Bone Abstracts

Background: Dual-energy X-ray absorptiometry (DEXA) is the gold standard used for measuring bone mineral density and such readings are currently used to predict osteoporosis and osteoporotic fractures. However, no similar prediction model has been developed to identify the age that a patient will become osteoporotic based on DEXA scanning.

Objective: The aim of this study was to develop a mathematical model to determine the TTO based on two or more DEXA scans with TTO defined as the age at which the patient will enter the osteoporotic T-score range.

Methods: Fifty patients who had previously undertaken two or more DEXA scans were identified from the DEXA database. T-scores were graphed against patient age using GraphPad Prism Software. Straight line curves for the most recent scans were generated with the age at which the curve intersects T=−2.5 being classed as TTO. A multiple-point best fit curve was used to generate an overall osteoporotic trajectory over time.

Results: The mathematical model developed successfully predicted the age to osteoporosis for each patient, as well as creating a cumulative osteoporotic trend based on total DEXA scans performed. Additionally, if the patient was classified as osteoporotic following DEXA scanning, the model also successfully predicted the age that the patient would leave the osteoporotic range.

Conclusions: The TTO provides a simple and informative parameter of DEXA scanning that a patient can immediately comprehend and understand, while also providing a more simple measure to monitor response to therapy. This parameter has the potential to further empower patients and revolutionise compliance of treatment strategies. Based on the results presented TTO can be incorporated into future DEXA scans result summaries.