Department of Radiology and Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
J Bone Miner Res. 2018 May;33(5):860-867. doi: 10.1002/jbmr.3383. Epub 2018 Feb 5.
We sought to determine if vertebral trabecular attenuation values measured on routine body computed tomography (CT) scans obtained for a variety of unrelated indications can predict future osteoporotic fractures at multiple skeletal sites. For this Health Insurance Portability and Accountability Act (HIPAA)-compliant and Institutional Review Board (IRB)-approved retrospective cohort study, trabecular attenuation of the first lumbar vertebra was measured in 1966 consecutive older adults who underwent chest and/or abdominal CT at a single institution over the course of 1 year. New pathologic fragility fractures that occurred after a patient's CT study date were identified through an electronic health record database query using International Classification of Diseases (ICD)-9 codes for vertebral, hip, and extremity fractures. Univariate and multivariate Cox proportional hazards regression were performed to determine the effect of L trabecular attenuation on fracture-free survival. Age at CT, sex, and presence of a prior fragility fracture were included as confounders in multivariate survival analysis. Model discriminative capability was assessed through calculation of an optimism-corrected concordance index. A total of 507 patients (mean age 73.4 ± 6.3 years; 277 women, 230 men) were included in the final analysis. The median post-CT follow-up interval was 5.8 years (interquartile range 2.1-11.0 years). Univariate analysis showed that L attenuation values ≤90 Hounsfield units (HU) are significantly associated with decreased fracture-free survival (p < 0.001 by log-rank test). After adjusting for age, sex, prior fracture, glucocorticoid use, bisphosphonate use, chronic kidney disease, tobacco use, ethanol abuse, cancer history, and rheumatoid arthritis history, multivariate analysis demonstrated a persistent modest effect of L attenuation on fracture-free survival (hazard ratio [HR] = 0.63 per 10-unit increase; 95% confidence interval [CI] 0.47-0.85). The model concordance index was 0.700. Ten-year probabilities for major osteoporosis-related fractures straddled the treatment threshold for most subcohorts over the observed L HU range. In conclusion, for patients undergoing body CT scanning for any indication, L vertebral trabecular attenuation is a simple measure that, when ≤90 HU, identifies patients with a significant decrease in fracture-free survival. © 2018 American Society for Bone and Mineral Research.
我们旨在确定在因各种非相关原因进行的常规全身计算机断层扫描（CT）检查中测量的椎体小梁衰减值是否可以预测多个骨骼部位的未来骨质疏松性骨折。这项符合《健康保险流通与责任法案》（HIPAA）和机构审查委员会（IRB）规定的回顾性队列研究，对在一年时间内在一家机构进行胸部和/或腹部 CT 检查的 1966 名老年患者的第一腰椎小梁衰减进行了测量。通过电子健康记录数据库查询，使用国际疾病分类（ICD）-9 椎体、髋部和四肢骨折的代码，确定 CT 检查日期后发生的新的病理性脆性骨折。在多变量生存分析中，将 CT 时的年龄、性别和既往脆性骨折的存在作为混杂因素。使用计算校正后的一致性指数来评估模型的区分能力。共纳入 507 例患者（平均年龄 73.4 ± 6.3 岁；277 例女性，230 例男性）进行最终分析。CT 后中位随访时间为 5.8 年（四分位距 2.1-11.0 年）。单变量分析表明，L 衰减值≤90 亨氏单位（HU）与骨折无生存显著相关（对数秩检验 p < 0.001）。在校正年龄、性别、既往骨折、糖皮质激素使用、双膦酸盐使用、慢性肾脏病、吸烟、酗酒、癌症病史和类风湿关节炎病史后，多变量分析显示 L 衰减对骨折无生存的影响仍然适度（风险比[HR]每增加 10 个单位为 0.63；95%置信区间[CI] 0.47-0.85）。模型一致性指数为 0.700。10 年主要骨质疏松性骨折的概率跨越了大多数亚组在观察到的 L HU 范围内的治疗阈值。总之，对于因任何原因进行全身 CT 扫描的患者，L 椎体小梁衰减是一种简单的测量方法，当 L 衰减值≤90 HU 时，可识别出骨折无生存显著降低的患者。
