Diabetic Complications

One of the biggest problems is that there are several complications associated with these conditions:

  • Non-enzymatic glycosylation (NEG) of macrovessels – this leads to atherosclerosis

– Causes cardiovascular disease – MI is 4x more common in diabetes and stroke 2x common

– Causes peripheral vascular disease – leading cause of non-traumatic amputations.

– If foot pulses cannot be felt, use Doppler pressure measurements. Ensure regular chiropody to remove callus to reduce risk of ulcers


  • Non-enzymatic glycosylation (NEG) of microvessels – leads to hyaline arteriosclerosis

– Causes Nephropathy – nephrotic syndrome characterized by Kimmelstiel-Wilson nodules in glomeruli

– Gives microalbuminuria (when the urine dipstick is negative for protein but the urine albumin:creatinine ratio is >4mg/mmol)

– Diabetic patients get annual screening to measuring morning albumin:creatinine ratio


  • Diabetic retinopathy – glucose enters Schwan cells, the lens and retinal blood vessels damaging them

– Results in osmotic damage

– Leads to Cataracts + Rubeosis iridis (new vessels on iris leading to glaucoma)

– Diabetes is the leading cause of blindness in the developed world.

  • Diabetic peripheral neuropathy – This is loss of sensation which often occurs in the feet

– Patient shows loss of sensation in “stocking” distribution + numbness/tingling

– Also leads to neuropathic deformity e.g. claw toes, Charcot Joint

– Pain is felt, worse at night  –> 1st line treatment is Duloxetine

  • Diabetic Autonomic Neuropathy

– Causes decreased lower oesophageal sphincter pressure giving GORD

– Can lead to chronic diarrhoae worse at night

– Gastroparesis –> Bloating and vomiting, alleviated with prokinetic antimimetics


  • Hyperosmolar Hyperglycaemic State – This is where hyperglycaemia results in osmotic diuresis, severe dehydration and electrolyte deficiencies.

– High glucose leads to osmotic diuresis with loss of sodium and potassium

– Gives severe volume depletion giving raised serum osmolality (>320mosmol/kg), making blood viscous



General malaise –> Fatigue, nausea + vomiting

Neurological –> Low consciousness, headaches, papilloedema

Haematological –> MI and peripheral thrombosis (due to hyperviscosity)

Cardiovascular –> Tachycardia + Hypotension (similar to hypovolaemic shock)



  1. Hypovolaemia
  2. Marked Hyperglycaemia (>30 mmol/L) without much ketones or acidosis
  3. Significantly raised serum osmolarity (> 320 mosmol/kg)


Management – manage in HDU.

– 1st fluid resuscitation – IV 0.9% sodium chloride solution


– 2nd normalise blood glucose – only give insulin if ketones are high, as fluids will naturally reduce glucose

– If no ketones avoid insulin, as it leads to a rapid decline in glucose and serum osmolality increasing risk of central pontine myelinosis or cardiovascular collapse


– 3rd replace potassium as required – prevents arrhythmias.

  • Hypoglycaemia:

This is the most common endocrine emergency characterized by plasma glucose <3mM.


Causes: Diabetic – Insulin or sulphonylurea treatment e.g. increased activity missed meal, overdose.


Non-Diabetic – The causes of non-diabetic hypoglycaemia are remembered by acronym (EXPLAIN).

The cause can be found by taking drug history , excluding liver failure and monitoring.


EX = Exogenous drugs

P=Pituitary insufficiency

L=Liver failure

A= Addison’s 

I= Insulinoma

N=Non-pancreatic neoplasms


SymptomsAutonomic – sweating, anxiety, tremor, dizziness

Neurological – Confusion, drowsiness, can be confused with a stroke


Treatment – If conscious, 15-20g of fast carbohydrate snack (orange juice) and recheck glucose after 10 min

– If conscious but not cooperative –> put glucose gel between teeth and gums

– If unconscious –> start glucose IV (10% and 200mL/15min) or glucagon 1mg IM (not in malnourished)

– Once blood glucose >4mM, give long acting carbohydrate e.g. slice of toast.


  • Insulinoma

This is a benign pancreatic islet cell tumour which is sporadic or commonly seen with MEN-1


Symptoms – fasting hypoglycaemia with mental status change that is relieved by administration of glucose

Whipple’s triad –> Symptoms associated with fasting/exercise

                              –> Recording hypoglycaemia with symptoms

                              –> Symptoms relieved by glucose


Diagnosis – Give insulin and measure C-peptide levels

– This is because exogenous insulin usually inhibits C-peptide production, but not in an insulinoma

– You will therefore find low serum glucose levels in the presence of high insulin and C-peptide


Treatment – Surgical excision


3. J. Terrence Jose Jerome / CC BY (https://creativecommons.org/licenses/by/3.0)

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