Alzheimer Disease Blood Biomarker Levels Increase With Impaired Kidney Function

THURSDAY, Dec. 4, 2025 (HealthDay News) — Impaired kidney function is associated with increased circulating levels of most Alzheimer disease (AD) blood biomarkers, but is not associated with an independently increased risk for dementia, according to a study published online Dec. 3 in Neurology.

Francesca Gasparini, Ph.D., from the Karolinska Institutet and Stockholm University, and colleagues examined the associations of estimated glomerular filtration rate (eGFR) with blood-based biomarkers of AD and dementia development using data from the Swedish National Study on Aging and Care in Kungsholmen, a longitudinal population-based study.

The study included 2,279 dementia-free participants with available blood samples at baseline. The researchers found that apart from amyloid β42/40, lower eGFR was associated with higher median z-score levels of all AD blood biomarkers examined in a nonlinear pattern. At an eGFR of 30 mL/min/1.73 m², the estimated differences were β = 0.22, 0.20, 0.24, 0.88, and 0.10 for phosphorylated tau (p-tau)181, p-tau217, total-tau, neurofilament light chain (NfL), and glial fibrillary acidic protein, respectively. Three hundred sixty-two participants developed dementia during a mean follow-up of 8.3 years. In multivariable-adjusted models, there was no association seen for impaired versus preserved kidney function with an increased hazard of dementia (hazard ratio, 0.93; 95 percent confidence interval, 0.72 to 1.21). Individuals with impaired versus preserved kidney function had a stronger relationship between increased NfL and dementia (hazard ratios [95 percent confidence intervals], 3.85 [1.87 to 7.95] versus 1.84 [1.34 to 2.53]).

“While we did not find that having reduced kidney function increased the risk of developing dementia, we did find that impaired kidney function may accelerate the onset of dementia in people who have higher levels of biomarkers,” Gasparini said in a statement.

Abstract/Full Text