Grey-matter brain healthcare quotient and cognitive function: A large cohort study of an MRI brain screening system in Japan.

There is sometimes a divergence between brain atrophy and impairments in cognitive function. The present study aimed to assess the relationship between cognitive function and the grey-matter brain healthcare quotient (GM-BHQ), which represents brain volume as a deviation value. In addition, we aimed to investigate lifestyle factors that can help maintain cognitive function despite brain atrophy. A total of 1,757 adults included in a Japanese MRI brain screening cohort underwent MRI. We classified the participants into two age groups: under 65 years old (young adult/middle age group) and over 64 years old (elder group). The GM-BHQ was more strongly correlated with cognitive function in the young adult/middle age group than in the elder group (p < .01). Regression analysis revealed that years of education was associated with the maintenance of cognitive function despite brain atrophy (p < .05). In conclusion, our findings suggest that the relationship between brain volume and cognitive function becomes more obscure with age.