Electrolytes and clinical outcomes in patients with acute ischemic stroke or transient ischemic attack

Background Abnormal electrolytes were closely related to the prognosis of various diseases, the prognostic role of electrolytes in stroke has not been investigated well. We aimed to investigate the association between electrolytes and clinical outcomes in patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA). Methods Data were recruited from the China National Stroke Registry III study. Patients were classified into three groups according to tertiles and the normal range of each electrolyte. Multivariable logistic and Cox proportional hazards regressions were adopted to explore the associations of electrolytes with poor functional outcomes [modified Rankin Scale (mRS) 3-6/2-6] and all-cause death at 3 months and 1 year. Results A total of 10,299 eligible patients were enrolled. After adjusted for confounding factors, the first tertile electrolytes were associated with increased risk of poor functional outcome (mRS score 3-6) at 1 year, the adjusted odds ratios (95% confidence intervals) were 1.33 (1.14-1.55) for potassium, 1.41 (1.20-1.60) for sodium, 1.27 (1.08-1.48) for chloride, compared with the second tertile. Similar results were found when poor functional outcome was defined as mRS score 2-6 and all-cause death. However, almost no significant association was present of calcium with these outcomes. All results were consistent when each electrolyte was classified into three groups according to the normal range and the outcomes timepoint was set at 3 months. Conclusions Lower levels of potassium, sodium, chloride but not calcium were associated with higher risk of poor functional outcomes and death in patients with AIS or TIA.