Complications of DM

Question 1

Macrovascular complications of DM

Answer 1

• Coronary artery disease is a major cause of death in diabetics
• Peripheral ischaemia causes poor healing, ulcers and “diabetic foot”
• Stroke
• Hypertension

Question 2

Microvascular complications of DM

Answer 2

• Peripheral neuropathy
• Retinopathy
• Kidney disease, particularly glomerulosclerosis

Question 3

Infection related complications of DM

Answer 3

• Urinary Tract Infections
• Pneumonia
• Skin and soft tissue infections, particularly in the feet
• Fungal infections, particularly oral and vaginal candidiasis

Question 4

Diabetic nephropathy

Answer 4

• Most common cause of glomerular pathology and CKD in the UK. The chronic high level of glucose passing through the glomerulus causes scarring. This is called glomerulosclerosis.
• Proteinuria is a key feature. This is due to damage to the glomerulus allowing protein to be filtered from blood to urine.
• Patients with diabetes should have regular screening for diabetic nephropathy by testing the albumin:creatinine ratio and U&Es.
• Treatment is by optimising blood sugar levels and blood pressure.
• ACE inhibitors are the treatment of choice in diabetics for blood pressure control. They should be started in patients with diabetic nephropathy even if they have a normal blood pressure.

Question 5

Features of diabetic retinopathy

Answer 5

• Hyperglycaemia leads to damage to the retinal small vessels and endothelial cells. Increased vascular permeability leads to leakage from the blood vessels, blot haemorrhages and the formation of hard exudates. Hard exudates are yellow/white deposits of lipids in the retina.
• Damage to the blood vessel walls leads to microaneurysms and venous beading. Microaneurysms are where weakness in the wall causes small bulges. Venous beading is where the walls of the veins are no longer straight and parallel and look more like a string of beads or sausages.
• Damage to nerve fibres in the retina causes fluffy white patches to form on the retina called cotton wool spots.
• Intraretinal microvascular abnormalities (IMRA) is where there are dilated and tortuous capillaries in the retina. These can act as a shunt between the arterial and venous vessels in the retina.
• Neovascularisation is when growth factors are released in the retina causing the development of new blood vessels.

Question 6

Classification of diabetic retinopathy

Answer 6

• Diabetic retinopathy can be split into two broad categories: non-proliferative and proliferative depending on whether new blood vessels have developed. Non-proliferative is often called background or pre-proliferative retinopathy as it can develop in to proliferative retinopathy. A condition called diabetic maculopathy also exists separate from non-proliferative and proliferative diabetic retinopathy.
• These conditions are classified based on the findings on fundus examination include:
  
  • Non-proliferative Diabetic Retinopathy
    
    • Mild: microaneurysms
    • Moderate: microaneurysms, blot haemorhages, hard exudates, cotton wool spots and venous beading
    • Severe: blot haemorrhages plus microaneurysms in 4 quadrants, venous beating in 2 quadrates, intraretinal microvascular abnormality (IMRA) in any quadrant
  • Proliferative Diabetic Retinopathy
    
    • Neovascularisation
    • Vitreous haemorrhage
  • Diabetic Maculopathy
    
    • Macular oedema
    • Ischaemic maculopathy

Question 7

Complications of diabetic retinopathy

Answer 7

• Retinal detachment
• Vitreous haemorrhage (bleeding in to the vitreous humour)
• Rebeosis iridis (new blood vessel formation in the iris)
• Optic neuropathy
• Cataracts

Question 8

Management of diabetic retinopathy

Answer 8

• Laser photocoagulation
• Anti-VEGF medications such as ranibizumab and bevacizumab
• Vitreoretinal surgery (keyhole surgery on the eye) may be required in severe disease