complications of diabetes Flashcards
what are some macrovascular complications of diabetes?
- stroke
- IHD (ischaemic heart disease)
what are some microvascular complications of diabetes?
- neuropathy
- nephropathy
- retinopathy
what is done to try detect complications early?
screening!!
annual review where we do:
- digital retinal screening
- foot risk assessment
- urine albumin: creatinine ratio, creatinine
what increases risk of complications?
-higher HbA1c
are microvascular and macrovascular complications seen if patient doesnt have diabetes?
macrovascular can be seen in patients without diabetes
microvascular only seen in patients with diabetes
how can excess glucose cause osmotic damage?
- excess glucose can trigger the polyol pathway which is controlled by aldose reductase
- polyol pathway produces sorbitol
- sorbitol can cause osmotic damage
- osmotic damage leads to production of reactive oxygen species
how can excess glucose create NADPH oxidase?
- excess glucose means more gluco-6-phopshate
- this triggers pentose phosphate pathway which can produce NADPH oxidase
- NADPH oxidase can increase reactive oxygen species
how may excess glucose affect the hexosamine pathway?
- excess glucose means more fuctose-6-phosphate
- hexosamine pathway means UDP-GlcNAC is created from fructose-6-phosphate
- UDP-GlcNAC causes inflammation and fibrosis
- this causes an increase in reactive oxygen species
how can excess glucose cause protein kinase C?
- excess glcuose means more glycerederide-3-phosphate
- G3P can form Diacyl Glycerol (DAG) which then can activate protein kinase C and cause inflammation and fibrosis
- this causes increase in reactive oxygen species
(THIS OFTEN CAUSES NEPHROPATHY IN KIDNEYS)
how can excess glucose cause advanced glycation end products (AGE) to be produces from G3P?
- excess glucose means there’s an increase in methyl glyoxal
- increase in methyl glyoxal causes production of Advanced glycation end products (AGE)
- AGE bind the RAGE (receptors of AGE) and trigger inflammatory response and increase reactive oxygen species
what are the stages of retinopathy?
progressive disease
- mild non proliferative (background)
- moderative non proliferative
- severe non proliferative
- proliferative
what are cotton wool spots in retinopathy?
-ischaemic areas
what are hard exudates in retinopathy?
-lipid break down products
what are IRMA in retinopathy?
intral retinal microvascular abnormalities (abnormalities of blood vessels/precursor to neovascularisation but blood vessels are patents (non leaky))
how is retinopathy graded?
R0-R4
how is maculopathy graded?
M0-M2
what are first changes diabetics get in retinopathy
micro aneurysms (benign)
what are the different type of haemorrhages in retinopathy?
- dot haemorrhage (small)
- blot haemorrhage (bit bigger)
- flame haemorrage (looks like flame)
what do hard exudates look like in retinopathy?
white marks
what do IRMAs look like?
-vascular changes (red blobs)
what is a sign of a patient going to haemorrage soon in retinopathy?
-new blood vessels forming
what can lead to loss of vision?
a bleed
how is a bleed in retina fixed?
surgery
what is treatment for pre proliferative retinopathy?
Pan retinal photocoagulation (laser zapping and killing off back of the retina)
-this reduces oxygen requirement of retina and ischaemia that is driving the retinopathy
what is used to assess diabetic macular oedema?
-optical coherence tomography is used to assess oedema
what treatment is used for diabetic macular oedema?
- eye is injected with intravitreal anti-VEGF (vacular endothelial growth factor)
- if this doesnt work then grid laser may be used
what is diabetic nephropathy?
-a progressive kidney disease caused by damage to the capillaries in the kidneys’ glomeruli
what characterises diabetic nephropathy?
-by proteinuria and diffuse scarring of glomeruli
what are consequences of diabetic nephropathy?
- development of hypertension
- relentless decline in renal function reduction in GFR of 1ml/min/month if untreated
- accelerated vascular disease
whats ACR?
Albumin: creatinine ratio
whats PCR?
Protein: creatinine ratio
whats a normal ACR in males and females?
Female <3.5 ACR
male <2.5 ACR
what ACR and PCR would indicate microalbuminuria?
ACR <30
PCR < 50
test repeated twice, etablish microalbumin is 2/3 positive
what ACR and PCR would indicate proteinuria?
