|

Diabetic Neuropathy

Last updated:

Overview

Diabetic neuropathy is a complication of both type 1 diabetes and type 2 diabetes. It is characterised by the signs and symptoms of peripheral or autonomic nerve dysfunction. Motor, sensory, and autonomic nerves may all be affected by diabetic neuropathy.

Epidemiology

  • Can affect around 70% of people with diabetes
  • Diabetes is the most common cause of peripheral neuropathy globally

Risk Factors

  • Poorly-controlled hyperglycaemia
  • Prolonged hyperglycaemia
  • Increasing age
  • Hypertension
  • Dyslipidaemia
  • Coexisting cardiovascular disease or risk factors
  • Obesity
  • Smoking

Presentation

Peripheral neuropathy

  • Pain – usually “glove and stocking” distribution – distal portions of the nerve are affected first. The fibres are affected according to the length of the axon instead of the root or nerve trunk distribution
  • Loss of sensation
  • Abnormal sensation – burning/tingling
  • Painless injuries – usually over pressure points such as the metatarsal heads

Autonomic neuropathy

Investigations

Diagnosis is clinical, other investigations are to rule out underlying causes:

  • Blood glucose and HbA1c:
    • Raised
  • Full blood count (FBC):
    • Normal
  • Erythrocyte sedimentation rate (ESR):
    • Normal
  • Thyroid function tests (TFTs):
    • Normal
  • Urea and electrolytes (U&Es):
    • Normal
  • Liver function tests (LFTs):
    • Normal
  • B12 and folate:
    • Normal
  • Serum lipids:
    • May show hyperlipidaemia

Management

Neuropathic pain

  • Manage as mentioned in Neuropathic Pain
  • If resistant, consider referral to a pain management clinic

Autonomic dysfunction

  • Orthostatic hypotension: lifestyle changes and consider midodrine
  • Gastroparesis: prokinetic agents such as metoclopramide, domperidone, or erythromycin

Monitoring and Patient Advice

Monitoring

  • Patients should be assessed at least annually for complications of diabetes and should have their blood glucose, blood lipids, and blood pressure monitored
  • Foot examinations should be carried out at each visit

Patient Advice

  • Patients should have good foot care:
    • Examine feet daily and wear proper footwear
    • Report any signs and symptoms that arise
    • Control their blood glucose as best as possible
  • Patients should know what to do if they have hypoglycaemia
  • Patients should avoid smoking and excess alcohol consumption

Complications and Prognosis

Complications

  • Foot wounds/ulcers – due to loss of protective pain sensation
  • Wound infection/gangrene
  • Limb amputation
  • Charcot foot
  • Silent myocardial infarction – due to cardiovascular autonomic neuropathy
  • Death

Prognosis

  • Autonomic neuropathy is associated with a high mortality rate
  • People with diabetes are more likely to undergo lower limb amputation

Author