Metabolic complications in myotonic dystrophy type 1: A cross-sectional survey using the National Registry of Japan.

Myotonic dystrophy type 1 (DM1) is the most common form of muscular dystrophy in adults, affecting multiple organs, including the eyes, heart, endocrine system, and central nervous system. The broad spectrum of DM1 symptoms has been attributed to the aberrant pre-mRNA splicing of various genes due to an abnormal expansion of the CTG repeat in the 3' untranslated region of the DMPK gene. The current challenge in the clinical care of DM1 is the lack of well-established protocols for the management of each organ disorder or symptom. Moreover, the current status of clinical management has not been adequately explored. Metabolic disturbance in DM1 has been less explored among the DM1 manifestations, even though impaired glucose tolerance is a widely known metabolic disorder associated with DM1. We investigated the metabolic disturbance related to DM1 using the national registry of neuromuscular diseases in Japan, Registry of Muscular Dystrophy (Remudy), and assessed the metabolic complications in DM1 and the current treatments. We obtained comprehensive information on the current status of liver dysfunction and dyslipidemia in a sizeable DM1 cohort (~300). We confirmed that the incidence of liver dysfunction and dyslipidemia, particularly hypertriglyceridemia, as well as impaired glucose tolerance, were significantly higher in DM1 patients. Furthermore, the majority of DM1 patients with dyslipidemia were not receiving pharmacotherapy. Our data highlight the current status of DM1 patients in Japan, which can guide the establishment of the standard of care for metabolic issues consequent to DM1.