Prevalence and correlates of cognitive impairment in kidney transplant recipients

BMC Nephrol. 2017 May 12;18(1):158. doi: 10.1186/s12882-017-0570-1.


Background: There is a high prevalence of cognitive impairment in dialysis patients. The prevalence of cognitive impairment after kidney transplantation is unknown.

Methods: Study Design: Cross-sectional study.

Setting and participants: Single center study of prevalent kidney transplant recipients from a transplant clinic in a large academic center.

Intervention: Assessment of cognition using the Montreal Cognitive Assessment (MoCA). Demographic and clinical variables associated with cognitive impairment were also examined. Outcomes and Measurements: a) Prevalence of cognitive impairment defined by a MoCA score of <26. b) Multivariable linear and logistic regression to examine the association of demographic and clinical factors with cognitive impairment.

Results: Data from 226 patients were analyzed. Mean (SD) age was 54 (13.4) years, 73% were white, 60% were male, 37% had diabetes, 58% had an education level of college or above, and the mean (SD) time since kidney transplant was 3.4 (4.1) years. The prevalence of cognitive impairment was 58.0%. Multivariable linear regression demonstrated that older age, male gender and absence of diabetes were associated with lower MoCA scores (p < 0.01 for all). Estimated glomerular filtration rate (eGFR) was not associated with level of cognition. The logistic regression analysis confirmed the association of older age with cognitive impairment.

Conclusion: Cognitive impairment is common in prevalent kidney transplant recipients, at a younger age compared to general population, and is associated with certain demographic variables, but not level of eGFR.

Keywords: Cognitive impairment; Kidney transplantation; MoCA.

MeSH terms

  • Age Distribution
  • Causality
  • Cognitive Dysfunction / diagnosis
  • Cognitive Dysfunction / epidemiology*
  • Comorbidity
  • Cross-Sectional Studies
  • Diabetes Mellitus / epidemiology*
  • Educational Status
  • Female
  • Glomerular Filtration Rate*
  • Humans
  • Kansas / ethnology
  • Kidney Failure, Chronic / diagnosis
  • Kidney Failure, Chronic / epidemiology*
  • Kidney Failure, Chronic / therapy*
  • Kidney Transplantation / statistics & numerical data*
  • Male
  • Middle Aged
  • Prevalence
  • Risk Factors
  • Sex Distribution