You are asked to see a 24 year old man in the emergency department for hypotension (80/40 mmHg) and hypoglycaemia (2.2mmol/L) with associated drowsiness.  He has a long-standing history of insulin dependant diabetes mellitus (IDDM) which has been well controlled until recently, when he was admitted for a short stay in hospital with diabetic keto acidosis (DKA).

a. List 4 likely causes of hypoglycaemia in this patient.

[Click here to toggle visibility of the answers]

College Answer

a. List 4 likely causes of hypoglycaemia in this patient.
•    Accidental or non accidental overdose of long acting insulin
•    Sepsis
•    Glucocorticoid deficiency
•    Hypothyroidism
•    Insulin secreting tumour
•    Less likely: severe liver disease

Discussion

The causes of hypoglycaemia are protean. Here are just a few:

Causes of Hypoglycaemia

Drugs

  • Insulin (duh)
  • Glucagon
  • Indomethacin
  • Lithium
  • ACE-inhibitors
  • β-blockers
  • Alcohol
  • Sulfonylurea drugs
  • Perhexiline
  • THAM

Illness

  • Starvation
  • Hepatic failure
  • Cardiac failure
  • Renal failure
  • Sepsis
  • Adrenal insufficiency
  • Insulinoma
  • Antibodies to insulin receptor
  • Hypothyroidism
  • Massive burden of bulky maligancy
  • Islet cell hyperplasia

Pragmatically speaking, it is very rarely anything quite as exciting as an insulinoma.

Pragmatically speaking, it is very rarely anything quite as exciting as an insulinoma. A study of patients admitted with hypoglycaemia has identified several common causes, listed below and ordered from most to least common:

  • Inadequate intake of carbohydrate (28%)
  • Ingestion of alcohol (19%)
  • Deliberate overdose of insulin (13%)
  • Accidental overdose of insulin (6%)
  • Strenuous exercise (7%)

References

UpToDate has a nice article on this for the paying customer.

Cryer, Philip E., Stephen N. Davis, and Harry Shamoon. "Hypoglycemia in diabetes." Diabetes care 26.6 (2003): 1902-1912.

Hart, S. P., and B. M. Frier. "Causes, management and morbidity of acute hypoglycaemia in adults requiring hospital admission." Qjm 91.7 (1998): 505-510.