Serum 24S-hydroxycholesterol and hippocampal size in middle-aged normal individuals.

The present study assessed the association between serum 24S-hydroxycholesterol (24S-OH-Chol) and 27-hydroxycholesterol (27-OH-Chol) and hippocampal volumes in 69 middle-aged cognitively normal individuals. Results showed that subjects with high levels of oxysterols had significantly larger hippocampal volumes than subjects with low levels of oxysterols. Multiple regression analysis revealed that 24S-OH-Chol, but not 27-OH-Chol or cholesterol, was able to significantly predict hippocampal size. Future studies should elucidate whether high brain cholesterol metabolism in the middle age is protective against hippocampal atrophy and cognitive decline.