Introduction To Diabetes Flashcards
What is diabetes?
Metabolic disorder characterised by chronic hyperglycaemia due to defects in insulin secretion and/or action
How do you diagnose diabetes?
Fasting plasma glucose of 7mmol/mol or more
2hrs after Oral Glucose Tolerance test over 11.1mmol/mol
Random plasma glucose > 11.1mmol/mol
Should have accompanying symptoms to diagnose
What causes T1DM?
Autoimmune or idiopathic destruction of pancreatic B cells leading to an absolute deficiency in insulin
What causes T2DM?
Decreased sensitivity to insulin occurs, more insulin needs to be made which can also lead to impaired insulin secretion over time
What blood test can be used to diagnose T2DM?
HbA1c > 48mmol
Repeated 1 month later to confirm if no other signs and symtoms
What are some other forms of diabetes (not T1DM or T2DM)?
Secondary diabetes:
-Cushings
-acromegaly
-Phaeochromocytoma
-thyrotoxicosis
Syndromic:
-Huntington’s chorea
-turners
-klinefelters
Infections:
-CMV
-congenial rubella
Drug induced:
-steroids
-thyroxine
-thiazides
What is the typical presentation of a patient with T1DM?
Young
Acute presentation
HYPERGLYCAEMIA
Polyuria
Polydipsia
Weight loss
Diabetic Keto-Acidosis presentation
What is the diagnostic criteria for diabetic ketoacidosis?
Hyperglycaemia > 11.1mmol
Ketosis >3mmol
Acidosis pH < 7.3
Why does the patient typically have high serum K+ when in DKA?
Patient is insulin deficient
Insulin needed to internalise K+ into cells
How does a patient with Type 2 diabetes typically present?
Older
Insidious symptoms of hyperglycaemia and diabetes complications
What are the 2 categories of complications of diabetes?
Microvascular
Macrovascular
What are some microvascular complications of diabetes?
Diabetic neuropathy
Diabetic nephropathy
Diabetic retinopathy
Erectile dysfunction
What are some macroscopic complications of diabetes?
Coronary heart disease (MI)
Stroke
Peripheral ischaemia (foot ulcers)
Hypertension
What are the 3 classifications of diabetic retinopathy?
R1 = Background retinopathy
R2 = Pre-proliferative
R3 = Proliferative
What does M1 refer to with diabetic retinopathy?
Maculopathy
What does O mean in reference to diabetic retinopathy?
Other non diabetic lesion
What does P mean in terms of diabetic retinopathy?
Previous laser therapy/photocoagulation
What does U mean in terms of diabetic retinopathy?
Unclassified often due to cataract
What are the characteristic appearances of R1 (Background Retinopathy)?
Microaneurysms, dot haemorrhages, cotton wool spots and hard exudates
What are the characteristic appearances of R2 pre-proliferative diabetic retinopathy?
Multiple blots, IntraRetinal Microvascular abnormalities , venous beading
What are the characterstic appearances of Proliferative R3 diabetic retinopathy?
Neo vascularisation of Disc (NVD)
Neo vascularisation Elsewhere (NVE)
Retinal detachment
Vitreous haemorrhage
When is a patient with diabetic retinopathy referred IMMEDIATELY to ophthalmology?
Rubeosis iridis/neovascular glaucoma
Vitreous haemorrhage
Retinal detachment
When does a patient need an urgent referral for ophthalmology? 2weeks or less
R3
When does a patient need a routine referral for ophthalmology? 13 weeks or less
R2 or M1 changes
What is the medical treatment for diabetic retinopathy?
Improve glycaemic control
BP control
Lipid control
Antiplatelet
Smoking cessation
What is the surgical management of diabetic retinopathy?
Laser therapy
Vitrectomy
Intravitreal VEGF
How do you define Diabetic nephropathy?
Urine dipstick:
+proteinuria
+
Albumin concentration > 300mg/L
What is the most common cause of CKD in the UK?
Diabetic nephropathy
What is the pathophysiology of diabetic nephropathy?
Hyperfiltration
How does Hyperfiltration negatively impact the kidneys?
Lots of glucose reabsorbed with Na+ through SGLT2
Low Na+ in filtrate
RAAS activates initially leading to increased GFR
You get early stage tubular hypertrophy and hyperplasia
Later on get accumulation of matrix and diffuse Glomerulosclerosis , which can then form in nodules
Tubular interstitial changes occur due to loss of nephron
What is the name of the nodules that can form in diabetic nephropathy?
Kimmelsteil-Wilson nodules
How do you manage Diabetic nephropathy?
Improve glycaemic control
BP control (ACEi or ARBs bp 130/80)
Lipid control
Diet lower in protein (<0.8g/kg)
Manage anemia hyperphosphatemia, Hyperkalaemia or Vit D deficiency
When may a patient with diabetic nephropathy need a nephrology referral?
Family History of PKD
CKD 4 or 5
Rapidly declining GFR
Systemic disease like lupus
Haematuria
What is diabetic neuropathy?
What part of nerve is affected?
Where you got focal demyelination and distal axonal loss with attempts at nerve regeneration
Vasa nevorum
What are the 4 types of diabetic neuropathies?
Sensory motor neuropathy
Autonomic neuropathy
Proixmal motor neuropathy
Mononeuropathy
What is diabetic sensory motor neuropathy?
Starts distal moves proximal (diabetic feet and sensation loss spreads proximal)
What are some examples of diabetic autonomic neuropathy?
Erectile dysfunction
Gastroparesis
Postural hypotension
What is an example of diabetic proximal motor neuropathy?
Diabetic amyotrophy (pain in quadriceps)
What nerve is often affected by diabetic mononeuropathy?
Cranial nerve III
How do you treat diabetic neuropathy?
NSSRIs like duoloxetine, gabapentin
Smoking cessation
Antiplatelets
BP control
When performing a diabetic foot exam what are you looking for?
Skin changes
Ulcers
Hair loss
Pallor
How do you assess the neurovascular status of a diabetic foot?
Vascular:
-cap. Refil
-dorsalis pedis
-posterior tibial
Neuro is touch
How do you assess the different aspects of touch in a diabetic foot exam?
Cotton wool = crude touch
Sharp point = pain
Monofilament = fine touch
Tuning fork = vibration at 1 MTP
Proprioception
If a patient within diabetic foot cant feel the vibration of the tuning fork at their 1MTP joint what should you do?
Move to medial malleouls
If cant feel move tibial tuberosity
If cant feel do move to ASIS
What is the first sensation to typically be lost with diabetic feet?
Vibration
What are some features of neuropathic feet?
Warm
Dry skin
Palpable pulses
Not normally painful
Callused
What are some features of Ischaemic feet?
Cold
Atrophic
No pulse
Painful
Claudication/rest pain
Skin blanching on elevation
What is the classification system for diabetic feet?
Wangers classification
(G1-G5)
How does charcots foot present?
Warm hot swollen MTPJs
Painful foot
Rocker bottom deformity
What is the pathophysiology of charcots foot?
Increased blood flow to the foot due to loss of sympathetic nerve loss
This leads to increased osteoclast activity and increased bone turnover which can lead to bony deformity
What is the management of charcots foot?
Immobilise and don’t weight bare for 2-3months until inflammation resolves
