Greater Risks Of Dementia Among Kidney Transplant Recipients

There is a high burden of dementia and Alzheimer’s disease (AD) after kidney transplantation (KT) and these diagnoses put KT recipients at twice the risk of subsequent mortality and 1.5-fold increased risk of graft loss, according to a new study.

“Dementia is a well-recognized complication of end-stage renal disease; among dialysis patients, development of dementia predicts poor outcomes including disability, hospitalization, and death,” the researchers said. “However, the risk and consequences of dementia or AD after KT are unclear. We hypothesized that older KT recipients are at elevated risk for dementia or AD due to their long-standing kidney disease as well as dependence on neurotoxic immunosuppressant agents.”
______________________________________________________________________________________________________________________
RELATED CONTENT
Does HIV/Hep C Infection Affect Kidney Transplant Outcomes
Discontinuation of Steroids After Kidney Transplant Safe
______________________________________________________________________________________________________________________

The researchers studied 40,918 older (aged ≥55 years) KT recipients (January 1, 1999-December 31, 2011) linked to Medicare claims through the US Renal Data System. They estimated dementia and AD risk (cumulative incidence) and studied factors associated with these sequelae using competing risks models. The investigators estimated the risk of death-censored graft loss and mortality after developing dementia or AD subtype of dementia, separately, using adjusted Cox proportional hazards models.

Older recipients had a 10-year dementia risk ranging from 5.1% for recipients 55-60 years old to 17% for recipients aged ≥75 years; 10-year AD risk ranged from 1%-6.7%, respectively. They found the strongest predictors for dementia and AD to be older recipient age and pre-transplant diabetes. The 10-year graft loss risk was 28.8% for those who did not develop dementia and 43.1% for those who did, and the corresponding mortality risks were 55.7% and 89.9%, respectively. Older recipients with dementia had a 1.52-fold increased risk of graft loss and a 2.38-fold increased risk of mortality. They observed similar results for AD.

“The risk of dementia and AD should be weighed against the burden of dialysis and not adversely impact the decision to transplant otherwise acceptable older KT candidates,” the researchers concluded. “There is the need for greater awareness of the risk for dementia and AD in older patients undergoing KT.”

For future work, the investigators plan to further explore the changes in cognitive function after transplantation.

—Mike Bederka

Reference:

McAdams-DeMarco MA, Bae S, Chu N, et al. Dementia and Alzheimer’s disease among older kidney transplant recipients [published online December 15, 2016]. J Am Soc Nephrol. doi: 10.1681/ASN.2016080816.