Endo 16 - Microvascular and Macrovascular Complications of DM Flashcards
State the three main sites of microvascular complications.
Retinal artiers
Glomerular arteries
Vasa Vasorum
What factors correlate with the risk of microvascular and macro complications?
HbA1c - glycaemic control
hypertension
Describe the mechanism of glucose damage to blood vessels
Hyperglycaemia leads to oxidative stress and hypoxia
triggers inflammatory cascade which leads to damage
What are the 4 types of diabetic retinopathy?
Background
Pre-proliferative
Proliferative
Maculopathy
What 3 things do you see in background retinopathy?
hard exudates
microaneurysms
blot haemiorrhages
What are hard exudates caused by?
leakage of lipid contents - looks cheesy
Describe pre-proliferative diabetic retinopathy.
soft exudates - cotton wool
haemorrhages
What do soft exudates indicated?
Retinal ischaemia
Describe proliferative retinopathy.
formation of new blood vessels in response to retinal ischaemia
new blood vessels are fragile and can bleed easily
Describe maculopathy
presence of hard exudates in the macula
threatens direct vision
How would you manage background retinopathy?
control blood glucose
What is the treatment for pre-proliferative and proliferative retinopathy?
pan-retinal photocoagulation
Describe the treatment of maculopathy.
grid of photocoagulation
What is the overproduction of matrix in diabetic nephropathy caused by?
prolonged exposure to high glucose
angiotensin II
State 3 clinical features of diabetic nephropathy.
Progressive proteinuria
increased blood pressure
deranged renal function
Whatis the normal range for proteinuria?
<30mg/24 hours
Why do patients with diabetic nephropathy get oedematous?
increased proteinuria = decreased serum albumin = decreased osmotic potential = less fluid drawn back in
Describe some strategies for intervention for patients with diabetic nephropathy.
Better blood glucose control
blood pressure control
inhibition of RAAS system
What effect does angiotensin II have on endothelial cells?
makes endothelial cells more rigid
Where is renin produced?
Juxtoglomerular cells
What can stimulate renin release?
low renal perfusion e.g. low blood pressure
Where is ACE found?
Lungs
State some drug target sites in the RAAS.
ACE inhibitors
ARB
What causes diabetic neuropathy?
occlusion of vasa vasorum
State 6 different types of diabetic neuropathy.
Peripheral polyneuropathy Mononeuropathy Mononeuritis multiplex Radiculopathy Autonomic neuropathy Diabetic amyotrophy
What can peripheral neuropathy lead to?
loss of sensation can lead to damage not being noticed
loss of ankle verks and vibrational sense
How would you test for peripheral neuropathy?
Monofilament examination - produces a certain amount of force, see if patient can feel
What is mononeuropathy?
Sudden motor loss .e.g wrist drop
Why is the pupil spared in pupil sparing third nerve palsy?
parasympathetic fibres that are responsible for the diameter of the pupil run on the outside of the main nerve so don’t lose blood supply
How would an aneurysm causing third nerve palsy present
differently to third nerve palsy caused by diabetes?
There would be fixed pupil dilation
This is because the parasympathetic fibres would also be affected
What is mononeuritis multiplex?
random combination of peripheral nerve lesions
What is radiculopathy?
pain over spinal nerves
What are the effects of autonomic neuropathy on the GI?
difficulty swallowing
late gastric emptying
constipation
What are the effects of autonomic neuropathy on the CVS?
Postural hypotension
