Background: Duchenne muscular dystrophy (DMD) is caused by mutations in the dystrophin gene and results in a progressive muscular damage and degeneration. Endocrine complications result from decreased energy expenditure, immobility and glucocorticoid (GC) treatment. Due to the multidisciplinary management and emerging genetic and molecular therapies longer survival is expected and there is an increasing emphasis on the quality of life in DMD. Aim of the study was to determine prevalence of selected endocrine complications in a national cohort of boys with DMD treated or not with GC.
Methods: 29 boys with DMD (age (mean+/-SD) 11.5+/-5.4 years) were studied at annual multidisciplinary visit. Levels of IGF-1, IGF-BP3, TSH, free T4, glucose, insulin and vitamin D3 were determined in the morning following an overnight fast. Bone mineral density and body composition were determined by DEXA. Data were expressed as mean+/-SD, groups were compared by T-test, correlations were made by Pearson's coefficient. P-values < 0.05 were considered statistically significant.
Results: 13/29 received GC (deflacort) for 3.6+/-3.1 year (starting at 6.9+/-.8 years). 7/29 were short stature (2 in GC group), 1/29 (0 in GC group) was underweight and 6/29 (3 in GC group) were overweight. HOMA-IR was increased in 8/29 (5 in GC group), none had impaired glucose tolerance or diabetes. No cases of acute adrenal insufficiency were reported. Lumbar spine-BMD was decreased in 8/29 (3 in GC group), 24/29 received vitamin D3 supplements and one subject needed antiresorptive therapy.
There were no differences in the mean values of selected parameters between those receiving or not-receiving GC. Glucocorticoid treatment duration however correlated positively with BMI-SDS and % fat mass (r=0,722, P= and r=0.84, P=.018 respectively) and negatively with % lean mass (-.88, P=.004).
Conclusions: Short stature, under and overweight, insulin resistance and decreased BMD are common however not obligatory endocrine complications in DMD. Although there were no differences in studied parameters between those receiving and not-receiving GC, there was a positive correlation between GC treatment duration and BMI-SDS and increased fat mass confirming GC as a risk factor for possible metabolic complications in DMD.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology