血镁水平与维持性血液透析患者全因死亡的相关性

Association of serum magnesium level with all-cause mortality in maintenance hemodialysis patients

目的探讨血液透析患者血镁(Mg)水平与全因死亡的相关性.方法纳入2015年6月至2016年6月于贵州省7家血液透析中心行维持性血液透析(MHD)治疗3个月以上的门诊成人患者.收集并记录患者人口学资料、稳定透析3个月以上且第一年随访时的临床及实验室检查作为基线数据.所有患者随访至2018年6月30日.根据患者基线血Mg水平四分位数将所有患者分为4组.采用Kaplan-Meier法比较各组患者生存率.采用Cox回归模型分析Mg与全因死亡的相关性.采用Logistic回归分析低血镁水平的影响因素.结果共868例具有基线Mg数据的血液透析患者被纳入研究,年龄(55.47±16.17)岁,其中男性516例(59.4%);低镁血症(Mg<0.7 mmol/L)患者11例(1.3%),高镁血症(Mg>1.05 mmol/L)患者432例(49.8%),Mg>2.0 mmol/L患者16例(1.8%).Mg水平中位数(四分位数间距)为1.05(0.95,1.24)mmol/L.Mg四分位数组间比较显示,4组间年龄、血红蛋白、血清白蛋白、血钙、甲状旁腺素(PTH)、血肌酐、血尿酸和血尿素氮水平差异均有统计学意义(均P<0.05).经过中位24个月的随访,207例患者死亡.Kaplan-Meier生存曲线显示基线血Mg≤0.95 mmol/L患者全因死亡率较高(Log-rank检验χ^2=15.11,P=0.002).但经年龄、合并症及生化指标(尤其是白蛋白)等校正后,4组患者全因死亡的风险比差异无统计学意义.多因素Logistic回归分析结果显示,低血清白蛋白(OR=0.946,95%CI 0.913~0.979,P=0.002)及低血尿酸(OR=0.994,95%CI 0.992~0.997,P<0.001)是基线血Mg≤0.95 mmol/L发生的危险因素.结论MHD患者中低镁血症少见,而高镁血症较常见.血Mg≤0.95 mmol/L与MHD患者全因死亡风险增加相关,但可能并非其独立危险因素.基线血清Mg≤0.95 mmol/L的发生与较低的血清白蛋白及血尿酸水平有关.

Objective To investigate the association of serum magnesium(Mg)level with all-cause mortality in maintenance hemodialysis patients.Methods A multicenter retrospective cohort study was conducted in seven hemodialysis centers of Guizhou province.The adult outpatients who underwent hemodialysis for more than 3 months were included from June 2015 to June 2016.Demographics,baseline clinical and laboratory test results were collected.All patients were followed up until June 30,2018.Patients were divided into 4 groups according to their baseline serum Mg levels(interquartile range).Kaplan-Meier method was used to compare the survival rates of the four group.Cox regression model was used to analyze the association of Mg with all-cause mortality.Logistic regression was used to analyze the influencing factors of low Mg level.Results A total of 868 hemodialysis dialysis patients with baseline Mg data were enrolled in this study,with age of(55.47±16.17)years old,among whom 59.4%were male.There were 11(1.3%)patients with hypomagnesemia(Mg<0.7 mmol/L),432(49.8%)patients with hypermagnesemia(Mg>1.05 mmol/L),and 16(1.8%)patients with Mg>2.0 mmol/L.Median Mg was 1.05 mmol/L and interquartile range was 0.95-1.24 mmol/L.The comparison between Mg quartile groups showed that the difference in age,hemoglobin,serum albumin,serum calcium,parathyroid hormone(PTH),serum creatinine,uric acid and urea nitrogen was statistically significant(all P<0.05).After a median follow-up of 24 months,207 patients died.Kaplan-Meier curves showed higher all-cause mortality in patients with Mg≤0.95 mmol/L(Q1 group)(Log-rank testχ^2=15.11,P=0.002).However,after adjusting for age,comorbidities and biochemical indicators(especially albumin),there was no statistically significant difference in the hazard ratio for all-cause death among the four groups.Multiple logistic regression analysis results showed that low serum albumin(OR=0.946,95%CI 0.913-0.979,P=0.002)and low serum uric acid(OR=0.994,95%CI 0.992-0.997,P<0.001)were the risk factors for baseline Mg≤0.95 mmol/L.Conclusions Hypomagnesemia is rare in MHD patients,while hypermagnesemia is more common.Baseline serum Mg≤0.95 mmol/L in MHD patients is correlated with increased risk of all-cause death,but it may be not an independent risk factor.Baseline serum Mg≤0.95 mmol/L that occurred is associated with low levels of albumin and serum uric acid.