Knapen M H, Nieuwenhuijzen Kruseman A C, Wouters R S, Vermeer C
Department of Biochemistry, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
Calcif Tissue Int. 1998 Nov;63(5):375-9. doi: 10.1007/s002239900543.
Serum immunoreactive osteocalcin (irOC) consists of two fractions that differ from each other by their affinity for hydroxyapatite. The high and low affinity fractions are referred to as irOCbound and irOCfree, respectively. To evaluate whether these fractions are determinants for different characteristics of bone or bone metabolism, we have performed a cross-sectional study among 212 apparently healthy women between 20 and 90 years of age. Bone mineral density (BMD) was determined at the lumbar spine, and the right femur neck, trochanter, and Ward's triangle using dual-energy X-ray absorptiometry (DXA). Biochemical markers for bone formation and resorption were determined in serum and in urine. After classification according to menopausal age, an inverse correlation was found in the 1-10 years postmenopausal women between irOCfree and BMD, notably of the Ward's triangle and femur neck. It is concluded that in 1-10 years postmenopausal women, irOCfree is an independent marker for BMD, but that in other age groups the association is less clear or is absent.
血清免疫反应性骨钙素（irOC）由两个部分组成，这两个部分对羟基磷灰石的亲和力不同。高亲和力部分和低亲和力部分分别称为结合型irOC和游离型irOC。为了评估这些部分是否是骨骼或骨代谢不同特征的决定因素，我们对212名年龄在20至90岁之间的明显健康女性进行了一项横断面研究。使用双能X线吸收法（DXA）测定腰椎、右股骨颈、大转子和沃德三角区的骨密度（BMD）。测定血清和尿液中骨形成和骨吸收的生化标志物。根据绝经年龄分类后，在绝经后1至10年的女性中，游离型irOC与BMD呈负相关，尤其是在沃德三角区和股骨颈。结论是，在绝经后1至10年的女性中，游离型irOC是BMD的独立标志物，但在其他年龄组中，这种关联不太明确或不存在。
