Immunological hypoglycemia induced by exogenous human insulin or insulin analogues: cases summary and related literature review

Objective To investigate the clinical characteristics of immunological hypoglycemia induced by exogenous human insulin or insulin analogues. Methods The clinical data of 3 new cases from the Peking Union Medical College Hospital and 14 cases from MEDLINE or national core periodical were retrospectively analyzed. Results Three patients were admitted in hospital for recurrent hypoglycemia when exogenous insulin had been stopped for at least 1 month. They had blood glucose(BG) wide fluctuation and dissociation between C-peptide(C-P) and insulin or C-P and BG during 5 h oral glucose tolerance test(OGTT). In literature review, 14 cases of this kind of complication had been reported. The overwhelming majority (88.2%) of these 17 patients were Asian people. The lowest BG was 2.2(1.0-3.3)mmol/L, accompanied by high titer of insulin autoantibody (IAA). About half of the patients needed steroid treatment with or without plasmapheresis or cyclophosphamide, while another half would be spontaneous remission in about 2.4(0.5-8.0)months. Conclusions (1) Immunological hypoglycemia induced by exogenous human insulin or insulin analogues is a rare complication which easy to be missed and delayed diagnosis for the hypoglycemic effect of insulin itself. (2) The Asian people are most vulnerable to this disease. The episodes of hypoglycemia are irregular and the degree of hypoglycemia can be various, range from mild to severe even unconsciousness. (3) Hypoglycemia can be induced by oral glucose test and in which the tendency of C-P and insulin are separated from each other. (4) The high titer of IAA had a confirmed diagnostic value, however, the choice of therapy option was not related to titer of IAA. Key words: Hypoglycemia, immunological; Exogenous human insulin; Insulin autoimmune antibody