The effect of corticosteroids on pulmonary function in a large cohort of late adolescents and adults with Duchenne muscular dystrophy

Introduction/Aims: Corticosteroids (CS) are routinely prescribed for children with Duchenne muscular dystrophy (DMD) to delay disease progression. However, evidence supporting their use beyond adolescence into adulthood is limited, resulting in inconsistent clinical practice. The aim of this study was to assess the effect of continuing CS on respiratory function in males with DMD age ≥ 16 years and to understand the impact of CS discontinuation. Methods: This was a multicenter, retrospective cohort study. Pulmonary function data from medical records of 208 males, stratified into three groups (CS-continued, CS-stopped, CS-naïve) was assessed. Results: Data was available for 208 subjects (age 16y–40.5 years). Continued CS use was associated with delayed respiratory decline compared with CS-stopped or CS-naive, demonstrated by later attainment of key pulmonary milestones (forced vital capacity (FVC) < 1 L (24.75 years vs. 19.25 years vs. 20.5 years; p < 0.0001), FVC percent predicted < 50% (17.5 years vs. 16.25 years vs. 16.75 years; p = 0.0031) and < 30% (22.79 years vs. 17.04 years vs. 18.38 years; p < 0.0001)) and initiation of noninvasive ventilation (NIV) (median age 19.17 years vs. 16 years vs. 17.33 years; p = 0.0031). Longitudinal measures of lung function declined fastest in the CS-stopped group (p < 0.05). Discussion: Continuing CS therapy into late adolescence and adulthood slows respiratory decline in DMD, even at doses below recommended levels. The most rapid rate of decline appeared in the CS-stopped group. Clinically, these findings support long-term CS continuation in DMD to preserve pulmonary function and delay the onset of NIV. However, the balance of benefits versus side effects of long-term CS and optimal CS dose in adults remains unclear.