Micro- and Macro-vascular Complications of Diabetes Mellitus

Question 1

What are examples of microvascular complications of DM?

Answer 1

• retinopathy
• nephropathy
• neuropathy

Question 2

What are examples macrovascular complications of DM?

Answer 2

• Cerebrovascular disease
• Ischaemic heart disease
• Peripheral vascular disease

Question 3

What is strongly associated with the risk of developing microvascular complications?

Answer 3

The extent of hyperglycaemia

Question 4

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

Answer 4

53mmol/mol (<7%)

Question 5

What is the relationship between rising systolic BP and risk of MI and microvascular complication in people T1DM and T2DM?

Answer 5

• positive relationship

- high BP leads to higher risk of MI and microvascular complications in those with T1DM and T2DM

Question 6

What is required for the prevention of complications of DM?

Answer 6

reduction in:

• HbA1c
• BP (should be controlled)

Question 7

What are the factors associated with the development of microvascular complications?

Answer 7

• duration of diabetes
• smoking (endothelial dysfunction)
• genetic factors (development irrelevant of glycaemic control)
• hyperlipidaemia
• hyperglycaemic memory

Question 8

What is hyperglycaemic memory?

Answer 8

inadequate glucose control early on > high risk of later complications (even if HbA1c improves)

Question 9

What is the general mechanism of damage involved in microvascular complications?

Answer 9

• increased formation of mitochondrial superoxide free radicals in the endothelium
• generation of glycated plasma proteins to form advanced glycation end products (AGEs)
• Activation of Inflammation pathways
• Damaged endothelium leads to: ‘leaky’ capillaries and Ischaemia

Question 10

What does hyperglycaemia and hyperlipidemia trigger?

Answer 10

• AGE-RAGE
• Oxidative stress
• Hypoxia

Question 11

What does AGE-RAGE, Oxidative stress and Hypoxia trigger?

Answer 11

• Inflammatory Signalling Cascade
• Local activation of pro-inflammatory cytokines
• Inflammation

Question 12

How prevalent is Diabetic Retinopathy?

Answer 12

main cause of:

• visual loss in people with diabetes
• blindness in people of working age

Question 13

Why is Diabetic Retinopathy screening

needed?

Answer 13

• early stages are asymptomatic

Question 14

What is the aim of Diabetic Retinopathy Screening?

Answer 14

• detect it early

- before it causes visual disturbance and loss

Question 15

How often is Diabetic Retinopathy screening for diabetes patients?

Answer 15

UK - annual screening

Question 16

What is the visual presentation of Background Retinopathy?

Answer 16

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

Question 17

What is the physical presentation of Pre-Proliferative Retinopathy?

Answer 17

• Soft exudates (cotton wool spots)
• haemorrhage
• representative of retinal ischaemia

Question 18

What characterises Proliferative Retinopathy?

Answer 18

• visible new vessels

on disk or elsewhere in retina

Question 19

What is Maculopathy?

Answer 19

• same as background retinopathy but near macula
• hard exudates/oedema near the macula
• threatens vision

Question 20

What is the Macula?

Answer 20

• central, high resolution, colour vision

Question 21

What is the optic disc?

Answer 21

• point of origin of the blood vessels of the eye

Question 22

What is the first treatment plan for all retinopathys and maculopathys?

Answer 22

• improve HbA1c
• smoking cessation
• lipid lowering
• blood pressure control (good, <130/80mmHg)

Question 23

What further should be used to treat Background Retinopathy?

Answer 23

• continued annual surveillance

Question 24

What further should be done to treat Pre-proliferative Retinopathy?

Answer 24

• if left alone, will lead to new vessel growth

- Early Panretinal Photocoagulation

Question 25

What further should be done to treat Proliferative Retinopathy?

Answer 25

-Panretinal photocoagulation

Question 26

What can be done to further treat Diabetic Maculopathy?

Answer 26

- Oedema: Anti-VEGF (Vascular Endothelial Growth Factor) injections directly into the eye - Grid Photocoagulation

Question 27

What is Pan-retinal Photocoagulation?

Answer 27

- for: retinal ischemic disease - creating thermal burns in the peripheral retina leading to tissue coagulation - improved retinal oxygenation

Question 28

What is diabetic nephropathy associated with?

Answer 28

- progression to end-stage renal failure requiring haemodialysis - increased risk of cardiovascular events

Question 29

How do you diagnose diabetic nephropathy?

Answer 29

- progressive proteinuria (urine albumin:creatinine ratio) - Increased BP - Deranged Renal Function (eGFR) - Advanced: peripheral oedema

Question 30

What values would you see when diagnosing diabetic nephropathy?

Answer 30

- Microalbuminuria, >2.5mg/mmol - ACR, >30mg/mmol - Nephrotic Range, >3000mg/24hr

Question 31

What is the mechanism of diabetic nephropathy?

