Department of Biometry and Medical Informatics, Otto-von-Guericke University, Magdeburg, Germany.
Maturitas. 2012 Feb;71(2):169-72. doi: 10.1016/j.maturitas.2011.11.024. Epub 2011 Dec 23.
Cathepsin K (CatK) is expressed in high levels in osteoplasts and therefore plays an important role in bone resorption. Thus CatK serum levels may be useful in the diagnosis of chronic bone disorders such as osteopenia and osteoporosis. Therefore we aimed at studying CatK levels in women putatively free of known skeletal disorders.
In total, 121 voluntary women, 27 premenopausal women aged between 20 and 45 years, and 94 postmenopausal women aged 59-81 years, all free of known skeletal disorders were included. All women underwent bone density measurement, routine labor parameter and measurement of serum CatK levels.
Based on WHO criteria, women were stratified in four groups (premenopausal: healthy; postmenopausal: healthy, osteopenia, osteoporosis), and their CatK levels were statistically analyzed.
Using WHO criteria 21 postmenopausal women had normal bone mineral density (BMD), 49 had osteopenia and 24 had osteoporosis. All 27 premenopausal women had normal BMD. There were no significant differences in CatK between these groups. ROC analysis resulted in poor diagnostic validity of CatK, where the area under curve was 0.544. There was no correlation neither between CatK and other biomarkers as C-telopeptide crosslaps (CTX) or bone-specific alkaline phosphatase (BAP) nor between CatK and age.
Serum levels of CatK are not suitable to differentiate women with osteoporosis from healthy subjects.
组织蛋白酶 K（CatK）在破骨细胞中高表达，因此在骨吸收中起重要作用。因此，CatK 血清水平可能有助于诊断骨质疏松症和骨量减少等慢性骨骼疾病。因此，我们旨在研究假定无已知骨骼疾病的女性的 CatK 水平。
共有 121 名自愿参加的女性，27 名年龄在 20-45 岁的绝经前女性和 94 名年龄在 59-81 岁的绝经后女性，均无已知骨骼疾病。所有女性均接受骨密度测量、常规劳动参数和 CatK 血清水平测量。
根据世界卫生组织（WHO）标准，将女性分为四组（绝经前：健康；绝经后：健康、骨质疏松症、骨质疏松症），并对其 CatK 水平进行统计学分析。
根据 WHO 标准，21 名绝经后女性骨密度正常（BMD），49 名女性患有骨质疏松症，24 名女性患有骨质疏松症。所有 27 名绝经前女性的 BMD 均正常。这些组之间的 CatK 水平没有显著差异。ROC 分析表明 CatK 的诊断有效性较差，曲线下面积为 0.544。CatK 与其他生物标志物如 C 端肽交联（CTX）或骨特异性碱性磷酸酶（BAP）之间没有相关性，也与年龄无关。
CatK 血清水平不能区分骨质疏松症患者与健康受试者。
