强直性脊柱炎患者腰椎定量CT骨密度测定及分析

目的 测定强直性脊柱炎患者腰椎骨密度(BMD)，分析骨量变化相关因素，指导治疗。方法 选取强直性脊柱炎患者66例为实验组，26例健康查体者为对照组，登记一般资料及病程、ESR、CRP、BASFI及HLA-B27等指标，应用定量CT测定腰1-5椎体BMD，进行两组间BMD比较及危险因素相关分析。结果 实验组腰椎皮质骨及松质骨BMD均显著低于对照组（269.1±39.8 vs 308.2±49.3 mg/mL，140.8±18.6 vs 190.1±15.7 mg/mL，P<0.01），实验组腰椎松质骨BMD丢失百分率显著高于皮质骨（25.9±10.3% vs 12.7±13.2%，P<0.01），实验组骨量减少和骨质疏松发生率分别为45.5%和39.4%。病程及骶髂关节破坏程度与骨密度负相关，身高、体重、BMI、BASFI、ESR和/或CRP是否升高及HLA-B27阳性与否均与骨密度无相关性。结论 强直性脊柱炎患者腰椎BMD显著降低，骨质疏松发生率高，应早期评估BMD，及时应用生物制剂等防治骨量丢失。

Measurement and analysis of BMD of the lumbar vertebrae using QCT in patients with ankylosing spondylitis

Objective To measure the bone mineral density (BMD) in patients with ankylosing spondylitis (AS), to analyze the relevant factors of bone mass changes, and to guide the clinical treatment. Methods Sixty-six patients with AS were selected and divided into study group. Twenty-six subjects received healthy examination were divided into control group. General information, duration of disease, and indexes including ESR, CRP, Bath AS functional index (BASFI), and HLA-B27 were all recorded. BMD of the lumbar vertebrae (L1-5) was measured using quantitative computed tomography (QCT). The correlation between BMD and the risk factors was analyzed. Results BMD of both lumbar cortical bone and spongy bone in study group was significantly lower than that in control group (269.1±39.8 vs 308.2±49.3mg/ml, 140.8±18.6 vs 190.1±15.7mg/ml, P<0.01, respectively). The loss of BMD of the lumbar spongy bone was significantly higher than that of the lumbar cortical bone in study group (25.9±10.3% vs 12.7±13.2%, P<0.01). The incidence of osteopenia and osteoporosis of the lumbar vertebra was 39.4% and 45.5%, respectively, in study group. The duration of the disease and the degree of the destruction of the sacroiliac joint were negatively correlated with BMD (r=-0.394, P<0.05; r=-0.674, P<0.01). Height, weight, BMI, BASFI, increase of CRP and/or ESR, and positive /negative of HLA-B27 had no correlation with BMD. Conclusion The decrease of the BMD of the lumbar vertebrae in patients with AS is significant. The incidence of osteoporosis in patients with AS is high. So BMD should be measured in patients at the early stage. Biological agents should be used to prevent and treat the loss of bone mass timely.