Independent Association of hippocampal perivascular spaces with memory function in Type 2 diabetes

To investigate the associations of hippocampal perivascular space (H-PVS) volume and hippocampal volume with memory function in patients with type 2 diabetes mellitus (T2DM), and to compare their independent contributions to cognitive impairment.

A total of 75 cognitively normal patients (T2DM-NC) and 70 cognitively impaired patients (T2DM-CI) with T2DM were included, along with 79 healthy controls (HCs) matched for age, sex, and education. All participants underwent brain MRI scans and neuropsychological assessments. Multiple linear regression analyses were conducted in the T2DM group to assess the independent associations of H-PVS and hippocampal volumes with general cognitive and memory function.

Compared with HCs, the T2DM-CI group exhibited significantly larger H-PVS (P < 0.001) and choroid plexus volumes (P = 0.001). In patients with T2DM, H-PVS volume was not associated with hippocampal volume but was positively correlated with choroid plexus volume (P_FDR = 0.008). Multiple linearregression analysis showed that H-PVS volume was independently associated with memory function (β = -0. 212, P_FDR = 0. 033) in patients with T2DM, but not with the general cognitive function (P_FDR = 0.117). Hippocampal volume was not independently associated with either general cognitive function (P_FDR = 0.150) or memory function (P_FDR = 0.081).

H-PVS volume is independently associated with memory function in patients with T2DM, beyond the effects of hippocampal atrophy, suggesting that H-PVS volume may serve as a novel imaging biomarker for early identification of memory impairment in this population.