Abstract：
There is abundant evidence that bone mineral content is highly heritable, while the heritability of bone quality (i.e. trabecular bone score [TBS] and quantitative ultrasound index [QUI]) is rarely investigated. We aimed to disentangle the role of genetic, shared and unique environmental factors on TBS and QUI among Hungarian twins. Our study includes 82 twin (48 monozygotic, 33 same-sex dizygotic) pairs from the Hungarian Twin Registry. TBS was determined by DXA, QUI by calcaneal bone ultrasound. To estimate the genetic and environmental effects, we utilized ACE-variance decomposition. For the unadjusted model of TBS, an AE model provided the best fit with > 80% additive genetic heritability. Adjustment for age, sex, BMI and smoking status improved model fit with 48.0% of total variance explained by independent variables. Furthermore, there was a strong dominant genetic effect (73.7%). In contrast, unadjusted and adjusted models for QUI showed an AE structure. Adjustments improved model fit and 25.7% of the total variance was explained by independent variables. Altogether 70-90% of the variance in QUI was related to additive genetic influences. We found a strong genetic heritability of bone quality in unadjusted models. Half of the variance of TBS was explained by age, sex and BMI. Furthermore, the adjusted model suggested that the genetic component of TBS could be dominant or an epistasis could be present. In contrast, independent variables explained only a quarter of the variance of QUI and the additive heritability explained more than half of all the variance.
摘要：
有大量证据表明骨矿物质含量具有高度遗传性，而很少研究骨质量的遗传度（即小梁骨评分[TBS]和定量超声指数[QUI]）。我们的目的是解开遗传的作用，匈牙利双胞胎在TBS和QUI上共享和独特的环境因素。我们的研究包括82对双胞胎(48个单卵，来自匈牙利双胞胎登记处的33对同性异卵）对。TBS由DXA测定，QUI经跟骨超声检查。为了估计遗传和环境影响，我们利用了ACE-方差分解。对于未调整的TBS模型，AE模型提供了>80%加性遗传遗传力的最佳拟合。调整年龄，性别,BMI和吸烟状况改善了模型拟合，总方差的48.0％由自变量解释。此外，有很强的显性遗传效应(73.7%)。相比之下,未调整和调整后的QUI模型显示AE结构。调整改进了模型拟合，总方差的25.7%由独立变量解释。QUI中总共70-90％的变异与加性遗传影响有关。我们在未调整的模型中发现了骨质量的强遗传遗传性。TBS变异的一半是由年龄解释的，性别和BMI。此外，调整后的模型表明，TBS的遗传成分可能是显性的或可能存在上位性。相比之下,自变量仅解释了QUI方差的四分之一，而加性遗传力解释了所有方差的一半以上。
