Relevant clinical data including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), apolipoprotein A1, apolipoprotein B were collected, and the Mini-Mental State Examination (MMSE) score and Montreal Cognitive Assessment (MoCA) score were used to assess the cognitive function in patients with T2DM. Here, APOB is linked to type 2 diabetes mellitus.