Answer 31

- hyperglycemia and hypertension - glomerular hypertension - proteinuria - glomerular and interstitial fibrosis - glomerular filtration rate decline - renal failure

Question 32

Where does Angiotensin II act?

Answer 32

via angiotensin receptors

Question 33

What do ACE inhibitors do?

Answer 33

- antihypertensives | - block ACE

Question 34

What do ARBs (Angiotensin Receptor Blockers) do?

Answer 34

- antihypertensives | - block angiotensin receptors

Question 35

What is the common suffix of ACE inhibitors?

Answer 35

- pril

Question 36

What is the common suffix of ARBs?

Answer 36

- sartan

Question 37

What does blocking the Renin-Angiotensin System using ACE/ARB do?

Answer 37

- reduces blood pressure | - slows the progression of diabetic nephropathy

Question 38

When should diabetes patients have a ACEi/ARB?

Answer 38

- microalbuminuria/proteinuria | - EVEN, if normotensive

Question 39

When should patients be on both ACEi and ARB?

Answer 39

- never | - no clinical benefit

Question 40

What is microalbuminuria a risk factor for?

Answer 40

cardiovascular disease

Question 41

What is involved in the management of diabetic nephropathy?

Answer 41

- tight glycaemic control - ACE/ARB with microalbuminuria - reduce BP (<130/80) - Smoking cessation - SGLT-2 inhibitor is T2DM?

Question 42

What is neuropathy?

Answer 42

When vasa nervorum (small vessels supplying nerves) get blocked

Question 43

What is the most common cause of neuropathy?

Answer 43

- Diabetes Mellitus | most common cause of lower limb amputation

Question 44

What are the risk factors of neuropathy?

Answer 44

- age - duration of diabetes - poor gylcaemic control - height (longer nerves in lower limbs) - smoking - presence of diabetic retinopathy

Question 45

Where is diabetic neuropathy most common?

Answer 45

- in the feet (longest nerves in the feet) | - most common: glove and stocking distribution (peripheral neuropathy)

Question 46

What is the danger of diabetic neuropathy?

Answer 46

- can be painful | - not being able to sense an injury to the foot

Question 47

What is included in the annual foot check (for those with diabetes)?

Answer 47

- foot deformity? - ulceration? - sensation? (monofilament, ankle jerks) - foot pulses? (dorsalis pedis, posterior tibial)

Question 48

Where is there a risk of foot ulceration?

Answer 48

- reduced foot sensation (peripheral neuropathy) - poor vascular foot supply (peripheral vascular disease)

Question 49

What is involved in the management of peripheral neuropathy?

Answer 49

- regular foot inspection (self) - good footwear - avoid barefoot walking - IF needed: podiatry and chiropody

Question 50

What is involved in the management of peripheral neuropathy with ulceration?

Answer 50

- multidisciplinary diabetes foot clinic - offloading - revascularisation if concomitant PVD - antibiotics if infected - orthotic footwear - LAST RESORT: amputation

Question 51

What is mononeuropathy?

Answer 51

- sudden motor loss (eg: wrist and foot drop) | - cranial nerve palsy - double vision due to oculomotor nerve palsy

Question 52

How to visually confirm 3rd (oculomotor) nerve palsy?

Answer 52

eye looks DOWN and OUT

Question 53

What is autonomic neuropathy?

Answer 53

damage to the sympathetic and parasympathetic nerves innervating: GI tract, bladder and cardiovascular system

Question 54

What is the impact of autonomic neuropathy on the GI tract?

Answer 54

- delayed gastric emptying: nausea vomiting (problematic for prandial SA insulin) - constipation - noturnal diarrhoea

Question 55

What is the impact of autonomic neuropathy on the cardiovascular system?

Answer 55

- postural hypotension (possibly disabling, collapsing on standing) - cardiac autonomic supply > sudden cardiac death

Question 56

What does the treatment/prevention of macro-vascular complications of DM involve?

Answer 56

- treatment aimed at hyperglycaemia has a minor effect on the increased risk of CVD - prevention of macro-vascular disease requires aggressive, multifactorial management

Question 57

What are the modifiable risk factors of macro-vascular disease?

Answer 57

- dyslipidaemia - hypertension - smoking - DM - central obesity

Question 58

What are the non-modifiable risk factors of macro-vascular disease?

Answer 58

- age - sex - birth weight - Genes

Question 59

How do you manage cardiovascular risk in DM?

Answer 59

- smoking cessation - weight loss (lifestyle changes or pharmacological options) - annual urine microalbuminuria screen - lipids: total cholesterol <4, LDL <2 - blood pressure, <140/80 or <130/80 with microvascular complications (multiple agents often required)