Impact of Cognitive Function Change on Mortality in Renal Transplant and End-Stage Renal Disease Patients.

BACKGROUND

Limited evidence from small-scale studies, mainly involving end-stage renal disease (ESRD) patients, suggests that kidney transplantation may improve cognitive function. We examined changes in cognitive function after a kidney transplant and its association with survival in advanced chronic kidney disease (CKD)/ESRD patients.

METHODS

In a prospective study design, cognitive performance of 90 patients (50.6 ± 13.1 years, 66.7% men, 27.8% blacks, 76% CKD stages 4-5) was assessed at the respective patients' residences using established neurocognitive tests.

RESULTS

Among the 90 patients, 44 received a kidney transplant (KTx group) while 46 did not (no-KTx group). After a mean follow-up of ∼19 months, there was no significant change in scores for majority of cognitive tests in either group. Older age, but not diabetes or renal function status (CKD vs. ESRD), was a determinant of poor follow-up cognitive performance. Additionally, poor attention/psychomotor speed and executive performance (as measured by Trails A and Stroop test, respectively) was associated with higher mortality over a mean follow-up of 4.7 years, even after adjustment for age, sex, diabetes, CKD or ESRD status and kidney transplant status.

CONCLUSION

Overall, cognitive function does not significantly improve after kidney transplant or significantly decline in non-transplanted, advanced CKD/ESRD patients. Poor attention, psychomotor speed and executive performance independent of transplant status were associated with higher mortality over time.