Lower urinary tract dysfunction in adults with myotonic dystrophy type 1: a multimodal clinical assessment

Lower urinary tract dysfunction is an underrecognized manifestation of myotonic dystrophy type 1 (DM1), despite the multisystem nature of the disease. This study aimed to characterize the prevalence and clinical profile of lower urinary tract symptoms (LUTS), urinary incontinence, and pelvic floor dysfunction in adults with DM1 and to explore their association with functional status. In this cross-sectional study, 36 adults with genetically confirmed DM1 (50% men; median age 43 years, IQR 33-52.8) completed validated questionnaires assessing LUTS, urinary incontinence, and overactive bladder (OAB). Functional independence was evaluated using the Modified Barthel Index and pelvic floor muscle strength using the Modified Oxford Scale. A control group of 20 healthy individuals (40% men; median age 30 years, IQR 25-43.5) completed the same urinary symptom assessment protocol. LUTS were present in 75.0% of patients, predominantly storage symptoms. OAB symptoms were identified in 44.5% and urinary incontinence in 58.3% of the cohort. Pelvic floor muscle contractions were weak or absent in most evaluated patients. Compared with controls, patients with DM1 had significantly higher prevalence of LUTS (75.0%vs 35.0%, p = 0.005), OAB symptoms (44.5%vs 10.0%, p = 0.009), and urinary incontinence (58.3%vs 15.0%, p = 0.002). Urinary incontinence was also more frequent among patients with greater functional dependence. Lower urinary tract dysfunction is common in DM1 and is mainly characterized by storage symptoms, OAB, and urinary incontinence. Routine screening for urinary dysfunction should therefore be considered in the clinical management of patients with DM1.