Data from: Low serum sodium levels at hospital admission: outcomes among 2.3 million hospitalized patients

Background: Hyponatremia is the most common electrolyte disorder among hospitalized patients. Controversies still exist over the relationship between hyponatremia and outcomes of hospitalized patients. Methods: To analyze the association of low serum sodium levels at hospital admission with in-hospital mortality and patient disposition and to compare the distribution of the risk of death associated with hyponatremia across the lifespan of hospitalized patients, we conducted an observational study of 2.3 million patients using data extracted from the Cerner Health Facts database between 2000 and 2014. Logistic regression models were used in the analyses. Results: At hospital admission 14.4% of hospitalized patients had serum sodium levels [Na] <135 mEq/L. In adjusted multinomial logistic regression analysis, we found that the risk of in-hospital mortality significantly increases for [Na] levels < 135 or ≥143 to ≤145 mEq/L compared to the reference interval of 140 to <143 mEq/L (p<0.001). We observed similar trends for the relationship between [Na] levels and discharge to hospice or to a nursing facility. We demonstrated that younger age groups (18 to <45, 45 to <65) had a higher risk of in-hospital mortality compared to older age groups (65 to <75, ≥75) for [Na] levels <130 mEq/L or 143 to ≤145 mEq/L (p<0.001). Conclusions: Hyponatremia is common among hospitalized patients and is significantly associated with in-hospital mortality, discharge to hospice or to a nursing facility. The risk of death and other outcomes was more evident for [Na] <135 mEq/L. The mortality associated with low [Na] was significantly higher in younger versus older patients.

背景：低钠血症（Hyponatremia）是住院患者中最为常见的电解质紊乱性疾病，目前关于低钠血症与住院患者临床预后的关联仍存在诸多争议。方法：为探讨住院患者入院时血清钠水平降低与住院死亡率及患者出院去向的关联，并比较低钠血症相关死亡风险在住院患者全生命周期中的分布差异，本研究依托2000年至2014年从Cerner Health Facts数据库提取的230万例患者数据开展了一项观察性研究，分析过程采用logistic回归（Logistic regression）模型。结果：入院时，14.4%的住院患者血清钠浓度[Na]＜135 mEq/L。经校正的多项logistic回归分析显示，以140~＜143 mEq/L为参考区间，当患者血清钠浓度＜135 mEq/L或处于≥143~≤145 mEq/L区间时，其住院死亡风险均显著升高（p＜0.001）。血清钠水平与患者临终关怀出院或转入护理机构的相关性亦呈现相似趋势。进一步分析表明，对于血清钠＜130 mEq/L或143~≤145 mEq/L的患者，年轻年龄组（18~＜45岁、45~＜65岁）的住院死亡风险显著高于年长年龄组（65~＜75岁、≥75岁）（p＜0.001）。结论：低钠血症在住院患者中较为高发，且与住院死亡率、临终关怀出院或转入护理机构的临床结局显著相关。当血清钠浓度＜135 mEq/L时，患者的死亡及其他临床结局风险更为突出。与老年患者相比，低钠血症相关的住院死亡率在年轻患者中显著更高。