<h4>Objective</h4>This study aims to investigate the changes in cardiometabolic index (CMI) levels in newly diagnosed type 2 diabetes mellitus (T2DM) patients before and after undergoing short-term continuous subcutaneous insulin infusion (CSII) intensive treatment and analyse its correlation with insulin resistance.<h4>Methods</h4>This study retrospectively collected data from 604 patients who were initially diagnosed with T2DM and received short-term CSII treatment during their hospitalisation in the Endocrinology Department of the Affiliated Hospital of Jiangsu University. Here, INS is linked to diabetes mellitus.