ESPE Abstracts

Background: Glucocorticoid (GC) therapy is standard of care of management of Duchenne Muscular Dystrophy (DMD) but its use is associated with a range of side-effects. Weight gain leading to significant obesity is common in GC treated boys. There are limited studies evaluating body composition in DMD following initiation of GC, and the timing of increase in fat mass is not known.

Aim(s): To evaluate changes in growth parameters: height-SDS, weight-SDS, body mass index(BMI)-SDS, lean mass index(LMI)-SDS and fat mass index(FMI)-SDS following initiation of daily GC in DMD.

Methods: Between 2013-2017, 24 boys with DMD were commenced on daily GC. 18 boys who had DXA for assessment of bone health at baseline(prior to initiation of GC but no more than after 3 months), 1-year, 2-year and 3-year were included. Height-SDS, weight-SDS, BMI-SDS and DXA measured body composition: LMI and FMI-SDS were compared between time-points. Data were expressed as mean(SEM). P<0.05 was accepted as statistical significance.

Results: Mean age prior to initiation of GC was 5.2(0.36) years. Mean GC dose was 0.6(0.01) mg/kg/day in Prednisolone equivalent and remained stable throughout the follow-up. Mean height-SDS continued to decline following initiation of GC with significant differences between 3-year of GC and baseline with difference of means -0.99 [95% CI: -1.89 to -0.09; P=0.03]. There were no significant mean differences in weight-SDS, BMI-SDS and LMI-SDS between time-points. Mean FMI-SDS began to rise after one year of GC exposure. Mean FMI-SDS after 3-year of GC was significantly different from baseline (difference of means +0.71 [95% CI: +0.20 to 1.22; P=0.003]) and 1-year of GC (difference of means = +0.85 (95% CI: 0.34 to 1.36; P<0.0001]). After 3-years of GC therapy(mean age 8.6 years, 11/18(61%) were categorised overweight, obese or severely obese, whereas this was noted in 9/18(50%) at 2-year of GC; 5/18(28%) at 1-year of GC and baseline.

Conclusion: Substantial increase in fat mass occurs early after the first year of initiation of daily GC in young boys with DMD. Routine structured nutritional input for all boys with DMD should be part of clinical care following initiation of GC. Current management strategies of childhood obesity and its complication may not be not suitable for boys with DMD(eg exercise and use of statins contraindicated). Clinical pathways of evaluation and management of obesity-metabolic complications in DMD should now be developed.