Endo 18: Microvascular complications of diabetes Flashcards
(48 cards)
3 sites of microvascular complication
Retinal arteries
Glomerular arterioles (kidney)
Vasa nervorum (tiny blood vessels that supply nerves)
What determines microvascular complications
- Severity of hyperglycaemia
- Affects retinopathy the most, then nephropathy then neuropathy - HTN
- Genetic
- Hyperglycaemia memory
What causes microvascular complications, generally
Tissue damage through originally reversible and later irreversible alterations in proteins
What is hyperglycaemia memory
The fact that previous glucose control affects microvascular outcomes at a given time
How does hyperglycaemia cause microvascular damage?
High glucose levels cause many changes in the inflammatory cascades.
This then leads to inflammation, causing problems in the eyes, kidneys and nerves.
There are pathways that make this damage worse:
- Polyol pathway
- AGEs
- Protein kinase C
- Hexosamine
What is the main cause of blindness in people of working age
Diabetic retinopathy is the main cause of visual loss in people with diabetes and the main cause of blindness in people of working age
Outline the cause of proliferative diabetic retinopathy
Hyperglycaemia leads to inflammation (polyol, AGEs, PKC, hexosamine etc)
This leads to vascular endothelial dysfunction. Hypertension also leads to this.
This all leads to retinal ischaemia, promoting VEGF and erythropoietin.
There is increased vascular permeability, leading to diabetic macular oedema, and RETINAL NEOVASCULARISATION, leading to PDR compliations
What will be see in background diabetic retinopathy
Hard exudates (cheese colour, lipid)
Microaneurysms (“dots”)
Blot haemorrhages
What is seen in pre-proliferative diabetic retinopathy
Cotton wool spots also called soft exudates
Represent retinal ischaemia
What is seen in proliferative retinopathy
Visible new vessels
On disk or elsewhere in retina
What is maculopathy
Hard exudates near the macula
T/F maculopathy has a distinct pathological process to background diabetic retinopathy
NO!
It’s background diabetic retinopathy, but happens to be near macula
Can threaten direct vision
Management of background diabetic retinopathy
Background:
- improve control of blood glucose
- warn patient that warning signs are present
Management of pre-proliferative diabetic retinopathy
If left alone, new vessels WILL grow
Needs: Pan retinal photocoagulation
Management of proliferative diabetic retinopathy
Also needs:
-Pan retinal photocoagulation
In which case would you need to use photocoagulation when you only have background retinopathy
Maculopathy
Only have problem around macula
Needs only a GRID of photocoagulation
(NOT pan retinal photocoagulation)
What is diabetic nephropathy
Hypertension
Progressively increasing proteinuria
Progressively deteriorating kidney function
Classic histological features
T/f diabetic nephropathy is associated with morbidity not mortality
F… both
What is the most significant set of risk factors for cardiovascular disease
Diabetes and CKD
Histological features at the glomerulus in nephropathy
Mesangial expansion
Basement membrane thickening
Glomerulosclerosis
What might indicate that a patient’s kidney problems are not due to diabetes
If retinopathy has not already been detected
What is the proportion of diabetics getting nephropathy
Type 1 DM: 20-40% will have nephropathy after 30-40 years
• Type 2 DM: Probably equivalent – BUT there are a few caveats
What affects the likelihood of a T2DM patient getting nephropathy
Age at development of disease
Racial Factors
Age at presentation
Loss due to cardiovascular morbidity
Clinical features of diabetic nephropathy
Progressive proteinuria
Increased BP
Deranged renal function
