Microvascular complications of diabetes Flashcards
What are the three major sites of damage from hyperglycemia?
- retinal arteries
- renal glomerular arterioles
- Vasa nervorum - tiny blood vessels that supply nerve
what’s the biggest factor that is associated with development of microvascular complications?
high blood pressure
hyperglycaemia and hyperlipidaemia cause beta cells to die due to what?
oxidative stress
what does AGE stand for in diabetes?
advanced glycated end products
what happens with advanced glycated end products in diabetes?
disrupts how proteins function eg. proteins in blood vessel wall get glycated
hypoxia caused by hyperglycaemia and hyperlipidaemia activates what?
pro-inflammatory cytokines resulting in microvascular damage
the Polyol pathway is involved with?
neuropathy formation
what is the mechanism of diabetic retinopathy?
- Activation of various pathways in the presence of hyperglycaemia
- Leads to dysfunction of the endothelium
- which leads to retinal ischaemia
- which leads to vascular permeability which is also worsened by hypertension
- this can lead to diabetic macular oedema
- ischaemia can also increase the production of haemoglobin, resulting in neovascularisation
what are the four stages of retinopathy?
- background retinopathy
- pre-proliferative retinopathy
- proliferative retinopathy
- maculopathy (can occur at any stage)
what is background retinopathy?
hard exudates (bit of fluid and associated proteins have leaked out of the vessel and settled in the retina
microaneurysms
blot haemorrhages
what is pre-proliferative retinopathy?
‘cotton wool’ spots which look less crisp than hard exudates, called soft exudates - they represent retinal ischaemia
proliferative retinopathy is what?
visible new vessels on disc or elsewhere in retina (neovascularization)
what is maculopathy?
hard exudates/ oedema / soft exudates near the macula, can threaten vision
what is the treatment for retinopathy?
Improve HbA1c and blood pressure
what sort of reviews would someone with background retinopathy have?
continued annual surveillance
what specific treatment would someone with pre-proliferative or proliferative retinopathy receive?
pan-retinal photocoagulation (burning vessels off to stop new vessel formation which will compromise vision)
What treatment would someone with new vessel formation around the macula receive?
grid laser therapy/ photocoagulation
and
anti-VEGF intra-ocular injections to reduce oedema in macula
how is diabetic nephropathy diagnosed?
take a spot urine sample and take a creatinine: urine albumin ratio
normal range is <2.5mg/mmol in men
<3.5mg/mmol in women
(microalbuminuria)
if greater than 30mg/mmol you would do a proper proteinuria assessment
progressively increasing proteinuria
progressively deteriorating kidney function
classic histological features
are linked with?
diabetic retinopathy
what are the classic histological features of diabetic nephropathy?
- mesangial expansion
- basement membrane thickening
- glomerulosclerosis
what are risk factors for diabetic nephropathy in T2DM?
- age at development of disease
- ethnic differences
- age at presentation
- loss due to cardiovascular morbidity
what do you look for when diagnosing diabetic nephropathy?
- progressive proteinuria (urine albumin:creatinine ratio)
- increased BP
- deranged eGFR
- advanced: peripheral oedema
what are the strategies for intervention for diabetic nephropathy?
- decrease HbA1c
- manage blood pressure with anti-hypertensive treatment
- Inhibit renal-angiogtensin-aldosterone system (ACE inhibitor)
- SGLT-2 inhibition
- stop smoking
