Hypoglycaemia in the adult

Area of Science:

• Endocrinology
• Metabolic Disorders
• Clinical Medicine

Background:

• Hypoglycaemia is a common reason for hospital emergency department referrals, frequently iatrogenic, but also a symptom of various underlying disorders.
• Neuroglycopenic symptoms due to intermittent hypoglycaemia necessitate outpatient investigation.
• Understanding diverse causes is crucial for accurate diagnosis and patient management.

Purpose of the Study:

• To review and discuss important causes of hypoglycaemia beyond iatrogenic origins.
• To highlight diagnostic approaches for key hypoglycaemia etiologies.
• To provide an overview of less common but significant causes of low blood glucose.

Main Methods:

• Literature review and synthesis of information on various hypoglycaemia causes.
• Discussion of diagnostic criteria for hyperinsulinism, non-islet cell tumors, and autoimmune hypoglycaemia.
• Categorization of hypoglycaemia based on underlying pathophysiology.

Main Results:

• Hyperinsulinism diagnosis involves elevated insulin, C-peptide, and proinsulin during hypoglycaemia.
• Non-islet cell tumor-induced hypoglycaemia (NICTH) shows suppressed insulin/C-peptide, with a high IGF-II:IGF-I ratio.
• Autoimmune hypoglycaemia can result from antibodies to insulin or insulin receptors.
• Idiopathic reactive hypoglycaemia is rare; other causes include endocrinopathies, sepsis, organ failure, inborn errors, and toxins like alcohol.

Conclusions:

• Accurate diagnosis of hypoglycaemia requires careful history, clinical presentation, and targeted laboratory investigations.
• Distinguishing between different causes of endogenous hyperinsulinism pre-surgery is challenging.
• Non-islet cell tumors and autoimmune conditions represent significant, albeit less common, causes of hypoglycaemia.
• A broad differential diagnosis, including metabolic, endocrine, infectious, and toxic causes, is essential for managing hypoglycaemia.