Diabetes (microvascular & macrovascular complications) Flashcards
What are the microvascular complications of diabetes?
Microvascular disease, unlike macrovascular disease is specific to diabetes.
- Small vessels of the retina, glomeruli and nere sheaths are particuarly affected
- Symptoms manifest 10-20 years after diagnosis in young patients
Diabetic eye disease - Most common cause of blindness in under 65s
Diabetic Retinopathy (DR) - can be non-prolifertive (NPDR) or proliferative (PDR)
Diabetic malculopathy - retinopathy that affects the macula
Cataract formation - clouding of the lens in the eye which leads to a decrease in vision
Glaucoma - optic nerve damaged
Describe what diabetic retinopathy is in more detail?
Types?
It can be non-proliferative (NPDR) or proliferative (PDR)
Non-proliferative diabetic retinopathy (NPDR)
- Usually asymptomatic, and always occurs at some severity after 8-10y of DM
- Features on fundoscopy;
- Micro-aneurysms
- Exudates: due to leaky vasculature
- Haemorrhages: dot, blot, flame shaped
- Cotton wool spots (>5 indicates ‘pre-proliferative’ retinopathy)
- Can progress into proliferative diabetic retinopathy
Proliferative diabetic retinopathy (PDR) -more common in T2DM
- Characterised by the development of new vessels on the optic disc or retina as a response to significant retinal ischaemia (ischaemia leads to vascular endothelial growth factor (VEFG) production)
- The vessels are fragile, and likely to bleed with the traction that occurs when they are growing forward to give a pre-retinal or vitreous haemorrhage
- If untreated, the blood vessels will cause fibrosis and a tractional retinal detachment, again leading to loss of acuity
- They can also cause acute angle closure glaucoma due to iris neovascularisation, known as rubeosis iridis
Describe diabetic maculopathy is more detail
How does it present?
Types?
- More common in type II diabetes
- Maculopathy is damage to the macula, the part of the eye which provides us with our central vision. A common from of damage is from diabetic macular oedema (DMO) in which fluid builds up on the macula.
- Typically presents with as blurring of vision
- 3 subtypes: focal, diffuse and ischemic
What is cataracts?
Symptoms?
Is it more likely in diabetics?
A cataract is a clouding of the lens in the eye which leads to a decrease in vision
- Symptoms are trouble with bright light/headlights and reading vision
- Increased rates of age-related cataracts in diabetics
- Postior sub-capsular cataracts are the most common
List the neurological complications of diabetes mellitus
- Symmetrical polyneuropathy
- Acute painful neuropathy
- Mononeuropathy
- Diabetic amyotrophy
- Autonomic neuropathy
What is symmetrical polyneuropathy?
- ‘Glove and stocking’ sensory loss, with vibration, deep pain and temperature lost first
- Patients complain of losing their balance when eye are closed, e.g. when washing their face, due to proprioception (walking on cotton walk feeling is common)
- Interosseous wasting of the small muscle of the feet results in a charactistic foot shape, and abnormal pressure areas lead to ulcers
- Unrecognised trauma with poor wound healing may also lead to ulcers
- Neuropathic arthropathy can also develop -Charcot’s foot - progressive degeneration of a weight bearing joint, a process marked by bony destruction, bone resorption, and eventual deformity
What is acute painful neuropathy?
- Painful burning pains in the feet, shins and anterior thighs
- Associated with poor glycaemic control
- Typically worse at night (pressure from bedclothes may be intolerable)
- Usually remits after 3-12 months of good glycaemic control
- More chronic forms may be resistant to all forms of therapy
What is mononeuropathy?
What types of mononeuropathy may occur in diabetes?
What is mononeurtis complex?
- Type of damage to nerves outside the brain and spinal cord
Commonest types of mononeuropathy that may occur in diabetes:
- Cranial nerve lesions can occur in patients with diabetes
- Mainly CNs III, IV and VI; ocular palsies
- Isolated peripheral nerve lesions can also occur
- Any nerve compression syndrome is more common in diabetes, e.g. carpal tunnel syndrome
- Foot drop may occur due to lesions of the sciatic nerve
- When more than one nerve is affected, this is known as mononeuritis complex
What is diabetic amyotrophy?
How does it present?
- Amyotrophy is progressive wasting of muscle tissues
- It is rare, usually developing in middle aged men
- In diabetes, it presents as painful wasting of quadriceps
- Course is variable, often with gradual but incomplete improvement
What is autonomic neuropathy?
How does it present?
- Autonomic neuropathy is a group of symptoms that occur when there is damage to the nerves that manage every day body functions
- Sympathetic dysfunction leads to postural hypotension, ejaculatory failure, reduced sweating and Horner’s syndrome
- Parasympathic dysfunction leads to erectile dysfunction, constipation, urinary retention and a Holmes-Adie pupil (large and irregular pupil)
Outline the natural history of renal complications of diabetes
- Usually manifests 15-25 years after diagnosis
- CKD is leading cause of premature death in young diabetics (neuropathy will affect 30%)
- Most important intervention is adequate blood pressure control
What are the macrovascular complications of diabetes?
- Diabetes is a risk factor in the development of atherosclerosis
- Increased risk:
- 2x increased risk of stroke
- 4x increased risk of MI
- 50x increased risk of amputation for gangrene
What are the causes and consequence of diabetic foot?
- 10-15% of diabetic patients develop foot ulcers at some point in their lives.
- Foot problems are responsible for 50% of diabetes-related hospital admissions.
- Ischaemia, infection and neuropathy combine to produce tissue necrosis.
- Medical supervision and patient education hope to reduce the number of amputations required.
- Patients may lose some proprioceptive function and fall more easily.
