Sanders Jason L, Newman Anne B
Epidemiol Rev. 2013;35(1):112-31. doi: 10.1093/epirev/mxs008. Epub 2013 Jan 9.
Telomeres are nucleoprotein caps flanking DNA. They are shortened by cell division and oxidative stress and are lengthened by the enzyme telomerase and DNA exchange during mitosis. Short telomeres induce cellular senescence. As an indicator of oxidative stress and senescence (2 processes thought to be fundamental to aging), telomere length is hypothesized to be a biomarker of aging. This hypothesis has been tested for more than a decade with epidemiologic study methods. In cross-sectional studies, researchers have investigated whether leukocyte telomere length (LTL) is associated with demographic, behavioral, and health variables. In prospective studies, baseline LTL has been used to predict mortality and occasionally other adverse health outcomes. Conflicting data have generated heated debate about the value of LTL as a biomarker of overall aging. In this review, we address the epidemiologic data on LTL and demonstrate that shorter LTL is associated with older age, male gender, Caucasian race, and possibly atherosclerosis; associations with other markers of health are equivocal. We discuss the reasons for discrepancy across studies, including a detailed review of methods for measuring telomere length as they apply to epidemiology. Finally, we conclude with questions about LTL as a biomarker of aging and how epidemiology can be used to answer these questions.
端粒是位于DNA两侧的核蛋白帽。它们会因细胞分裂和氧化应激而缩短，并在有丝分裂过程中通过端粒酶和DNA交换而延长。短端粒会诱导细胞衰老。作为氧化应激和衰老（这两个过程被认为是衰老的基础）的一个指标，端粒长度被假设为衰老的一个生物标志物。十多年来，这一假设一直通过流行病学研究方法进行检验。在横断面研究中，研究人员调查了白细胞端粒长度（LTL）是否与人口统计学、行为和健康变量相关。在前瞻性研究中，基线LTL已被用于预测死亡率，偶尔也用于预测其他不良健康结局。相互矛盾的数据引发了关于LTL作为整体衰老生物标志物价值的激烈辩论。在这篇综述中，我们阐述了关于LTL的流行病学数据，并证明较短的LTL与年龄较大、男性、白种人以及可能的动脉粥样硬化有关；与其他健康标志物的关联尚不确定。我们讨论了各研究结果存在差异的原因，包括对适用于流行病学的端粒长度测量方法的详细综述。最后，我们以关于LTL作为衰老生物标志物的问题以及如何利用流行病学来回答这些问题作为结论。
