Complex Assessment of Metabolic Effectiveness of Insulin Pump Therapy in Patients with Type 2 Diabetes Beyond HbA1c Reduction

BACKGROUND This prospective single-center study recruited insulin-resistant continuous subcutaneous insulin infusion (CSII) therapy-naive patients with type 2 diabetes (T2D) using insulin analog-based multiple daily injections (MDI) therapy and metformin. METHODS A total of 23 individuals with T2D (70% male), aged a mean ± standard deviation 57.2 ± 8.03 years, with body mass index of 36.2 ± 7.02 kg/m2, diabetes duration of 13.3 ± 4.64 years, and HbA1c of 10.0% ± 1.05% were randomly assigned to a CSII arm or an MDI continuation arm to explore glucose control, weight loss, total daily insulin dose (TDD), and insulin resistance. Insulin dosing was optimized over a 2-month run-in period. RESULTS At 6 months, patients assigned to the CSII arm achieved a significant mean HbA1c reduction of -0.9% (95% confidence interval [CI] = -1.6, -0.1), while reducing their TDD by -29.8 ± 28.41 U/day (33% of baseline [92.1 ± 20.35 U/day]) and achieving body mass (BM) reduction of -0.8 ± 5.61 kg (0.98% of baseline [104.8 ± 16.15 kg]). MDI patients demonstrated a nonsignificant HbA1c reduction of -0.3% (95% CI = -0.8, 0.1) with a TDD reduction of 5% from baseline (99.0 ± 25.25 U/day to 94.3 ± 21.25 U/day), and a BM reduction of -1.0 ± 2.03 kg (0.99% of baseline [108.9 ± 20.55 kg]). After 6 months, the MDI arm crossed over to CSII therapy. At 12 months, patients continuing CSII demonstrated an additional mean 0.7% HbA1c reduction with 54.6% achieving HbA1c<8%. The final TDD reduction was -9.7 U/day in comparison to baseline; BM increased by 1.1 ± 6.5 kg from baseline. The MDI patients that crossed to CSII showed an HbA1c reduction of -0.5% ± 1.04%, HbA1c response rate of 27.3%, a TDD reduction of -17.4 ± 21.06 U/day, and a BM reduction of -0.3 ± 3.39 kg. Diabetic ketoacidosis or severe hypoglycemia did not occur in either arm. CONCLUSION CSII therapy safely and significantly improved metabolic control with less insulin usage, with no sustainable reduction of BM, blood pressure, and lipid profile, in insulin-resistant T2D patients. Treatment adherence and satisfaction in these patients were excellent.