Microvascular and Macrovascular Complications of Diabetes Mellitus

Question 1

What are the 3 chronic microvascular complications with diabetes?

Answer 1

• Retinopathy
• Neuropathy
• Nephropathy

Question 2

What is the relationship between HbA1c and microvascular disease?

Answer 2

• The higher the HbA1c the greater the microvascular and myocardial infarction risk

Question 3

What factors increase the risks of complications of diabetes (6)?

Answer 3

• Hypertension
• Duration of diabetes
• Smoking
• Genetic factors
• Hyperlipidaemia
• Hyperglycaemic memory

Question 4

What is the mechanism of damage of complications of diabetes (from hyperglycaemia to complications) (6)?

Answer 4

1. Increased formation of mitochondrial superoxide free radicals in the endothelium
2. Generation of glycated plasma proteins to form advanced glycation end products (AGEs)
3. Activation of inflammatory pathways
4. Damaged endothelium results in
5. ‘Leaky’ capillaries
6. Ischaemia

Question 5

How does background retinopathy present?

Answer 5

• Hard exudates (cheese colour, lipid)
• Microaneurysms (“dots”)
• Blot haemorrhages

Question 6

How does pre-proliferative retinopathy present?

Answer 6

• Cotton wool spots also called soft exudates
  
  • Represent retinal ischaemia

Question 7

How does proliferative retinopathy present?

Answer 7

• Visible new vessels on disc or elsewhere in retina

Question 8

How does maculopathy present?

Answer 8

• Hard exudates / oedema near the macula
• Same disease as background, but happens to be near macula

This can threaten vision

Question 9

How is retinopathy treated (4)?

Answer 9

• Improve HbA1c
• Stop smoking
• Lipid lowering
• Good blood pressure control < 130/80 mmHg

Question 10

How is the oedema present in maculopathy treated?

Answer 10

Anti-VEGF injections directly into the eye

VEGF: vascular endothelial growth factor

Question 11

What stage of diabetic retinopathy can be observed rather than treated?

Answer 11

Background retinopathy

Question 12

How is diabetic nephropathy diagnosed (4)?

Answer 12

• Progressive proteinuria (urine albumin:creatinine ratio - ACR)
• Increased blood pressure
• Deranged renal function (eGFR)
• Advanced: peripheral oedema

Question 13

What is the mechanism of diabetic nephropathy?

Answer 13

Question 14

How is diabetic nephropathy managed (4)?

Answer 14

• Aim for tighter glycaemic control
• ACEi/ARB even if normotensive as soon as patient has microalbuminuria
• Reduce BP (aim < 130/80 mmHg) usually through ACEi or A2RB
• Stop smoking

Question 15

When does diabetic neuropathy occur?

Answer 15

Neuropathy results when vasa nervorum get blocked

Small vessels supplying nerves are called vasa nervorum

Question 16

What are the risk factors of diabetic neuropathy (6)?

Answer 16

• Age
• Duration of diabetes
• Poor glycaemic control
• Height (longer nerves in lower limbs of tall people)
• Smoking
• Presence of diabetic retinopathy

Question 17

What does an annual feet check involve (3)?

Answer 17

• Look for foot deformity, ulceration
• Assess sensation (monofilament, ankle jerks)
• Assess foot pulses (dorsalis pedis and posterior tibial)

Question 18

Which patients have an increased risk of foot ulceration?

Answer 18

Patients with:
* Peripheral neuropathy
* Peripheral vascular disease

Question 19

How is diabetic peripheral neuropathy managed (4)?

Answer 19

• Regular inspection of feet by affected individual
• Good footwear
• Avoid barefoot walking
• Podiatry and chiropody if needed

Question 20

How is diabetic peripheral neuropathy with ulceration managed (6)?

Answer 20

1. Multidisciplinary diabetes foot clinic
2. Offloading
3. Revascularisation if concomitant PVD
4. Antibiotics if infected
5. Orthotic footwear
6. Amputation if all else fails

Question 21

What would be the effect of autonomic neuropathy to the GI tract (4)?

Answer 21

• Nausea and vomiting (can make prandial short-acting insulin challenging)
• Constipation
• Nocturnal diarrhoea

Question 22

What would be the effect of autonomic neuropathy to the cardiovascular system (2)?

Answer 22

• Postural hypotension
• Cardiac autonomic supply: sudden cardiac death

Question 23

What are the 3 forms of macrovascular disease in diabetes?

Answer 23

• Ischaemic heart disease
• Cerebrovascular disease
• Peripheral vascular disease

Question 24

What are the non-modifiable risk factors for macrovascular disease (4)?

Answer 24

• Age
• Sex
• Birth weight
• FH/Genes

Question 25

What are the modifiable risk factors for macrovascular disease (5)?

Answer 25

• Dyslipidaemia
• Hypertension
• Smoking
• Diabetes mellitus
• Central obesity

Question 26

What is the main cause of death in patients with diabetes?

Answer 26

• Ischaemic heart disease

Question 27

How is the cardiovascular risk in diabetes mellitus managed (5)?

Answer 27

• Encourage to stop smoking
• Blood pressure < 140/80 mmHg, < 130/80 mmHg if microvascular complication
• Lipid profile - total chol < 4, LDL < 2
• Weight – discuss lifestyle intervention +/- pharmacological treatments
• Annual urine microalbuminuria screen – risk factor for cardiovascular disease