Clinical Features

• Varies greatly, but most adults become symptomatic when blood glucose level is less than approx. 50 mg/dL (2.8 mmol/L)

• The threshold of symptoms is especially variable in individuals with type 1 diabetes and those with longstanding type 2 diabetes due to hypoglycemia-associated autonomic failure (HAAF). [4]

  • Recurrent hypoglycemia → changes in the counterregulatory autonomic response (e.g., decreased epinephrine release) → lower glucose threshold needed to trigger symptoms → asymptomatic hypoglycemia

  • The initial symptom of hypoglycemia in patients with HAAF is often confusion.

• Can also vary due to medication: Beta blockers can mask signs of hypoglycemia.

• Neurogenic/autonomic

  • Increased sympathetic activity: tremor, pallor, anxiety, tachycardia, sweating, and palpitations

  • Increased parasympathetic activity: hunger, paresthesias, nausea, and vomiting

• Neuroglycopenic

  • Agitation, confusion, behavioral changes

  • Fatigue

  • Seizure, focal neurological signs

  • Somnolence → obtundation → stupor → coma → death

Beta blockers can mask signs of hypoglycemia.