Table_1_Telomere length as a marker of changes in body composition and fractures-an analysis of data from the NHANES 2001-2002.docx

PurposeThere has been an association between changes in body composition, fracture incidence, and age in previous studies. Telomere length (TL) has been proposed as a biomarker of aging. However, the relationship between body composition, fractures, and TL has rarely been studied. Therefore, this study aimed to investigate the correlation between TL and body composition and fractures.
Patients and methods: 20950 participants from the 2001-2002 National Health and Nutrition Examination Survey (NHANES) were included in the final analysis. In NHANES, body compositions were measured with DXA, and TL was determined with quantitative PCR. Correlation analysis of TL and body composition was conducted using multivariate weighted linear regression and logistic regression models.
ResultsThe results showed that TL positively correlated with bone mineral density (BMD) and bone mineral content (BMC) in most body parts. However, BMD and BMC were negatively connected with TL in the upper limbs and skull. Fat content was negatively associated with TL, while muscle content was positively linked to TL. In addition, TL’s trend analysis results were consistent with the regression model when transformed from a continuous to a classified variable. An increase in TL was associated with a higher incidence of wrist fractures, while a decrease in spine fractures. The above correlation also has a certain degree of sex specificity.
ConclusionOur study indicate that TL is associated with body composition as well as fractures, but further research is needed to confirm these contrasting associations in the skull, upper limbs, and wrists.

研究目的：过往研究已证实身体成分变化、骨折发生率与年龄之间存在关联。端粒长度（Telomere length, TL）被提议作为衰老的生物标志物。然而目前针对身体成分、骨折与端粒长度三者之间关系的研究仍较为匮乏。因此本研究旨在探讨端粒长度与身体成分及骨折之间的相关性。
患者与方法：本研究最终纳入2001-2002年美国国家健康与营养调查（National Health and Nutrition Examination Survey, NHANES）的20950名参与者作为最终分析对象。在NHANES研究方案中，身体成分通过双能X线吸收测定法（DXA）进行测量，端粒长度则采用定量PCR（quantitative PCR）进行测定。本研究采用多变量加权线性回归与逻辑回归模型，开展端粒长度与身体成分的相关性分析。
研究结果：结果显示，在多数身体部位中，端粒长度与骨密度（Bone Mineral Density, BMD）及骨矿物质含量（Bone Mineral Content, BMC）呈正相关。但在上肢与颅骨部位，骨密度与骨矿物质含量则与端粒长度呈负相关。脂肪含量与端粒长度呈负相关，而肌肉含量与端粒长度呈正相关。此外，当端粒长度从连续变量转换为分类变量时，趋势分析结果与回归模型结果一致。端粒长度增加与腕部骨折发生率升高相关，而与脊柱骨折发生率降低相关。上述相关性还存在一定程度的性别特异性。
结论：本研究表明端粒长度与身体成分及骨折均存在关联，但针对颅骨、上肢与腕部的上述反向关联，仍需开展进一步研究予以验证。