Osteoporosis Prevention & Treatment Clinic and Bone Densitometry Service, University of Alabama at Birmingham, Birmingham, AL 35294-1270, USA.
J Clin Densitom. 2010 Oct-Dec;13(4):385-91. doi: 10.1016/j.jocd.2010.07.003.
High bone mineral density (BMD) is currently not defined by the International Society for Clinical Densitometry with a specific Z-score cutoff; however, it has been suggested that a Z-score greater than or equal to 2.5 is not normal. Institutional Review Board approval was obtained. We evaluated a University dual-energy X-ray absorptiometry database over the previous 24 mo to define Z-score distributions. A Z-score greater than or equal to 2.5 was selected as the outcome event of interest in a logistic regression for adjusted odds ratio. The covariates were height; weight; body mass index (BMI); gender; menopausal status; use of female hormones; presence of insufficiency fractures after 50 yr of age; previous fractures; previous surgeries (back surgeries, vertebroplasty, or kyphoplasty); transplant history; presence of long-term chronic conditions (asthma, lupus, rheumatoid arthritis, or cystic fibrosis); eating disorder; current use of glucocorticoids; smoking status; and current and past use of osteoporosis pharmacological therapies. The study included a total of 8216 patients; 7212 (87.8%) were females, and 1044 (12.2%) were males. In the total population, 13.6% had a Z-score greater than or equal to 2.5 at the lumbar spine, femoral neck, or total hip. Only 0.2% of the males and 0.8% of the females had a Z-score greater than or equal to 2.5 at all 3 sites. The 97.5th percentiles for Z-scores in our population for men and women, respectively, were 3.4 and 3.9 at the lumbar spine, 1.5 and 2.1 at the femoral neck, and 1.6 and 2.2 at the total hip. The 99th percentile for Z-scores for men and women, respectively, were 4.9 and 4.7 at the lumbar spine, 2.4 and 2.7 at the femoral neck, and 2.2 and 2.7 at the total hip. At the lumbar spine, female gender and weight were found to be risk factors for a high Z-score (≥ 2.5). The use of glucocorticoids, bone-active medications, BMI, and smoking were significantly less likely to predict a lumbar spine Z-score greater than or equal to 2.5. A high total-hip Z-score is predicted by increasing weight, whereas those patients using bone-active medications were less likely to have high BMD at the total hip. At the femoral neck, there were no significant risk factors related to a Z-score greater than or equal to 2.5; those taking bone-active medications were significantly less likely to have a high Z-score. These data suggest that a high Z-score is common at 1 or more sites. Further research about the criteria for the diagnosis of high BMD is warranted.
骨矿物质密度（BMD）较高目前并未被国际临床密度测定学会以特定的 Z 评分截断值定义；然而，已有研究表明 Z 评分≥2.5 并不正常。本研究获得了机构审查委员会的批准。我们评估了过去 24 个月内的大学双能 X 射线吸收仪数据库，以确定 Z 评分分布。选择 Z 评分≥2.5 作为感兴趣的对数回归调整比值比的结果事件。协变量包括身高；体重；体重指数（BMI）；性别；绝经状态；女性激素的使用；50 岁以后出现骨量减少性骨折；既往骨折；既往手术（背部手术、椎体成形术或后凸成形术）；移植史；长期慢性疾病（哮喘、狼疮、类风湿关节炎或囊性纤维化）；饮食失调；当前使用糖皮质激素；吸烟状况；以及当前和既往骨质疏松症药物治疗。该研究共纳入了 8216 名患者；7212 名（87.8%）为女性，1044 名（12.2%）为男性。在总人群中，13.6%的人在腰椎、股骨颈或全髋关节处的 Z 评分≥2.5。只有 0.2%的男性和 0.8%的女性在所有 3 个部位的 Z 评分≥2.5。我们人群中男性和女性 Z 评分的第 97.5 百分位数分别为腰椎 3.4 和 3.9，股骨颈 1.5 和 2.1，全髋关节 1.6 和 2.2。男性和女性 Z 评分的第 99 百分位数分别为腰椎 4.9 和 4.7，股骨颈 2.4 和 2.7，全髋关节 2.2 和 2.7。在腰椎处，女性性别和体重是 Z 评分较高（≥2.5）的危险因素。使用糖皮质激素、骨活性药物、BMI 和吸烟显著降低了腰椎 Z 评分≥2.5 的预测概率。体重增加可预测全髋关节 Z 评分较高，而使用骨活性药物的患者全髋关节的骨密度较低。在股骨颈处，没有与 Z 评分≥2.5 相关的显著危险因素；使用骨活性药物的患者出现高 Z 评分的可能性较小。这些数据表明，1 个或多个部位的 Z 评分较高较为常见。进一步研究制定高 BMD 的诊断标准是有必要的。
