CCL2 and hippocampal atrophy: MCP-1 was significantly associated with hippocampal atrophy (n = 299) when used as continuous (β = −0.0000005, 95%CI = −0.0000009, −0.00000007; p = 0.022), whereas in the categorical approach, the MCP-1+ group did not show a greater hippocampal atrophy over the follow-up (mean = 966.1 ± 111 days), compared to MCP-1− (between-group difference: β = −0.04, 95%CI = −0.10, 0.01; p = 0.107).