Baker-Lepain Julie C, Lynch John A, Parimi Neeta, McCulloch Charles E, Nevitt Michael C, Corr Maripat, Lane Nancy E
University of California, San Francisco, CA, USA.
Arthritis Rheum. 2012 May;64(5):1457-65. doi: 10.1002/art.34526.
To test whether single-nucleotide polymorphisms (SNPs) of the FRZB gene are associated with hip shape, and to determine whether FRZB variant alleles affect the relationship between hip shape and radiographic osteoarthritis (OA) of the hip.
A nested case-control study of Caucasian women, age ≥65 years, from the Study of Osteoporotic Fractures cohort was performed. Cases (n = 451) were defined as subjects with radiographic evidence of incident hip OA during followup, while controls (n = 601) were subjects in whom no radiographic hip OA was identified at baseline or followup. Statistical shape modeling (SSM) of the digitized hip radiographs was performed to assess the shape of the proximal femur, using 10 independent modes of shape variation generated by principal components analysis. In addition, center-edge angle and acetabular depth were assessed as geometric measurements of acetabular shape. The association of the rs288326 and rs7775 FRZB variant alleles with hip shape was analyzed using linear regression. The effect of these alleles on the relationship between hip shape and radiographic hip OA was analyzed using a logistic regression model with or without inclusion of interaction terms.
The rs288326 and rs7775 alleles were associated with the shape of the proximal femur (SSM mode 2). There was a significant interaction between the rs288326 SNP and proximal femur shape (SSM mode 2) in predicting radiographic hip OA (P for interaction = 0.022). Among subjects with the rs288326 variant allele, there was an increased likelihood of radiographic hip OA in association with increasing quartiles of proximal femur shape mode 2 (for the fourth quartile of mode 2, odds ratio 2.5, 95% confidence interval 1.15, 5.25; P for linear trend = 0.02).
The rs288326 and rs7775 FRZB SNPs are associated with the shape of the proximal femur. The presence of the rs288326 SNP alters the relationship between proximal femur shape and incident radiographic hip OA. These findings suggest that FRZB may serve an important role in determining hip shape and may modify the relationship between hip shape and OA.
检测FRZB基因的单核苷酸多态性（SNP）是否与髋关节形态相关，并确定FRZB变异等位基因是否影响髋关节形态与髋关节影像学骨关节炎（OA）之间的关系。
对来自骨质疏松性骨折研究队列中年龄≥65岁的白人女性进行巢式病例对照研究。病例（n = 451）定义为随访期间有新发髋关节OA影像学证据的受试者，而对照（n = 601）为在基线或随访时未发现髋关节OA影像学表现的受试者。对数字化髋关节X线片进行统计形状建模（SSM），以评估股骨近端的形状，使用主成分分析生成的10种独立形状变化模式。此外，评估中心边缘角和髋臼深度作为髋臼形状的几何测量指标。使用线性回归分析rs288326和rs7775 FRZB变异等位基因与髋关节形态的关联。使用包含或不包含交互项的逻辑回归模型分析这些等位基因对髋关节形态与髋关节影像学OA之间关系的影响。
rs288326和rs7775等位基因与股骨近端形状（SSM模式2）相关。在预测髋关节影像学OA时，rs288326 SNP与股骨近端形状（SSM模式2）之间存在显著交互作用（交互作用P = 0.022）。在携带rs288326变异等位基因的受试者中，随着股骨近端形状模式2四分位数的增加，髋关节影像学OA的可能性增加（模式2的第四四分位数，比值比2.5，95%置信区间1.15，5.25；线性趋势P = 0.02）。
rs288326和rs7775 FRZB SNPs与股骨近端形状相关。rs288326 SNP的存在改变了股骨近端形状与新发髋关节影像学OA之间的关系。这些发现表明，FRZB可能在确定髋关节形态方面起重要作用，并可能改变髋关节形态与OA之间的关系。
