Skeletal disproportion in glucocorticoid-treated boys with Duchenne muscular dystrophy

We aimed to compare body segment and bone lengths in glucocorticoid-treated boys with Duchenne muscular dystrophy (DMD) with healthy controls using dual-energy absorptiometry (DXA) images. Total height (Ht), sitting height (SH), leg length (LL) and bone lengths (femur, tibia) in boys with DMD and age-matched control boys were measured using DXA. Thirty boys with DMD (median age 10.0 years (6.1, 16.8)) were compared with 30 controls. SH in DMD was 3.3 cm lower (95% CI - 6.1, - 0.66; p = 0.016). LL in DMD was 7.3 cm lower (95% CI - 11.2, - 3.4; p < 0.0001). SH:LL of boys with DMD was higher by 0.08 (95% CI 0.04, 0.12; p < 0.0001). Femur length in DMD was 2.4 cm lower (95% CI - 4.6, - 0.12; p = 0.04), whereas tibial length in DMD was 4.8 cm lower (95% CI - 6.7, - 2.9; p < 0.0001). SH:LL was not associated with duration of glucocorticoid use (SH:LL β = 0.003, 95% CI - 0.01 to 0.002, p = 0.72).Conclusion: Glucocorticoid-treated boys with DMD exhibit skeletal disproportion with relatively shorter leg length and more marked reduction of distal long bones. As glucocorticoid excess is not associated with such disproportion, our findings raise the possibility of an intrinsic disorder of growth in DMD. What is Known • Severe growth impairment and short stature are commonly observed in boys with Duchenne muscular dystrophy (DMD), especially those treated with long-term glucocorticoids (GC). • In other groups of children with chronic conditions and/or disorders of puberty, skeletal disproportion with lower spinal length has been reported. What is New • Growth impairment in GC-treated boys with DMD was associated with skeletal disproportion in relation to age, with lower limbs and distal long bones affected to a greater degree.