Growth patterns in duchenne muscular dystrophy

Résumé

Introduction. Duchenne muscular dystrophy (DMD) is a genetic disorder that significantly affects growth and development, characterised by progressive degeneration of skeletal and cardiac muscles, typically beginning in early childhood, between 2 and 5 years old. 

Purpose of the study. To assess longitudinal growth parameters (height, weight, BMI) in children with genetically confirmed DMD compared with healthy age- and sex-matched controls.

Materials and methods. A total of 100 children were included: 50 with DMD and 50 controls. Anthropometric data were collected at 3 follow-up visits over a 12-month period and analysed using Microsoft Excel (Office 365) and StatTech v.4.6.3.

Results. Children with DMD exhibited impaired growth compared with controls:  lower height (median 1.25 m [1.10–1.44] vs 1.56 m [1.37–1.68]; p<0.001), lower height z-score (−0.95±1.57 vs 0.42±1.41; p<0.001), and lower height percentile (16.0 vs 63.7; p<0.001). Body weight was also lower (27.7 kg [18.5–34.0] vs 46.0 kg [29.3–58.0]; p<0.001), with reduced weight z-score (−0.61 vs 0.57; p=0.003) and percentile (26.9 vs 71.6; p=0.003). BMI was lower in the DMD group (15.9 vs 18.4 kg/m²; p=0.007), whereas BMI z-scores and percentiles did not differ significantly (p>0.05). Growth velocity declined over time (height increase of 0.03 m from Visit 1 to Visit 2 vs 0.01 m from Visit 2 to Visit 3; p<0.01). Among patients with DMD stratified by duration of deflazacort treatment, the >12-month subgroup showed the greatest growth gains, although differences between subgroups were not statistically significant.

Conclusions. Children with DMD  had a delayed growth compared with their peers, with progressive slowing over time. Regular auxological monitoring is essential, and further studies are needed to clarify the effects of corticosteroid therapy.