A prospective cohort study on the association of cognitive impairment and all-cause mortality in the middle and elderly adult patients undergoing maintenance hemodialysis / 中华肾脏病杂志

ABSTRACT

Objective:To investigate the association between cognitive impairment and all-cause mortality in middle and elderly adult patients undergoing maintenance hemodialysis (HD).Methods:A prospective cohort study was conducted. Patients from 11 HD centers in Beijing between April and June 2017 were enrolled. Baseline data were collected, and a series of neuropsychological batteries covered 5 domains of cognitive function were applied for the assessment of cognitive function. The patients were then classified as normal and cognitive impairment groups according to the fifth version of the Diagnostic and Statistical Manual of Mental Disorders criteria (DSM-V) and followed-up until June 2018. The clinical characteristics of the two groups of patients were compared. Kaplan-Meier survival analysis was used to compare the difference in the cumulative survival rate between the two groups. Multivariate Cox regression model was used to analyze the independent influencing factors of all-cause mortality, to determine the relationship between cognitive impairment and different cognitive domain impairments and all-cause death.Results:A total of 613 patients were enrolled, of which 496(80.91%) patients had cognitive impairment. Compared with the normal cognitive function group, the patients in the cognitive impairment group tended to be older, longer dialysis vintage, a higher proportion of diabetes, hypertension, and stroke, increased serum iPTH level, and lower education level and urea clearance index (Kt/V) (all P<0.05). After (49.53±8.42) weeks of follow-up, Kaplan-Meier survival analysis showed that the cumulative survival rate of cognitive impairment group was significantly lower than that of cognitive normal group (Log-rank χ2=8.610, P=0.003). Multivariate Cox regression analysis showed that history of diabetes ( HR=2.742, 95% CI 1.598-4.723, P<0.001), coronary heart disease ( HR=1.906, 95% CI 1.169-3.108, P=0.010), dialysis vintage (every increase of 1 month, HR=1.007, 95% CI 1.003-1.011, P=0.001), serum level of albumin (every increase of 1 g/L, HR=0.859, 95% CI 0.809-0.912, P<0.001), cognitive impairment ( HR=2.719, 95% CI 1.088-6.194, P=0.032) were independently associated with all-cause mortality. Multivariate Cox regression analysis on different cognitive domains also indicated that memory impairment ( HR=2.571, 95% CI 1.442-4.584, P<0.001), executive function impairment ( HR=3.311, 95% CI 1.843-5.949, P=0.001) and three, four, five domains combined impairment ( HR=5.746, 95% CI 1.880-17.565, P=0.002; HR=12.420, 95% CI 3.690-41.802, P<0.001; HR=13.478, 95% CI 3.381-53.728, P<0.001) were independently related to all-cause mortality. Conclusions:Cognitive impairment is an independent risk factor of all-cause mortality in middle and elderly adult patients undergoing maintenance hemodialysis, and the risk is significantly increased in patients with the impairment of the domains of memory, executive function, or in the combination of three to five cognitive domains.