Kang Kwi Young, Kim In Je, Jung Seung Min, Kwok Seung-Ki, Ju Ji Hyeon, Park Kyung-Su, Hong Yeon Sik, Park Sung-Hwan
Arthritis Res Ther. 2014 Jun 16;16(3):R124. doi: 10.1186/ar4581.
Ankylosing spondylitis (AS) is associated with an increased incidence of vertebral fractures (VFs); however the actual incidence and predictors of morphometric VFs are unknown. The present study examined the incidence and predictors of new VFs in a large AS cohort.
In total, 298 AS patients who fulfilled the modified New York criteria were enrolled and spinal radiographs were evaluated biennially. Clinical and laboratory data and radiographic progression were assessed according to the Bath AS Disease Activity Index, erythrocyte sedimentation rate, C-reactive protein (CRP), and the Stoke AS spine score (SASSS). VF was defined according to the Genant criteria. The incidence of VFs at 2 and 4 years was evaluated using the Kaplan-Meier method. The age-specific standardized prevalence ratio (SPR) for AS patients in comparison with the general population was calculated.
Of 298 patients, 31 (10.8%) had previous VFs at baseline. A total of 30 new VFs occurred in 26 patients over 4 years. The incidence of morphometric VFs was 4.7% at 2 years and 13.6% at 4 years. Multivariate logistic regression analysis showed that previous VFs at baseline and increased CRP levels at 2 years were predictors of new VFs (odds ratio (OR) =12.8, 95% confidence interval (CI) = 3.6-45.3 and OR = 5.4, 95% CI = 1.4-15.9). The age-specific specific standardized prevalence ratio of morphometric VFs in AS was 3.3 (95% CI 2.1-4.5).
The incidence of morphometric VFs increased in AS. Previous VFs and increased CRP levels predicted future VFs. Further studies are needed to identify the effects of treatment interventions on the prevention of new VFs.
强直性脊柱炎（AS）与椎体骨折（VF）的发病率增加有关；然而，形态计量学椎体骨折的实际发病率和预测因素尚不清楚。本研究调查了一个大型AS队列中新发椎体骨折的发病率和预测因素。
共纳入298例符合改良纽约标准的AS患者，并每两年评估一次脊柱X线片。根据巴斯强直性脊柱炎疾病活动指数、红细胞沉降率、C反应蛋白（CRP）和斯托克强直性脊柱炎脊柱评分（SASSS）评估临床和实验室数据以及影像学进展。椎体骨折根据Genant标准定义。采用Kaplan-Meier方法评估2年和4年时椎体骨折的发病率。计算AS患者与一般人群相比的年龄特异性标准化患病率比（SPR）。
298例患者中，31例（10.8%）在基线时有既往椎体骨折。4年期间，26例患者共发生30例新发椎体骨折。形态计量学椎体骨折的发病率在2年时为4.7%，在4年时为13.6%。多因素logistic回归分析显示，基线时的既往椎体骨折和2年时CRP水平升高是新发椎体骨折的预测因素（比值比（OR）=12.8，95%置信区间（CI）=3.6-45.3；OR=5.4，95%CI=1.4-15.9）。AS中形态计量学椎体骨折的年龄特异性标准化患病率比为3.3（95%CI 2.1-4.5）。
AS中形态计量学椎体骨折的发病率增加。既往椎体骨折和CRP水平升高可预测未来椎体骨折。需要进一步研究以确定治疗干预对预防新发椎体骨折的影响。
