Effects of multiple daily insulin injections on peripheral glucose disposal in Latin Americans with type 2 diabetes mellitus

Objective: To evaluate the effects of insulin in multiple daily injections (MDI) on peripheral glucose disposal in Latin American patients with type 2 diabetes. Methods and Results: Ten Latin American patients (four men and six women) with type 2 diabetes between the ages of 32 and 45 years were evaluated. All women were premenopausal and had regular menstrual periods. A hyperinsulinemic-euglycemic clamp procedure was performed at baseline and was repeated approximately 2 years after insulin monotherapy on MDI was initiated. Both genders had comparable baseline anthropometric and laboratory features, including a mean body mass index > 30 kg/m² and percent body fat > 30%. Baseline percent hemoglobin A_1c (HbA_1c%) was 9.5 ± 1.5%, and post-intervention HbA_1c% was 7.0 ± 1.2%. The peripheral glucose disposal rate at baseline was 4.5 ± 2.2 mg/kg/min fat-free mass and at postintervention was 3.6 ± 2.3 mg/kg/min fat-free mass. Conclusions: Despite a significant improvement in glycemic control, MDI did not seem to increase the insulin-mediated glucose disposal rate. Underlying obesity and increased percent body fat may have been the most counteracting factors on the potential improvement in insulin sensitivity expected with insulin monotherapy.