Microvascular Complications Flashcards
What are the major macrovascular complications of diabetes?
Coronary heart disease and stroke
What are the major microvascular complications of diabetes?
Neuropathy, nephropathy, retinopathy
The main mortality in diabetes is due to what?
Increased CV risk
What are the end stages of each of the main microvascular complications of diabetes?
Blindness, dialysis, amputation
The pathophysiology of microvascular complications begins as a result of what?
Hyperglycaemia and hyperlipidaemia
As a result of hyperglycaemia and hypertriglyceridaemia, there is hypoxia, oxidative stress, inflammation and mitochondrial dysfunction of where in the body?
The vessels
What causes damage to the nerves?
Reduced blood flow
How does microvascular disease tend to present?
Often asymptomatic and so can be quite severe on presentation
What are some risk factors for neuropathy?
Increased length of diabetes, poor control, high cholesterol/lipids, smoking and alcohol, inherited traits, mechanical injury
Patients with which type of diabetes are at increased risk of neuropathy?
Type 1
What is meant by inherited traits being a risk factor for neuropathy?
Certain families with diabetes may be susceptible to a particular microvascular complication
Peripheral neuropathy usually affects which nervous system? What can happen if it gets very severe?
Predominantly sensory, though in very severe cases the motor aspect can also be involved
What are some symptoms of peripheral neuropathy?
Numbness, tingling/burning, sharp pains/cramps, loss of balance and coordination
What complications can peripheral neuropathy lead to?
Painless trauma, foot ulcers and Charcot foot
What is usually the cause of foot ulcers in peripheral neuropathy?
Ill-fitting shoes or something in the shoe which cannot be felt
Do diabetic foot ulcers heal well? Why/why not?
They do not heal well because of the vascular compromise. There will be delayed healing which can result in chronic ulcers.
Why does Charcot foot occur?
As a result of loss of proprioception
What happens in Charcot foot?
There are multiple traumas which the patient is unaware of which damages the deep structures of the foot and leads to increased bone resorption (osteoclastic activity)
If peripheral neuropathy is painful, what analgesics can be used?
Atypicals such as amitriptyline or gabapentin
If atypical analgesics are not recommended for a patient with localised pain from diabetic neuropathy, what can be used?
Capsaicin cream
What is the onset of focal neuropathy?
Sudden onset
What nerves does focal neuropathy affect?
Specific nerves, most often in the head, torso or leg
If nerves of the eye are involved in focal neuropathy, what can this lead to?
Inability to focus eyes, diplopia, aching behind eyes
Within which group of neuropathies is entrapment neuropathy included?
Focal neuropathy
What is entrapment neuropathy?
Weakness in one nerve or a group of nerves which cause muscle weakness or pain e.g. Carpal tunnel
What does proximal neuropathy include?
Lumbosacral plexus neuropathy, femoral neuropathy, diabetic amyotrophy (wasting)
How does proximal neuropathy often present?
Pain in the thighs, hips, buttocks or legs, usually on one side of the body
Who is proximal neuropathy most common in?
Elderly patients with T2DM and marked weight loss
The nerves involved in autonomic neuropathy control what?
Regulation of the heartbeat and BP, as well as control of lots of internal organs
How can autonomic neuropathy often be picked up?
Tachycardia
How can autonomic neuropathy present in terms of the GI system?
Gastric slowing/frequency, constipation/diarrhoea
How can gastroparesis as a result of autonomic neuropathy present?
Persistent nausea and vomiting, bloating and loss of appetitie
If a patient has hypoglycaemia around 30 mins after eating, what can this suggest?
Gastroparesis (slow stomach emptying)
What are some treatment options for gastroparesis?
Improved glycemic control, small and frequent meals, promotability drugs, pain relief
Autonomic neuropathy can involve the nerves which control sweating. What can this lead to?
Profuse sweating at night or while eating
How can excessive sweating as a result of diabetic neuropathy be treated?
Glycopyrolate
What effect can autonomic neuropathy have on the eyes? When can this cause problems?
Less responsive to changes in light. Can cause problems when a light is turned on in a dark room or when driving at night
What investigation can determine the type and extent of nerve damage and how well muscles respond to nerve stimuli?
Nerve conduction studies or electromyography
What investigation can be used to asses whether the bladder and urinary tract are working properly in terms of neuropathy?
Ultrasound
What tests can be done for gastroparesis?
Gastric emptying studies
How often should diabetic patients be screened for neuropathy?
Yearly
What should be done when assessing a diabetic patient for neuropathy?
Assess feet and circulation to assess the risk of ulceration
Describe diabetic nephropathy?
Progressive kidney disease caused by damage to the capillaries in the glomeruli
What characterises diabetic nephropathy?
Nephrotic syndrome and scarring of the glomeruli
In diabetic nephropathy there can be classic nodules which are seen in no other condition. What are these known as?
Kimmelstein-Wilson nodules
Why is screening necessary for nephropathy?
It does not present with symptoms until it is well established
What are some consequences of diabetic nephropathy?
Hypertension, decline in renal función, accelerated vascular disease
What is used to screen for nephropathy?
Urinary albumin to creatinine ratio
When should screening for diabetic nephropathy occur?
At the time of diagnosis and annually from age 12 onwards
If microalbuminuria occurs in diabetes, what should you do?
Check if there is any other cause for renal disease and also check for retinopathy and hypertension
What can slow the progression of nephropathy?
Improved glycemic control
What are some risk factors for the progression of nephropathy?
Hypertension, high cholesterol, smoking, poor glycemic control, microalbuminuria
What is the drug of choice to control hypertension in diabetes?
ACE inhibitor (ARB if intolerant)
Where should blood pressure be maintained in all patients with diabetes?
< 130/80
Any patient with microalbuminuria or proteinuria should be started on what therapy?
ACE inhibitor/ARB
What is the target HbA1c for good control?
53mmol/mol
What may need to happen to the dose of insulin if a patient has renal impairment?
Decreased (since it will be excreted slower by the kidneys)
What are some eye pathologies which can occur in diabetes?
Diabetic retinopathy, cataracts, glaucoma
Acute hyperglycaemia can have what effect on the eyes?
Reversible blurring of vision
Dot/blot/flame on fundoscopy refers to what?
Haemorrhage
Cotton wool spots on fundoscopy refer to what?
Ischaemic areas
Hard exudates on funduscopy refer to what?
Lipid breakdown products
What may be seen in mild, non proliferative retinopathy?
Haemorrhages and microaneurysms
What may be seen in moderate, non proliferative retinopathy?
Microaneurysms, hard exudates, haemorrhages
What may be seen in severe, non proliferative retinopathy?
Microvascular abnormalities, venous bleeding, haemorrhages
What will be seen in proliferative retinopathy?
New vessel formation
In terms of the eyes, what conditions are screened for annually?
Retinopathy and maculopathy
What are some complications of bleeding in the eye?
Sudden changes in vision, floaters, secondary glaucoma, retinal detachment
How can retinopathy be treated?
Lasers or surgery (vitrectomy)
How common in erectile dysfunction in diabetics?
50% of men
What are some medications which can cause erectile dysfunction?
Anti-hypertensives, beta blockers, CNS drugs
