MICROVASCULAR AND MACROVASCULAR COMPLICATIONS OF DIABETES MELLITUS

Question 1

List the microvascular complications of DM

Answer 1

Retinopathy
Nephropathy
Neuropathy

Question 2

List the macrovascular complications of DM

Answer 2

Cerebrovascular disease
Ischaemic heart disease
Peripheral vascular disease

Question 3

What is the target HbA1c to reduce risk of microvascular complications?

Answer 3

< 53 mmol/mol (<7%)

Question 4

What are the factors which can increase the risk of microvascular complications in DM?

Answer 4

Hyperglycaemia
Hypertension (rising systolic BP)
Duration of DM
Smoking (endothelial dysfunction)
Genetic factors
Hyperlipidaemia (+ high cholesterol)
Hyperglycaemic memory (poor glucose control early on even if improved)

Question 5

How do we try and prevent diabetic retinopathy in the UK?

Answer 5

Annual retinal screening in the UK for all diabetes patients since early stages of retinopathy are asymptomatic

Question 6

What is the macula?

Answer 6

Center of the retina which is responsible for the central vision, most of colour vision and high resolution.

Question 7

Name the stages of retinopathy

Answer 7

Background retinopathy
Pre-proliferative retinopathy
Proliferative retinopathy

Question 8

What can be seen in background retinopathy?

Answer 8

Hard exudates (lipids leaked out) giving cheese colour
Microaneurysms (dots)
Blot haemorrhages

Question 9

What can be seen in pre-proliferative retinopathy?

Answer 9

Cotton wool spots (soft exudates)
Haemorrhage
Retinal ischaemia

Question 10

What can be seen in proliferative retinopathy and why?

Answer 10

Visible new blood vessels grown due to hypoxia in order to try and prevent ischaemia.
But they are very weak and liable to haemorrage

Question 11

What can be seen in maculopathy?

Answer 11

Hard exudates/oedema near macula
(same as background retinopathy but near macula)
Can threaten vision

Question 12

How can you treat retinopathy and maculopathy?

Answer 12

Improve HbA1c
Stop smoking
Lower lipids
Control BP (<130/80 mmHg)

Question 13

What should the specific treatment for a patient with background retinopathy be?

Answer 13

Continued annual surveillance

Question 14

What should the specific treatment for a patient with pre-proliferative retinopathy be?

Answer 14

Early panretinal photocoagulation as if left alone will progress to proliferative retinopathy

Question 15

What should the specific treatment for a patient with proliferative retinopathy be?

Answer 15

Panretinal photocoagulation

Question 16

What should the specific treatment for a patient with diabetic maculopathy be?

Answer 16

If oedema:
- Anti-VEGF injections into eye which inhibits
inflammation cascade

Grid photocoagulation

Question 17

What is photocoagulation and when is it done?

Answer 17

Burn through retina preventing new blood vessels from forming and causing existing one to shrink and scar up decreasing the risk of haemorrhage

The patient will lose some peripheral vision

Pre-proliferative and proliferative retinopathy - panretinal photocoagulation

Maculopathy - grid photocoagulation

Question 18

Why does diabetic nephropathy need to be taken seriously?

Answer 18

Associated with progression to end-stage renal failure requiring haemodialysis

Associated with increased risk of cardiovascular events

Healthcare burden

Question 19

What is the diagnosis of diabetic nephropathy?

Answer 19

Increased BP
Progressive proteinuria (urine albumin:creatinine > 30mg/mmol)
Microalbuminuria > 2.5 mg/mmol

End stage diabetic kidney disease:

• Deranged renal function (eGFR)
• Peripheral oedema

Question 20

Describe the mechanism of diabetic nephropathy

Answer 20

Hyperglycaemia and hypertension leading to glomerular hypertension causing proteinuria, glomerular and interstitial fibrosis and thus glomerular filtration rate decline.

Resulting in renal failure

Question 21

What are some antihypertensives to help prevent diabetic nephropathy?

Answer 21

ACE inhibitors

Angiotensin receptor blockers (ARBs)

Question 22

What is the suffix for ACE inhibitors and ARBs?

Answer 22

ACEi = "-pril"
ARB = "-sartan"

Question 23

Who should be prescribed ACEi/ARBs?

Answer 23

All diabetic patients who have microalbuminuria/proteinuria even if normotensive

Question 24

What is microalbuminuria a risk factor for?

Answer 24

Cardiovascular disease

Question 25

What is the management for diabetic nephropathy?

Answer 25

``` Tighter glycaemic control ACEi/ARB if patient has microalbuminuria Reduce BP < 130/80 mmHg Stop smoking If T2DM start SGLT-2 inhibitor ```

Question 26

What is the name of the small vessels which supply nerves?

Answer 26

Vasa nervorum

Question 27

What is neuropathy in DM a result of?

Answer 27

Vasa nervorum getting blocked

Question 28

What are the risk factors for neuropathy in DM?

Answer 28

``` Age Duration of diabetes Poor glycaemic control Height (longer nerves in lower limbs of tall people) Smoking Diabetic retinopathy ```

Question 29

Where is diabetic neuropathy most commonly found?

Answer 29

Feet since it is supplied by the longest nerves

Question 30

What is the common distribution of neuropathy in the body?

Answer 30

Glove and stocking

Question 31

What is examined in an annual foot check for a diabetic patient?

Answer 31

``` Look for foot deformity, ulceration Assess sensation (using monofilament, ankle jerks) Assess foot pulses ```

Question 32

What are the risk factors for foot ulceration in patients?

Answer 32

``` Peripheral neuropathy (reduced sensation) Peripheral vascular disease preventing blood supply to heal ulcer ```

Question 33

What is the management of diabetic patients with only peripheral neuropathy?

Answer 33

Regular inspection of feet Good footwear Avoid barefoot walking

Question 34

What is the management of diabetic patients with peripheral neuropathy with ulceration?

Answer 34

``` Multidisciplinary diabetes foot clinic Offloading Revascularisation if concomitant PVD Antibiotics if infected Orthotic footwear Amputation if all else fails ```

Question 35

What are some neuropathies which don't affect the feet?

Answer 35

Mononeuropathy | Autonomic neuropathy

Question 36

What does mononeuropathy present as?

Answer 36

Sudden motor loss e.g. wrist/foot drop | Cranial nerve palsy e.g 3rd nerve palsy (double vision)

Question 37

What does autonomic neuropathy present as?

Answer 37

Damage to SNS and PNS innervating Gi tract, bladder, cardiovascular system GI: - Delayed gastric emptying (nausea and vomiting) - Constipation/ nocturnal diarrhoea Cardiovascular: - Postural hypotension - Sudden cardiac death

Question 38

What are the non-modifiable risk factors for macrovascular disease of DM?

Answer 38

Age Sex Birth weight Genes

Question 39

What are the modifiable risk factors for macrovascular disease of DM?

Answer 39

``` Dyslipidaemia Hypertension Smoking Diabetes mellitus Central obesity ```

Question 40

How should prevention of macrovascular disease in DM be carried out?

Answer 40

Aggressive management of multiple risk factors

Question 41

List the factors which should be changed to manage cardiovascular risk in diabetes mellitus

Answer 41

- Smoking cessation - Blood pressure < 140/80 mmHg, <130/80 mmHg is microvascular complication - Lipid profile (total chol < 4, LDL < 2) - Weight - Annual urine microalbuminuria screen as it is risk factor for cardiovascular disease