microvascular comp diabetes

Question 1

site of microvascular complications

Answer 1

retinal arteries
renal glomerular arterioles
vasa nervorum - tiny blood vessels that supply nerves

Question 2

what can be used to approximate risk of microalbuminuria, neuropathy, nephropathy, retinopathy

Answer 2

HbA1c (mmol/mol)

Question 3

factors relating to development of microvascular complications

Answer 3

• severity of hyperglycemia
• hypertension
• genetic factors
• hyperglycaemia memory
• duration/glucose variability?

Question 4

mechanism of damage

Answer 4

hyperglycaemia/lipidemia leads to:

• AGE-RAGE/ oxidative stress/ hypoxia
• inflammatory signalling cascades
• local activation of pro-inflammatory cytokines
• inflammation
• nephropathy, retinopathway, neuropathy

Question 5

what is the main cause of visual loss in people with diabetes and the main cause of blindness of people of working age?

Answer 5

diabetic retinopathy

Question 6

what kind of symptoms do you get in the early stages of diabetes?

Answer 6

asymptomatic

- visual issues due to osmotic changes in lens early on in diagnosis

Question 7

increased vascular permeability in diabetic retinopathy causes what?

Answer 7

• retinal neovascularisation

- diabetic macular oedema

Question 8

where do the blood vessels emerge from in the eye?

Answer 8

the optic disc

Question 9

stages of retinopathy

Answer 9

1. background retinopathy
2. preproliferative retinopathy
3. proliferative retinopathy
4. maculopathy

Question 10

background retinopathy features

Answer 10

• hard exudates (lipid looks like cheese)
• microaneurysms (dots)
• blot haemorrhages

Question 11

preproliferative retinopathy features

Answer 11

1. cotton wool spots - soft exudates

- > represent retinal ischaemia

Question 12

proliferative retinopathy features

Answer 12

• visible new vessels over the disc (neovascularisation)

Question 13

maculopathy features

Answer 13

• hard exudates/ oedema near macula
• same disease as background but near macula
• can threaten vision

Question 14

treatment for retinopathy

Answer 14

• improve HbA1c

- improve BP

Question 15

pan-retinal photocoagulation

Answer 15

• burning eye vessels to stop neovascularisation (for proliferative nephropathy)

Question 16

How can we treat diabetic maculopathy?

Answer 16

anti-VEGF injections directly into eye (vascular endothelial growth factor)
- grid photocoagulation

Question 17

maculopathy can threaten what?

Answer 17

direct vision

Question 18

features of diabetic nephropathy: (4)

Answer 18

• hypertension
• progressively increasing proteinuria
• progressive decline in kidney function
• classic histological features
  anyone with diabetes at risk of it

Question 19

how is albumin recorded

Answer 19

expressed as a ratio to creatinine

Question 20

why is nephropathy important?

Answer 20

• assocaited with progression to end stage renal failure requiring haemodialysis
• healthcare burden
• associated with increased risk of cardiovasc events

Question 21

histological features of nephropathy

Answer 21

• mesangial expansion (glomerular changes)
• basement membrane thickening
• glomerulosclerosis

Question 22

epidemiology of nephropathy

Answer 22

20-40% of T1DM have it after 30-40 years

T2DM similar but depends on age at development of disease, ethnic differences, age at presentation,

Question 23

diagnosis of nephropathy

Answer 23

• progressive proteinuria
• increased blood pressure
• deranged renal function
• advanced peripheral oedema

Question 24

managing nephropathy

Answer 24

• manage BP (aim for <130/80 mmHg) with ACEi or ARBs
• Give ACEi/ARB even if normotensive as soon as they have microalbuminuria
• Stop smoking
• tighter glycaemic control
• SGLT-2 inhibitor if T2DM (not official guidance)

Question 25

why does RAS blockage work?

Answer 25

In diabetes the RAS system is in overdrive Blocking RAS with ACE inhibitors or ARBs (angiotensin 2 receptor blocker) reduces BP and progression of diabetic nephropathy No benefit of giving ACEi/ARB simultaneously- end up with K problems

Question 26

what makes neuropathy happen?

Answer 26

- vasa nervorum blocked | - nerves don't get blood supply

Question 27

commonest manifestation of diabetic neuropathy

Answer 27

- in feet (longest nerves supply feet) - Glove and sock distribution- peripheral neuropathy - loss of sensation (issues with ulceration and DFD)

Question 28

clinical features of peripheral neuropathy

Answer 28

- loss of sensation - loss of vibration sense - loss of temperature sensation - loss of proprioception - loss of ankle jerks - glove and stocking distribution -

Question 29

management (prevention) of peripheral neuropathy

Answer 29

1. regular inspection of affected feet 2. good footwear 3. avoid barefoot walking

Question 30

management of peripheral neuropathy with ulceration

Answer 30

1. Multidisciplinary diabetic foot clinic 2. offloading ( a term generally understood as relieving pressure from an ulcerated area. ) 3. revascularisation if concomitant peripheral vascular disease 4. Antibiotics if infected 5. orthotic footwear 6. amputation if all else fails

Question 31

other neuropathies

Answer 31

- mononeuropathy e.g. cranial (III) nerve palsy - mononeuritis multiplex - radiculopathy (SN) - autonomic neuropathy

Question 32

What is autonomic neuropathy?

Answer 32

Damage to sympathetic and parasympathetic nerves innervating GI tract, bladder and cardiovascular system ``` Symptoms: Delayed gastric emptying causing nausea and vomiting Constipation / nocturnal diarrhoea Postural hypotension Sudden cardiac death ```

Question 33

what symtpoms let you know you're developing diabetic nephropathy?

Answer 33

- asymptomatic - detected by screening Aim of screening is to detect it early when it can be detected- annual retinal screening in UK for diabetic patients

Question 34

How is the endothelium affected in microvascular complications?

Answer 34

Increased formation of mitochondrial superoxide free radicals in the endothelium Generation of glycated plasma proteins to form advanced end products (AGEs) Damaged endothelium leads to leaky capillaries and ischaemia

Question 35

what does vascular endothelial dysfunction lead to?

Answer 35

- retinal ischaemia | - vascular permeability

Question 36

diabetic mechanism of renal failure?

Answer 36

- hyperglycaemia and hypertension - leads to glomerular hypertension - followed by proteinuria - then glomerular and interstitial fibrosis - then GFR decline - then renal failure

Question 37

how to disrupt mechanism of renal failure?

Answer 37

hyperglycaemic treatments | - ACEi/ARB