INS and Hyperglycemia: 1. Small-scale RCT (n = 48, 4-year follow-up): After initial remission via short-term intensive insulin therapy, metformin (1000 mg/day) reduced hyperglycemia recurrence risk by ~70% vs. placebo, and extended median remission duration from ~10 months to 16 months (mechanism: improved β-cell function).2. No standalone long-term remission data; serves as core for sustaining remission in combination strategies.