Department of Cardiology, Peking University First Hospital, Beijing, China.
Department of Occupational and Environmental Health Sciences, School of Public Health, Peking University, Beijing, China.
Front Endocrinol (Lausanne). 2022 Jun 2;13:844073. doi: 10.3389/fendo.2022.844073. eCollection 2022.
The present investigation was designed to test the association between leukocyte telomere length (LTL) and two simple markers of insulin resistance, that is, homeostatic model assessment of insulin resistance (HOMA-IR) and triglyceride-glucose (TyG) index in U.S. adults without metabolic diseases.
A total of 6489 U.S. adults without diabetes from NHANES 1999-2002 were analyzed. TyG index was calculated as ln [fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2]. HOMA-Index was calculated as fasting plasma glucose (mmol/L) × fasting serum insulin (mU/mL)/22.5. LTL was obtained using the quantitative polymerase chain reaction method. Multivariate linear regression analysis was assessed to evaluate the association of TyG index HOMA-IR with LTL. We further conducted a generalized additive model (GAM) and a fitted smoothing curve with penalized spline method.
It was found that the mean LTL was 5796.1 bp in the measured healthy adults. Overall, TyG index was significantly associated with LTL, while HOMA-IR was not. Compared with participants in tertile 1 of the TyG index, the β (95% CI) for those in the second (8.27 to 8.77) and third (≥ 8.77) were -4.31 (95% CI: -48.1239.49) and -95.98 (95% CI: -145.08-46.89), respectively. Subjects with TyG index ≥ 8.77 had statistically significant shorter LTL (β = -93.33, 95%CI: -134.33~-52.32), compared with TyG index < 8.77. We further explored a dose-response relation between TyG index by a decile approach [≤ 7.81 (reference), 7.81-8.04, 8.04-8.21, 8.21-8.37, 8.37-8.52, 8.52-8.68, 8.68-8.83, 8.83-9.03, 9.03-9.33, and >9.33] and LTL. Five subgroups (TyG index 7.81-8.04, 8.04-8.21, 8.21-8.37, 8.37-8.52, and 8.52-8.68) did not show significant effect on LTL; while there was a significantly shorter LTL for participants with the TyG index > 8.68, supporting a threshold effect of TyG index on LTL.
The results suggested that higher TyG index (> 8.68) was closely related to shorter LTL and the TyG index was better associated with LTL than HOMA-IR.
本研究旨在检测白细胞端粒长度（LTL）与两种简单的胰岛素抵抗标志物（即稳态模型评估的胰岛素抵抗指数（HOMA-IR）和甘油三酯-葡萄糖（TyG）指数）在美国无代谢疾病的成年人中的关联。
对来自 NHANES 1999-2002 年的 6489 名美国无糖尿病成年人进行了分析。TyG 指数的计算方法为 ln[空腹甘油三酯（mg/dL）×空腹血糖（mg/dL）/2]。HOMA-Index 的计算方法为空腹血浆葡萄糖（mmol/L）×空腹血清胰岛素（mU/mL）/22.5。使用定量聚合酶链反应（PCR）方法获取 LTL。采用多元线性回归分析评估 TyG 指数和 HOMA-IR 与 LTL 的相关性。我们进一步进行了广义加性模型（GAM）和带惩罚样条的拟合平滑曲线分析。
在被测量的健康成年人中，平均 LTL 为 5796.1bp。总体而言，TyG 指数与 LTL 显著相关，而 HOMA-IR 则不然。与 TyG 指数三分位 1 组相比，第二（8.27-8.77）和第三（≥8.77）组的β（95%CI）分别为-4.31（95%CI：-48.1239.49）和-95.98（95%CI：-145.08-46.89）。TyG 指数≥8.77的受试者 LTL 明显缩短（β=-93.33，95%CI：-134.33~-52.32），与 TyG 指数<8.77的受试者相比。我们进一步通过十分位数方法[≤7.81（参考），7.81-8.04，8.04-8.21，8.21-8.37，8.37-8.52，8.52-8.68，8.68-8.83，8.83-9.03，9.03-9.33 和>9.33]探讨了 TyG 指数与 LTL 之间的剂量反应关系。五个亚组（TyG 指数 7.81-8.04、8.04-8.21、8.21-8.37、8.37-8.52 和 8.52-8.68）对 LTL 没有显著影响；而 TyG 指数>8.68的参与者的 LTL 明显缩短，支持 TyG 指数对 LTL 存在阈值效应。
结果表明，较高的 TyG 指数（>8.68）与较短的 LTL 密切相关，且 TyG 指数与 LTL 的相关性优于 HOMA-IR。
