Endocrine Abstracts

Background: Glucocorticoid (GC) therapy is the standard management for Duchenne Muscular Dystrophy (DMD), but its use is associated with significant side effects, including weight gain. Limited research exists on the impact of GC initiation on body composition in DMD, particularly regarding the timing of fat mass increase.

Objective: This study aimed to assess changes in growth parameters, namely height-SDS, weight-SDS, body mass index (BMI)-SDS, lean mass index (LMI)-SDS, and fat mass index (FMI)-SDS, following the initiation of GC therapy in individuals with DMD.

Methods: Twenty-four boys with DMD began daily GC therapy (2013–2017). Eighteen who underwent DXA scans were included in this study-assessments conducted at baseline (prior to GC initiation but no more than three months after), 1-year, 2-year, and 3-year time points. Growth parameters (height, weight, BMI) and DXA-measured body composition parameters (LMI and FMI–SDS) were compared. The data were expressed as mean (S.E.M.), and statistical significance was set at P<0.05.

Results: The mean age at baseline was 5.2 (0.36) years. Mean height–SDS continued to decline significantly following the initiation of GC therapy, with a notable difference between the 3-year mark and baseline (difference of means: −0.99 [95% CI: −1.89 to −0.09; P=0.03]). No significant mean differences were observed in weight–SDS, BMI–SDS, and LMI–SDS at any time points. However, mean FMI–SDS began to rise after 1-year of GC exposure with significant differences of FMI–SDS at 3-year of GC compared to baseline (difference of means: +0.71 [95% CI: +0.20 to 1.22; P=0.003]) and 1-year (difference of means: +0.85 [95% CI: 0.34 to 1.36; P<0.0001]). After 3 years of GC (mean age: 8.6 years), 11/18 individuals (61%) were classified as overweight, obese, or severely obese, while this was observed in 9/18 (50%) at 2-years, and 5 /18 (28%) at 1-year and baseline.

Conclusion: Significant increase in fat mass occurs early, within 1-year, following the initiation of daily GC therapy in young boys with DMD. Incorporating nutritional support as part of the clinical care for all boys with DMD soon after GC initiation is paramount. National clinical pathways for management of obesity-related metabolic complications in DMD should be developed.