Trabecular Bone Score Uncovers Osteopenia and Osteoporosis in a Large Fraction of Patients with the Metabolic Syndrome
Presentation Number: SUN 304
Date of Presentation: April 2nd, 2017
Vanessa Rouach*1, Yonit Marcus2, Jessica Sack3, Mariana Yaron4, Yael Sofer5, Galina Shenkerman6, Brurya Tal3, Eliezer Carmeli7, Gabi Shefer8 and Naftali Stern4
1tel aviv sourasky medical center, tel aviv, Israel, 2Tel Aviv Medical Center, Tal Aviv, Israel, 3Tel Aviv Medical Center, Tel Aviv, Israel, 4Tel Aviv Sourasky Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel, 5Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, 6Tel Aviv Sourasky Medcl Ctr, Tel Aviv, Israel, 7University of Haifa, Haifa, Israel, 8Tel Aviv Sourasky Medical Center, Tel Aviv
Background: The metabolic syndrome (MetS) is a constellation of medical conditions consisting of central obesity, hyperglycemia, hypertension, and dyslipidemia, in which each acts on bone tissue in different ways. Since MetS often precedes diabetes mellitus (DM) and much like type 2 DM is largely driven by obesity, bone fragility might be under-estimated by bone mineral density (BMD) alone in MetS patients, as is the case in DM. The trabecular bone score (TBS) is a recently introduced non-invasive tool which indirectly assesses bone quality and fracture risk independently of BMD.
Aim: To assess the added value of TBS in subjects with the MetS.
Subjects and methods: A retrospective cross-sectional study of 104 Caucasian subjects diagnosed with the MetS using the ATPIII criteria. Body composition and bone density were assessed by dual X-ray absorptiometry (GE Lunar Prodigy) and the lumbar spine images were also analyzed using the TBS iNsight (version 2.1.2, Med-Imaps) in order to generate TBS-adjusted T-scores.
Results: The study group consisted of 57 men (55%) and 47 women (45%) with a mean age of 58 ±10 (±SD) and a mean BMI 32.9 ±4.4. The mean T-score was +0.05±1.3 while the mean TBS adjusted T-score was -0.8±1.4. Classified by lumbar BMD T-score, bone density was normal in 83 subjects (80%) but indicative of osteopenia in 19 (18%) and osteoporosis in 2 (2%) participants. After TBS adjustment, however, the number of subjects with abnormal T-score more than doubled to 43%, out of which 29 (28%) were classified as osteopenic and 16 (15%) were clearly within the osteoporosis range. Indeed, most osteoporotic subjects (14/16) were missed by standard BMD but identified by TBS-adjusted BMD. Notably, after TBS adjustment 31% of subjects originally defined as "normal" by BMD alone, had to be reclassified as osteopenic, and 6 % as osteoporotic. Likewise, 32% of BMD-defined osteopenic subjects were reclassified as osteoporotic after TBS adjustment. Subjects reclassified as osteoporotic were significantly heavier (105 kg±5.5 versus 93kg±1.7 p=0.015). Men were more likely to be reclassified than women but this was not statistically significant, the age of the subjects reclassified was not significantly different either.
Conclusions: In this sample of metabolic syndrome patients, bone mineral density identified only one of 7-8 subjects at risk for fragility fractures. In this setting, the assessed bone status is significantly shifted downwards following TBS-adjustment. Hence, the trabecular bone score seems to provide added value over standard bone mineral density in assessing bone fragility in metabolic patients and it needs to be further validated in this population.
Nothing to Disclose: VR, YM, JS, MY, YS, GS, BT, EC, GS, NS