INS and type 2 diabetes mellitus: We hypothesized that (1) INI has a long-term effect on increasing HPC/mPFC rsFC of T2DM participants, including HPC-mPFC rsFC, (2) the larger HPC/mPFC rsFC is associated with improved cognition, faster walking speed, and less insulin resistance at baseline, and (3) the long-term HPC/mPFC rsFC increases after treatment are associated with increased cognition, faster walking speed, and reduced insulin resistance.