Introduction. Mildly increased bilirubin concentration has a protective effect on oxidative stress–related diseases. However, it remains unknown whether elevated circulating bilirubin is associated with longer telomere length. The aim of this cross-sectional study was to examine the association between total bilirubin concentration and telomere length. Methods. We used the data from the National Health and Nutrition Examination Survey (NHANES) 1999-2002. The multivariable linear regression model was used to examine the association between total bilirubin concentration and telomere length. The nonlinear relationship was analyzed using a generalized additive model with the smoothing plot. Results. A total of 7818 participants with a mean age of years were included. Compared with the lowest concentration of total bilirubin (Q1), the highest quartile of total bilirubin concentration was associated with longer telomere length in male (, 95 CI%: 0.00, 0.07, ) and female (, 95 CI%: 0.02, 0.04, ). Furthermore, an inverted U-shaped relationship between total bilirubin and telomere length was found. On the left of turning points (), total bilirubin concentration was positively associated with telomere length (, 95 CI%: 0.14, 0.32, ). However, the association between total bilirubin concentration and telomere length was not significant (, 95% CI: -0.01, 0.04, ) above the turning point. Conclusion. This is the first evidence based on a nationally representative survey demonstrating a positive and nonlinear association between total bilirubin concentration and telomere length. Future large-scale prospective studies are warranted to confirm our findings.

中文翻译：

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血清总胆红素浓度与端粒长度的关系：全国健康和营养调查

简介。胆红素浓度轻度升高对氧化应激相关疾病具有保护作用。然而，尚不清楚循环胆红素升高是否与更长的端粒长度相关。这项横断面研究的目的是检查总胆红素浓度与端粒长度之间的关联。方法。我们使用了 1999-2002 年全国健康和营养调查 (NHANES) 的数据。多变量线性回归模型用于检查总胆红素浓度与端粒长度之间的关联。使用带有平滑图的广义加性模型分析非线性关系。结果。共有 7818 名参与者，平均年龄为年被包括在内。与总胆红素（Q1）的最低浓度相比，总胆红素浓度最高的四分位数与男性端粒长度较长有关（, 95 CI%: 0.00, 0.07,)和女性 (, 95 CI%: 0.02, 0.04,）。此外，发现总胆红素和端粒长度之间存在倒 U 型关系。在转折点的左侧 (），总胆红素浓度与端粒长度呈正相关（, 95 CI%: 0.14, 0.32,）。然而，总胆红素浓度与端粒长度之间的关联并不显着（, 95% CI: -0.01, 0.04,)高于转折点。结论。这是基于全国代表性调查的第一个证据，表明总胆红素浓度与端粒长度之间存在正向和非线性关联。未来的大规模前瞻性研究有必要证实我们的发现。