Lai Ying-Ho, Leu Hsin-Bang, Yeh Wen-Ting, Chang Hsing-Yi, Pan Wen-Harn
Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Number 1, Section 4, Roosevelt Road, Taipei, Taiwan.
Healthcare and Management Center, Division of Cardiology, Department of Internal Medicine, Taipei Veterans General Hospital, Number 201, Section 2, Shih-Pai Road, Taipei, Taiwan.
J Formos Med Assoc. 2015 Jun;114(6):517-25. doi: 10.1016/j.jfma.2015.01.001. Epub 2015 May 23.
BACKGROUND/PURPOSE: Several studies have already reported that serum potassium (SK) correlated inversely with adverse events among patients with preexisting cardiovascular disease and impaired renal function; less is known about the prognostic value of SK at the normal range in community-based elderly individuals. This study aimed to examine whether low normal SK value was associated with cardiovascular and all-cause mortalities in elderly people.
A prospective study was conducted using two independent elderly Taiwanese community cohorts that included 2065 individuals with relatively normal SK values (2.8-5.6 mmol/L). The participants were grouped as follows: low (2.8-3.4 mmol/L), low-normal SK (3.5-3.8 mmol/L), normal (3.9-4.4 mmol/L), and high-normal SK (4.5-5.6 mmol/L). Proportional hazards model was applied to compare the association between SK concentration groups and mortality.
The relationship between baseline SK and all-cause and cardiovascular mortality was U-shaped, with the lowest mortality rates observed in patients with SK levels of 3.9-4.4 mmol/L. The low-normal SK group had significantly higher risks of all-cause (hazard ratio, 1.3; 95% confidence interval, 1.0-1.6) and cardiovascular mortality (hazard ratio, 1.6; 95% confidence interval, 1.1-2.3) than the normal SK group. The high-normal SK group had higher but nonsignificant risk compared to the normal group.
Our findings suggest that low-normal SK may be used as a marker of poor survival for elderly outpatient cares.
背景/目的：多项研究已报道，在已有心血管疾病和肾功能受损的患者中，血清钾（SK）与不良事件呈负相关；而关于社区老年人群正常范围内SK的预后价值，人们了解较少。本研究旨在探讨正常低限的SK值是否与老年人的心血管死亡率和全因死亡率相关。
使用两个独立的台湾老年社区队列进行了一项前瞻性研究，纳入了2065名SK值相对正常（2.8 - 5.6 mmol/L）的个体。参与者被分为以下几组：低（2.8 - 3.4 mmol/L）、正常低限SK（3.5 - 3.8 mmol/L）、正常（3.9 - 4.4 mmol/L）和正常高限SK（4.5 - 5.6 mmol/L）。应用比例风险模型比较SK浓度组与死亡率之间的关联。
基线SK与全因死亡率和心血管死亡率之间的关系呈U形，SK水平为3.9 - 4.4 mmol/L的患者死亡率最低。正常低限SK组的全因死亡风险（风险比，1.3；95%置信区间，1.0 - 1.6）和心血管死亡风险（风险比，1.6；95%置信区间，1.1 - 2.3）显著高于正常SK组。正常高限SK组与正常组相比风险更高，但无统计学意义。
我们的研究结果表明，正常低限SK可能作为老年门诊患者生存不良的一个标志物。
