Brain health and inflammation in older adults: Preventive care insights from the association between high-sensitivity CRP and hippocampal volume

• Serum hs-CRP levels were examined in community-dwelling older adults aged ≥ 65 years. • Higher hs-CRP levels were associated with smaller hippocampal volume. • Systemic inflammation may relate to brain health in aging. This study aimed to investigate the association between serum high-sensitivity C-reactive protein (hs-CRP) levels, cognitive function, and brain structure in community-dwelling older adults aged 65 years and older. Given the role of inflammation in neurodegeneration, we hypothesized that higher hs-CRP levels would be associated with hippocampal volume and cognitive performance. This cross-sectional study included 93 participants (25 men, 68 women) from Kurokawa-cho, Japan. Cognitive function was assessed using the Mini-Mental State Examination (MMSE), Frontal Assessment Battery (FAB), and Clinical Dementia Rating (CDR). Serum hs-CRP levels were measured using an enzyme-linked immunosorbent assay. Brain structural analysis was conducted using voxel-based morphometry (VBM) on MRI scans. Multiple regression analyses were performed, adjusting for age, sex, years of education, and total intracranial volume. Serum hs-CRP levels were not significantly associated with cognitive function scores. However, VBM analysis revealed a significant negative association between hs-CRP levels and brain volume in the region including the right hippocampus (P < 0.05, corrected for multiple comparisons using family-wise error and false discovery rate corrections). A similar negative association was observed in the region including the left hippocampus, though it did not reach statistical significance. These findings suggest that systemic inflammation, as indicated by hs-CRP levels, may be linked to smaller hippocampal volume in older adults, independent of cognitive function. This potential association highlights the role of inflammation in brain aging and underscores the importance of preventive healthcare strategies aimed at mitigating inflammation-related neurodegeneration.