Prevalence of smooth muscle dysfunction among children with Duchenne muscular dystrophy.

Smooth muscle dysfunction in Duchenne muscular dystrophy (DMD) has been rarely studied. A cross-sectional study was conducted to estimate the prevalence of smooth muscle dysfunction (vascular, upper gastrointestinal, and bladder smooth muscle) in children with DMD using questionnaires (Pediatric Bleeding Questionnaire, Pediatric Gastroesophageal Symptom Questionnaire, and Dysfunctional Voiding Symptom Score). Investigations included bleeding time estimation, nuclear scintigraphy for gastroesophageal reflux, and uroflowmetry for urodynamic abnormalities. Ninety-nine subjects were included in the study. The prevalence of vascular, upper gastrointestinal, and bladder smooth muscle dysfunction was 27.2%. Mean bleeding time was prolonged by 117.5 seconds. The prevalence of gastroesophageal reflux was 21%. Voided volume/estimated bladder capacity over 15% and abnormal flow curves on uroflowmetry were seen in 18.2% and 9.7% of the subjects, respectively. Our study highlights the need for addressing issues related to smooth muscle dysfunction in the routine clinical care of patients with DMD.