DUCHENNE MUSCULAR DYSTROPHY RESPIRATORY PROFILES FROM REAL-WORLD REGISTRY DATA: A RETROSPECTIVE LONGITUDINAL STUDY

INTRODUCTION:Understanding real-world profiles from neuromuscular databases is helpful for optimizing clinical care and planning research studies. The Canadian Neuromuscular Disease Registry (CNDR) has respiratory data from a population of boys with Duchenne Muscular Dystrophy (DMD).OBJECTIVES:To describe cross-sectional respiratory profiles from a national DMD real-world dataset. To explore the relationship between forced vital capacity percent predicted (FVC%) and disease severity parameters: scoliosis, ambulation and ventilation status.METHODS:Descriptive statistics summarized the respiratory profiles. The CNDR registry enrolls and collects DMD clinic data from 36 Canadian centers.RESULTS:There were 414 participants enrolled. The age ranged from 2 to 36 years old. Pulmonary function test data were available for 323 participants. The use of ventilatory support was seen in a significant proportion (19.5%) of subjects by age 14-16 years and was used by the majority (69.2%) by age 20-22 years. FVC% declined at a rate of 3.19% per year with every 1-year increase in age. FVC% declined annually by 2.47% in nonambulatory participants versus by 0.96% in ambulatory participants. FVC% did not significantly change over age with the presence of scoliosis or use of ventilatory technology.CONCLUSIONS:The data from this large cohort are valuable for understanding real-world patterns of clinical care and disease progression. There is a significant association between the loss of ambulation and the rate of FVC% decline. Further longitudinal studies are needed to better understand the impact of disease parameters on pulmonary function decline and the need for ventilatory support.