Micro + Macrovascular complications of diabetes Flashcards
What do microvascular complications affect and what are three examples?
Small Vessels: Retinopathy, Nephropathy, Neuropathy (remember pathy)
What do macrovascular complications affect and what are three examples?
Large Vessels: Cerebrovascular Disease, Ischaemic Heart Disease, Peripheral Vascular Disease (remember disease)
What level of HbA1c proposes a higher risk of microcomplications?
53mmol/mol (7%) (42-48 impaired tolerance // 48+ is diabetes)
Effect of hypertension on complication risk
Increases the risk of complications
What are 5 factors that can lead to microvascular complications?
Blood pressure, causes endothelial damage
Smoking, causes endothelial dysfunction
Hyperlipidaemia, high cholesterol clogs arteries
Genetics, may develop complications despite good glycemic control
Duration of Diabetes, risk increases with time
Hyperglycaemic Memory (inadequate glucose memory early on), damage from earlier lack of control can affect later life
What is the mechanism for damage for microvascular complications?
Risk factors cause formation of free radicals in the endothelium which cause damage by activating inflammatory pathways.
Causes leaky capillaries, releasing exudates which lead to further damage
Causes ischemia due to restricted blood flow
What is the problem with detecting diabetic retinopathy?
Early stages are asymptomatic
.: do annual retinal screening
What are the three stages of retinopathy?
Background Retinopathy,
Pre-proliferative Retinopathy,
Proliferative Retinopathy
with worsening retinal ischaemia
What do soft exudates represent?
Retinal ischaemia
What can you see in proliferative retinopathy?
Visible new vessels on retina or optic discs
angiogenesis, new vessels are highly friable and subject to rupturing
What is maculopathy?
background retinopathy but in the macula
see hard exudates near macula
(centre of retina used for central vision - like reading)
Background retinopathy treatment
Continued annual surveillance
check glycemic control, cholesterol, bp, smoking status
Pre-proliferative and proliferative retinopathy treatment
Panretinal photocoagulation
to try and stop angiogenesis, burn the area around retina with a laser
How do you treat maculopathy?
Anti-VEGF (Vascular Endothelial Growth Factor) Injections, Grid Photocoagulation
What is the disadvantage of panretinal photocoagulation?
Loss of peripheral vision
Why should diabetic nephropathy be taken seriously?
Can lead to end-stage kidney failure and increased risk of cardiovascular events (with microalbuminuria)
How do you diagnose nephropathy?
Urine screening for protein, using albumin:creatinine ratio (microalbuminuria > 3mg/mmol ,
proteinuria > 30mg/mmol)
What is the downside of measuring ACR
False positives common .: must be taken twice to be indicative of microalbuminuria
What is the earliest feature of diabetic nephropathy?
Microalbuminuria (>2.5mg/mmol)
What is the mechanism for diabetic nephropathy?
Glomerular hypertension can lead to proteinuria (pushes proteins through). This leads to glomerular fibrosis and lower eGFR
Renin - Angiotensin system
Angiotensinogen from the liver
Renin from the kidneys causes conversion to angiotensin 1
ACE converts to angiotensin 2
Ang2 is a vasoconstrictor and stimulates zona glomerulosa to produce aldosterone
How would you treat diabetic nephropathy?
Block rennin-angiotensin system -> using ACE Inhibitor (-pril) or ARB (Angiotensin receptor blocker, - sartan) EVEN if they are normotensive
How should you manage diabetic nephropathy?
Tighter glycaemic control,
Reduce blood pressure (<130/80),
Smoking cessation,
Start SGLT-2 inhibitor (can delay nephropathy)
How does diabetic neuropathy happen?
Damage to vasa nervosum (blood vessels that supply nerves)
