Objective  To explore the influencing factors of cognitive impairment in non-dialysis patients with chronic kidney disease (CKD).

Methods  A total of 60 hospitalized non-dialysis patients with CKD in the Department of Nephrology of Northern Jiangsu People′s Hospital Affiliated to Yangzhou University from September 2022 to September 2023 were enrolled as research objects. According to the estimated glomerular filtration rate (eGFR), they were divided into stage 1 to 2 of CKD group eGFR≥60 mL/(min·1.73 m²) with 23 cases, the stage 3 of CKD group eGFR≥30~ < 60 mL/(min·1.73 m²) with 20 cases, and stage 4 to 5 of CKD group eGFR < 30 mL/(min·1.73 m²) with 17 cases. The Montreal Cognitive Assessment Scale (MoCA) was used to evaluate the cognitive function of the patients. Basic data and common clinical laboratory indicators on hospital admission were collected to analyze the differences in cognitive function levels under different renal function statuses and to explore the influencing factors of cognitive impairment.

Results  The incidence rates of cognitive impairment in the stage 1 to 2 of CKD group, stage 3 of CKD group, and stage 4 to 5 of CKD group were 47.8%, 85.0%, and 94.1% respectively, the median MoCA scored 26, 24 and 20 respectively, with statistically significant between-group differences (P < 0.05). Cognitive function was significantly negatively correlated with age(r=-0.634, P < 0.001), blood urea nitrogen (BUN) (r=-0.574, P < 0.001), serum creatinine (Cr) (r=-0.417, P < 0.001), cystatin C (Cys-C) (r=-0.327, P=0.011), serum β₂-microglobulin (β₂-MG) (r=-0.259, P=0.046), and N-terminal pro-brain natriuretic peptide (NT-proBNP) (r=-0.474, P < 0.001), and was significantly positively correlated with hemoglobin (HB) (r=0.401, P=0.001) and eGFR (r=0.485, P < 0.001). Multivariate Logistic regression analysis showed that age (P=0.006) and NT-proBNP (P=0.041) were influencing factors of cognitive impairment in non-dialysis patients with CKD. Receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC), sensitivity, and specificity of age for prediction were 0.860, 0.864 and 0.812 respectively, the AUC, sensitivity, and specificity of NT-proBNP for prediction were 0.808, 0.795 and 0.875 respectively, and the combined prediction of age and NT-proBNP had an AUC, sensitivity, and specificity of 0.893, 0.955, and 0.750, respectively.

Conclusion  As renal function deteriorates, the incidence rate and severity of cognitive impairment in non-dialysis patients with CKD tend to increase. Advanced age, renal function deterioration, high NT-proBNP level, and anemia are associated with the occurrence of cognitive impairment in non-dialysis patients with CKD, among which age and NT-proBNP are influencing factors for cognitive impairment.