The Relationship between Calcium-phosphorus Metabolism Disorder and Cognitive Impairment in Maintenance Hemodialysis Patients

Objective To explore the correlation between calcium-phosphorus metabolism disorders and the occurrence of mild cognitive impairment(MCI) in maintenance hemodialysis(MHD) patients and examine its value in predicting maintenance hemodialysis associated mild cognitive impairment (MHD-MCI). Methods From June 2020 to June 2021, 117 MHD patients were recruited from our blood purification center. Clinical profiles and laboratory parameters were recorded. Montreal Cognitive Assessment(MoCA) scale was utilized for evaluating overall cognitive function. They were divided into two groups of cognitive impairment and non-cognitive impairment. Correlations between MoCA scores and calcium and phosphorus metabolic variables were analyzed by Spearman's method. Logistic regression was utilized for examining the influencing factors of the occurrence of MHD-MCI. Receiver operating characteristic(ROC) curve was plotted for evaluating the value of potential risk factors in predicting MHD-MCI. Results Among them, 71 patients developed MCI with an incidence rate of 60.7%. No statistical difference existed in the incidence of MHD-MCI in patients with different serum levels of calcium(Ca) and phosphorus(P). With a rising serum level of iPTH/ALP(intact parathyroid hormone/alkaline phosphatase), the incidence of MHD-MCI gradually increased. Spearman's correlation analysis revealed that MoCA score was negatively correlated with serum level of iPTH/ALP. The correlation coefficients were-0.443 and-0.643 respectively and the difference was statistically significant (P< 0.001). Multivariate Logistic regression indicated that diabetes mellitus and serum level of ALP/iPTH were possible risk factors for MHD-MCI. ROC curve Results implied that serum levels of iPTH and ALP had some value for judging MHD-MCI. Delong test showed that ALP was superior to iPTH in predicting MHD-MCI(Z=2.246, P=0.0153<0.05). Conclusion The incidence of MHD-MCI is 60.7%. Elevated serum levels of ALP and iPTH are independent risk factors for the occurrence of MHD-MCI. Serum ALP/iPTH has some value for predicting the occurrence of MHD-MCI and ALP may offer a better diagnostic performance.