This study investigates the predictive value of peripheral glial fibrillary acidic protein (GFAP) and neurofilament light chain (NfL) as early biomarkers for dementia using data from the UK Biobank. The study enrolled 48,542 participants who were followed up for dementia diagnosis over an average period of 13.18 years. Key findings include: 1. **Elevated GFAP and NfL Levels**: Both GFAP and NfL levels increased up to 15 years before dementia diagnosis, suggesting early biomarker changes. 2. **Cognitive Impairment**: Higher levels of GFAP and NfL were associated with decreased numeric memory, prolonged reaction time, and poorer cognitive function. 3. **Dementia Risk**: Elevated GFAP and NfL levels significantly increased the risk of various types of dementia, including Alzheimer's disease (AD), vascular dementia (VD), and frontotemporal dementia (FTD). 4. **Genetic Correlation**: The AD genetic risk score and the number of APOE*4 alleles were strongly correlated with GFAP and NfL levels, indicating shared genetic factors. 5. **Predictive Value**: Combining GFAP and NfL with existing models improved the prediction of dementia, particularly in younger participants. The study concludes that peripheral GFAP and NfL are potential early biomarkers for dementia, suggesting the possibility of early interventions targeting neuroinflammation and neuronal damage.This study investigates the predictive value of peripheral glial fibrillary acidic protein (GFAP) and neurofilament light chain (NfL) as early biomarkers for dementia using data from the UK Biobank. The study enrolled 48,542 participants who were followed up for dementia diagnosis over an average period of 13.18 years. Key findings include: 1. **Elevated GFAP and NfL Levels**: Both GFAP and NfL levels increased up to 15 years before dementia diagnosis, suggesting early biomarker changes. 2. **Cognitive Impairment**: Higher levels of GFAP and NfL were associated with decreased numeric memory, prolonged reaction time, and poorer cognitive function. 3. **Dementia Risk**: Elevated GFAP and NfL levels significantly increased the risk of various types of dementia, including Alzheimer's disease (AD), vascular dementia (VD), and frontotemporal dementia (FTD). 4. **Genetic Correlation**: The AD genetic risk score and the number of APOE*4 alleles were strongly correlated with GFAP and NfL levels, indicating shared genetic factors. 5. **Predictive Value**: Combining GFAP and NfL with existing models improved the prediction of dementia, particularly in younger participants. The study concludes that peripheral GFAP and NfL are potential early biomarkers for dementia, suggesting the possibility of early interventions targeting neuroinflammation and neuronal damage.