MICROVASCULAR AND MACROVASCULAR COMPLICATIONS OF DIABETES MELLITUS Flashcards
List the microvascular complications of DM
Retinopathy
Nephropathy
Neuropathy
List the macrovascular complications of DM
Cerebrovascular disease
Ischaemic heart disease
Peripheral vascular disease
What is the target HbA1c to reduce risk of microvascular complications?
< 53 mmol/mol (<7%)
What are the factors which can increase the risk of microvascular complications in DM?
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)
How do we try and prevent diabetic retinopathy in the UK?
Annual retinal screening in the UK for all diabetes patients since early stages of retinopathy are asymptomatic
What is the macula?
Center of the retina which is responsible for the central vision, most of colour vision and high resolution.
Name the stages of retinopathy
Background retinopathy
Pre-proliferative retinopathy
Proliferative retinopathy
What can be seen in background retinopathy?
Hard exudates (lipids leaked out) giving cheese colour Microaneurysms (dots) Blot haemorrhages
What can be seen in pre-proliferative retinopathy?
Cotton wool spots (soft exudates)
Haemorrhage
Retinal ischaemia
What can be seen in proliferative retinopathy and why?
Visible new blood vessels grown due to hypoxia in order to try and prevent ischaemia.
But they are very weak and liable to haemorrage
What can be seen in maculopathy?
Hard exudates/oedema near macula
(same as background retinopathy but near macula)
Can threaten vision
How can you treat retinopathy and maculopathy?
Improve HbA1c
Stop smoking
Lower lipids
Control BP (<130/80 mmHg)
What should the specific treatment for a patient with background retinopathy be?
Continued annual surveillance
What should the specific treatment for a patient with pre-proliferative retinopathy be?
Early panretinal photocoagulation as if left alone will progress to proliferative retinopathy
What should the specific treatment for a patient with proliferative retinopathy be?
Panretinal photocoagulation
What should the specific treatment for a patient with diabetic maculopathy be?
If oedema:
- Anti-VEGF injections into eye which inhibits
inflammation cascade
Grid photocoagulation
What is photocoagulation and when is it done?
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
Why does diabetic nephropathy need to be taken seriously?
Associated with progression to end-stage renal failure requiring haemodialysis
Associated with increased risk of cardiovascular events
Healthcare burden
What is the diagnosis of diabetic nephropathy?
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
Describe the mechanism of diabetic nephropathy
Hyperglycaemia and hypertension leading to glomerular hypertension causing proteinuria, glomerular and interstitial fibrosis and thus glomerular filtration rate decline.
Resulting in renal failure
What are some antihypertensives to help prevent diabetic nephropathy?
ACE inhibitors
Angiotensin receptor blockers (ARBs)
What is the suffix for ACE inhibitors and ARBs?
ACEi = "-pril" ARB = "-sartan"
Who should be prescribed ACEi/ARBs?
All diabetic patients who have microalbuminuria/proteinuria even if normotensive
What is microalbuminuria a risk factor for?
Cardiovascular disease
What is the management for diabetic nephropathy?
Tighter glycaemic control ACEi/ARB if patient has microalbuminuria Reduce BP < 130/80 mmHg Stop smoking If T2DM start SGLT-2 inhibitor
What is the name of the small vessels which supply nerves?
Vasa nervorum
What is neuropathy in DM a result of?
Vasa nervorum getting blocked
What are the risk factors for neuropathy in DM?
Age Duration of diabetes Poor glycaemic control Height (longer nerves in lower limbs of tall people) Smoking Diabetic retinopathy
Where is diabetic neuropathy most commonly found?
Feet since it is supplied by the longest nerves
What is the common distribution of neuropathy in the body?
Glove and stocking
What is examined in an annual foot check for a diabetic patient?
Look for foot deformity, ulceration Assess sensation (using monofilament, ankle jerks) Assess foot pulses
What are the risk factors for foot ulceration in patients?
Peripheral neuropathy (reduced sensation) Peripheral vascular disease preventing blood supply to heal ulcer
What is the management of diabetic patients with only peripheral neuropathy?
Regular inspection of feet
Good footwear
Avoid barefoot walking
What is the management of diabetic patients with peripheral neuropathy with ulceration?
Multidisciplinary diabetes foot clinic Offloading Revascularisation if concomitant PVD Antibiotics if infected Orthotic footwear Amputation if all else fails
What are some neuropathies which don’t affect the feet?
Mononeuropathy
Autonomic neuropathy
What does mononeuropathy present as?
Sudden motor loss e.g. wrist/foot drop
Cranial nerve palsy e.g 3rd nerve palsy (double vision)
What does autonomic neuropathy present as?
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
What are the non-modifiable risk factors for macrovascular disease of DM?
Age
Sex
Birth weight
Genes
What are the modifiable risk factors for macrovascular disease of DM?
Dyslipidaemia Hypertension Smoking Diabetes mellitus Central obesity
How should prevention of macrovascular disease in DM be carried out?
Aggressive management of multiple risk factors
List the factors which should be changed to manage cardiovascular risk in diabetes mellitus
- 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
