INS and Hypoglycemia: A critical sample obtained during a hypoglycemic event revealed elevated levels of C-peptide (774 pmol/L; normal range during hypoglycemia: <100 pmol/L) and insulin (21 μIU/mL; normal fasting range: 2-6 μIU/mL) (Table 1). These findings were inconsistent with the initial diagnosis and suggested inappropriate endogenous insulin secretion, prompting a reevaluation of the patient's condition.