Young onset type 2 diabetic patients might be more sensitive to metformin compared to late onset type 2 diabetic patients.

It is unknown whether YOD (young onset diabetes) and LOD (late onset diabetes) require similar insulin doses for intensive insulin therapy with a metformin add-on to achieve glycemic control. We analyzed data from our two previously performed randomized, controlled open-label trials. Patients were randomized to receive either continuous subcutaneous insulin infusion (CSII) therapy or CSII combined with metformin therapy for 4 weeks. The studies concentrated on the differences in the insulin doses used for the two groups. We included 36 YOD (age < 40 yrs) and 152 LOD (age > 40 yrs) patients. YOD patients who received metformin combined with CSII therapy required significantly lower insulin doses to maintain euglycemic control compared to patients with LOD. A multivariate analysis, controlled for gender and the fasting blood concentration, was performed to determine the significance of the differences between groups, particularly with respect to the total and basal insulin doses. There was a trend toward improvement in β-cell function and insulin resistance in terms of ΔHOMA-B and ΔHOMA-IR in patients with YOD compared to those with LOD. Newly diagnosed T2D patients with YOD required significantly lower insulin doses, particularly basal insulin doses, to maintain glycemic control compared to the LOD patients.