Biological aging and its association with serum neurofilament light chain levels in middle-aged African Americans: a prospective observational study

This study examines the association between DNA methylation-based epigenetic aging indices and neurofilament light chain levels in middle-aged African Americans to advance the understanding of neurodegeneration and cognitive decline. Epigenetic aging was assessed in samples from 2008 and 2019 by applying HorvathAgeAccel, HannumAgeAccel, PhenoAgeAccel, GrimAgeAccel, and DunedinPACE. Controlling for financial strain, exercise, age, gender, cell-type composition, and <i>APOE-ε4</i>, second- and third-generation DNA methylation-based aging-PhenoAgeAccel, GrimAgeAccel, and DunedinPACE-were significantly associated with serum neurofilament light chain levels. In contrast, first-generation DNA methylation-based clocks, including HorvathAgeAccel and HannumAgeAccel, were not significantly related to neurofilament light chain. These findings suggest that newer DNA methylation-based aging indices are more strongly associated with neurodegenerative biomarkers. Integrating advanced DNA methylation-based clocks with neurofilament light chain levels may improve early detection of cognitive decline and dementia, supporting personalized medicine by identifying biological aging profiles linked to neurodegenerative risks.