SP619NEUROCOGNITION IN PATIENTS WITH ESRD: THE COURSE OF COGNITIVE FUNCTION IN THE EARLY PHASE OF PERITONEAL AND HEMODIALYSIS

Abstract

INTRODUCTION AND AIMS: Cognitive function (CF) is essential for adherence, self-care, and decision-making abilities in ESRD. With decreasing renal function, CF is likely to decline, with cognitive dysfunction improving after initiation of dialysis and even being generally reversible after successful renal transplantation. However, little is known about changes in CF during early-phase dialysis, particularly regarding different treatment modalities. This multicenter study focused on the long-term course of CF, comparing peritoneal dialysis (PD) to hemodialysis (HD) patients. METHOD(S): Within the CORETH-project, two well-validated cognitive tests, assessing executive functioning (Trail Making Test B [TMT-B]) and attention (d2-Revision Test [d2-R]); as well as the self-reported Kidney Disease Quality of Life Short Form Cognitive Function subscale (KDQOL-CF) were administered to a sample of 271 patients at baseline and again at one-year follow-up. The subsamples were matched by propensity score, adjusting for age, comorbidity, education, and employment status. Only cases with complete data (HD = 96 and PD = 103) were compared. The effects of time and treatment modality were investigated, controlling for well-known confounders: age, comorbidity, education level, employment status, depression, and psychotropic drug intake. RESULT(S): Results from both cognitive tests showed that CF improved over one year (B TMT-B = -9.29, 95% CI -12.98 to -5.60, p < 0.001; B d2-R = 6.19, 95% CI 4.09 to 8.29, p < 0.001), with PD significantly outperforming HD patients (B TMT-B = -9.38, 95% CI - 18.31 to -0.45, p = 0.04; B d2-R = 7.45, 95% CI 0.06 to 14.83, p = 0.05). The opposite pattern applied to the self-reports: CF estimates tendentially declined with HD patients stating significantly better CF than PD patients (BKDQOL-CF = 3.34, 95% CI 0.22 to 6.56, p = 0.04). A higher depression level had a significant negative impact on patients' selfratings but not on the cognitive tests, whereas a higher age and a lower education level had a significant negative effect on test performance but not on the self-report. Moreover, a higher comorbidity score significantly negatively influenced TMT-B results. There was no evidence for effects of employment status or psychotropic drug intake on any cognitive outcome. CONCLUSION(S): This study, for the first time, casts light on long-term CF in HD vs. PD patients during early-phase dialysis while controlling for well-known confounders. Both groups show improvement over one year, with PD patients indicating better executive functioning and attention abilities than HD patients. For the self-reported CF, the opposite pattern applies, possibly due to the nature of the assessment method. Presumably, our longitudinal findings underpin the beneficial effects of dialysis on CF and strengthen previous indications of PD being associated with better CF than HD.