Deng Ting, Wu Die, Liu Shan-Shan, Chen Xing-Lin, Zhao Zhen-Wei, Zhang Lan-Lang
Department of Urology, Fuyong People's Hospital of Baoan District, Shenzhen, Guangdong Province, China.
Department of Chinese Medicine and Anorectology, Fuyong People's Hospital of Baoan District, Shenzhen, Guangdong Province, China.
PLoS One. 2025 Jan 14;20(1):e0317315. doi: 10.1371/journal.pone.0317315. eCollection 2025.
Blood urea nitrogen (BUN) is a commonly used biomarker for assessing kidney function and neuroendocrine activity. Previous studies have indicated that elevated BUN levels are associated with increased mortality in various critically ill patient populations. The focus of this study was to investigate the relationship between BUN and 28-day mortality in intensive care patients.
This was a multi-centre retrospective cohort study that made use of data from the eICU Collaborative Research Database. The primary exposure variable was BUN, and the outcome was 28-day mortality. The following variables were included as covariates: age, gender, BMI, white blood cell count, creatinine, GCS score, APACHE IV score, and diabetes. The statistical analyses included univariate and multivariate logistic regression, as well as generalized additive modelling, which was employed to assess the non-linear relationship between BUN and mortality.
A total of 63,757 elderly patients were included in the study, with a 28-day mortality of 6.5%. The univariate analysis indicated that elevated BUN quartiles were associated with an increased risk of mortality. The results of the multivariate analysis further confirmed the non-linear relationship between BUN and mortality. When BUN was less than 32 mg/dL, there was a significant positive association, with an adjusted odds ratio of 1.230 (95% CI: 1.154-1.311, p<0.0001) for every 10 mg/dL increase in BUN. However, when BUN was greater than or equal to 32 mg/dL, BUN level had no significant effect on mortality.
BUN showed a nonlinear, threshold correlation with 28-day mortality in critically ill patients. The higher the BUN, the greater the risk of death if the BUN is below the threshold.
血尿素氮（BUN）是评估肾功能和神经内分泌活动常用的生物标志物。既往研究表明，BUN水平升高与各类重症患者人群死亡率增加相关。本研究的重点是调查重症监护患者中BUN与28天死亡率之间的关系。
这是一项多中心回顾性队列研究，利用了eICU协作研究数据库中的数据。主要暴露变量为BUN，结局为28天死亡率。以下变量作为协变量纳入：年龄、性别、体重指数、白细胞计数、肌酐、格拉斯哥昏迷评分（GCS）、急性生理与慢性健康状况评分系统IV（APACHE IV）评分以及糖尿病。统计分析包括单变量和多变量逻辑回归，以及广义相加模型，用于评估BUN与死亡率之间的非线性关系。
本研究共纳入63757例老年患者，28天死亡率为6.5%。单变量分析表明，BUN四分位数升高与死亡风险增加相关。多变量分析结果进一步证实了BUN与死亡率之间的非线性关系。当BUN低于32mg/dL时，存在显著正相关，BUN每升高10mg/dL，调整后的比值比为1.230（95%CI：1.154 - 1.311，p<0.0001）。然而，当BUN大于或等于32mg/dL时，BUN水平对死亡率无显著影响。
在重症患者中，BUN与28天死亡率呈非线性、阈值相关性。如果BUN低于阈值，BUN越高，死亡风险越大。