ACR>30
PCR>50
is microalbuminuria detected on a dipstix?
no- it would come back negative so make sure to do ACR/PCR test
would proteinuria be detected by a dipstix?
yes it would come up positive but would also need to do ACR/PCR test
why do you need to repeat ACR and PCR test for microalbuminuria?
as UAER (urinary albumin excretion rate) varies
it varies with:
- day: night
- day:day
- exercise
- protein load
- fluid load
also there can be false positives due to:
- menstruation
- vaginal discharge
- UTI
- pregnancy
- non diabetic renal disease
what levels of ACR would define incipient nephropathy?
ACR > 2.5 (3.5)- 30
what levels of ACR and PCR would suggest overt nephropathy?
ACR>30 PCR>50
what is done for diabetic patients to try prevent nephropathy?
screening
-all patients with diabetes have their urinary albumin concentration and serum creatinine measured at diagnosis and at regular intervals (usually annually)
is microlbuminuria high risk?
yes
is someome test positive for microalbuminuria what treatment should be given?
ACEI
ARB
what types of neuropathy are there?
- peripheral
- proximal
- autonomic
- focal neuropathy
what effect does peripheral neuropathy have on diabetic patients?
pain/loss of feeling in feet and/or hands
- numbness/insensitivity
- tingling/burning
- sharp pains or cramps
- sensitivity to touch
- loss of balance and coordination
what effect does proximal neuropathy have on diabetic patients?
pain in thighs, hips or buttocks leading to weakness in the legs (amyoptrophy)
what effect does autonomic neuropathy have on diabetic patients?
changes in bowel, bladder function, sexual response, sweating, heart rate and blood pressure
what effect does focal neuropathy have on diabetic patients?
sudden weakness in one nerve or group of nerves causing muscle weakness or pain
e.g. carpal tunnel, ulnar mono neuropathy, foot drop, bells palsy, cranial nerve palsy
what increases risk of neuropathy?
- increased length of diabetes
- poor glycaemic control
- type 1 diabetes> type 2
- high cholesterol/lipids
- smoking
- alcohol
- genes inherited
- mechanical injury
what are some consequences or peripheral neuropathy?
- painless trauma
- charcot foot
- foot ulcer
what can usually go along with peripheral neuropathy?
peripheral vascular disease
what is charcot arthropathy?
-a destructive inflammatory process that can occur due to fractures/bony density causing deformity in foot that is a consequence of peripheral neuropathy
how does charcot arthropathy usually present?
-hot swollen foot in someone with neuropathy
what investigation should be done for someone with charcot arthropathy?
MRI as it is hard to differentiate with infection
Charcot arthropathy will see mishapen bones on MRI
what is the treatment for charcot arthropathy?
non weight bearing
Total contact cast or aircast boot
foot risk assessment chart (not question)
what is the treatment for painful neuropathy?
- amitriptyline (off label)
- duloxetine
- gabapentin
- pregablin
(combinations not recommended)
if pain is localised the patient can use oral treatments and topical Capsaicin cream
who is diabetic amyotrophy more common in ?
elderly T2DM
what does diabetic amyotrophy cquse?
starts with pain in the thighs, hips, buttocks or legs usually in one side of the body and eventually causes proximal muscle weakness (weight loss is indicator for muscle waisting)
what are some effects autonomic neuropathy could have on the gut?
- constipation
- diarrhoea
- gastroparesis (slow stomach emptying)
- oesophagus nerve damage that can make swallowing difficult
what is dangerous about gastroperesis?
can make blood glucose levels fluctuate widely due to abnormal food digestion
what is gastroparesis treatment?
- improved glycaemic control
- smaller more frequent meals, low in fat and low in fiber
- promotility drugs (metoclopramide, domperidone and erythromycin)
- anti nausea drugs
- NSAIDS, low does tryciclin antidepressants, gabapentin, tramadol and fentanyl for abdominal pain
- botulinum toxin
- gastric pacemaker
Can autonomic neuropathy have an effect on sweat glands?
yes
can cause excess sweating
what are some signs/symptoms that someone has autonomic neuropathy?
- blood pressure may drop sharply after sitting or standing, causing a person to feel light headed or faint
- heart rate may stat high instead of falling in response to normal body functions and physical activity
