Bone Abstracts

Objectives: To evaluate bone health and body composition in Greek patients with Duchenne muscular dystrophy (DMD), hypothesizing that prepubertal patients would not be fatter than controls, given the Greek obesity epidemic. Greece ranks among the first countries in overweight and obesity prevalence globally; 30 and 13% of childhood population respectively.

Methods: Cross-sectional study, conducted at the Greek Institute of Child Health (Athens) over a 2-year period. Steroid-dependent DMD subjects underwent dual-energy x-ray absorptiometry (DXA) and laboratory evaluation and were compared to a group of healthy Greek boys.

Results: 42 patients and thirty-one controls were studied. 26 patients were on prednisolone and sixteen were on deflazacort. 11 DMD subjects were using a wheelchair and all of them had reached puberty. Seven patients sustained a total of eight fractures, of which four were verterbral. Overall, DMD subjects were shorter (height z-score=−1.4, P=0.01). Their bone mineral density (BMD) was low (lumbar spine BMD z-score=−1.2, P<0.01, subcranial total body BMD z-score=−1.8, P<0.01). Lean tissue mass (LTM) was also decreased (LTM z-score=−2.2, P<0.01). The above findings were more pronounced in adolescence, when loss of ambulation occurs. Regarding adiposity, increased fat mass (FM) was found only in pubertal DMD patients (FM z-score=1.4, P<0.01), whereas prepubertal, able-bodied patients did not differ from controls, thus confirming the initial hypothesis. Finally, 65% of DMD subjects had increased bone resorption markers and 57% had low vitamin D levels, despite supplementation with 400 IU/d of cholecalciferol.

Conclusion: Abnormal body composition and suboptimal bone profile is evident in DMD patients and is more striking during puberty. Regular laboratory and DXA monitoring, starting in the prepubertal period, could aid in prevention of severe osteoporosis, sarcopenia and obesity. Ideally, native reference population should be used in body composition analysis, as it includes subjects living in the same area, with comparable dietary habits and lifestyle.

Disclosure: The authors declared no competing interests.