Nationwide incidence of myotonic dystrophy type 1 and the status of multi-organ involvement

This study aimed to investigate the incidence of myotonic dystrophy type 1 (DM1) and the status of multi-organ involvement. This was a nationwide, population-based, cohort study using data from the Korean National Health Claims database. All patients with DM1 from the entire population aged ≤ 80 years were included. To identify possible systemic diseases along with DM1, we searched for concurrent codes for systemic diseases. To assess the recent status of systemic evaluation, concurrent codes for various diagnostic and treatment modalities were collected. Cumulative incidence during 2016–2019 was first evaluated then systemic evaluation for those patients was assessed during 2010–2019. A total of 387 patients (47.8% men) during the recent 4-year study period (2016–2019) were diagnosed with DM1. The cumulative incidence in the general population was 0.77 (95% confidence interval: 0.76–0.77) per 100,000 persons. In newly developed incidental cases, cardiac involvement developed in 51.2%, pneumonia in 30.7%, diabetes in 26.9%, brain involvement in 18.1%, cataract in 13.7%, and cancers in 5.4% of total patients. Electrocardiography was performed in 93.8%, Holter in 33.9%, and echocardiography in 31.3% of the total patients for cardiac evaluation. The incidence estimates of DM1 in the Asian population were lower than those of Caucasians. This study provides the real situation of screening and treatment for systemic diseases related to DM1. These detailed estimates could promote an understanding of the current disease status and allow for appropriate planning within the healthcare system.