Study On Correlation Between Body Cell Mass Index And Cognitive Impairment In Maintenance Hemodialysis Patients

Objective:To investigate the relationship between body cell mass index(BCMI)and cognitive impairment in Maintenance hemodialysis(MHD)patients.Methods:A multi-center cross-sectional study was conducted in 20 hemodialysis centers in Guizhou province from June to September 2020.Clinical data,physical parameters,body composition data and laboratory valuesof MHD patients were collected.The body composition was measured by bioelectrical impedance method,and the BCMI value was calculated.The subjects were divided into normal cognitive function group(score≥27)and cognitive impairment group(score<27)according to the score ofmini-mental state estimate(MMSE).The cognitive impairment group was further divided into mild cognitive impairment group(score 23-26),moderate cognitive impairment group(18-23)and severe cognitive impairment group(score<18).BCMI was divided into Q1,Q2,Q3 and Q4groups according to the three cut-off points of its quartile(7.40kg/m~2,8.73kg/m~2and10.58kg/m~2).BMI groups included pre-dialysis BMI group(G group)and post-dialysis BMI group(D group),which were divided into G1/D1(BMI<18.5kg/m~2),G2/D2(18.5kg/m~2≤BMI<25.0kg/m~2),G3/D3(25.0kg/m~2≤BMI<30.0kg/m~2),G4/D4(BMI≥30.0 kg/m~2)groups according to WHO standards.Two groups of people with normal cognitive function and cognitive impairment with similar baseline data(gender,age and education)were obtained by propensity score matching(PSM).Binary logistic regression was used to analyze the relationship between BCMI and the risk of cognitive impairment in patients with MHD.Receiver operating characteristic curve(ROC)was used to evaluate the predictive effect of BCMI on cognitive impairment in MHD patients.Results:A total of 2008 subjects were included in this study,including 1145 males(57%)and 863 females(43%),1541(76.7%)in the cognitive normal group,467(23.3%)in the cognitive impairment group,257(12.8%)in the mild cognitive impairment group,and 159(7.9%)in the moderate cognitive impairment group,fifty-one patients(2.5%)in the severe cognitive impairment.There were 46(8.6%),153(20.3%),185(33.6%)and 83(49.4%)patients with cognitive impairment aged≤45,46-59,60-74 and≥75 years,respectively.Compared with the cognitive normal group,the education level,dry weight,extracellular water,lean tissue index,lean tissue mass,somatic cell mass index,albumin and serum creatinine in the cognitive impairment group were lower,and the proportion of male patients and smoking patients were fewer,while the age,adipocyte tissue index,platelet/lymphocyte ratio(PLR),neutrophil/lymphocyte ratio(NLR)were higher,the differences were statistically significant(P<0.05).A total of 407 pairs of patients were accurately matched after PSM.Multivariate logistic regression analysis showed that in the unadjusted model,the incidence risk of BCMI Q1 group was 8.99 times higher than that of Q4 group(95%CI:5.74～14.09,P<0.001).After adjusting for dialysis age,smoking,hypertension,diabetes,creatinine,albumin,hemoglobin,OH,FTI and PLR,the incidence risk of BCMI Q1 group was 7.236 times higher than that of Q4 group(OR 7.236,95%CI4.140～12.646 P<0.05).The incidence risk of pre-dialysis BMI G1 group was 2.366 times higher than that of G4 group(OR 2.366,95%CI:1.056～5.300,P<0.05),the incidence risk of post-dialysis BMI D1 group was 3.513 times higher than that of G4 group(OR3.513,95%CI:1.419～8.693,P<0.05).After adjusting for related risk factors,PLR and FTI,there was no statistically significant correlation between BMI and the risk of cognitive dysfunction in MHD patients before and after dialysis(P>0.05).ROC curve analysis showed that the best threshold of BCMI for predicting cognitive impairment in MHD patients was 9.05,the sensitivity and specificity were 71.5%and 62.7%respectively,and the area under the curve was 0.713(95%CI:0.678～0.748,P<0.001),higher than the pre-dialysis BMI(AUC=0.571)and post-dialysis BMI(AUC=0.570).Conclusion:(1)Low BCMI is an independent risk factor for cognitive impairment in MHD patients.(2)Compared with low BMI,low BCMI has higher predictive value for the occurrence of cognitive impairment in MHD patients.(3)The prevalence of cognitive impairment in MHD patients increased with age.