Sawnani H, Horn PS, Wong B, et al. Comparison of Pulmonary Function Decline in Steroid-Treated and Steroid-Naive Patients with Duchenne Muscular Dystrophy. J Pediatr-Us 2019;210:194-200 e2
OBJECTIVE: To describe and compare the lung function decline in patients with Duchenne muscular dystrophy on glucocorticoid therapy in contrast with glucocorticoid-naive patients, and to define the deciles of pulmonary decline in glucocorticoid-treated patients.
STUDY DESIGN: This retrospective study examined lung function of patients with Duchenne muscular dystrophy over 6 years of age followed between 2001 and 2015 at 2 centers-glucocorticoid-treated patients in Cincinnati, Ohio, and glucocorticoid-naive patients in Paris, France. Forced vital capacity (FVC, FVC%), forced expiratory volume in 1 second, maximal inspiratory pressure, maximal expiratory pressure, and peak expiratory flow data were analyzed. Only FVC data were available for the French cohort.
RESULTS: There were 170 glucocorticoid-treated patients (92%), 5 patients (2.7%) with past glucocorticoid use, and 50 French glucocorticoid-naive patients. The peak absolute FVC was higher and was achieved at earlier ages in glucocorticoid-treated compared with glucocorticoid-naive patients (peak FVC, 2.4 +/- 0.6 L vs 1.9 +/- 0.7 L; P < .0001; ages 13.5 +/- 3.0 years vs 14.3 +/- 2.8 years; P = .03). The peak FVC% was also higher and was achieved at earlier ages in glucocorticoid-treated patients (peak FVC%, 105.1 +/- 25.1% vs 56 +/- 20.9%; P < .0001; ages 11.9 +/- 2.9 years vs 13.6 +/- 3.2 years; P = .002). Rates of decline for both groups varied with age. Maximal rates of decline were 5.0 +/- 0.26% per year (12-20 years) for glucocorticoid-treated and 5.1 +/- 0.39% per year for glucocorticoid-naive patients (11-20 years; P = .2). Deciles of FVC% decline in glucocorticoid-treated patients show that patients experience accelerated decline at variable ages.
CONCLUSIONS: These data describe nonlinear rates of decline of pulmonary function in patients with Duchenne muscular dystrophy, with improved function in glucocorticoid-treated patients. FVC% deciles may be a useful tool for clinical and research use.