Table 304.1. Differential diagnosis of hyperinsulinism

Table 304-1. Differential diagnosis of hyperinsulinism
	POSTABSORPTIVE VENOUS PLASMA GLUCOSE <45 mg/dl
	INSULIN	C PEPTIDE	INSULIN ANTIBODIES	OTHER
Exogenous hyperinsulinism		*	+
Endogenous hyperinsulinism
Insulinoma			—	Proinsulin
Sulfonylurea			—	Positive sulfonylurea assay
Autoimmune hypoglycemia
Antibodies to insulin	^a	*	+
Antibodies to insulin receptor		?	—	Insulin receptor antibodies present; associated autoimmune disorder
*Free C-peptide levels are low, but total C-peptide levels may not be because of cross reactivity with antibody-bound proinsulin.
^aInsulin antibodies artifactually increase insulin levels measured by double-antibody radioimmunoassay.