The Correlation Between Red Blood Cell Distribution Width And Severity Of Brain White Matter Lesions

BackgroundWhite matter lesions(WML),also known as leukoaraiosis or white matter hyperintense.WML,an imaging term,is used to describe the spotted or flaky lesions in the periventricular or deep white matter,is highly signal-positive in the Magnetic Resonance Imaging T2-weighted and T2-weighted FLAIR sequences of the brain,is an equal signal or a low signal in the Magnetic Resonance Imaging T1-weighted.Numerous studies have shown that severe WML can cause cognitive decline,depression,urinary septic dysfunction,balance and gait disturbances.Besides,WML is closely related to predict stroke risk,myocardial infarction,vascular death,disability,mortality and other aspects[1,2]Red blood cell distribution width(RDW)is a laboratory test index that a simple and easily available,which reflects the dispersion of the red blood cell volume.The increase of RDW means that the red blood cell volume is different and the difference is increased.The RDW is related to generation and degradation of red blood cell,such as iron deficiency anemia,vitamin B12 deficiency,folate deficiency,bone marrow suppression,et resulting in ineffective red blood cell production increased or red blood cell destruction(hemolysis),blood transfusion will lead to increase RDW levels.the RDW traditionally used in the diagnosis of differential anemia[3].The current study have found that RDW levels is a good predictive evaluation index in cardiovascular diseases(such as congestive heart failure,acute coronary syndrome,hypertension,et.)or non-cardiovascular diseases(such as acute pulmonary embolism,community acquired pneumonia,diabetes,acute pancreatitis,et.)[3],RDW can be used to assess the prognosis of multiple system diseases.However,the relationship between RDW and severity of WML is less studied at present.This study will explore the relationship between RDW and severity of WML in middle-aged and elderly WML patients.ObjectiveExplore the correlation between RDW and severity of WML in middle-aged and elderly WML patients through retrospective analysis.Methods and materials1.1 Object of studyWe retrospectively collected consecutive patients admitted to our department of neurology from June 2015 to April 2017.Inclusion criteria:(1)age ≥40 years old;(2)confirmed the presence of WML in MRI(including T1MRI,T2MRI,T2-FLAIR sequence);(3)complete the routine blood,clotting function,liver and kidney function,blood lipids,serum uric acid,blood homocysteine and other tests.Exclusion criteria:(1)non-vasculogenic WML such as multiple sclerosis and leukodystrophy;(2)patients with a history of acute stroke or previous stroke;(3)cancer,dementia and mental disease;(5)severe liver and kidney dysfunction;(6)there are other conditions or diseases that may affect the RDW value,such as coronary heart disease,atrial fibrillation,heart failure,severe infection,inflammatory bowel disease.1.2 Data collection1.2.1 Clinical dataIncluding name,gender,age,with or without hypertension,with or without diabetes.1.2.2 Blood Index DataAll patients were harvest fasting venous blood in the next moming.The fasting venous blood was sent to our hospital clinical laboratory to complete the routine blood,clotting function,liver and kidney function,blood lipids,serum uric acid,blood homocysteine and other tests.Collecting indicators include white blood cell count,red blood cell count,hemoglobin,hematocrit,mean corpuscular volume,platelet count,RDW,fibrinogen,creatinine,uric acid,total cholesterol,triglycerides,high density lipoprotein,low density lipoprotein,homocysteine and so on.1.2.3 Imaging data collectionAll patients enrolled in the hospital were accepted 1.5T MRI examination(including T1MRI,T2MRI,T2-FLAIR sequence).Then two clinically experienced neurologists using double-blind method based on the amount of Fezakas Table to evaluate the severity of WML[4],once a one has dissent,then the severity of WML will be decide by a third neurologist re-evaluation.Periventricular and deep white matter lesions were scored separately.Periventricular white matter lesions score:1 point:"caps" or pencil-thin lining;2 points:smooth "halo";3 points:irregular periventricular white matter lesions extending into the deep white matter.Deep white matter lesions score:1 point:punctate foci;2 points:beginning confluence of foci;3 points:large confluent areas.The two-part scores were added to calculate the total scores.Total scores<3 was mild group,total scores≥3 was moderate to severe group.1.3 Statistical analysisUsing SPSS 22.0 statistical software to analysis.The measurement data of normal distribution were expressed as mean±standard deviation,and two independent samples t-test were used to compare between groups.The enumeration datas expressed as a percentage,two groups were compared by chi-square test.Based on the results of univariate analysis,meaningful independent variables were included in the multivariate logistic regression model,and the independent risk factors of moderate to severe WML were screened out.The predictivevalue of the relevant indicators was drawn by plotting the receiver operating curve(ROC curve).P<0.05 was considered statistically significant.Results:1.Clinical featuresA total of 409 patients were enrolled in this study,with an average age of 61.82±11.20 years.There were 241 female patients(58.9%)and 168 male patients(41.1%).227(55.5%)had no hypertension and 182(44.5%)had hypertension.357(87.3%)were non-diabetic and 52(12.7%)were diabetic.266(65%)patients were mild WML and 143(35%)patients were moderate to severe WML.2.The resultes of univariate analysis for the mild and moderate to severe WMLCompared with mild WML,moderate to severe WML was more older(P<0.001),the prevalence of hypertension was higher(P<0.001),the erythrocyte count,hemoglobin and total cholesterol were lower.While the RDW,fibrinogen,creatinine,homocysteine levels of moderate to severe WML were higher,in addition to,also found the severity of white matter lesions has nothing to do with the white blood cell count,hematocrit,mean corpuscular volume,platelet count,uric acid,triglyceride,high-density lipoprotein,low-density lipoprotein levels,also has nothing to do with the gender,the prevalence of diabetes.3.The resultes of multivariate regression analysis for the moderate to severe WMLAccording to the univariate analysis,the independent variables of P<0.1,were included in the multivariate logistic regression model.RDW was used as continuous variable data.After adjusted confounding factors,age(OR=1.158,95%CI:1.122-1.195,P<0.001),hypertension(OR=2.103,95%CI:1.254-3.526,P=0.005).RDW(OR=1.308,95%CI:1.062-1.610,P=0.011)were independent risk factors for moderate to severe WML.When RDW was divided into four grades by quartiles.The four concentration levels:Q1:≤12.2%,Q2:12.3-12.6%,Q3:12.7-13.2%,Q4:>13.3%.After adjusted confounding factors,age(OR=1.160,95%CI:1.123-1.198,P<0.001),hypertension(OR=2.161,95%CI:1.280-3.648,P= 0.004)were independent risk factors for moderate to severe WML.In patients with WML,the risk of developing moderate to severe WML at RDW>13.3%was 2.861 times greater than RDW≤12.2%(OR = 2.861,95%CI:1.387-5.898,P = 0.004).4.Plot the receiver operating curve(ROC curve)between RDW and moderate to severe WMLThe area under the ROC curve(AUC)was 0.643(95%CI:0.587-0.699,P<0.001).The best cut-off value determined by Youden index was 13.05%for RDW with the sensitivity of 51.0%and the specificity of 74.1%.According to the optimal cut-off,RDW was divided into two layers RDW≤13.05%and RDW>13.05%.After adjusted confounding factors,age,hypertension and RDW were independent risk factors for moderate to severe WML.In patients with WML,the risk of developing moderate to severe WML at RDW>13.05%was 2.425 times greater than RDW≤13.05%(OR= 2.425,95%CI:1.419-4.144,P=0.001).ConclusionsAge,hypertension,and RDW were the independent risk factors for moderate to severe WML in patients with WML,High RDW provides a certain predictive value for moderate to severe WML.