Micro & Macro-vasculature complications of diabetes Flashcards by Dean Whaley

What are the Microvascular complications associated with diabetes?

Retinopathy
Neuropathy
Nephropathy

How well did you know this?

Not at all

Perfectly

What are the Macro-vascular complications of diabetes?

Cerebrovascular disease
Ischaemic heart disease
Peripheral vascular disease

How well did you know this?

Not at all

Perfectly

What is the relationship between glycemic control and microvascular complications?

Extent of hyperglycaemia (as judged by HbA1c) is strongly associated with the risk of developing microvascular complications

How well did you know this?

Not at all

Perfectly

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

53 mmol/mol

How well did you know this?

Not at all

Perfectly

What is the relationship between systolic BP & microvascular complications?

Clear relationship between rising systolic BP and risk of MI and microvascular complications in people with T1DM and T2DM

Therefore, prevention of complications requires reduction in HbA1c and BP control

How well did you know this?

Not at all

Perfectly

What other risk factors are related to the development of microvascular complications?

Duration of diabetes
Smoking – endothelial dysfunction
Genetic factors – some people develop complications despite reasonable glycaemic control
Hyperlipidaemia
Hyperglycaemic memory – inadequate glucose control early on can result in higher risk of complications LATER, even if HbA1c improved

How well did you know this?

Not at all

Perfectly

What is the mechanism of damage that leads to microvascular complications?

DO NOT NEED TO MEMORISE
Increased formation of mitochondrial superoxide free radicals in the endothelium
Generation of glycated plasma proteins to form advanced glycation end products (AGEs)
Activation of inflammatory pathways
Damaged endothelium results in
- ‘Leaky’ capillaries
- Ischaemia

How well did you know this?

Not at all

Perfectly

Why is diabetic retinopathy important?

Main cause of
visual loss in people with diabetes
blindness in people of working age
The early stages of retinopathy are all asymptomatic, therefore screening is needed

How well did you know this?

Not at all

Perfectly

What is the aim of retinopathy screening?

To detect retinopathy EARLY when it can be treated before it causes visual disturbance / loss
Annual retinal screening in the UK for all diabetes patients.

How well did you know this?

Not at all

Perfectly

What is visible in Background retinopathy?

Hard exudates (cheese colour, lipid)
Microaneurysms (“dots”)
Blot haemorrhages
Needs continual annual surveillance

How well did you know this?

Not at all

Perfectly

What is visible in pre-proliferative retinopathy?

Cotton wool spots also called soft exudates
Represent retinal ischaemia
Early panretinal photocoagulation

How well did you know this?

Not at all

Perfectly

What is visible in proliferative retinopathy?

Visible new vessels
On disc or elsewhere in retina
Panretinal photocoagulation

How well did you know this?

Not at all

Perfectly

What is visible in Maculopathy?

Hard exudates / oedema near the macula
Same disease as background, but happens to be near macula
This can threaten visionOedema: Anti-VEGF injections directly into the eye (VEGF: vascular endothelial growth factor)
Grid photocoagulation

How well did you know this?

Not at all

Perfectly

What is a negative of Panretinal photocoagulation?

Patient can lose some peripheral vision

How well did you know this?

Not at all

Perfectly

Why is diabetic nephropathy important

Associated with progression to end-stage renal failure requiring haemodialysis
Healthcare burden
Associated with increased risk of cardiovascular disease

How well did you know this?

Not at all

Perfectly

How do you diagnose diabetic nephropathy?

Progressive proteinuria (urine albumin:creatinine ratio - ACR)

Increased blood pressure

Deranged renal function (eGFR)

Advanced: peripheral oedema

What is the cut off for Microalbuminuria?

2.5 mg/mmol

What is the threshold for Proteinurea?

Proteinuria = ACR > 30mg/mmol

What is the threshold for Nephrotic Proteinurea?

> 3000mg/24hr

What is the mechanism of action for diabetic nephropathy?

Hyperglycemia & Hypertension
Glomerular Hypertension
Proteinurea
Glomerular and interstitial fibrosis
Glomerular filtration rate decline
Renal failure

What system do we want to manipulate in diabetic nephropathy?

Renin-Angiotensin System

What 2 drugs are used to treat diabetic nephropathy?

ACE inhibitor ( end in -pril)
Angiotensin 2 receptor blocker ( end in -sartan)
they reduce BP & progression of diabetic nephropathy, should be prescribed to all normotensive patients with microalbuminuria /proteinurea.
No benefit to having both

What is Microalbuminurea a risk factor for?

Cardiovascular disease

What are the management principles for diabetic nephropathy?

Aim for tighter glycemic 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
Start an SGLT-2 inhibitor if T2DM?

Why is diabetic neuropathy important?

Diabetes mellitus is the most common cause of neuropathy and therefore lower limb amputation

What are the small vessels supplying nerves called?

vasa nervorum Neuropathy results when vasa nervorum get blocked

What are the risk factors for diabetic neuropathy?

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

Where is diabetic neuropathy most common?

Longest nerves supply feet – so more common in feet Commonly glove & stocking distribution – peripheral neuropathy Can be painful Danger is that patients will not sense an injury to the foot (eg. stepping on a nail)

What would you do in an annual foot check?

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

Which patients have an increased risk of foot ulceration?

- reduced sensation to feet (peripheral neuropathy) | - poor vascular supply to feet (peripheral vascular disease)

What is the management for Peripheral neuropathy?

1. Regular inspection of feet by affected individual 2. Good footwear 3. Avoid barefoot walking Podiatry and chiropody if needed

What is the management for Peripheral neuropathy with ulceration?

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

What is Mononeuropathy?

Usually, sudden motor loss eg wrist drop, foot drop Cranial nerve palsy double vision due to 3rd (oculomotor) nerve palsy

What is Autonomic neuropathy?

Damage to sympathetic and parasympathetic nerves innervating GI tract, bladder, cardiovascular system

What would happen with autonomic neuropathy of the GI Tract?

Delayed gastric emptying: nausea and vomiting (can make prandial short-acting insulin challenging) - Constipation / nocturnal diarrhoea

What would happen with autonomic neuropathy of the Cardiovascular system?

Postural hypotension: can be disabling - collapsing on standing. - Cardiac autonomic supply: sudden cardiac death

What are the non modifiable risk factors for macrovascular disease?

Age Sex Birth weight FH/Genes

What are the modifiable risk factors for macrovascular disease?

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

What are the management criteria for managing cardiovascular risk in diabetes mellitus?

Smoking status – support to quit Blood pressure < 140/80 mmHg, < 130/80 mmHg if microvascular complication (NB often needs multiple agents) Lipid profile – total chol <4, LDL <2 Weight – discuss lifestyle intervention +/- pharmacological treatments Annual urine microalbuminuria screen – risk factor for cardiovascular disease