Changes in serum bone turnover markers and bone mineral density Z-score in children with osteogenesis imperfecta after zoledronic acid treatment

The study aimed to investigate the changes in the levels of serum bone turnover markers (BTMs) and bone mineral density (BMD) Z-score in pediatric patients with osteogenesis imperfecta (OI) after intravenous bisphosphonate therapy and their association with age and estimated glomerular filtration rate (eGFR). This retrospective study analyzed data from 10 pediatric OI patients treated with intravenous zoledronic acid for over 1 year. Patients' clinical data were collected. The levels of BTMs and BMD Z-score before and after zoledronic acid treatment were analyzed. Significant improvement in BMD Z-score was observed after 6 and 12 months of treatment compared to baseline (all p < 0.05). The N-terminal propeptide of type I procollagen (PINP) levels decreased over time (all p < 0.05), indicating that zoledronic acid treatment decreased bone turnover. The levels of beta-C-terminal telopeptide of type I collagen remained stable after treatment. No correlation was found between PINP level and age, eGFR, or BMD (all p > 0.05). Bisphosphonate treatment can improve BMD and decrease bone turnover (indicated by decreased levels of PINP) in pediatric OI patients. PINP may serve as an independent indicator for monitoring the efficacy of bisphosphonate treatment in pediatric OI patients, particularly in those under the age of 6, where standardized BMD Z-score criteria are lacking.