Effects of Bisphosphonate Therapy on Bone Mineral Density in Boyswith Duchenne Muscular Dystrophy

摘要

The objective of this study was to estimate the comparative effectiveness ofbisphosphonate therapy on bone mineral density (BMD) in patients withcorticosteroid-treated Duchenne muscular dystrophy (DMD). A retrospective,comparative effectiveness study evaluating changes in BMD and fragilityfractures in patients with DMD presenting to British Columbia Children’sHospital from 1989 to 2017 was conducted. Marginal structural generalizedestimating equation models weighted by stabilized inverse-probability oftreatment weights were used to estimate the comparative effectiveness of therapyon BMD. Of those treated with bisphosphonates (N = 38), 7 (18.4%), 17 (44.7%),and 14 (36.8%) cases were treated with pamidronate, zoledronic acid, or acombination of both, respectively, while 36 cases of DMD were untreated. Meanage of bisphosphonate initiation was 9.2 (SD 2.7) years. Mean fragilityfractures declined from 3.5 to 1.0 following bisphosphonate therapy. Compared tothe treated group, the untreated group had an additional 0.63-SD decrease (95%confidence interval [CI]: −1.18, −0.08, P = .026) in total BMDand an additional 1.04-SD decrease (95% CI: −1.74, −0.34; P =.004) in the left hip BMD, but the change in lumbar spine BMD (0.15, 95% CI:−0.36, 0.66; P = .57) was not significant. Bisphosphonatetherapy may slow the decline in BMD in boys with corticosteroid-treated DMDcompared to untreated counterparts. Total number of fragility fracturesdecreased following bisphosphonate therapy.