甲状腺癌导致肾脏疾病的发病率在全球范围内不断上升。观察性研究无法确定甲状腺癌是否独立与肾脏疾病相关。我们采用Mendelian randomization (MR)方法进行遗传学调查，研究甲状腺癌对免疫球蛋白A肾病(IgAN)的因果关系。我们通过MR分析探讨了甲状腺癌对IgAN的因果效应。与甲状腺癌相关的遗传座位和单核苷酸多态性有52个。这个MR分析的主要方法是逆方差加权(IVW)方法，MR-Egger是次要方法。权重模式和带惩罚的加权中位数方法用于进行敏感性分析。本研究中，随机效应IVW模型显示了预测的甲状腺癌对IgAN风险的因果影响(OR，1.191；95% CI为1.131-1.253，P < 0.001)。在权重模式方法(OR，1.048；95% CI为0.980-1.120，P = 0.179)和带惩罚的加权中位数方法(OR，1.185；95% CI为1.110-1.264，P < 0.001)中也得到了类似的结果。然而，MR-Egger方法显示甲状腺癌减少了IgAN的风险，但差异不显著(OR，0.948；95% CI为0.855-1.051，P = 0.316)。留一外敏感性分析没有显示任何个体SNP对甲状腺癌和IgAN之间的关联有推动作用。IVW模型表明甲状腺癌与IgAN之间存在显著的因果关系。然而，MR-Egger方法的点估计方向相反。根据MR原则，本研究的证据不支持甲状腺癌和IgAN之间存在稳定显著的因果关联。结果仍需未来研究进行确认。© 2023. BioMed Central Ltd., part of Springer Nature.

The incidence of kidney disease caused by thyroid cancer is rising worldwide. Observational studies cannot recognize whether thyroid cancer is independently associated with kidney disease. We performed the Mendelian randomization (MR) approach to genetically investigate the causality of thyroid cancer on immunoglobulin A nephropathy (IgAN).We explored the causal effect of thyroid cancer on IgAN by MR analysis. Fifty-two genetic loci and single nucleotide polymorphisms were related to thyroid cancer. The primary approach in this MR analysis was the inverse variance weighted (IVW) method, and MR‒Egger was the secondary method. Weighted mode and penalized weighted median were used to analyze the sensitivity. In this study, the random-effect IVW models showed the causal impact of genetically predicted thyroid cancer across the IgAN risk (OR, 1.191; 95% CI, 1.131-1.253, P < 0.001). Similar results were also obtained in the weighted mode method (OR, 1.048; 95% CI, 0.980-1.120, P = 0.179) and penalized weighted median (OR, 1.185; 95% CI, 1.110-1.264, P < 0.001). However, the MR‒Egger method revealed that thyroid cancer decreased the risk of IgAN, but this difference was not significant (OR, 0.948; 95% CI, 0.855-1.051, P = 0.316). The leave-one-out sensitivity analysis did not reveal the driving influence of any individual SNP on the association between thyroid cancer and IgAN.The IVW model indicated a significant causality of thyroid cancer with IgAN. However, MR‒Egger had a point estimation in the opposite direction. According to the MR principle, the evidence of this study did not support a stable significant causal association between thyroid cancer and IgAN. The results still need to be confirmed by future studies.© 2023. BioMed Central Ltd., part of Springer Nature.