbA1c

Question 7

What hormones cause a change from glucose to lipid metabolism in diabetic ketoacidosis?

Answer 7

Glucagon, catecholamines, cortisol, GH

Question 8

What exasperates hyperglycaemia in diabetic ketoacidosis?

Answer 8

Free fatty acids and AAs from lipolysis and proteolysis are used to increase gluconeogenesis

Question 9

Why does ketogenesis increase in diabetic ketoacidosis?

Answer 9

Increase in free FAs which are broken down to produce ketones
Acetone produced a sweet smell on the breath

Question 10

What are the symptoms of DKA?

Answer 10

Dehydration
Fruity smelling breath
Increased respiration (increased blood acidity)
Nausea and vomiting
Abdominal pain
Lethargy, coma, shock

Question 11

What is needed to diagnose DKA?

Answer 11

Hyperglycaemia, >11mM
Ketonaemia
Acidaemia, pH <7.3, anion gap> 12mmol/L

Question 12

What is the treatment for DKA?

Answer 12

IV fluid replacement
IV insulin
K+ replacement

Question 13

What is microvascular damage caused by?

Answer 13

Prolonged hyperglycaemia produces Advanced Glycation End Products

Question 14

How do AGEs affect protein function?

Answer 14

Denaturation and functional decline
Alter enzyme activity
Interfere with receptor recognition
Organopathy (accumulation in tissue)

Question 15

What happens when AGEs interact with RAGEs?

Answer 15

Alter gene expression

Induce pro-inflammatory status

Question 16

What is non-proliferative diabetic retinopathy?

Answer 16

Caused by AGE build up
Micro-aneurysms
Haemorrhages
Exudates (lipoprotein leaks from vessels)

Question 17

What is proliferative diabetic retinopathy?

Answer 17

Development of new blood vessels
Debilitating loss of vision
More haemorrhages
Local ischaemia triggers transcription factors eg. Hypoxia-inducible factor (HIF)
HIF expression induces the formation of new blood vessels

Question 18

What are the symptoms of diabetic retinopathy?

Answer 18

Discoloured spots
Blurred vision
Vision blocked by patches or streaks
Decreased night vision
Sudden vision loss

Question 19

What is peripheral diabetic neuropathy characterised by?

Answer 19

Numbness in toes, feet, fingers, arms
Burning and pain
Loss of sensation
Decreased circulation
Ulcer and gangrene leading to amputation

Question 20

What is autonomic diabetic neuropathy characterised by?

Answer 20

Damage of nerves involved in regulation of BP, cardiac function, respiration, GIT, urinary systems
Gastroparesis (unable to empty stomach), diarrhoea, constipation, weight loss
Erectile disfunction
Incontinence
No chest pain during MI

Question 21

What is diabetic nephropathy?

Answer 21

Thickening of glomerulus and basement membrane
Microalbuminaemia
Increased destruction of glomeruli
Albumin in urine
Chronic kidney failure

Question 22

What is the treatment of diabetic nephropathy?

Answer 22

ACE inhibitors
AT receptor blockers
Dialysis and transplant

Question 23

What results from diabetic macrovascular disease?

Answer 23

Heart disease, stroke, peripheral vascular disease

Question 24

What effects does hyperglycaemia have on macrovascular disease?

Answer 24

Damages vascular endothelium
Increased platelet aggregation
Decreased thrombolysis
Promotes inflammatory responses