To our knowledge, it is the first study to examine the association of kidney function with dementia risk and dementia-related blood biomarkers in the same the cohort, the first to use the eGFRcr-cys equation, the first to consider reverse causation between the dementia-related blood biomarkers and kidney function, and the first to explore the association with GFAP levels in blood. This evidence concerns the gene GFAP and dementia.