Glucocorticoids Linked to Significant Bone Deficit in Pediatric Crohn Disease

The following article is part of conference coverage from the 2018 American Society for Bone and Mineral Research (ASBMR) Annual Meeting in Montreal, Canada. Rheumatology Advisor’s staff will be reporting breaking news associated with research conducted by leading experts on bone health. Check back for the latest news from ASBMR 2018 .

Regardless of disease activity, children diagnosed with Crohn disease experienced significant bone deficits associated with glucocorticoid exposure, while muscle mass was positively associated with trabecular volumetric bone mineral density (BMD), cortical area, and dual energy X-ray absorptiometry (DXA) Z-scores. This research was presented at the ASMBR 2018 Annual Meeting held September 28 to October 1, 2018, in Montreal, Quebec, Canada.

The 12-month, double-blind, placebo-controlled study included 138 children, aged 8 to 21 years, with a diagnosis of Crohn disease. The results of low magnitude mechanical stimuli on the cohort’s bone health was evaluated over 12 months, followed by 1 year open-label extension in which the authors performed a secondary analysis to identify factors relating to bone outcomes. Peripheral quantitative computed tomography (CT) and DXA bone density scans were obtained at baseline, 6, 12, and 24 months. Longitudinal multivariate models were used to ascertain correlations of bone Z-scores (adjusted for height) with patient demographics, pediatric Crohn Disease Activity Index, leg lean mass Z-scores, physical activity, glucocorticoid exposure, and vitamin D levels.

In all participants, the study results showed a significant improvement in bone Z-scores for tibia quantitative CT volumetric BMD and cortical area, spine quantitative CT trabecular BMD, all-site DXA BMD, and DXA leg lean mass (P <.001 for all). Greater BMD was most often associated with younger patients, and gains in leg lean mass were linked to greater physical activity and lesser disease activity. Exposure to glucocorticoid therapy was associated with significantly lower DXA BMD across all sites and lower trabecular volumetric BMD in the tibia and spine.

The only association the authors observed between vitamin D and bone outcomes was greater trabecular volumetric BMD in the tibia. Greater physical activity was also associated with greater tibia trabecular volumetric BMD as well as femoral neck BMD. Besides cortical BMD, greater muscle mass was highly and positively correlated with all other bone outcomes. Associations with age and physical activity were diminished when the authors adjusted for leg lean mass.

Independent of disease activity, glucocorticoid therapy was associated with significant bone deficits across multiple bone sites in children. The authors suggest that the effect of glucocorticoid therapy suppresses bone formation while older cortical bone with greater density accumulates. Across all sites, muscle mass was positively associated with trabecular volumetric BMD, cortical area, and DXA Z-scores.

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Reference

Long J, Lee D, Herskovitz R, Zemel B, Leonard M. Multimodality study of glucocorticoid induced osteoporosis in pediatric Crohn’s disease. Presented at: ASBMR 2018 Annual Meeting; September 28-October 1, 2018; Montreal, Canada. Abstract 0126.