促甲状腺激素水平与ICU患者预后的关联——基于MIMIC-Ⅲ数据库的资料分析

Association between levels of thyroid-stimulating hormone and prognosis of patients admitted to intensive care units:an analysis using the MIMIC-Ⅲ

目的探讨重症监护病房(ICU)患者入ICU时促甲状腺激素(TSH)水平与预后的关联。方法通过美国重症监护医学信息数据库Ⅲv1.4(MIMIC-Ⅲv1.4)收集2001至2012年在美国贝斯以色列迪康医学中心ICU住院且入ICU 24 h内有TSH检测记录患者的相关资料,包括性别、年龄、种族、入院类型、入ICU首日是否接受机械通气(MV)或肾脏替代治疗(RRT)、合并疾病及入ICU 24 h内TSH水平,并根据参数计算序贯器官衰竭评分(SOFA)、简化急性生理学评分Ⅱ(SAPSⅡ)及反映合并疾病负担的Elixhauser评分(SID30)。以院内死亡作为主要结局指标,以数据库中提供的关于TSH水平是否异常的二分类变量为准,比较TSH正常患者与TSH异常患者基线资料和结局指标间的差异;采用多因素Logistic回归法分析校正混杂因素后TSH异常与结局指标的关联;以0.30~3.00 mU/L作为TSH的正常参考值范围,将患者分为TSH过低、TSH正常及TSH过高3个亚组,并进行敏感性分析。结果共有3425例ICU患者纳入分析,其中TSH正常2692例(占78.60%),TSH异常733例(占21.40%)。TSH正常与异常两组患者性别、年龄、种族、入院类型及入ICU首日MV比例差异无统计学意义;但与TSH正常组相比,TSH异常组患者具有更高的SOFA、SAPSⅡ、SID30评分及入ICU首日RRT比例〔SOFA评分(分):4(2,7)比4(2,6),SAPSⅡ评分(分):38.02±13.76比36.53±13.75,SID30评分(分):11(4,22)比11(0,20),RRT比例:5.32%(39/733)比3.49%(94/2692),均P<0.05〕。TSH异常组患者院内病死率明显高于TSH正常组〔9.82%(72/733)比5.94%(160/2692),P<0.01〕。多因素Logistic回归分析显示,校正混杂因素后,TSH异常与院内死亡显著相关〔优势比(OR)=1.71,95%可信区间(95%CI)为1.24~2.35,P=0.001〕。敏感性分析显示,以0.30~3.00 mU/L作为TSH的正常参考值范围,与TSH正常相比,TSH过低或过高均与患者院内病死率增加密切相关(TSH过低:OR=2.36,95%CI为1.40~3.97,P=0.001;TSH过高:OR=1.44,95%CI为1.05~1.98,P=0.023)。结论患者入ICU 24 h内的TSH水平异常是其院内死亡的独立危险因素。

Objective To explore the association between levels of thyroid-stimulating hormone(TSH)on admission and prognosis of patients admitted to intensive care unit(ICU).Methods The data were collected from patients who were admitted to the ICU of the Beth Israel Deaconess Medical Center in the United States from 2001 to 2012 with available TSH test records within 24 hours after the ICU admission via the Medical Information Mart for Intensive Care-Ⅲv1.4(MIMIC-Ⅲv1.4).Information including gender,age,ethnicity,type of admission,mechanical ventilation(MV)or renal replacement therapy(RRT)received on admission,comorbidities,and TSH test records within 24 hours after the ICU admission were collected.The sequential organ failure assessment(SOFA)score,simplified acute physiology scoreⅡ(SAPSⅡ)and the comorbidities index Elixhauser(SID30)score were calculated according to the parameters.The primary outcome was hospital mortality.Differences in baseline characteristics and prognosis were examined between patients with normal TSH levels and abnormal TSH levels which was determined according to a dichotomous variable provided by the data.Multivariable Logistic regression was used to analyze the association between TSH levels and prognosis after adjusting for confounding factors.A sensitivity analysis was conducted which categorized the study population as three groups(i.e.,decreased,normal,and elevated TSH levels)using the range of 0.30-3.00 mU/L as the normal range of TSH.Results A total of 3425 ICU patients were enrolled in the study,of which 2692(78.60%)were with normal TSH and 733(21.40%)were with abnormal TSH.There was no statistically significant difference in gender,age,ethnicity,type of admission and the ratio of MV between the normal TSH and abnormal TSH groups.Compared with normal TSH group,the patients in abnormal TSH had a higher SOFA,SAPSⅡand SID30 scores as well as the ratio of RRT[SOFA score:4(2,7)vs.4(2,6),SAPSⅡscore:38.02±13.76 vs.36.53±13.75,SID30 score:11(4,22)vs.11(0,20),RRT ratio:5.32%(39/733)vs.3.49%(94/2692),all P<0.05].The hospital mortality of patients in normal TSH was significantly higher than that of those in abnormal TSH[9.82%(72/733)vs.5.94%(160/2692),P<0.01].After adjusting for confounding factors,abnormal TSH was significantly associated with hospital mortality[odds ratio(OR)=1.71,95%confidence interval(95%CI)was 1.24-2.35,P=0.001].In the sensitivity analysis in which the range of 0.30-3.00 mU/L was used as the normal range of TSH,compared with normal TSH,decreased TSH(OR=2.36,95%CI was 1.40-3.97,P=0.001)and elevated TSH(OR=1.44,95%CI was 1.05-1.98,P=0.023)were both significantly associated with increased hospital mortality.Conclusion An abnormal level of TSH within 24 hours after admitted to ICU is an independent risk factor for hospital mortality among ICU patients.