Endocrine Abstracts

Introduction: Trabecular bone score (TBS) was introduced in FRAX, to evaluate more precisely the risk for fracture. However, FRAX is a method for editing a risk, not for making a diagnosis. WHO established conventionally, based on the level of standard deviation (SD), named T score, for Bone Mineral Density (BMD) that <−2,5 SD is compatible with the diagnosis of osteoporosis.

Aim: Our aim was to analyze if it is possible to used T score (SD) for TBS in the diagnosis of vertebral osteoporosis, in the same manner, i.e. conventionally, as it is used BMD. Two arguments could sustain our goal: 1. since the predictive ability to show the fractures of TBS is independent of FRAX clinical risk factors and femoral neck BMD; and 2. the calculated probabilities for fracture have been shown to be more accurate when classical FRAX was computed with TBS.

Method: 1. DEXA machine - GE-Lunar Prodigy Pro #500074. TBS soft - TBS iNsight®, version 3.0.2.0. 2. There were registered 4 TBS/BMD T scores: a. the highest T scores; b. the lowest TBS T score; c. BMD T scores corresponding to ‘a’ and, respectively, ‘b’. 3. T test was performed for analyzing the difference between scores. 4. Conventionally - 2,5, and -1 T scores were used for an interference graphic between TBS and BMD.

Results: A. Patients: no. 536 women: 508 men: 28 (5.22%), mean age: 65.94 years. B. T score averages: Lowest TBS: −3.48. Corresponding BMD: −1.61. Highest TBS: −1.43. Corresponding DMO: −1.32. C. T tests: for highest TBS/BMD scores: P<< 0.001. For lowest TBS/BMD scores: P=0.19. D. Interference graphic: a. TBS > −1: BMD > −1=24/4.5%; BMD −1 - −2.5=6/1.1%, BMD < −2.5=4/0.7%. b. TBS −1 - −2.5: BMD >−1=41/7.6%; BMD −1 - −2.5=51/9.5%, BMD < −2.5=21/3.9%. c. TBS < −2.5: BMD >−1=69/12.9% (lack of diagnostic); BMD −1 - −2.5=187/34.9% (lack of diagnostic), BMD < −2.5=133/24.8%.

Conclusions: 1. The lowest TBS T score was more altered than the lowest BMD T score, P<<0.001, suggesting that the vertebral microarchitecture modify before losing bone. 2. This should be the moment when considering the starting treatment. 3. When interfering TBS T score with BMD T score, it seems that 47.8% (12.9+34.9) of patients lack the osteoporosis diagnostic. 4. Therefore, TBS should be used as a tool for osteoporosis diagnostic not only for calculating risks.