Instrument variables.

Infertility is a significant challenge in modern society, and observed studies have reported the association between telomere length and infertility. Whether this relationship is causal remains controversial.We employed two-sample mendelian randomization (MR) to investigate the causal relationship between leukocyte telomere length (LTL) and major causes of infertility, including male and female infertility, sperm abnormalities, and endometriosis. MR analyses were mainly performed using the inverse variance weighted (IVW) method and complemented with other MR methods.Our findings demonstrate a causal association between LTL and endometriosis (OR1.304, 95% CI (1.122,1.517), p = 0.001), suggesting its potential as a biomarker for this condition. However, we did not observe a significant causal relationship between LTL and other infertility causes.Our study presents compelling evidence on the relationship between LTL and endometriosis. Meanwhile, our study demonstrates that there is no causal relationship between LTL and infertility. This research contributes to the field by shedding light on the importance of LTL in the early diagnosis and intervention of endometriosis.

不孕症是现代社会面临的一项重大健康挑战，已有观察性研究报道了端粒长度与不孕症之间的关联，但二者的关系是否具有因果性仍存在争议。本研究采用两样本孟德尔随机化（two-sample Mendelian randomization, MR）方法，探究白细胞端粒长度（leukocyte telomere length, LTL）与不孕症主要病因之间的因果关联，涵盖男性不孕症、女性不孕症、精子异常及子宫内膜异位症。孟德尔随机化分析主要采用逆方差加权（inverse variance weighted, IVW）法，并辅以其他孟德尔随机化分析方法。研究结果显示，白细胞端粒长度与子宫内膜异位症存在因果关联，优势比（odds ratio, OR）=1.304，95%置信区间（confidence interval, CI）为1.122~1.517，P=0.001，提示白细胞端粒长度或可作为该疾病的生物标志物。然而，本研究未发现白细胞端粒长度与其他不孕症病因存在显著因果关联。本研究为相关领域提供了关于白细胞端粒长度与子宫内膜异位症关联的有力证据。同时，本研究证实白细胞端粒长度与总体不孕症之间不存在因果关联。本研究通过阐明白细胞端粒长度在子宫内膜异位症早期诊断与干预中的重要意义，为该领域的研究作出了重要贡献。