Description

• Deficiency in counterregulatory hormones (glucagon, epinephrine, cortisol, growth hormone) or excessive insulin response
• Serum glucose <70 mg/dL

Risk Factors

• Strict glycemic control with insulin
• Prior hypoglycemia episodes
• Hypoglycemia unawareness
• Decreased counterregulation
• <5 yr of age or elderly
• Comorbid conditions:
  • Renal disease
  • Malnutrition
  • Coronary artery disease
  • Liver disease

• Congenital metabolic and endocrine disorders that decrease gluconeogenic ability (e.g., hereditary fructose intolerance)
• Congenital hyperinsulinism
• Neonatal diabetes mellitus (often a mutation effecting an ATP-dependent potassium channel)

Etiology

• Increased insulin levels:
  • Overdose of oral hypoglycemic agent or insulin
  • Oral antihyperglycemics (i.e., α-glucosidase inhibitors, biguanides, and thiazolidinediones) do not cause hypoglycemia alone, but may enhance the risk when used with insulin or sulfonylureas
  • Sepsis
  • Insulinoma
  • Autoimmune hypoglycemia
  • Alimentary hyperinsulinism
  • Renal failure (partially responsible for insulin metabolism)
  • Liver cirrhosis (responsible for significant insulin metabolism)
• Underproduction of glucose:
  • Alcohol (inhibitory effect on glycogen storage and gluconeogenesis)
  • Drugs
  • Salicylates
  • β-blockers (including eye drops)
  • SSRIs
  • Some antibiotics (e.g., sulfonylureas, pentamidine)
  • Adrenal insufficiency
  • Malnutrition
  • Dehydration
• Cerebral edema
• Extremes of age
• Congestive heart failure
• Counterregulatory hormone deficiency
• Hypothyroidism or hyperthyroidism

• Third-trimester pregnant patients risk relative substrate deficiency–induced hypoglycemia
• The fetus is less likely to become hypoglycemic during mother's hypoglycemic episode secondary to active glucose transport across placenta:
  • Oral hypoglycemic use in pregnancy may lead to profound and prolonged neonatal hypoglycemia