Background: Information on the long-term efficacy of intravenous pamidronate therapy in Asian patients with osteogenesis imperfecta (OI) is limited. We report our experience using pamidronate in Taiwanese patients with OI.
Methods: Twenty-six patients with type I, III, or IV OI (eight males and 18 females; age range at last follow-up, 2.9-39.2 years) who received (or were currently receiving) intravenous pamidronate treatment (30mg/m2/dose, every month) were retrospectively analyzed. Patients were followed for 1.0-7.3 years over the study period from February 2000 to October 2007.
Results: The mean standard deviation score (SDS) for bone mineral density (BMD) had increased significantly from -4.72 to -3.37 (p < 0.005) after 1 year of treatment. In 16 patients evaluated after 4 years and eight after 6 years, the mean SDS continued to improve, to -2.69 (p < 0.001) and -1.54 (p < 0.005), respectively. The fracture rate decreased significantly (from 2.8 +/- 1.1 to 0.6 +/- 0.6, p < 0.001), and nine patients (35%) had no fractures while receiving treatment. The response to pamidronate was significantly better in patients with poorer initial BMD SDS (1 year: r = -0.71, p < 0.01; 4 years: r = -0.81, p < 0.01).
Conclusion: This retrospective study suggests that Taiwanese patients with OI can benefit from pamidronate treatment, leading to a reduced incidence of fractures and increased BMD, especially in patients with poor baseline BMD.