Effects of Intensive Insulin Therapy Within One Week on Glycemic Control and β-Cell Function in Patients with T2DM

Objective: To evaluate the impact of intensive insulin therapy (IIT) within 1 week on glycemic control and β-cell function indices in patients with type 2 diabetes mellitus (T2DM). Methods: This retrospective study included 726 patients with T2DM who underwent continuous subcutaneous insulin infusion within 1 week. Patients were divided into three groups based on disease duration: short (≤1 year), medium (>1 and <10 years), and long (≥10 years) duration groups. The primary outcome was the changes in glycemic control and β-cell function indices after IIT. Factors influencing the improvement in β-cell function metrics were also analyzed. Results: After IIT within 1 week, fasting plasma glucose (FPG) and postprandial plasma glucose (PPG) levels significantly decreased (p < 0.01 for both). HOMA-β, 30 min insulinogenic index, 30 min disposition index, and insulin secretion sensitivity index-2 markedly improved from baseline [37.69 (41.03) VS. 32.40 (46.06), 3.16 (3.97) VS. 2.12 (3.51), 336.85 (397.05) VS. 188.93 (263.45), and 185.92 (122.89) VS. 120.81 (90.12), respectively] (p < 0.01 for all). Insulin sensitivity, measured by HOMA-IR and Matsuda index, significantly improved (p < 0.01 for both). Significantly greater improvements in glycemic control and β-cell function measures were observed in patients with a shorter diabetes duration. Age, duration of diabetes, BMI, HbA1c, duration of IIT, and time in range were significantly associated with improvements in β-cell function indices. Conclusions: IIT within 1 week was associated with improved glycemic control and β-cell function indices in T2DM patients, with the most pronounced benefits observed in those with a shorter disease duration.