Systematic Review-Type B Insulin Resistance With Isolated Hypoglycemia and Suppressed Insulin

Type B insulin resistance syndrome is a rare autoimmune disorder affecting glucose homeostasis, characterized by serum autoantibodies to the insulin receptor (AIRAbs). Patients typically present with severe insulin resistance. A mixed hyper- and hypoglycemia phenotype may also occur, as may isolated hypoglycemia. The classic biochemical pattern comprises elevated insulin levels despite hypoglycemia; however, a small proportion of cases demonstrate "isolated hypoglycemia with low insulin." The primary objectives of this systematic review were to identify the clinical characteristics and outcome of this subgroup.

Systematic review of cases with hypoglycemia with suppressed insulin. Exclusions: hyperglycemia, elevated insulin, AIRAbs not confirmed.

PubMed, Medline, and Embase databases were searched up until February 2023 and complemented by manual citation search. The Joanna Briggs Institute critical appraisal checklist for case reports was used to assess bias.

A total of 5342 articles were identified after duplicate removal. Eleven, all case reports, met all inclusion criteria and were included. Cases belonging to this subgroup were more diverse in sex, age, and ethnicity when compared with type B insulin resistance as a whole. Of the 11 cases, 3 developed lymphoma. High-dose corticosteroid therapy appeared to be effective therapy for the hypoglycemia, with often rapid response.

Isolated hypoglycemia with low insulin forms a rare subgroup of type B insulin resistance. These patients lack the common characteristics of hyperinsulinemic hypoglycemia and hyperglycemia/insulin resistance. Furthermore, while coexisting autoimmune disease is commonly observed, there is potentially an association with aggressive lymphoma, the onset of which may be delayed.