Cofrogliptin and Linagliptin as add-on Therapy to Insulin in Type 2 Diabetes

Inclusion Criteria: 1. Sign the informed consent form. 2. Aged ≥18 years. 3. Diagnosed with type 2 diabetes mellitus (meeting the 1999 WHO diagnostic criteria). 4. Recently tested HbA1c 7%-9% and FPG ≤11 mmol/L, with stable treatment using insulin ± OADs for at least 12 weeks prior to enrollment. Insulin regimens are limited to: basal insulin once daily or once weekly, premixed insulin once or twice daily, or IDegAsp once or twice daily. OAD classes are limited to metformin, SGLT2 inhibitors, and α-glucosidase inhibitors and with no more than three agents in total. 5. Willing to start or have already initiated cofrogliptin or linagliptin treatment (at the physician's discretion in accordance with clinical practice). The treatment decision is independent of study enrollment, must be made before signing the informed consent, and cofrogliptin or linagliptin initiation must occur either within 2 weeks before or within 2 weeks after signing the informed consent. Exclusion Criteria: 1. Allergic to the study drug. 2. Diagnosed with type 1 diabetes. 3. Unable to comply with study-specific procedures. 4. Current or planned pregnant, or currently breastfeeding. 5. With any other situation judged by the investigator, that is unsuitable for participation in this trial.