It is reported herein that certain muscle diseases and conditions, including forms of muscular dystrophy, are characterized by impaired insulin-dependent signaling in the muscle tissue, in essence, a form of insulin resistance. The present disclosure relates to therapeutic agents, compositions and methods for treating a muscle disease or condition characterized by impaired insulin-dependent signaling by targeting components of the defective insulin signaling pathway. The disease or condition may be treated by administering a therapeutic agent that activates the insulin signaling pathway, in particular, therapeutic agents that act post-insulin receptor to modulate intracellular effector molecules. An exemplary modulator is metformin. Metformin may be administered alone or may be co-administered with another therapeutic agent for treating the muscle disease or condition, such as a corticosteroid.
