Liu Qiu-Die, Wang Dao-Xin
Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
Int J Chron Obstruct Pulmon Dis. 2025 May 15;20:1493-1508. doi: 10.2147/COPD.S517676. eCollection 2025.
The Prognostic Nutritional Index (PNI), an integrative measure of body's immune and nutritional status, has demonstrated its prognostic value across a range of diseases. However, its role in critically ill patients with Chronic Obstructive Pulmonary Disease (COPD) remains unclear. This study investigates the association between PNI levels and clinical outcomes in critically ill COPD patients, with a focus on identifying its role as a potential predictor of mortality.
A retrospective analysis of 1,250 critically ill COPD patients from the MIMIC-IV (v2.2) database was conducted. Patients were grouped by PNI tertiles. Primary and secondary outcomes were 28-day and 90-day mortality, respectively. Associations were evaluated using restricted cubic splines, Cox proportional hazards regression analysis, and Kaplan‒Meier survival curves. The predictive performance of PNI was assessed via receiver operating characteristic (ROC) curves analysis, and a nomogram integrating Boruta-selected features was developed to enhance clinical utility.
The final cohort comprised 1,250 critically ill COPD patients, with observed mortality rates of 25.3% and 33.2% at 28 and 90 days, respectively. Higher PNI levels were associated with reduced risk of both 28-day and 90-day mortality [28-day HR: 0.95 (95% CI: 0.93-0.97), P < 0.001; 90-day HR: 0.94 (95% CI: 0.93-0.96), P < 0.001]. Restricted cubic spline analysis confirmed this trend. Furthermore, ROC analysis demonstrated the utility of PNI as a predictor for 28-day mortality (AUC: 0.61). Boruta-selected features reinforced the importance of PNI, and the constructed nomogram exhibited excellent predictive accuracy (AUC: 0.712).
Higher PNI is linked to reduced mortality risk in critically ill COPD patients, indicating its potential as a prognostic marker.
预后营养指数（PNI）是一种综合衡量机体免疫和营养状况的指标，已在多种疾病中显示出其预后价值。然而，其在慢性阻塞性肺疾病（COPD）重症患者中的作用仍不明确。本研究调查了COPD重症患者PNI水平与临床结局之间的关联，重点是确定其作为死亡潜在预测指标的作用。
对MIMIC-IV（v2.2）数据库中的1250例COPD重症患者进行回顾性分析。患者按PNI三分位数分组。主要和次要结局分别为28天和90天死亡率。使用受限立方样条、Cox比例风险回归分析和Kaplan-Meier生存曲线评估关联。通过受试者工作特征（ROC）曲线分析评估PNI的预测性能，并开发了一个整合Boruta选择特征的列线图以提高临床实用性。
最终队列包括1250例COPD重症患者，28天和90天的观察死亡率分别为25.3%和33.2%。较高的PNI水平与28天和90天死亡率风险降低相关[28天HR：0.95（95%CI：0.93 - 0.97），P < 0.001；90天HR：0.94（95%CI：0.93 - 0.96），P < 0.001]。受限立方样条分析证实了这一趋势。此外，ROC分析表明PNI可作为28天死亡率的预测指标（AUC：0.61）。Boruta选择的特征强化了PNI的重要性，构建的列线图显示出优异的预测准确性（AUC：0.712）。
较高的PNI与COPD重症患者的死亡风险降低相关，表明其作为预后标志物的潜力。
