Micro/macrovascular Flashcards
examples of microvascular complications?
neuropathy, retinopathy, nephropathy
examples of macrovascular complications?
cerebrovascular disease, ischaemic heart disease, peripheral vascular disease
what is one factor strongly associated with developing microvascular complications?
HbA1c levels
What should patients aim for
target 53 mmol/L
main other factor that increases risk?
Hypertension
Smoking
Duration of diabetes
Genetic factors
Hyperlipidaemia
Hyperglyaemic memory
Hyperglycemic memory
inadequate glucose control early on can cause complications later even if HbA1c is brought under control
How does hyperglycemias cause vascular complications
increased formation of mitochondrial free radicals in endothelium
formation of advanced glycation end products (AGE)
hypoxia
Leads to inflammatory signaling
What does inflammatory signalling result in
inflammation → endothelium damage → leaky capillaries, ischaemia
What does diabetic retinopathy result in
Vision loss
Why is screening so important
Early stages are asymptomatic
what does background retinopathy look like?
hard exudates, blot haemorrhages, dots → microaneurysms
What is the next stage of background retinopathy
Pre proliferation retinopathy
Pre proliferative
cotton wool spots → soft exudates, represent retinal ischaemia
haemorrhages
Next stage of pre proliferative
Proliferative retinopathy
Proliferative retinopathy
visible new vessels on optic disc or elsewhere
what is maculopathy?
hard exudates/oedema near macula
can threaten vision
Clinical relevance of maculopathy
Same disease as background but can threaten vision
what is the treatment approach for each stage?
background → annual screening
pre-proliferative → early panretinal photocoagulation
proliferative → panretinal photocoagulation
macular → anti-VEGF injections, grid photocoagulation
clinical relevance of diabetic nephropathy?
associated with progression to end stage renal failure, increased cardiovascular event risk
- how is surveillance for nephropathy done?
urine sample looking for albumin:creatinine ratio
Benchmark for microalbuminurea
3+ mmol/L
Benchmark for proteinuria
30+ mmol/L
Nephrotic range
3000mg/24hr
considerations for UACR test?
false positives common eg fever/infection → positive albumin needs to be repeated to confirm microalbuminuria
What is the mechanism behind diabetic nephropathy
hyperglycaemia + hypertension = glomerular hypertension
leads to proteinuria, glomerular fibrosis, filtration rate decline, renal failure
treatment options for diabetic nephropathy?
ACE inhibitor ,angiotensin 2 receptor blocker
Give one of the two to all diabetes patients with microalbumin/proteinuria even if normotensive
Clinical relevance of microalbuminuria
risk factor for cardiovascular disease
how is diabetic nephropathy managed?
aim for good glycaemic control, manage bp, ACEi/ARB if normotensive + microalbuminuria, stop smoking, SGLT-2 possible for type II DM
What is diabetic neuropathy
Blockage of small vessels supplying nerves (small vessels are called vasa nervorum)
Risk factors for diabetic neuropathy
age, duration of DM, HbA1c, height as longer nerves in taller ppl, smoking, presence of retinopathy
Where are complications most common present and what’s the clinical release
Feet (longest nerves supplying)
Painful, patients might not sense injury to affected area
Risks associated with disease development
Reduced sensation in feet and poor vascular supply to feet causes higher risk of foot ulceration
How do you screen for complications
Annual foot checks
Check for foot deformity,ulceration,sensation,pulses
if all fails then foot amputation
Other neuropathies
Mononeuropathy
Autonomic neuropathy
What does mononeuropathy involve
Sudden motor loss usually eg foot drop,wrist drop
Cranial nerve palsy also possible eg 3rd causes double vision and improper eye movement
What does autonomic neuropathy involve
Damage to parasympathetic and sympathetic nerves innervating GI,cardiovascular,bladder etc
GI tract manifestations
Delayed gastric emptying causes nausea,vomiting which makes short acting insulin challenging,constipation,nocturnal diarrhoea
Cardiovascular manifestations
postural hypotension (possibly disabling)
cardiac autonomic supply compromised → sudden cardiac death
form of autonomic neuropathy
how does treatment of hyperglycaemia alone affect macrovascular disease?
minor effect, multiple risk factors need to be monitored
Examples of CVD non modifiable risk factors
Age
Sex
Birth weight
FH
Genes
Examples of modifiable risk factors
Dylipidaemia
Hypertensive
Smoking
DM
Central obesity
What should be screened for annually
Microalbuminuria
What lipid profile is ideal
Total cholesterol less than 4,LDL less than 2
Ideal bp if microvascular complication present
130/80
