Motivation: Traditional neuroimaging studies have analyzed the effects of cardiometabolic factors on brain structure and cognition but often lack sensitivity to subtle micro-structural changes. Past studies have been limited by small sample sizes and a focus on simple volumetric or circuit-level analyses. Goal(s): To investigate the impact of cardiometabolic disease on the brain at the fixel level using large-scale cohort data. Approach: Using fixel-based analysis, we examined tract- and network-specific fixels affected by metabolic syndrome and analyzed their relationships with cardiometabolic indicators. Results: We identified significant fixel-based metric differences influenced by specific cardiometabolic indicators, leading to improved predictive modeling for cognitive function impacts. Impact: This study aims to capture micro-structural brain changes undetected in prior research. Fixel-based analysis allows precise mapping of cardiometabolic factors' effects on specific tracts and networks, enhancing predictive accuracy for cognitive function correlations at the individual level.