Abstract: Background　In recent years，the prevalence of papillary thyroid carcinoma（PTC）has been increasing in China. Literature suggests an association between non-alcoholic fatty liver disease（NAFLD）and PTC. However，there is limited research on the relationship between metabolic dysfunction-associated steatotic liver disease（MASLD）- the latest definition incorporating metabolic criteria - and the occurrence of PTC. Objective　To explore the influencing factors of PTC onset and evaluate the predictive value of MASLD for PTC development. Methods　A total of 642 patients who underwent thyroid nodule resection at the Third Affiliated Hospital of Soochow University from May to September 2023 were included in the study. Among them，323 PTC patients were assigned to the malignant group，and 319 patients with benign nodules were assigned to the benign group. General characteristics were compared between the benign and malignant groups，as well as between male and female patients. Univariate and multivariate Logistic regression analyses were performed to identify factors influencing PTC. A nomogram prediction model was constructed to estimate the risk of PTC development. The predictive performance and discriminative ability of each factor and the model were assessed using receiver operating characteristic（ROC）curve analysis. Results　Compared to the benign group，the malignant group had lower age，high-density lipoprotein cholesterol（HDL-C），and total cholesterol（TC），but higher proportions of males，BMI，thyroid-stimulating hormone（TSH），and MASLD（P< 0.05）. Male patients had higher BMI，alanine aminotransferase（ALT），triglycerides（TG），neutrophil count，lymphocyte count，monocyte count，and MASLD prevalence，but lower HDL-C，TC，platelet count，platelet-to-lymphocyte ratio（PLR），and lymphocyte-to-monocyte ratio（LMR）than female patients（P<0.05）. Multivariate Logistic regression analysis showed that male sex（OR=1.581，95%CI=1.040-2.412，P=0.033），elevated BMI（OR=1.066，95%CI=1.002-1.136，P=0.045）and elevated TSH（OR=1.662，95%CI=1.401-1.997，P<0.001）were risk factors for PTC，while older age（OR=0.931，95%CI=0.916-0.945，P<0.001）was a protective factor. Based on the regression equation Logit（P）=0.381+0.466×sex-0.070×age+0.503×TSH+0.086×BMI，a nomogram prediction model for PTC risk was established. The model achieved an AUC of 0.798（95%CI=0.764-0.832）for predicting PTC，with an optimal cutoff value of 0.502，a sensitivity of 0.721，and a specificity of 0.752. Conclusion　Male gender，increased BMI，and elevated TSH are independent risk factors for the development of PTC，while increasing age is a protective factor. MASLD is not an independent risk factor. The constructed combined prediction model has good clinical predictive value for the development of PTC.

Key words: Thyroid cancer, papillary；Metabolic dysfunction-associated steatotic liver disease；Inflammatory marker；BMI；Thyroid stimulating hormone；Nomograms

摘要： 背景　近年来，甲状腺乳头状癌（PTC）的患病率在国内呈上升趋势。文献表明非酒精性脂肪肝（NAFLD）与PTC相关。NAFLD最新纳入代谢因素的定义代谢相关脂肪变性肝病（MASLD）与PTC发生的相关文献较少。目的　探究PTC发病的影响因素，并评价MASLD对PTC发病的预测价值，方法　选取苏州大学附属第三医院2023年5—9月行甲状腺肿物切除术的出院患者642例为研究对象，其中PTC患者323例归为恶性组，良性结节患者319例归为良性组。比较良性组和恶性组及不同性别患者的一般资料。采用单因素和多因素Logistic回归分析探究PTC的影响因素，构建包含各因素预测PTC发病风险的列线图预测模型，采用受试者工作特征（ROC）曲线分析各因素及预测模型对PTC的预测性能和判别能力。结果　恶性组患者年龄、高密度脂蛋白胆固醇（HDL-C）、总胆固醇（TC）低于良性组，男性比例、BMI、促甲状腺激素（TSH）、MASLD比例高于良性组（P<0.05）；男性患者BMI、丙氨酸氨基转肽酶（ALT）、三酰甘油（TG）、中性粒细胞计数、淋巴细胞计数、单核细胞计数、MASLD比例高于女性患者，HDL-C、TC、血小板计数、血小板与淋巴细胞比值（PLR）、淋巴细胞与单核细胞比值（LMR）低于女性患者（P<0.05）。多因素Logistic回归分析结果显示，男性（OR=1.581，95%CI=1.040~2.412，P=0.033）、BMI升高（OR=1.066，95%CI=1.002~1.136，P=0.045）、TSH升高（OR=1.662，95%CI=1.401~1.997，P<0.001）是PTC发病的危险因素，年龄增长（OR=0.931，95%CI=0.916~0.945，P<0.001）是PTC发病的保护因素。根据回归方程Logit（P）=0.381+0.466×性别-0.070×年龄+0.503×TSH+0.086×BMI，建立PTC发病风险列线图预测模型，该模型预测PTC发病的AUC为0.798（95%CI=0.764~0.832），最佳截断值为0.502，灵敏度为0.721，特异度为0.752。结论　男性、BMI升高、TSH升高为PTC发病的独立危险因素，年龄增大是保护因素，MASLD不是独立危险因素。构建的联合预测模型对PTC发病具有较好的临床预测价值。

关键词: 甲状腺癌, 乳头状；代谢相关脂肪变性肝病；炎症标志物；体质指数；促甲状腺激素；列线图