Biochemistry

Question 1

What hormones is insulin action balanced against?

Answer 1

Catabolic hormones - glucagon, catecholamine, cortisol, GH

Question 2

What are the lesser degrees of hyperglycaemia?

Answer 2

• Non-diabetic hyperglycaemia
• Impaired glucose tolerance
• Impaired fasting glucose

Question 3

Describe type 1 diabetes

Answer 3

• Beta cell destruction
• Early viral trigger - most childhood onset
• Ketosis prone (without insulin, people burn fat and produce ketones)

Question 4

Describe type 2 diabetes

Answer 4

• Insulin resistance and beta cell dysfunction
• Most adult onset
• Ketosis onset

Question 5

What does GLP1 do?

Answer 5

Involved in intermediary metabolism, stimulates insulin secretion for beta cells.

Question 6

What can happen to the eyes in diabetic retinopathy?

Answer 6

• Hard exudates surrounding the fovea - yellow patches around middle circle
• Optical coherence tomography allows us to see oedema on the fovea
• Cotton wool spots - retinal ischaemia, haemorrhages

Question 7

What can happen that causes total blindness in a patient?

Answer 7

• Intra-vitreal haemorrhage
• Intra-vitreal fibrosis
• Traction retinal detachment
• Secondary new vessel glaucoma

Question 8

What happens in proliferative diabetic retinopathy?

Answer 8

New vessels can burst and fill up the vitreous fluid with blood. Patient becomes blind. Dark on examination. Fibrous reaction - ground glass appearance, can contract and pull the retina off.

Question 9

What complications can occur in a diabetic pregnancy?

Answer 9

• 1st trimester - congenital abnormalities caused by hyperglycaemia
• 2nd + 3rd trimester - accelerated growth (IUGR) - lead to cardiomyopathy, still birth, intrauterine growth restriction (increased glucose)

Question 10

Describe heart failure as a complication of diabetes

Answer 10

It confers the highest risk of death in short term. It is more prevalent in people from South Asian ethnic groups but less common in Black ethnic groups.

Question 11

What hormones contribute to DKA and HHS?

Answer 11

• Insulin deficiency +/or resistance
• Glucagon excess due to removal of the normal suppressive effect of insulin - contributes to DKA but doesn’t cause it
• Increase secretion of cortisol and GH cause increase in glucose

Question 12

Which type of diabetes are DKA and HHS usually associated with?

Answer 12

DKA - T1DM

HHS - T2DM

Question 13

What is the pathology of HHS?

Answer 13

High sugars (30s) and then the diuresis this induces (and subsequent dehydration). Usually older patients and presents slower.

Question 14

What is the pathology of DKA?

Answer 14

Lack of insulin

Question 15

How do you treat DKA and HHS?

Answer 15

DKA - insulin infusion and fluids

HHS - fluid rescusitation