Renal-Electrolyte Division, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
Renal Section, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, USA.
Nephron. 2018;140(1):58-62. doi: 10.1159/000490008. Epub 2018 Jul 4.
The widespread use of diuretics, potassium supplements, and medications that block renin angiotensin system puts the chronic kidney disease (CKD) population at high risk for dyskalemia, both hyperkalemia and hypokalemia. The optimal potassium level in a CKD patient is unknown. Subject of review: Two recent studies found conflicting results on the association of dyskalemia with outcomes. The Renal Research Institute CKD study [Clin J Am Soc Nephrol 2010; 5: 762-769] found increased mortality and incidence of end-stage renal disease (ESRD) with mild to moderate hypokalemia, whereas hyperkalemia was not significantly associated, compared to eukalemia. On the other hand, the Multi-Ethnic Study of Atherosclerosis (MESA)/Cardiovascular Health Study [Clin J Am Soc Nephrol 2017; 12: 245-252] showed both cardiovascular and noncardiovascular mortality to be higher with hyperkalemic patients, whereas associations with hypokalemic patients were statistically nonsignificant. Second opinion: If mild hypo- or hyperkalemia is associated with adverse outcomes, is it related to the hyperkalemia per se or to conditions associated with dyskalemia, such as kidney disease or cardiovascular disease? We interpret these articles in the context of criteria to support causality in epidemiologic studies. The cardiovascular effects of dyskalemia is well described and there is biological plausibility for increased cardiovascular mortality but the association of increased non-cardiovascular mortality with dyskalemia has little mechanistic basis. The explanation for a causal association of dyskalemia with ESRD is not adequate. Based on current evidence, targeting a potassium level of 4-5 mmol/L can be considered safe.
利尿剂、钾补充剂和肾素-血管紧张素系统阻滞剂的广泛使用使慢性肾脏病 (CKD) 患者发生电解质紊乱（高钾血症和低钾血症）的风险很高。CKD 患者的最佳钾水平尚不清楚。
最近的两项研究发现电解质紊乱与结局之间的关联存在矛盾结果。肾脏病研究协会 (Renal Research Institute) 的 CKD 研究 [Clin J Am Soc Nephrol 2010; 5: 762-769] 发现，与低钾血症相比，轻度至中度低钾血症与死亡率和终末期肾脏疾病 (ESRD) 发生率增加相关，而高钾血症与死亡率增加无关。另一方面，多民族动脉粥样硬化研究 (Multi-Ethnic Study of Atherosclerosis，MESA)/心血管健康研究 [Clin J Am Soc Nephrol 2017; 12: 245-252] 表明，高钾血症患者的心血管和非心血管死亡率均较高，而低钾血症患者的死亡率与高钾血症患者无显著相关性。
如果轻度低钾血症或高钾血症与不良结局相关，是与高钾血症本身相关，还是与电解质紊乱相关的疾病相关，如肾脏病或心血管疾病相关？我们根据支持流行病学研究因果关系的标准来解释这些文章。电解质紊乱对心血管的影响已有明确描述，且心血管死亡率增加具有生物学合理性，但电解质紊乱与非心血管死亡率增加之间的关联机制基础很小。电解质紊乱与 ESRD 之间因果关系的解释尚不足。基于目前的证据，将钾水平目标值设定为 4-5mmol/L 可以认为是安全的。
