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/m(2), 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.