White Matter but not Gray Matter Volumes Are Associated with Cognition in Community-Dwelling Chinese Populations

Background: Few studies have investigated the association between cognition and brain volume associated with cerebral small vessel disease (CSVD).
Objective: We investigated the association between cognition and brain volume and neuroimaging markers of CSVD in a community-dwelling population.
Methods: Participants (n = 993, age≥35 years) from the community-based Shunyi Study were included to investigate the association between neuroimaging markers and cognition cross-sectionally. Magnetic resonance imaging markers included brain volume measurements of the total cerebrum, white matter, gray matter, and CSVD imaging markers. Cognitive performance was assessed using neuropsychological tests of the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Fuld Object Memory, digit span, Trail Making Test (TMT)-A, and TMT-B.
Results: For brain volume measurement, subcortical white matter fraction was positively associated with MMSE score (  = 0.034, p = 0.0062) and MoCA score (  = 0.034, p = 0.0174), and negatively associated with TMT-A and TMT-B completion time (  = –2.319, p = 0.0002;   = –2.827, p = 0.0073, respectively). For evaluation of CSVD imaging markers, the presence of lacunes was positively associated with TMT-B completion time (  = 17.241, p = 0.0028).
Conclusion: In community-dwelling populations, reduced white matter volumes, as a consequence of aging and vascular damage, are associated with worse global cognition and executive function. Our findings provide potential insights into the correlation between cognition and CSVD-associated subcortical white matter injury.