Department of Neurology, Chang-Gung Memorial Hospital, Keelung Branch, Taipei, Taiwan, ROC.
Cerebrovasc Dis. 2012;34(1):55-62. doi: 10.1159/000338906. Epub 2012 Jun 29.
Hyponatremia is the most common electrolyte disorder in hospitalized patients, and is frequently a marker of a significant underlying disease. The prognostic value of hyponatremia in patients with acute first-ever ischemic stroke is not known. We aimed to analyze whether hyponatremia in the acute stroke stage contributed to the risk of mortality or recurrent stroke in these patients.
We studied 925 patients presenting with acute first-ever ischemic stroke between 2002 and 2004. Sodium levels were obtained on arrival at the emergency room within 3 days of acute stroke onset. Hyponatremia was defined as a serum sodium concentration of 134 mmol/l or less. Clinical presentation, stroke risk factors, associated medical disease, and outcome were recorded. All patients were followed for 3 years for survival analysis. A multivariate Cox proportional hazards model was used to identify risk factors for 3-year mortality in these patients. We also constructed Kaplan-Meier survival curves, and compared groups with hyponatremia and normonatremia by means of log rank tests for significant differences.
Among the patients with acute first-ever ischemic stroke, 107 (11.6%) were hyponatremic. Among stroke risk factors, the prevalence of diabetes mellitus was significantly higher among hyponatremic patients (p < 0.001). Prevalence of chronic renal insufficiency was also higher in the hyponatremic group (p = 0.002). Clinical presentations, such as the length of acute ward stay, initial impaired consciousness, and clinical course in acute stroke were similar among normo- and hyponatremic patients. Among the complications, pneumonia and urinary tract infection were significantly higher in hyponatremic than in normonatremic patients. After multivariate logistic regression analysis, diabetes mellitus and chronic renal insufficiency were associated with hyponatremia in these patients. Kaplan-Meier analysis indicated that the survival rate was significantly lower in hyponatremic patients than in normonatremic patients (log rank test; p value <0.001). After multivariate Cox proportional hazards model analysis, hyponatremia was a significant predictor of 3-year mortality in these patients after adjustment for related variables (p value = 0.003, hazard ratio = 2.23, 95% confidence interval: 1.30-3.82).
Hyponatremia in the acute stroke stage is a predictor of 3-year mortality in patients with acute first-ever ischemic stroke that is independent of other clinical predictors of adverse outcome.
低钠血症是住院患者中最常见的电解质紊乱，也是许多严重基础疾病的标志物。急性首发缺血性脑卒中患者的低钠血症的预后价值尚不清楚。我们旨在分析急性脑卒中阶段的低钠血症是否会增加这些患者的死亡率或复发性脑卒中的风险。
我们研究了 2002 年至 2004 年间就诊的 925 例急性首发缺血性脑卒中患者。在急性脑卒中发病后 3 天内，在急诊室到达时获得钠水平。低钠血症定义为血清钠浓度为 134mmol/L 或更低。记录临床特征、脑卒中危险因素、相关合并症和结局。所有患者均随访 3 年以进行生存分析。采用多变量 Cox 比例风险模型确定这些患者 3 年死亡率的危险因素。我们还构建了 Kaplan-Meier 生存曲线，并通过对数秩检验比较了低钠血症组和正常钠血症组之间的差异。
在急性首发缺血性脑卒中患者中，107 例（11.6%）为低钠血症患者。在脑卒中危险因素中，低钠血症患者中糖尿病的患病率明显更高（p<0.001）。低钠血症组慢性肾功能不全的患病率也较高（p=0.002）。低钠血症和正常钠血症患者的临床特征，如急性病房住院时间、初始意识障碍和急性脑卒中的临床病程相似。在并发症中，低钠血症患者的肺炎和尿路感染发生率明显高于正常钠血症患者。多变量 logistic 回归分析后，糖尿病和慢性肾功能不全与这些患者的低钠血症相关。Kaplan-Meier 分析表明，低钠血症患者的生存率明显低于正常钠血症患者（对数秩检验；p 值<0.001）。多变量 Cox 比例风险模型分析后，在校正相关变量后，低钠血症是这些患者 3 年死亡率的显著预测因素（p 值=0.003，风险比=2.23，95%置信区间：1.30-3.82）。
急性脑卒中阶段的低钠血症是急性首发缺血性脑卒中患者 3 年死亡率的预测因素，独立于其他不良预后的临床预测因素。
