Microvascular and Macrovascular Complications of Diabetes Mellitus Flashcards
-> Endocrine disorders: the pathology and pathophysiology of endocrine disorders. -> Endocrine disorders: Describe the clinical features and treatment options of endocrine disorders.
What are the 3 chronic microvascular complications with diabetes?
- Retinopathy
- Neuropathy
- Nephropathy
What is the relationship between HbA1c and microvascular disease?
- The higher the HbA1c the greater the microvascular and myocardial infarction risk
What factors increase the risks of complications of diabetes (6)?
- Hypertension
- Duration of diabetes
- Smoking
- Genetic factors
- Hyperlipidaemia
- Hyperglycaemic memory
What is the mechanism of damage of complications of diabetes (from hyperglycaemia to complications) (6)?
- Increased formation of mitochondrial superoxide free radicals in the endothelium
- Generation of glycated plasma proteins to form advanced glycation end products (AGEs)
- Activation of inflammatory pathways
- Damaged endothelium results in
- ‘Leaky’ capillaries
- Ischaemia
How does background retinopathy present?
- Hard exudates (cheese colour, lipid)
- Microaneurysms (“dots”)
- Blot haemorrhages
How does pre-proliferative retinopathy present?
- Cotton wool spots also called soft exudates
- Represent retinal ischaemia
How does proliferative retinopathy present?
- Visible new vessels on disc or elsewhere in retina
How does maculopathy present?
- Hard exudates / oedema near the macula
- Same disease as background, but happens to be near macula
This can threaten vision
How is retinopathy treated (4)?
- Improve HbA1c
- Stop smoking
- Lipid lowering
- Good blood pressure control < 130/80 mmHg
How is the oedema present in maculopathy treated?
Anti-VEGF injections directly into the eye
VEGF: vascular endothelial growth factor
What stage of diabetic retinopathy can be observed rather than treated?
Background retinopathy
How is diabetic nephropathy diagnosed (4)?
- Progressive proteinuria (urine albumin:creatinine ratio - ACR)
- Increased blood pressure
- Deranged renal function (eGFR)
- Advanced: peripheral oedema
What is the mechanism of diabetic nephropathy?
How is diabetic nephropathy managed (4)?
- Aim for tighter glycaemic control
- ACEi/ARB even if normotensive as soon as patient has microalbuminuria
- Reduce BP (aim < 130/80 mmHg) usually through ACEi or A2RB
- Stop smoking
When does diabetic neuropathy occur?
Neuropathy results when vasa nervorum get blocked
Small vessels supplying nerves are called vasa nervorum
What are the risk factors of diabetic neuropathy (6)?
- Age
- Duration of diabetes
- Poor glycaemic control
- Height (longer nerves in lower limbs of tall people)
- Smoking
- Presence of diabetic retinopathy
What does an annual feet check involve (3)?
- Look for foot deformity, ulceration
- Assess sensation (monofilament, ankle jerks)
- Assess foot pulses (dorsalis pedis and posterior tibial)
Which patients have an increased risk of foot ulceration?
Patients with:
* Peripheral neuropathy
* Peripheral vascular disease
How is diabetic peripheral neuropathy managed (4)?
- Regular inspection of feet by affected individual
- Good footwear
- Avoid barefoot walking
- Podiatry and chiropody if needed
How is diabetic peripheral neuropathy with ulceration managed (6)?
- Multidisciplinary diabetes foot clinic
- Offloading
- Revascularisation if concomitant PVD
- Antibiotics if infected
- Orthotic footwear
- Amputation if all else fails
What would be the effect of autonomic neuropathy to the GI tract (4)?
- Nausea and vomiting (can make prandial short-acting insulin challenging)
- Constipation
- Nocturnal diarrhoea
What would be the effect of autonomic neuropathy to the cardiovascular system (2)?
- Postural hypotension
- Cardiac autonomic supply: sudden cardiac death
What are the 3 forms of macrovascular disease in diabetes?
- Ischaemic heart disease
- Cerebrovascular disease
- Peripheral vascular disease
What are the non-modifiable risk factors for macrovascular disease (4)?
- Age
- Sex
- Birth weight
- FH/Genes
What are the modifiable risk factors for macrovascular disease (5)?
- Dyslipidaemia
- Hypertension
- Smoking
- Diabetes mellitus
- Central obesity
What is the main cause of death in patients with diabetes?
- Ischaemic heart disease
How is the cardiovascular risk in diabetes mellitus managed (5)?
- Encourage to stop smoking
- Blood pressure < 140/80 mmHg, < 130/80 mmHg if microvascular complication
- Lipid profile - total chol < 4, LDL < 2
- Weight – discuss lifestyle intervention +/- pharmacological treatments
- Annual urine microalbuminuria screen – risk factor for cardiovascular disease
