BACKGROUNDOsteogenesis imperfecta (OI) is a rare bone disease and its effective treatment is relatively deficient. We tried to assess the effects of new bisphosphonate, ibandronate on children with OI.

METHODSIn this open-label, prospective, controlled study, 30 children with OI were enrolled. They received either infusions of ibandronate (2 mg) in every three months or oral calcitriol 0.25 µg daily for 24 months. All patients took 500 mg calcium plus 200 U vitamin D daily together. The endpoints were the change of annual new fracture rate (observed by case history and X ray films of spine), bone mineral density (BMD, measured by dual energy X-ray absortiometry), serum concentration of carboxy-telopeptide cross-links of type I collagen (CTX, bone resorption marker) and alkaline phosphatase (ALP, bone formation marker) during the follow-up.

RESULTSAfter the cyclic infusions of ibandronate, the annual new fracture rate was significantly decreased from 1.9 to 0.13 time, obviously lower than that of calcitriol group, which decreased from 1.8 to 1.0 time after the treatment (P < 0.001). The significant increase of BMD at the lumbar spine, femoral neck, trochanter, total hip was found in the group of ibandronate by 59.0%, 42.0%, 47.5% and 36.6% in time dependent manner (compared with the baseline, P < 0.001). The increase of BMD in ibandronate group was greater than that of calcitriol group (P < 0.001). The concentrations of ALP and CTX were obviously decreased in ibandronate group, and the reduction of CTX was more significant than that of ALP (P < 0.001). The tolerance of the children to ibandronate was quite well. Mild fever and muscle pain were found in 9 cases within 1 - 3 days after the first infusion of ibandronate, which could relieve after 1 - 2 days without special management.

CONCLUSIONSThe benefits of cyclic infusions of ibandronate to children with OI are significant because ibandronate could significantly reduce annual bone fracture rate, increase lumbar and hip BMD, preserve vertebral morphometry of patients through inhibition of bone resorption.