L18 - Long term diabetic complications Flashcards
Long term microvascular complications of diabetes
- Retinopathy
- Nephropathy
- Neuropathy
Long term macrovascular complications of diabetes
- IHD
- CVD
- PVD
How do most cells respond to hyperglycaemia
- Most cells are able to reduce glucose transport in response to extracellular hyperglycaemia
Features of microvascular complication development
- Microvascular complications take many years to develop
- Rare before 5 years of type 1 diabetes
- May be detected at presentation of type 2 diabetes
Features of retinopathy
- Second commonest cause of blindness in those of working age
- 4000+ in England blind from diabetic retinopathy
- Risk of blindness increased 10-20 fold by DM
- Glaucoma and cataract risk increased
Features of retinal microcirculation
Low density of capillaries
- Little functional reserve
- Flow needs to respond to local needs
- Pericytes key to local regulation of flow
What are pericytes
- Pericytes are contractile cells that wrap around the endothelial cells that line the capillaries and venules throughout the body
Pathological findings of diabetic retinopathy
- Loss of pericytes
- Basement membrane thickening
- Capillary closure
- Ischaemia - VEGF production + increased capillary permeability
What is VEGF
Vascular endothelial growth factor (VEGF), originally known as vascular permeability factor (VPF),[1] is a signal protein produced by cells that stimulates the formation of blood vessels
Clinical stages of retinopathy
- Non-proliferative
- Background
- Pre-proliferative
- Proliferative
- Macular Oedema
- Sight threatening
- Non sight threatening
Features of diabetic retinopathy management
- Diabetic control important
- Blood pressure control important
- Laser treatment
- Pan retinal
- Focal
- Intra-vitreal anti VEGF Ab
What percentage of diabetic patients are affected by neuropathy
- Affects up to 50% of diabetic patients
Types of neuropathy
- Peripheral neuropathy
- Mononeuropathy
- Autonomic neuropathy
Complications of autonomic neuropathy
- Gastroparesis
- Postural hypotension
- Erectile dysfunction
- Gustatory sweating
- Diarrhoea
What is entrapment neuropathy
Nerve compression syndrome or compression neuropathy, also known as entrapment neuropathy, is a medical condition caused by direct pressure on a nerve
Features of renal microcirculation
- Fenestrated glomerular capillaries
- Basement membrane
- Highly specialised podocytes
Pathological findings of diabetic nephropathy
· Basement membrane thickening - Loss of negative charge · Podocyte loss - Loss of integrity of filtration barrier · Glomerular sclerosis · Mesangial expansion
At what level does the dipstick test become positive for albuminuria
- > 200ug.min^-1
- >300 mg.24hr^-1 - GFR
Features of diabetic neuropathy management
· Blood pressure control important
· Blockers of RAS system preferred
· Glucose control important but less so once overt proteinuria
· Associated with increased CVD risk
· Ultimately renal replacement / transplantation
Duration of macrovascular disease in patients with T1DM
- Patients with type 1 diabetes have long disease duration
What does the presentation of macrovascular disease depend on
- Angina/MI
- Stroke
- PVD
Modifiable risk factors linked to macrovascular disease
- Blood pressure
- Lipids
- Smoking
- Glucose control
Causes of diabetic foot ulcers
· Diabetes is the commonest cause of non-traumatic lower limb amputation
• PVD
• Neuropathy (neuropathic ulcer, Charcot change)
• Imapaired leucocyte function
Link between HbA1c levels and risk of microvascular complications
- Direct positive correlation
