Myasthenia gravis and diabetes mellitus: a 35-year retrospective study.

Background: The most common treatment of myasthenia gravis is high-dose prednisolone administration and thymectomy. A well-known adverse effect of prednisolone is hyperglycemia, however, to date there is no such detailed report.

Patients And Methods: We treated 325 myasthenia gravis patients in a recent 35 years period, and found 11 patients with diabetes mellitus. We compared these 11 diabetic patients with previously-reported cases.

Results: These 11 patients did not have any antibody against beta-cells in the pancreas such as anti-glutamic acid decarboxylase antibody. In 10 of 11 patients diabetes mellitus was controlled with oral medications.

Conclusion: Myasthenic patients with diabetes mellitus could be classified into 2 groups, one group with positive organ-specific autoantibodies to many organs (with type 1 diabetes mellitus), and the other group with diabetes mellitus onset during prednisolone administration (with type 2 diabetes mellitus).