Older adults with reduced kidney function show higher levels of Alzheimer's-related biomarkers in the blood, but are not more likely to develop dementia, according to a new study from Karolinska Institutet.
A research team guided by Assistant Professor Giulia Grande at the Aging Research Center , part of the Department of Neurobiology, Care Sciences and Society, has explored how kidney function affects blood biomarkers linked to Alzheimer's disease. The study, published in Neurology, involved 2,279 individuals in Stockholm, with an average age of 72 who did not have dementia at the start of the study. The participants were followed for an average of eight years.
Participants underwent medical examinations and blood tests to measure kidney function and levels of proteins associated with Alzheimer's disease, including phosphorylated tau proteins (like p-tau217), neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP). These biomarkers are becoming increasingly important for identifying early signs of neurodegeneration.
The researchers found that people with impaired kidney function had higher levels of most biomarkers in their blood, including p-tau217. However, poor kidney function did not increase the overall risk of developing dementia. Instead, among those with elevated biomarker levels-particularly NfL-dementia tended to develop earlier in individuals with reduced kidney function.
This suggests that kidney health may influence the timing of dementia symptoms in people already showing signs of neurodegeneration, rather than acting as a direct cause.
The findings highlight the importance of considering kidney function when interpreting blood tests for Alzheimer's disease, especially in older adults.
"When looking at these biomarkers in older adults, keeping an eye on kidney health may be more important than one might think," says first author Francesca Gasparini , research assistant at the Aging Research Center. "Monitoring kidney health may help clinicians better understand who is at risk for faster disease progression."
The study was based on data from the Swedish National study on Aging and Care in Kungsholmen (SNAC-K), and included extensive clinical assessments and long-term follow-up.
Publication
Kidney function, Alzheimer's disease blood biomarkers and dementia risk in community-dwelling older adults , Francesca Gasparini; Martina Valletta; Davide Liborio Vetrano; Giorgi Beridze; Debora Rizzuto; Amaia Calderón-Larrañaga; Claudia Fredolini; Matilda Dale; Bengt Winblad; Laura Fratiglioni; Giulia Grande, Neurology, online 3 December 2025, doi: 10.1212/WNL.0000000000214446.
