Abstract: Objective To explore the relationship between secondary hyperparathyroidism(SHPT) and mild cognitive impairment(MCI)in end-stage renal disease(ESRD)patients.Methods A total of 287 renal replacement therapy patients were enrolled.Based upon the diagnostic criteria of SHPT,MCI patients were divided into SHPT and NSHPT groups.The relationship between intact parathyroid hormone(iPTH)level and MCI incidence in SHPT patients was analyzed by Spearman's correlation analysis.Multivariate logistic regression was employed for examining the influencing factors of MCI.Occurrence of MCI or not and iPTH level were used as variables for plotting the receiver operating characteristic curve(ROC)and assessing the value of iPTH level for predicting MCI in ESRD patients.Results Among 189 MCI patients,the incidence rate was 65.9%(SHPT 82%).Spearman's correlation analysis revealed that the incidence of MCI rose with a higher level of iPTH(r=0.598,P<0.01).Multivariate Logistic regression analysis showed SHPT,iPTH,25-hydroxyvitamin D25(OH)D,alkaline phosphatase(ALP),dialytic mode and urea clearance index(Kt/V)were influencing factors of MCI(P<0.05).The results of ROC curve showed that the area under the curve of iPTH level predicting MCI in ESRD was 0.838 and the cutoff value was 492.25 ng/L with a sensitivity of 75.7% and a specificity of 95.9%.Conclusions SHPT is an influencing factor for MCI in ESRD patients.The higher the level of iPTH,the greater the incidence of MCI.Patients with iPTH levels>492.25 ng/L have an elevated risk of MCI.