Background: Serum creatinine (Cr) is a biosynthetic product of creatine phosphate metabolism in muscles and is closely related to total muscle mass, but it is not easily affected by diet. Several studies have tried to explore the role of serum Cr levels in amyotrophic lateral sclerosis (ALS), but the results were inconsistent. Therefore, our study aims to explore the differences of serum Cr levels between ALS patients and controls and whether serum Cr at baseline is an independent predictor of survival. Methods: We searched all the related studies that probed into the association between Serum Cr levels and ALS based on PubMed, EMBASE and Cochrane library from October 1952 to February 2019. The quality of the included studies was evaluated by using Newcastle-Ottawa Scale (NOS), and all the statistical analysis of this meta-analysis was performed by Stata version 12.0. Results: Eight studies with a total of 11377 ALS patients and 937 controls were included. Among them, five studies indicated that ALS patients had lower serum Cr levels (SMD = −0.78, 95%CI [−0.97, −0.60]) compared to controls, and three studies showed that higher serum Cr levels in ALS patients were related to lower overall mortality (HR 0.89, 95%CI [0.80, 0.99]). Conclusion: The levels of serum Cr in ALS patients are significantly lower than those in controls, and they are inversely related to overall mortality in ALS patients. Therefore, the serum Cr, an easily accessible serological factor, may serve as a prognostic biomarker.

背景：血清肌酐（Cr）是肌肉中磷酸肌酸代谢的生物合成产物，与肌肉总量密切相关，但不易受饮食影响。多项研究试图探讨血清 Cr 水平在肌萎缩侧索硬化 (ALS) 中的作用，但结果不一致。因此，我们的研究旨在探讨 ALS 患者和对照组之间血清 Cr 水平的差异，以及基线时的血清 Cr 是否是生存的独立预测因子。方法：我们检索了 1952 年 10 月至 2019 年 2 月基于 PubMed、EMBASE 和 Cochrane 图书馆探讨血清 Cr 水平与 ALS 之间关系的所有相关研究。采用纽卡斯尔-渥太华量表 (NOS) 评估纳入研究的质量，并且该荟萃分析的所有统计分析均由 Stata 12.0 版执行。结果：共纳入 8 项研究，共 11377 名 ALS 患者和 937 名对照者。其中，5项研究表明ALS患者血清Cr水平低于对照组（SMD=-0.78，95%CI[-0.97，-0.60]），3项研究表明ALS患者血清Cr水平较高与总体死亡率较低（HR 0.89, 95% CI [0.80, 0.99]）。结论：ALS患者血清Cr水平显着低于对照组，且与ALS患者的总体死亡率呈负相关。因此，血清 Cr 是一种易于获得的血清学因子，可作为预后生物标志物。