Unit 7 - Diabetes

Question 1

What are the criteria for diagnosing diabetes in an asymptomatic patient?

Answer 1

1. Two random finger prick of >11.1 mmol/l
2. Two fasting glucose of >7mmol (normal <6.1)

Question 2

What are the criteria for diagnosing diabetes in a symptomatic patient?

Answer 2

1. Random finger prick test of >11.1
2. Single fasting glucose test of > 7mmol (normal 6.1)
3. Glucose tolerance test of greater than 11.1 (2 hours after glucose)
4. HbA1c > 48mmol/mol

Question 3

What are the symptoms of diabetes?

Answer 3

1. Weight loss
2. Tiredness
3. Thirst
4. Polyurea
5. Nocturia
6. Genital itching/thrush
7. Poor wound healing
8. Blurred vision

Question 4

What % of diabetes is type 2?

Answer 4

>85% (Type 1 5-10%)

Question 5

What other causes of diabetes are there?

Answer 5

1. Genetic defects in pancreatic b cell function
2. Genetic defect in insulin action
3. Disease of the exocrine pancrease e.g. pancreatitis, cystic fibrosis
4. Endocrinopathies e.g. Cushing’s, acromegaly
5. Drug induced e.g. steroid, atypical antipsychotics
6. Gestational diabetes

Question 6

What is the incidence of diabetes in adults worldwide?

Answer 6

1 in 11

Question 7

How much more likely are you to get type 2 diabetes if you are south Asian or Caribean?

Answer 7

4-6X

Question 8

What is the pathogenesis of type 1 diabetes?

Answer 8

Autoimmune cells attack the B-cells in the islets of Langherans.

Question 9

What is the pathogenesis of type 2 diabetes?

Answer 9

B-cell dysfunction, failure of the B-cell to adapt to insulin resistance

Question 10

What are the risk factors for type 2 diabetes?

Answer 10

1. Obesity
2. Diet
3. Sedentray lifestyle
4. Genetic predisposition
5. Glucotoxicity

Question 11

What are the two major types of diabetic complications?

Answer 11

1. Microvascular
2. Macrovascular

Question 12

What are the major macrovascular complications of diabetes?

Answer 12

1. Coronary artery disease
2. Cerebrovascular disease
3. Peripheral arterial disease

Question 13

What are the major microvascular complications in diabetes?

Answer 13

1. Retinpathy
2. Nephropahty
3. Neuropathy

Question 14

What is the incidence of nephropathy in type1 and 2 diabetics?

Answer 14

20-40%

Question 15

What happens to insulin requirements with nephropathy and why?

Answer 15

Insulin requirements go down as kidneys clear insulin so if they’re packing up there is more insulin floating around.

Question 16

How soon after type 1 diagnosis should a patient be seen for retinal screening?

Answer 16

less than 3 months

Question 17

What is the management of type2 diabetes with drugs?

Answer 17

Metformin first then try:

• DPP4
• Glitazones
• Suphonylureas

Question 18

What are the symptoms of hypoglycaemia?

Answer 18

Autonmic:

• Tremor
• Sweating
• Palpitations

Neurglycopenic

• Confusion
• Drowsiness
• Slurring of speech

General malaise

• Headache
• Nausea

Question 19

What is the general treatment of hyperglycaemia?

Answer 19

Make patient drink 2-3 litres of fluid over 24 hours to prevent dehydration.

Question 20

What is the prevalence of blindness in type 1 and type 2 diabetics (not all attributable to DR)?

Answer 20

• Type 1 = 3.6%
• Type 2 = 1.6%

Question 21

What % of blindness is attributable to DR in type 1 and type 2?

Answer 21

Type 1 = 86%

Type 2 = 33%

Question 22

What is the pathogenesis of DR?

Answer 22

Exposure to glucose = loss of pericytes = basement membrane thickening = breakdown of endothelial barrier function and compromise of capillary lumen

Question 23

What biochemical abnormalities have been correlated with prevalence and severity of DR?

Answer 23

1. Increased platelet adhesiveness
2. Increased erythrocyte aggregation
3. Abnormal serum lipids
4. Abnormal levels of growth hormones
5. Upregulation of VEGF
6. Abrnormalities in serum and whole blood viscosity
7. Defective fibrinolysis

Question 24

What are the modifiable risk factors in the development of DR?

Answer 24

1. Glycaemic control
2. BP
3. Lipid levels
4. Smoking
5. Pregnancy

Question 25

What are the non-modifiable risk factors in DR?

Answer 25

1. Genetic factor (accounts to 25-50% of risk) 2. Gender 3. Duration of diabetes 4. **Renal impairment** 5. **Carotid arterial disease**

Question 26

What effects does diabetes have on the vasculature in retinopathy?

Answer 26

Pericyte and endothelial cell death = breakdown of BRB

Question 27

What effects does diabetes have on the glia and microglia in retinopathy?

Answer 27

Glia = altered contact with vessels results in a release of inflammatory mediators and iimpaired glutamate metabolism Microglia = Increase in phagocytes leads to increased inflammation and more cell death.

Question 28

What ocular tests should be conducted on a DR patient?

Answer 28

1. V/A 2. Colour vision, severity of defect = severity of DR 3. Colour photos 4. **Anterior segment; check for cataract, glaucoma and NVI** 5. FFA 6. OCT

Question 29

Where are CWS most commonly found and why?

Answer 29

Nasally as nerve fibre layer is thicker there.

Question 30

What are the clinical features of non-proliferative DR?

Answer 30

1. MA's 2. Blot haems 3. CWS 4. IRMA 5. Venous beeding

Question 31

What is an MA in DR?

Answer 31

Isolated capillary occlusions causing nearby non-occluded capillaries to form saccular swellings.

Question 32

What are blot haems and why?

Answer 32

* Deep retina infarcts * Occur when clusters of capillaries occlude to form intraretinal haems

Question 33

What are IRMA?

Answer 33

Shunt vessels. Either new vessel growth within the retina or remodeling of pre-existing vessels through endothelial proliferation.

Question 34

How do IRMA differ from NV?

Answer 34

IRMA are slightly larger in caliber and are always contained to the intraretinal layers. NV are finer and delicate . NV leak on FFA whereas IRMA's don't

Question 35

What is venous beeding caused by?

Answer 35

Endothelial cell proliferation.