Insulin autoimmune
syndrome (IAS) is characterized by spontaneous
hypoglycemia, extremely high
serum insulin levels, and high titers of
autoantibodies against endogenous
insulin, in the absence of exogenous
insulin injection. IAS often occurs following exposure to sulfhydryl-containing
drugs, including
alpha-lipoic acid (ALA). A 30-year-old
woman without diabetes visited our
outpatient clinic with recurrent
hypoglycemia. She had been taken ALA for
weight reduction since 3 weeks ago. Further
hypoglycemia work up revealed very high
insulin levels,
C-Peptide levels and positive
insulin antibodies. And conventional imaging examinations were negative for
insulinoma or other pancreatic
tumors. Finally, the
diagnosis of
Insulin autoimmune
syndrome (IAS) was made. Following the cessation of ALA,
hypoglycemia improved, with no medication, and the
patient experienced no further
hypoglycemic attacks over the next month. The use of ALA as a nutritional supplement is increasing. We
report a case of IAS associated with ALA in a non-diabetic
patient.