Endocrine Abstracts

Background: Osteogenesis imperfecta is a group of heterogenous disorders affecting connective tissue. The disorders are inherited by autosomal dominant or recessive patterns. The phenotypes vary both between and within the subgroups of which there are eight described by the modified Sillence criteria. The common features are reduced bone mineralization, predisposition to fracture and resulting bony deformities. In addition blue sclerae and joint hyperlaxity can be present.

Methods: Charts of 17 patients with OI attending a metabolic bone disease clinic in Dublin were reviewed. The subtype of OI was determined by clinical characteristics in most cases. The treatment given in the form of calcium, vitamin D and bisphosphonates was identified. The response to treatment was assessed by DXA and bone turnover markers: osteocalcin, bone alkaline phosphatase, procollagen I amino propeptide, carboxy telopeptide, all in serum, and urine amino telopeptide.

Results: The response to treatment varied between patient and OI subtype. In general there was an increase in bone mineral density in response to bisphosphonates. The response in terms of frequency of fracture was not possible to determine from our data.

Conclusion: OI is debilitating but the course of the disease can be improved by treatment that increases bone mineral density. The response to treatment in our cohort is shown here. The optimum time course for bisphosphonate treatment is unclear and further study is needed to determine this and outcomes in terms of fracture incidence.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.