Association of serum sodium level and its fluctuation with mortality in patients with hospital- acquired acute kidney injury
10.3760/cma.j.cn441217-20241029-01044
- VernacularTitle:院内急性肾损伤患者血钠水平及其波动与死亡的相关性分析
- Author:
Shuo XUE
1
;
Lingyi XU
;
Shiyue YAN
;
Si LIU
;
Linger TANG
;
Jinwei WANG
;
Xizi ZHENG
;
Li YANG
Author Information
1. 北京大学第一医院急诊科，北京 100034
- Publication Type:Journal Article
- Keywords:
Hypernatremia;
Hyponatremia;
Acute kidney injury;
Mortality
- From:
Chinese Journal of Nephrology
2025;41(8):587-594
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the serum sodium level and its fluctuation in patients with hospitalized acquired acute kidney injury (AKI) and explore their impacts on in-hospital mortality.Methods:It was a single-center retrospective study. The adult patients developing hospital-acquired AKI and receiving at least twice serum sodium tests admitted to Peking University First Hospital from January 1, 2018, to December 31, 2020 were included. Dysnatremia included hyponatremia (< 135 mmol/L) and hypernatremia (>145 mmol/L). The patients were divided into hyponatremia group, normal serum sodium group and hypernatremia group, and the differences of clinical data among the three groups were compared. The fluctuation of serum sodium level was evaluated by coefficient of variation. A restricted cubic spline was applied to investigate the association between serum sodium level at AKI onset and mortality. Poisson regression analysis was used to explore the mortality risk of dysnatremia at AKI onset, dysnatremia at admission, and coefficient of variation of serum sodium, respectively.Results:Among the enrolled 1 475 AKI patients, the age was 66.0 (55.0, 78.0) years, and 850 patients (57.6%) were males. The estimated glomerular filtration rate was 77.3 (50.4, 97.6) ml·min -1·(1.73 m 2) -1. The time from admission to AKI onset was 8 (4, 15) days. The incidence of hyponatremia and hypernatremia at admission were 19.6% (289/1 475) and 2.6% (39/1 475), respectively, while the incidence at AKI onset was 24.0% (354/1 475) and 12.7% (188/1 475), respectively. There was statistically significant difference in terms of age, the initial classification distribution of AKI, serum sodium at admission, serum sodium at the occurrence of AKI, the lowest serum sodium at hospitalization, the highest serum sodium at hospitalization, the coefficient of variation of serum sodium, and the proportions of heart failure, stroke, disseminated intravascular coagulation, sepsis, acute respiratory distress syndrome, shock, prerenal causes, circle diuretics and aldosterone antagonists among hyponatremia group, normal serum sodium group and hypernatremia group (all P<0.05). The restricted cubic spline analysis showed a "U"-shaped correlation between serum sodium level at AKI onset and in-hospital mortality. Poisson regression analysis showed that after adjusting for age, gender, number of chronic comorbidities, initial classification of AKI, basal estimated glomerular filtration rate and number of acute disease state, with normal serum sodium as the reference, hyponatremia ( RR=1.56, 95% CI 1.14-2.13) and hypernatremia ( RR=1.71, 95% CI 1.23-2.39) at AKI onset were correlated with an increased risk of in-hospital mortality. Hyponatremia at admission was correlated with an increased risk of in-hospital mortality ( RR=2.13, 95% CI 1.62-2.79), while there was no statistically significant association between hypernatremia and in-hospital mortality ( RR=1.22, 95% CI 0.62-2.44). After further adjusting serum sodium levels at admission and at the occurrence of AKI, the coefficient of variation of serum sodium level was still correlated with an increased risk of in-hospital mortality ( RR=1.23, 95% CI 1.14-1.33). Conclusions:Dysnatremia is common in patients with hospital-acquired AKI. The serum sodium level at AKI onset is correlated with in-hospital death in a "U" shape. Dysnatremia and serum sodium fluctuation are associated with an increased risk of in-hospital mortality.
