Effect of intensive insulin therapy on first-phase insulin secretion in newly diagnosed type 2 diabetic patients with a family history of the disease.

Intensive insulin treatment is known to improve β-cell function in the majority of patients with newly diagnosed type 2 diabetes mellitus (T2DM), and family history (FH) is known to be an important independent risk factor for T2DM. Thus, the aim of the present study was to investigate the difference in first-phase insulin secretion and the effect of intensive insulin therapy on the improvement of β-cell function between T2DM patients with and without a FH of diabetes. Patients with newly diagnosed T2DM and healthy controls were divided into groups according to their FH of diabetes. Improvement in β-cell function was evaluated with an arginine stimulation test after two weeks of continuous subcutaneous insulin infusion (CSII). Compared with the control group, the level of fasting insulin and the homeostasis model assessment of insulin resistance (HOMA2-IR) were higher in the DM group, while the homeostasis model assessment of β-cell insulin secretion (HOMA2-%β) and the first-phase peak ratio were lower (P<0.05). In addition, the first-phase peak ratio in the FH- control group was higher compared with that in the FH+ control group (P=0.023). Following CSII, all the patients achieved excellent blood glucose control in 6.2±3.6 days, without severe adverse effects. In the DM groups, the fasting insulin level and HOMA2-IR were lower, while the HOMA2-%β and first-phase peak ratio were higher, when compared with the values prior to treatment, particularly in the FH- DM group. The HOMA2-%β in the FH+ DM group was lower compared with the FH- DM group (P=0.027). Therefore, T2DM patients with and without a FH of the disease were shown to have a good response to CSII in the improvement of insulin resistance and β-cell function; however, the improvements were less significant in patients with a FH compared with patients without a FH of diabetes.