The significance of this project is to investigate the effects of adjunctive metformin
therapy in children and adolescents with double diabetes. Double diabetes describes a
clinical state where an individual possesses features of both type 1 and type 2 diabetes.
There is a paucity of data on the role of adjunctive metformin therapy in children and
adolescents with double diabetes. To help fill this knowledge gap, the investigators propose
a randomized, double-blind, placebo-controlled trial of metformin in double diabetes.
Specifically, the investigators will evaluate changes in hemoglobin A1c and anthropometry in
patients with a diagnosis of type 1 diabetes who also have features of type 2 diabetes or
metabolic syndrome as well as patients with type 2 diabetes who possess diabetes-associated
autoantibodies. This will help determine the safety profile, and efficacy of adjunctive
metformin therapy in these subjects.