Microvascular Complications of Diabetes Flashcards
diabetes is the leading cause of what 3 complications?
blindness
dialysis
amputation
how does HbA1c correlate to risk of microvascular complications in type 1?
higher HbA1c = higher risk of complications
- esp retinopathy
- parabolic curve
how does HbA1c correlate to risk of microvascular disease in type 2?
higher HbA1c = higher risk
linear curve
pathophysiology of microvascular disease?
hyperglycaemia and hyperlipidaemia cause - AGE RAGE - hypoxia - oxidative stress - inflammation -mitochondrial dysfunction via reduced blood flow which leads to nerve damage causes retinopathy, nephropathy and neuropathy
what are the 4 types of nephropathy?
peripheral - pain/loss of feeling in hands and feet
autonomic = changes in bowel, bladder, sexual response, sweating, HR, BP
proximal = pain in thighs, hips or buttocks leading to leg weakness
focal neuropathy = sudden weakness in one nerve or a group of nerves causing muscle weakness or pain (carpal tunnel, ulnar mono neuropathy, foor drop, bells palsy, cranial nerve palsy)
risk factors for neuropathy?
length of diabetes poor glycaemic control type 1 (more than 2) high cholesterol/lipids smoking lcohol genetics mechanical injury
what are the symptoms of peripheral neuropathy?
numbness/insensitivity tingling/burning sharp pain or cramps sensitivity to touch loss of balance and coordination
complications of peripheral neuropathy?
charcots foot
painless trauma
foot ulcer
advice for foot problems?
advice on footwear
remove calluses etc
pharmacological treatment for painful neuropathy?
amitriptyline, duloxetine, gabapentin or pregabalin
- combinations not recommended
topical capsaicin cream can be used if localized and patient wants to avoid medication
features of focal neuropathy?
sudden and affects specific nerves - usually head, torso or leg - cant focus eye double vision aching behind eye - bells palsy -pain in thigh/chest/lower back/pelvis pain on outside of foot
what is entrapment neuropathy?
weakness in one nerve or a group of nerves causing muscle weakness or pain (e.g carpal tunnel)
what are the 3 types of proximal neuropathy and how do they present?
lumbosacral plexus neuropathy
femoral neuropathy
diabetic amytrophy
starts with pain in thighs, hips, buttocks or legs often on one side
associated with proximal muscle weakness and weight loss
what does autonomic neuropathy do?
affects nerves regulating heart rate and BP as well as control of internal organs - gastric motility, resp function, urination, sexual, vision etc
common GI features of autonomic neuropathy?
gastric slowing/frequency
constipation/diarrhoea (can have both)
gastroparesis - can make blood glucose levels fluctuate widely
oesophagus nerve damage making swallowing difficult
how is gsatroparesis managed?
improved glycaemic control small, frequent meals with low fat and low fibre promotility drugs anti-nausea drugs pain control botulinum toxin gastric pacemaker
name some promotility drugs
metoclopramide
domperidone
name 2 anti-nausea medications
prochloperazine
ondansetron
how can autonomic neuropathy affect sweating?
can affect nerves which control sweating preventing them from working properly
can cause gustatory sweating as body cant control temp as it should
how is anhidrosis or hyperhidrosis in diabetics managed?
topical glycopyrrolate, clonidine
botox
how can autonomic neuropathy affect heart and blood vessels?
cardio nerve damage interferes with ability to adjust blood pressure and HR
can cause postural hypotension
HR can stay high instead of rising and falling in response to normal body functions and exercise
how can autonomic neuropathy affect the eyes?
can make pupils less responsive to changes in light
may be unable to see well when light turned on or in the dark
how can neuropathy be diagnosed?
nerve conduction studies/electromyography HR variability US gastric emptying studies foot screening
what is diabetic nephropathy and what are the characteristics?
AKA - nodular glomerulosclerosis, Kimmelsteil-wilson syndrome
progressive kidney disease caused by damage to the capillaries in the kidneys glomeruli
characterised by nephrotic syndrome and diffuse scarring of the glomeruli
histology features of diabetic nephropathy?
microvascular changes - angiopathy of capillaries
nodular glomerulosclerosis
what are the possible complications of diabetic nephropathy?
hypertension
decline in renal function
accelerated vascular disease
main tool used for nephropathy screening?
urine ACR (albumin:creatinine ratio)
SIGN guidelines for nephropathy screening?
screen all patients over 12 at diagnosis and annually
may use RANDOM rather than 1st pass urine as initial check
dipstick at point of care
confirm abnormal result with EMU
also do Us&Es (eGFR)
features of microalbuminaemia?
urine ACR male = 2.5-25 female = 3.5-35 24 hr urine albumin = 30-300 urine PCR male = 4-40 female = 6-60 24 hr urine protein = 50-500
features of macroalbuminaemia?
urine ACR male = >25 female = >35 24hr urine albumin = >300 urine PCR male = >40 female = >60 24hr urine protein = >500
management of microalbuminaemia?
screen for CVD, retinopathy, PVD, other causes of renal disease
monitor lipids, serum creatinine
tighten glycaemic control and discourage smoking
what are the risk factors for progression of nephropathy?
hypertension cholesterol smoking glycaemic control albuminuria
BP target for diabetics?
<130/80
SIGN = <130/70
what is given for patients with microalbuminaemia or proteinuria?
ACE inhibitor or ARB
what eye diseases can occur in diabetes?
diabetic retinopathy cataract glaucoma acute hyperglycaemia - reversible visual blurring retinal detachment
features of the back of the eye?
optic disc arteries veins macula fovea
what are the stages of retinopathy?
mild non-proliferative
moderate non-proliferative
severe non-proliferative
proliferative
possible features in diabetic retinopathy?
haemorrhages - dots/blots/flames
cotton wool spots - ischaemic areas
hard exudates - lipid breakdown products
IRMA - intra retinal microvascular abnormalities
what is IRMA?
abnormalities of blood vessels/precursor to neovascularisation but blood vessels are patent (not leaking)
how is retinal disease graded?
retinopathy and maculopathy are graded separately
what are the symptoms of bleeding in the eye?
sudden change in vision
floaters
how is maculopathy assessed?
optical coherence tomography
how is retinopathy treated?
laser
vitrectomy
anti-VGEF injections
who is screened for retinopathy and how often?
all low risk diabetes patients are screened annually
what causes erectile dysfunction in diabetes and how common is it?
vascular and neuropathy
occurs in 50% of men
(55% over 60)
what medications are associated with erectile dysfunction?
antihypertensives (mostly thiazides and beta blockers) CNS drugs (antidepressants, tricyclics, SSRIs, tranquilizers, sedatives, analgesics)
