Liu Jie, Zhao Jin, Yuan Jinguo, Yu Zixian, Qin Yunlong, Xing Yan, Zheng Qiao, Zhao Yueru, Ning Xiaoxuan, Sun Shiren
Department of Nephrology, Xijing Hospital, The Fourth Military Medical University.
Medical School, Yan'an University.
Environ Health Prev Med. 2025;30:21. doi: 10.1265/ehpm.24-00329.
Chronic kidney disease (CKD) poses a major global health challenge, often foreshadowing poor patient outcomes. The C-reactive protein to albumin ratio (CAR) serves as a pivotal biomarker, demonstrating a strong correlation with adverse outcomes in cardiovascular disease (CVD). This study sought to examine the correlation between CAR and the risk of all-cause and cardiovascular mortality in patients with CKD stages 3-5.
This study utilized data of CKD patients from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2010, with follow-up to December 31, 2019. The optimal CAR cutoff value was identified utilizing the method of maximally selected rank statistics. Multivariable Cox proportional hazards regression model, restricted cubic splines (RCS) model, and subgroup analysis were employed to assess the association between CAR and mortality among CKD patients.
During a median (with interquartile range) follow-up period of 115 (112,117) months among 2,841 CKD individuals, 1,893 deaths were observed, including 692 deaths due to CVD events. Based on the RCS analysis, a non-linear correlation was observed between CAR and mortality. Using 0.3 as the optimal CAR cutoff value, the cohort was divided into high and low groups. In the fully adjusted model, CKD patients with high CAR values exhibited an elevated risk of all-cause mortality (hazard ratio [HR] 1.53, 95% confidence interval [CI] 1.28-1.83, P < 0.001) and cardiovascular mortality (HR 1.48, 95% CI 1.08-2.02, P = 0.014). Compared to the population aged >65 years (HR 1.32, 95% CI 0.99-1.76, P = 0.064), the risk of cardiovascular mortality was significantly higher in those aged ≤65 years (HR 2.19, 95% CI 1.18-4.09, P = 0.014) with elevated CAR levels.
A notable correlation exists between the elevation of CAR and increased all-cause and cardiovascular mortality, suggesting its potential as an independent indicator for evaluating the prognosis of patients with CKD stages 3-5.
慢性肾脏病（CKD）是一项重大的全球健康挑战，常常预示着患者预后不良。C反应蛋白与白蛋白比值（CAR）是一种关键生物标志物，与心血管疾病（CVD）的不良结局密切相关。本研究旨在探讨CAR与3-5期CKD患者全因死亡和心血管死亡风险之间的相关性。
本研究利用了1999年至2010年美国国家健康与营养检查调查（NHANES）中CKD患者的数据，并随访至2019年12月31日。采用最大选择秩统计方法确定最佳CAR临界值。采用多变量Cox比例风险回归模型、限制性立方样条（RCS）模型和亚组分析来评估CAR与CKD患者死亡率之间的关联。
在2841例CKD患者中，中位（四分位间距）随访期为115（112,117）个月，观察到1893例死亡，其中692例死于CVD事件。基于RCS分析，观察到CAR与死亡率之间存在非线性相关性。以0.3作为最佳CAR临界值，将队列分为高、低两组。在完全调整模型中，CAR值高的CKD患者全因死亡风险升高（风险比[HR]1.53，95%置信区间[CI]1.28-1.83，P<0.001）和心血管死亡风险升高（HR 1.48，95%CI 1.08-2.02，P = 0.014）。与年龄>65岁的人群（HR 1.32，95%CI 0.99-1.76，P = 0.064）相比，年龄≤65岁且CAR水平升高的人群心血管死亡风险显著更高（HR 2.19，95%CI 1.18-4.09，P = 0.014）。
CAR升高与全因死亡和心血管死亡增加之间存在显著相关性，表明其有可能作为评估3-5期CKD患者预后的独立指标。
