CLINICAL RESEARCH SHORT REPORT Portions of this study were presented at the 17th International Congress on Neuromuscular Diseases, 2022. Abstract Introduction/Aims Urinary titin, an easy-to-obtain marker, has been investigated in muscular dystrophies, but not in myotonic dystrophy type 1 (DM1). We investigated the role of titin as a biomarker of muscle injury in DM1. Methods We compared the urinary titin N-fragment/creatinine ratio in 29 patients with DM1 vs. 30 healthy controls.