TBS (Trabecular Bone Score) and Diabetes-Related Fracture Risk

<jats:title>Abstract</jats:title><jats:sec><jats:title>Context:</jats:title><jats:p>Type 2 diabetes is associated with increased fracture risk but paradoxically greater bone mineral density (BMD). Trabecular bone score (TBS) is derived from the texture of the spine dual x-ray absorptiometry (DXA) image and is related to bone microarchitecture and fracture risk, providing information independent of BMD.</jats:p></jats:sec><jats:sec><jats:title>Objective:</jats:title><jats:p>This study evaluated the ability of lumbar spine TBS to account for increased fracture risk in diabetes.</jats:p></jats:sec><jats:sec><jats:title>Design and Setting:</jats:title><jats:p>We performed a retrospective cohort study using BMD results from a large clinical registry for the province of Manitoba, Canada.</jats:p></jats:sec><jats:sec><jats:title>Patients:</jats:title><jats:p>We included 29,407 women 50 years old and older with baseline DXA examinations, among whom 2356 had diagnosed diabetes.</jats:p></jats:sec><jats:sec><jats:title>Main Outcome Measures:</jats:title><jats:p>Lumbar spine TBS was derived for each spine DXA examination blinded to clinical parameters and outcomes. Health service records were assessed for incident nontraumatic major osteoporotic fractures (mean follow-up 4.7 years).</jats:p></jats:sec><jats:sec><jats:title>Results:</jats:title><jats:p>Diabetes was associated with higher BMD at all sites but lower lumbar spine TBS in unadjusted and adjusted models (all P &lt; .001). The adjusted odds ratio (aOR) for a measurement in the lowest vs the highest tertile was less than 1 for BMD (all P &lt; .001) but was increased for lumbar spine TBS [aOR 2.61, 95% confidence interval (CI) 2.30–2.97]. Major osteoporotic fractures were identified in 175 women (7.4%) with and 1493 (5.5%) without diabetes (P &lt; .001). Lumbar spine TBS was a BMD-independent predictor of fracture and predicted fractures in those with diabetes (adjusted hazard ratio 1.27, 95% CI 1.10–1.46) and without diabetes (hazard ratio 1.31, 95% CI 1.24–1.38). The effect of diabetes on fracture was reduced when lumbar spine TBS was added to a prediction model but was paradoxically increased from adding BMD measurements.</jats:p></jats:sec><jats:sec><jats:title>Conclusions:</jats:title><jats:p>Lumbar spine TBS predicts osteoporotic fractures in those with diabetes, and captures a larger portion of the diabetes-associated fracture risk than BMD.</jats:p></jats:sec>