Which condition is a common cause of persistent hypoglycemia?

• A. Hypopituitarism
• B. Insulinoma
• C. Galactosemia
• D. Addison's Disease

Answer: (B)

The main concept is endogenous hyperinsulinemia causing fasting hypoglycemia. An insulin-secreting pancreatic tumor (insulinoma) continuously releases insulin, especially during fasting, so blood glucose stays low and neuroglycopenic symptoms persist. The key feature is inappropriately high insulin levels when glucose is low, often with elevated C-peptide and proinsulin, indicating endogenous insulin production rather than external insulin use or other causes. This makes insulinoma a common cause of persistent hypoglycemia.

Other options can cause low glucose, but they are less typical for persistent hypoglycemia. Deficiencies in adrenal or pituitary hormones (as seen in Addison’s disease or hypopituitarism) can lead to hypoglycemia through reduced gluconeogenesis, but these are less commonly the cause of persistent hypoglycemia compared to endogenous insulin overproduction. Galactosemia causes hypoglycemia mainly in newborns due to liver dysfunction, not as a common persistent issue in adults.