School of Rehabilitation Therapy, Faculty of Health Sciences, Queen's University, Kingston, ON, Canada.
Manitoba Centre for Health Policy, Max Rady College of Medicine, Rady Faculty of Health Sciences, Winnipeg, MB, Canada.
J Bone Miner Res. 2019 Jun;34(6):1095-1100. doi: 10.1002/jbmr.3682. Epub 2019 Feb 27.
People with multiple sclerosis (MS) have a higher risk of low bone mineral density (BMD), osteoporosis, and osteoporotic fractures than healthy adults. The Fracture Risk Assessment tool (FRAX ) has been reported to underestimate fracture risk in people with MS when BMD is unknown. We tested FRAX performance for people with MS when BMD is known, and determined if MS is a risk factor for fracture independent of FRAX score. Using population-based databases in Manitoba, Canada, we identified people with MS who underwent BMD screening after MS diagnosis (n = 744) and controls matched on age, sex, and first BMD screening date (n = 3721). We calculated FRAX 10-year probabilities at the BMD screening date, and ascertained incident major osteoporotic fractures (MOF). Using Cox proportional hazards modeling we assessed the effect of MS on the hazard of MOF, adjusting for FRAX 10-year probabilities. MS cases had a higher mean FRAX 10-year probability of MOF calculated with BMD (8.32 ± 7.53) than controls (6.98 ± 5.18; p < 0.01). MS increased the risk for MOF after controlling for FRAX 10-year probability without BMD (HR 1.67; 95% confidence interval [CI], 1.29 to 2.16), and after controlling for FRAX individual risk factors (HR 1.45; 95% CI, 1.12 to 1.89). MS remained a risk factor for MOF even when controlling for FRAX 10-year probability of MOF with BMD (HR 1.48; 95% CI, 1.14 to 1.92). The FRAX 10-year probability with and without BMD underestimated the observed 10-year MOF risk in MS cases by 3% to 5%. Calibration improved when secondary osteoporosis was used to calculate FRAX without BMD. Calibration was best when the rheumatoid arthritis input was used to calculate FRAX probability along with BMD. Using secondary osteoporosis or rheumatoid arthritis as proxies for MS improves performance of FRAX and accurately predicts MOF outcomes in those with MS. This provides clinicians with a readily available approach to improve the accuracy of fracture prediction in MS. © 2019 American Society for Bone and Mineral Research.
多发性硬化症（MS）患者的骨密度（BMD）较低、骨质疏松症和骨质疏松性骨折的风险高于健康成年人。据报道，当 BMD 未知时，骨折风险评估工具（FRAX）会低估 MS 患者的骨折风险。我们在加拿大马尼托巴省的基于人群的数据库中，检测了已知 BMD 时 MS 患者的 FRAX 性能，并确定 MS 是否是独立于 FRAX 评分的骨折危险因素。我们在 MS 诊断后对接受 BMD 筛查的 MS 患者（n=744）和按年龄、性别和首次 BMD 筛查日期匹配的对照者（n=3721）进行了分析。我们在 BMD 筛查日期计算了 FRAX 10 年的概率，并确定了主要骨质疏松性骨折（MOF）的发生率。使用 Cox 比例风险模型，我们评估了 MS 对 MOF 发生风险的影响，调整了 FRAX 10 年的概率。与对照组相比（6.98±5.18;p<0.01），MS 患者的 BMD 计算的 FRAX 10 年 MOF 概率平均值较高（8.32±7.53）。在没有 BMD 的情况下，MS 增加了 FRAX 10 年概率后发生 MOF 的风险（HR 1.67;95%置信区间[CI]，1.29 至 2.16），在控制了 FRAX 个体风险因素后（HR 1.45;95%CI，1.12 至 1.89）。即使在控制了 BMD 的 FRAX 10 年 MOF 概率后，MS 仍然是 MOF 的危险因素（HR 1.48;95%CI，1.14 至 1.92）。FRAX 10 年概率（有和无 BMD）低估了 MS 患者 10 年 MOF 风险 3%至 5%。当使用继发性骨质疏松症来计算没有 BMD 的 FRAX 时，校准得到改善。当使用类风湿关节炎输入来计算 BMD 联合 FRAX 概率时，校准效果最佳。使用继发性骨质疏松症或类风湿关节炎作为 MS 的替代指标可以提高 FRAX 的性能，并准确预测患有 MS 患者的 MOF 结局。这为临床医生提供了一种现成的方法，可提高 MS 患者骨折预测的准确性。
