Correlation of plasma microRNA-21 expression and bone turnover markers in postmenopausal women

<b>Objectives:</b> This study assessed the correlation of plasma microRNA-21 expression and bone turnover markers (BTMs: CTx, P1NP) in healthy Thai postmenopausal women. We secondarily compared microRNA-21 expression between participants with normal and low bone mineral density (BMD: osteopenia and osteoporosis). <b>Methods:</b> Postmenopausal women who had never been diagnosed with fracture or never used anti-osteoporosis drugs were included in this study. Baseline characteristics were collected from all 195 participants. BTMs and plasma miR-21-5p were analyzed from blood collection at 8:00 and 9:00 am after overnight fasting for at least 8 h. <b>Results:</b> There was no significant correlation between miR-21-5p and any of the BTMs (CTx, <i>r</i> = 0.094, <i>p</i> = 0.19; P1NP, <i>r</i> = 0.05, <i>p</i> = 0.485). Significant correlation between miR-21-5p and P1NP was found when participants were further categorized into those aged ≥70 years (<i>r</i> = 0.46, <i>p</i> = 0.05) and those having osteoporosis (<i>r</i> = 0.51, <i>p</i> = 0.06). Slight negative correlations were found between miR-21-5p and BMD. There was statistically significant higher expression of miR-21-5p in those with low BMD when compared to the normal BMD group (<i>p</i> <b>Conclusion:</b> In this study, we did not find significant correlation between plasma microRNA-21-5p expression and the BTMs. Nevertheless, there seemed to be higher expression of miR-21-5p in the low BMD participants.

**研究目的**：本研究旨在评估健康泰国绝经后女性血浆微小RNA-21（microRNA-21）的表达水平与骨转换标志物（bone turnover markers, BTMs：CTx、P1NP）之间的相关性，并次要比较骨密度正常与骨密度降低（骨量减少与骨质疏松症）受试者的微小RNA-21表达差异。
**研究方法**：本研究纳入此前未被诊断为骨折、且未使用抗骨质疏松药物的绝经后女性。共收集195名受试者的基线特征信息。所有受试者均于隔夜空腹至少8小时后，在上午8:00至9:00采集血液样本，用于检测骨转换标志物及血浆miR-21-5p的表达水平。
**研究结果**：miR-21-5p的表达水平与所有骨转换标志物均无显著相关性（CTx：r=0.094，p=0.19；P1NP：r=0.05，p=0.485）。当将受试者进一步按年龄≥70岁分组，以及按骨质疏松症分组时，miR-21-5p与P1NP则呈现出显著相关性（年龄≥70岁组：r=0.46，p=0.05；骨质疏松症组：r=0.51，p=0.06）。miR-21-5p与骨密度之间存在轻度负相关。与骨密度正常组相比，骨密度降低组的miR-21-5p表达水平具有统计学意义的升高（p<）
**研究结论**：本研究未发现血浆miR-21-5p的表达水平与骨转换标志物之间存在显著相关性。然而，骨密度降低的受试者的miR-21-5p表达水平似乎更高。