Hypoglycemia in non diabetics

Etiology and workup of hypoglycemia in non diabetic patients? 

• Several conditions that can precipitate hypoglycemia including medications (e.g. insulin, sulfonylurea), ethanol use (inhibits gluconeogenesis), malnutrition (lack of substrate), critical illness (increased glucose utilization), renal failure (decreased clearance of insulin) and adrenal insufficiency (loss of cortisol causes increased insulin sensitivity) must be ruled out based on medical history.
• Subsequent work-up for hypoglycemia includes plasma glucose, insulin, c-peptide (marker for endogenous insulin production) and urine sulfonylurea screen.
• Based on findings additional studies including IGF-II levels, insulin antibodies and imaging can be considered.

Hypoglycemia in Nondiabetics

Etiology	Mechanism	History	Glc	INS	CP	Other Studies	CT scan
Insulinoma	Insulin producing tumor of pancreas	Fasting hypoglycemia	↓	↑	↑	—	Pancreatic mass
Nesidioblastosis	Excessive insulin production by pancreas	Postprandial hypoglycemia	↓	↑	↑	—	No mass
Insulin overdose	Intentional or unintentional (hospital/pharmacy error)	Hypoglycemia duration varies	↓	↑	↓	—	—
Sulfonylurea overdose	Intentional or unintentional (hospital/pharmacy error)	Prolonged hypoglycemia	↓	↑	↑	Positive Urine Sulfonylurea	—
Non-islet cell tumors	Insulin like growth factor (IGF-II) secreted by tumors (e.g. liver or colon cancer)	Weight loss, fatigue, hypoglycemia	↓	↓	↓	Positive IGF-II	Solid tumor
Insulin antibody	Antibodies bind to insulin receptor or insulin	Erratic blood sugars (highs and lows)	↓	↓	↓	Positive Insulin antibodies	—

CT, Computed tomography; Glc , glucose; INS , insulin; CP , C-Peptide; IGF, insulin-like growth factor.