Endocrine Abstracts

There is increasing awareness that children with chronic illnesses, particularly those with glucocorticoid use and neuromuscular disorders, have the potential to develop significant bone fragility due to osteoporosis. In such cases, osteoporosis manifests as low-trauma extremity fractures, with vertebral fractures an under-recognized consequence of reduced bone strength. We have studied the Genant semi-quantitative classification for characterizing vertebral fractures in children with chronic illness, and have shown that the strongest predictor of vertebral fractures in children with leukemia at 12 months was the presence of vertebral fractures around the time of diagnosis. We have further shown that even mild (Grade I) vertebral fractures were associated with increased odds for future spine fracture. These observations assign biological relevance to the Genant classification in children.

The use of clearly-defined, DXA-based bone mineral density (BMD) cut-offs for the diagnosis of osteoporosis in children with chronic illness has been challenging to date, in part due to the paucity of data on the relationship between BMD and fractures in children with underlying disorders. We have shown that such children can sustain vertebral fractures with spine BMD Z-scores well within 2 standard deviations (SD) below the mean, an observation which calls into question the use of – 2 SD as a definitive cut-off to define osteoporosis in the pediatric chronic illness setting.

The treatment of secondary osteoporosis in children presents unique issues due to the potential for spontaneous restitution of bone mass deficits and reshaping of vertebral bodies through bone growth, particularly when bone health threats are transient. As such, the identification of candidates for intervention involves not only confirmation of osteoporosis but assessment of the potential for spontaneous recovery. Bisphosphonates have been the most frequently used agents to treat secondary osteoporosis in children; a number of promising novel treatments on the horizon will also be discussed.

Declaration of interest: The author declares that there is a conflict of interest.

Funding: This work was supported, however funding details are unavailable.