Region-specific hippocampal atrophy is correlated with poor glycemic control in type 2 diabetes: a cross-sectional study

抄録

To examine the association between prediabetes/type 2 diabetes mellitus (T2DM) and hippocampal subfields and to investigate the effects of glycemic control (HbA1c and FBG)/diabetes duration on the volume of hippocampal subfields in T2DM patients. This cross-sectional study included 268 participants from Tianjin Union Medical Center between August 2019 and July 2022. The participants were divided into three groups: T2DM, prediabetes and no diabetes. All participants underwent brain MRI examination on a 3T MRI scanner. FreeSurfer was performed to segment hippocampus automatically based on T1 MPRAGE images. The relationships between glycemic status/glycemic control/diabetes duration and hippocampal subfield volumes were estimated by multiple linear regression analysis/generalized additive modeling (GAM). Among all participants, 76 (28.36%) had prediabetes, and 96 (35.82%) had T2DM. In multi-adjusted linear regression models, those with prediabetes had a significantly lower volume of bilateral parasubiculum (β_right = –5.540; β_left = –6.497). Those with diabetes had lower volume of parasubiculum (β_left = –7.868), presubiculum-head (β_left = –6.244) and fimbria (β_left = –7.187). We did not find relationship between diabetes duration and hippocampal subfield volumes. In stratified analysis, long duration with high FBG related with lower volume of right fimbria (β_right = –15.583). Long duration with high HbA1c related with lower volume of presubiculum-head (β_right = –19.693), subiculum-head (β_right = –28.303), subiculum-body (β_left = –38.599), CA1-head (β_right = –62.300, β_left = –47.922), CA1-body (β_right = –19.043), CA4-body (β_right = –14.392), GC-ML-DG-head (β_right = –20.521), GC-ML-DG-body (β_right = –16.293, β_left = –12.799), molecular_layer_HP-head (β_right = –44.202, β_left = –26.071) and molecular_layer_HP-body, (β_right = –31.368), hippocampal_tail (β_left = –80.073). Prediabetes related with lower bilateral parasubiculum volume, and T2DM related with lower left parasubiculum, presubiculum-head and fimbria. T2DM with chronic poor glycemic control had lower volume in multiple hippocampal subregions.