Adachi Y, Ota K, Minami I, et al. - This study was intended to investigate the relationship between diabetes-related parameters and hippocampal and parahippocampal gyrus atrophy (HPGA) in patients with type 2 diabetes mellitus to elucidate the risk factors for HPGA, which is often accompanied by Alzheimer’s disease. Researchers recruited a sum of 137 patients aged ≥ 50 years with type 2 diabetes mellitus (mean age 67.8 ± 9.8 years) who had undergone brain magnetic resonance imaging scans and comprehensive health examinations. They assessed the volume of interest – a portion of the inner temporal lobe that includes the hippocampus, amygdala, and entorhinal cortex (frontal part of the parahippocampal gyrus) – using the voxel-based specific regional analysis system for Alzheimer’s disease in each patient. The results demonstrated that in patients with type 2 diabetes mellitus, lower insulin secretion was significantly correlated with HPGA. The outcomes of this research support the hypothesis that insulin-signaling abnormalities are involved in the pathophysiology of Alzheimer’s disease.