Scibora L M
Health and Human Performance Department, University of St. Thomas, St. Paul, MN, USA.
Diabetes Obes Metab. 2014 Dec;16(12):1204-13. doi: 10.1111/dom.12363. Epub 2014 Sep 9.
Bariatric surgery is the most effective therapeutic approach to morbid obesity, resulting in substantial weight loss and improved cardiometabolic profiles; however, a growing body of evidence suggests that bariatric procedures increase both skeletal fragility and the risk of related future fracture secondary to excessive bone loss. Prospective evidence shows that areal bone mineral density (BMD) assessed by dual energy X-ray absorptiometry (DXA) declines by as much as 14% in the proximal femoral regions, including the femoral neck and total hip, 12 months postoperatively. Lumbar spine areal BMD outcomes show greater 12-month postoperative variability across surgical procedures (-8 to +6%) and contrast with no change in volumetric BMD outcomes measured by quantitative computed tomography. Diminished mechanical loading, micronutrient deficiency and malabsorption, along with neurohormonal alterations, offer plausible underlying mechanisms to explain these observed post-bariatric bone changes, but most remain largely unsubstantiated in this population. Importantly, DXA-based skeletal imaging may have limited utility in accurately detecting bone change in people undergoing bariatric surgery; partly because excessive tissue overlying bone increases the variability of areal BMD outcomes. Moreover, a paucity of fracture and osteoporosis incidence data raises questions about whether marked post-bariatric surgery bone loss is clinically relevant or a functional adaptation to skeletal unloading. Future studies that use technology which is able to accurately capture the site-specific volumetric BMD and bone architectural changes that underpin bone strength in people undergoing bariatric surgery, that consider mechanical load, and that better quantify long-term fracture and osteoporosis incidence are necessary to understand the actual skeletal effects of bariatric surgery.
减重手术是治疗病态肥胖最有效的方法，可实现显著减重并改善心脏代谢状况；然而，越来越多的证据表明，减重手术会增加骨骼脆性以及因骨质过度流失导致未来相关骨折的风险。前瞻性证据显示，术后12个月，通过双能X线吸收法（DXA）评估的股骨近端区域（包括股骨颈和全髋）的骨矿物质密度（BMD）面积下降多达14%。腰椎BMD面积结果显示，不同手术方式术后12个月的变异性更大（-8%至+6%），与定量计算机断层扫描测量的体积BMD结果无变化形成对比。机械负荷减少、微量营养素缺乏和吸收不良，以及神经激素改变，为解释这些观察到的减重术后骨骼变化提供了合理的潜在机制，但在这一人群中，大多数机制在很大程度上仍未得到证实。重要的是，基于DXA的骨骼成像在准确检测减重手术患者的骨骼变化方面可能效用有限；部分原因是覆盖骨骼的过多组织增加了BMD面积结果的变异性。此外，骨折和骨质疏松症发病率数据的匮乏引发了关于减重手术后明显的骨质流失在临床上是否相关或是否是对骨骼卸载的功能适应的疑问。未来的研究需要使用能够准确捕捉特定部位体积BMD和骨骼结构变化（这些变化是减重手术患者骨骼强度的基础）的技术，考虑机械负荷，并更好地量化长期骨折和骨质疏松症发病率，以了解减重手术对骨骼的实际影响。
