Factors associated with lower forced vital capacity in children and adults with Duchenne muscular dystrophy using non-invasive ventilation: a multicenter analysis

Background: Reduced forced vital capacity (FVC) is associated with morbidity and mortality in individuals with Duchenne muscular dystrophy (DMD). Non-invasive ventilation (NIV) is often prescribed for the treatment of sleep-disordered breathing (SDB), and chronic respiratory insufficiency. Despite the common practice of initiating NIV later in the progression of DMD, the factors influencing FVC subsequent to the commencement of NIV remain unclear. Objective: To evaluate the demographic, clinical and socioeconomic determinants of FVC% predicted across several cohorts of DMD children and adults prescribed NIV. Methods: A multicenter retrospective review of individuals with DMD prescribed NIV was performed between February 2016 to October 2020. Patients were identified from three sites: The Hospital for Sick Children, Canada; Rady Children’s Hospital San Diego, USA; and University of California San Diego Health, USA. Multivariate regression analysis was performed to determine factors that influence FVC. Results: Fifty-nine male patients with DMD prescribed NIV (mean ± SD for age and BMI was 20.1 ± 6.7 years and 23.8 ± 8.8 kg/m²) were included. Following multivariate analysis, a lower FVC% predicted was associated with older age (β = -1.44, p = 0.001), presence of scoliosis (β = -16.94, p = 0.002), absent deflazacort prescription (β = 14.43, p = 0.009), and use of in-ex sufflator (β = -39.73, p < 0.001), respectively. Conclusion: In our study, several factors were associated with reduced FVC% predicted in a DMD population using NIV. Future, prospective, longitudinal studies are imperative to comprehend the trajectory of FVC% predicted over time in individuals with DMD using NIV.