| Background and purpose：Inflammatory reaction is one of pathological process of the acute cerebralinfarction. White blood cell (WBC), which plays an important part in the inflammatoryreaction, is the major risk factor for the incidence of acute cerebral infarction. However,the relationship between the level of WBC in the acute phase after onset of acutecerebral infarction and clinical outcome is inconclusive. Besides, few researches oninteraction between WBC and other factors have been conducted in the past years. Weexamine the influence of WBC count and its interactions with other factors on prognosisamong patients with acute cerebral infarction in order to provide scientific evidence forthe effective controlling of the increased WBC in the acute phase of cerebral infarction.Method:1. Retrospective cohort studyA total of2,808acute cerebral infarction patients in the affiliated hospital ofHebei United University from January,2003to December,2009，were included in thepresent study. Demographic characteristics, lifestyle factors, WBC count and otherlaboratory examinations at admission, medical history, and clinical outcome werecollected by referring to the medical records. Study outcome was defined as in-hospitaldeath or dependency [Modified Rankin’s scale (MRs)≥3] at discharge. Statistic analysiswas conducted using SPSS16.0software. Differences of the baseline characteristicswere compared among acute cerebral infarction patients with different outcome (death,dependency, and non-dependency). Unadjusted and multiple adjusted logistic regressionmodels were used to analyze the relationship between WBC count at admission andin-hospital death or dependency among acute cerebral infarction patients. Relative Risk(RR) and95%confident interval (95%CI) were evaluated. The influence of the interaction between the increased WBC and other risk factors on study outcomes wasanalyzed among acute cerebral infarction patients.2. Prospective cohort studySubjects of the China stroke project (A randomized controlled trial of reducing BPamong acute ischemic stroke patients) which was conducted by China and Americacooperation were served as subjects in the present study. A total of2009patients wereobtained from August1st,2009to September31th,2011in the project. The2009patients were served as study subject999in the present study to explore relationshipbetween WBC count at admission and in-hospital outcome and3rd month outcomeamong acute cerebral infarction patients. Demographic characteristics, lifestyle factors,laboratory examinations at admission and medical history were collected, and the WBCcount in the first24hours was examined. We collected clinical outcomes（death ordependency）, NIHSS score and MRs scores on discharge. Follow-up study wasconducted in the3rd month after stroke onset among all of the participants, clinicaloutcome during this period and NIHSS scores, MRs scores were collected. Studyoutcome was defined as death or dependency (MRs≥3). Statistic analysis was conductedusing SAS9.1and SPSS16.0software. Differences of the baseline characteristics werecompared among the patients with various clinical outcomes, and the different levels ofWBC count. Unadjusted and multiple adjusted Cox proportional hazard models wereused to analyze the relationship between WBC count in the acute phase and studyoutcome in-hospital and in the3rd month after stroke onset among acute cerebralinfarction patients, which were evaluated by the relative risk (RR) and95%CI. Theinfluence of the interaction between the increased WBC and other risk factors on studyoutcomes was analyzed among cerebral infarction patients.Results:1. Retrospective cohort studyThe case-fatality rate and disability rate were4.2%and25.4%, respectively, inacute cerebral infarction patients. The case-fatality rate and disability rate were4.1%and22.4%respectively, for men,4.2%and29.1%respectively, for women. There wasno statistic difference in the case-fatality rate between men and women(p＞0.05). Thedisability rate of women patients was significantly higher than men patients (p <0.05).The patients with study outcomes (death and dependency) were older than those without study outcomes. The rates of smoking, drinking, diabetes,coronary heart diseases, and stroke history, the heart rate, the pulse, the systolic pressure,the NIHSS scores, and the number of consciousness disturbance were significantlyhigher in patients with study outcomes than those without study outcomes. The deathgroups were older than the dependency group. The medical history rates of smoking,drinking, hypertention, diabetes, coronary heart disease and stroke, the levels of thepulse and heart rate, the NIHSS scores, and the number of disturbance of consciousnesswere significantly higher in death patients than in dependency patients.The rates of hyperglycemia, dyslipidemia, liver dysfunction, and renal dysfunction,the level of uric acid, platelet and WBC counts were significantly higher in deathpatients than those with dependency and patient without study outcome. The rates ofhyperglycemia, dyslipidemia, liver dysfunction, and renal dysfunction, the levels ofuric acid, platelet and WBC counts were significantly higher in dependency patientsthan those without study outcome.The age, the history rates of smoking, drinking, hypertension and diabetes, therates of hyperglycemia and dyslipidemia were significantly