Cardiovascular disease (CVD) is the primary cause of death in patients undergoing peritoneal dialysis (PD) , with malnutrition being one of the significant risk factors for both CVD and mortality. The prognostic nutritional index (PNI) serves as a comprehensive indicator of a patient's immune, inflammatory, and nutritional status. Due to its convenience and reliability, PNI has been widely used in prognostic assessments across various diseases, including cancer. Recent studies have indicated that PNI not only reflects the prognosis of PD patients but is also closely related to their cardiovascular health. However, the relationship between nutritional status at different time points and the prognosis of PD patients requires further exploration.

To explore the relationship between first-year PNI and CVD mortality in PD patients.

This multicenter, retrospective observational cohort study included 1 640 PD patients who initiated treatment between January 1, 2000, and July 1, 2019, at four medical centers: Nanfang Hospital, Southern Medical University, Shunde Hospital of Southern Medical University, the First People's Hospital of Foshan, and Ganzhou People's Hospital. Patients were followed up until July 1, 2021, with the primary endpoint being CVD mortality. A restricted cubic spline (RCS) was used to further examine the non-linear association between PNI and the risk of CVD mortality. Survival curves were generated using the Kaplan-Meier method, and receiver operating characteristic (ROC) curves for predicting CVD mortality based on PNI were analyzed, with an optimal cut-off of 40.46 dividing patients into low PNI (703 patients) and high PNI (937 patients) groups. The impact of PNI on CVD mortality was assessed using Log-rank tests and Cox regression analysis.

The median follow-up period was 30 months, during which 148 patients died, 73 of whom from CVD (49.32%) . RCS results indicated a linear association between PNI and CVD mortality events (P for Nonlinear=0.655) . The area under the ROC curve (AUC) for PNI predicting CVD mortality was 0.717 (95%CI=0.659-0.775, P<0.001) , with a sensitivity of 74.0% and a specificity of 58.6%. Kaplan-Meier analysis showed statistically significant differences in CVD survival curves between the low and high PNI groups (χ²=26.685, P<0.001) . Multivariable Cox regression analysis, adjusted for gender, age, and history of CVD, indicated that a low PNI remains an independent predictor of CVD mortality (HR=7.76, 95%CI=1.72-35.06, P=0.008) . Subgroup analysis confirmed the robustness of these findings without significant interaction effects.

A reduced PNI is an independent factor influencing CVD mortality in PD patients, making the first-year PNI score a valuable tool for prognostic assessment in PD management.

心血管疾病（CVD）是腹膜透析（PD）患者死亡的主要原因，而营养不良是PD患者发生CVD及死亡的重要危险因素之一。预后营养指数（PNI）作为一种综合评估患者免疫、炎症和营养状态的指标，因其具有便利性与可靠性等优点，在肿瘤等多种疾病的预后评估中得到了广泛应用。然而，不同时间点的营养状态与PD患者预后之间的关系仍有待进一步探究。

探讨PD患者首年PNI与CVD死亡之间的关系。

本研究为多中心、回顾性观察性队列研究，纳入2000-01-01—2019-07-01在南方医科大学南方医院、南方医科大学顺德医院、佛山市第一人民医院以及赣州市人民医院4所中心置管并开始接受PD治疗的1 640例PD患者作为研究对象。对患者进行随访，随访截止时间为2021-07-01，终点事件为CVD死亡并记录患者生存时间及具体死亡原因。应用限制性立方条图（RCS）分析PNI与PD患者CVD死亡风险之间的非线性关联；采用Kaplan-Meier法绘制PD患者的生存曲线，绘制PNI预测PD患者CVD死亡的受试者工作特征（ROC）曲线，并根据最佳截断值（cut-off=40.46）将患者分为低PNI组703例与高PNI组937例；采用Log-rank检验和Cox风险回归模型分析探讨PNI对PD患者CVD死亡的影响。

本研究中位随访时间为30个月，随访期间共148例患者死亡，其中CVD死亡73例（49.32%）。RCS结果表明，PNI与CVD死亡事件呈线性关联（P for Nonlinear=0.655）。ROC曲线显示，PNI预测PD患者CVD死亡的曲线下面积（AUC）为0.717（95%CI=0.659~0.775，P<0.001），灵敏度为74.0%，特异度为58.6%。Kaplan-Meier生存分析结果显示，低PNI组CVD生存率低于高PNI组（χ²=26.685，P<0.001）。多因素Cox风险回归模型分析，校正性别、年龄及CVD病史等混杂因素后，低PNI组仍是CVD死亡的独立预测因素（HR=7.76，95%CI=1.72~35.06，P=0.008），亚组分析结果仍稳健，无明显交互作用。

PNI降低是PD患者CVD死亡的独立影响因素，PD首年PNI评分在评估PD患者预后有一定的指导意义。