Diabetic Complications Flashcards
What is diabetic nephropathy
Progressive kidney disease caused by damage to capillaries in the glomeruli (nodular glomerulosclerosis)
How is diabetic nephropathy characterised
Proteinuria
Diffuse scaring of glomeruli
Damage to capillaries in glomeruli
Diabetic nephropathy investigations
Albumin:creatinine ratio & urine dipstick
If ACR <30 or PCR <50 = microalbuminuria
1. Repeat twice as false positive readings are common
2. Established microalbuminuria if 2/3 positive
3. Microalbuminuria will not show as proteinuria on dipstick
If ACR >30 or PCR >50 = proteinuria (overt nephropathy)
1. Repeat on EMU
2. Proteinuria will show up on a urine dipstick
Diabetic nephropathy/ Microalbuminuria treatment
Diabetes & microalbuminuria
=> ACEi (or ARB) & SGLT2i
=> Allow for 20% decline in eGFR with ACEi
(dilate renal arterioles)
Diabetic neuropathy 4 subtypes
- Peripheral neuropathy & Charcot foot
- Autonomic neuropathy
- Proximal neuropathy
- Focal neuropathy
Describe peripheral neuropathy
Pain/loss of feeling in feet or hands in a ‘glove & stocking’ distribution
Diabetic peripheral neuropathy clinical features
- Numbness/insensitivity
- Tingling/burning
- Sharp pains or cramps
- Sensitivity to touch
- Loss of balace and coordination
Diabetic peripheral neuropathy complications
Painless trauma
Charcot’s foot
Venous ulcers
Claw foot & callus formation
Argyll Robertson pupil
What is Charcot foot - Pathophysiology & clinical presentation
- Well perfused foot but severe neuropathy
- Hot & swollen foot with bone destruction & deformity
Charcot foot management
MRI to differentiate from infection
Non weight bearing, full contact cast/boot
Peripheral neuropathy pain management
Oral Amitriptyline, duloxetine, gabapentin, pregabalin
Topical capsaicin cream
Autonomic (diabetic) neuropathy clinical features
- Sweat glands - profuse sweating
- Gastroparesis - Constipation, diarrhoea, N&V, bloating
- Oesophagus - Dysphagia
- Blood pressure - postural hypotension
- Heart - constant tachycardia
- ECG - loss of RR variability (complete loss of autonomic control over cardiac function)
Treatment of profuse sweating associated with diabetic, autonomic neuropathy
topical glycopyrolate, clonidine, botulium toxin
Treatment of gastroparesis associated with diabetic, autonomic neuropathy
- Conservative (diet, analgesia)
- Promotility drugs (metoclopramide)
- Anti-nausea drugs (procholrperazine/ ondansetron)
- Severe cases (Botox, gastric pacemaker)
What cause proximal neuropathy in diabetic patients
Damage of nerves of the lumbosacral plexus
Diabetic retinopathy pathophysiology
Hyperglycaemia =>
oxidative stress & inflammation =>
Vessels supplying retina dilate =>
microaneurysms & small haemorrhages
Increased vascular permeability & leakage =>
hard exudates
Retina oxygen starvation =>
Cotton wool spots
VEGF release =>
Neovascularisation
Neovascularisation in vitreous humor & retinal traction =>
Vitreous haemorrhage =>
Vision loss
Diabetic retinopathy investigations
Fundoscopy - diabetic retinopathy
Optical coherence tomography - maculopathy
Fluorescein angiography - severe disease, neovascularisation
Diabetic retinopathy grading
Micro-aneurysms & dot haemorrhages
(mild non proliferative DR)
+ Blot haemorrhages, hard exudates & cotton wool spots
(moderate non proliferative DR)
+ Beaded veins, IRMA, extensive retinal haemorrhage
(severe non proliferative DR )
+ Neovascularisation, fibrous proliferation of vitreous/retina
(proliferative DR)
Diabetic maculopathy grading
Mild-moderate maculopathy - hard exudates within 1-2 discs diameter of fovea
Severe maculopathy - hard exudates or blot haemorrhages within less than 1 disc diameter of fovea
Diabetic eye management
- Severe NPDR or PDR - Laser panretinal photocoagulation
- Vitreal haemorrhage - Vitrectomy
- Macular oedema & retinal traction - Vitrectomy
- Macular oedema - Anti-VEGF agents intra-vitreal injections
- Clinically significant macular oedema - Focal macular laser
Panretinal photocoagulation laser risks
Peripheral vision loss
Night vision loss
Macular oedema
Name three other eye pathologies other than retinopathy & maculopathy that are associated with diabetes
Cataract (lens clouding)
Glaucoma (optic nerve damage)
Reversible visual blurring in hyperglycaemic episodes
What three screening tests are carried out annually for all diabetic patients
- Digital retinal screening
- Foot risk assessment
- Urine albumin-to-creatinine ratio and serum creatinine
Microvascular complications (nephropathy, neuropathy, retinopathy) pathophysiology
Mitochondria can’t keep up with glucose levels & so glucose is used in harmful pathways including….
- Formation of advanced glycation end products (AGE)
- Increased glucose through the sorbitol-polyol pathway
- Increased flux of glucose through other pathways e.g. pentose phosphate pathway