higher in patients with WBC＞10.0×10~9/L than those in patients with WBC≤10.0×10~9/L. The case-fatality rate anddisability rate were12.9%and43.6%,respectively, in patients with WBC＞10.0×10~9/L,and the case-fatality rate and disability rate were1.7%and20.3%, respectively, inpatients with WBC≤10.0×10~9/L. The disability rate was significantly higher in patientswith WBC＞10×10~9/L than in those with WBC≤10.0×10~9/L (P <0.05).The levels of WBC count at admission were also significantly associated with therisk of death, dependency and combined outcome in-hospital in acute cerebral infarctionpatients. Compared with patients with WBC≤10.0×10~9/L, the multiple adjusted RRs ofdeath for patients with WBC11.0~11.9×10~9/L and≥12.0×10~9/L were5.60(2.14,13.08)and12.42(3.12,49.44), respectively. The multiple adjusted RRs of dependency forpatients with WBC11.0~11.9×10~9/L and≥12.0×10~9/L were4.92(2.16,11.20) and8.93(4.03,19.81), respectively. The multiple adjusted RRs of combined outcomes forpatients with WBC11.0~11.9×10~9/L and≥12.0×10~9/L were2.05(1.03,9.02) and6.08(3.09,11.71), respectively,(P <0.05).There were no significantly interactions between the increased WBC count anddiabetes, hyperuricaemia or coronary heart disease on the study outcomes (death, dependency or combined outcomes) among acute cerebral infarction patients inmultiplicative model (P>0.05). There were no significantly interactions between theincreased WBC count and diabetes on the outcomes (death, dependency or combinedoutcomes) among acute cerebral infarction patients in additive model (P>0.05). Therewere significantly interactions between the increased WBC count and hyperuricaemiaon the study outcomes (death and combined outcomes) among acute cerebral infarctionpatients in additive model. The RERIs of death and combined outcome were11.371and4.972, respectively. The APs of death and combined outcome were62.2%and41.6%,respectively. There were significantly interactions between the increased WBC countand coronary heart disease on the study outcomes (dependency and combined outcome)of acute cerebral infarction patients in additive model. The RERIs of dependency andcombined outcome were5.746and6.391, respectively, and the APs of dependency andcombined outcome were48.9%and49.0%, respectively.2. Prospective cohort studyA total of2009acute cerebral infarction patients were recruited in the study,1737patients completed the3rd month follow-up study. The case-fatality rates in hospital (infirst14days after stroke onset)and in the first3months were1.19%and2.94%,respectively. The disability rates in hospital and in the first3months54.90%and,40.87%, respectively.Patients died in hospital had a higher level of WBC count at admission than thosewith dependency or without study outcome (P <0.05).Patients died within first3months had a higher level of WBC count at admissionthan those with dependency or without study outcome (P <0.05).Subjects were divided into two groups by admission WBC count (group one：WBC<7.02×10~9/L, group two: WBC≥7.02×10~9/L). The case-fatality and disablity rate inhospital and in the first3months were significantly higher in group one than those ingroup two, respectively(P <0.05).Subjects were divided into four groups by admission WBC count (group one:WBC≤5.78×10~9/L, group two:5.79×10~9/L≤WBC≤7.01×10~9/L, group three:7.02×10~9/L≤WBC≤8.70×10~9/L, group four: WBC≥8.71×10~9/L). Compared with groupone, the multiple adjusted RRs of dependency in hospital in the group three werestatistically significant [RRs were1.20(1.01,1.43)], the multiple adjusted RRs for death, dependency and combined outcomes in hospital and in the first3months in the groupfour were statistically significant [RRs were4.75(1.49,15.15),1.29(1.10,1.53) and1.32(1.25,1.56) in hospital, respectively. RRs were6.37(2.64,15.41),1.45(1.17,1.78)and1.54(1.26,1.88) in the first3months, respectively.].RR of death in hospital associated with the interactions between the increasedWBC count at admission and coronary heart disease was2.31(P=0.051)in multiplicativemodel; RR of death in the first3months associated with the interactions between theincreased WBC count at admission and coronary heart disease was2.04(P=0.061) inmultiplicative model.RR of death in the first3months associated with the interactions between theincreased WBC count at admission and hyperuricaemia was4.99(P=0.058).There were no significantly interactions between the increased WBC count anddiabetes, hyperuricaemia or coronary heart disease on the study outcomes (death,dependency or combined outcomes) in hospital and in the first3months among acutecerebral infarction patients in additive model (P>0.05).Conclusion:1. Increased level of WBC count at admission was positively and significantlyassociated with risks of death and dependency in hospital and in the first3months afteronset among patients with acute cerebral infarction.2. Interactions between increased WBC and hyperuricaemia and coronary heartdisease probably increased the risk of short-term poor outcomes.3. This study suggests that further research of interaction between the increasedWBC count and other risk factors on the prognosis should be conducted among acutecerebral infarction patients, and randomized controlled trials should be conducted to testthe potential beneficial effects of controlling WBC levels in acute cerebral infarctionpatients. |
PDF Full Text Request