ABSTRACT
Objective To investigate the effects of basal and early phase insulin secretion on plasma glucose level in type 2 diabetes. Methods Plasma glucose and true insulin levels were measured at 0, 30, 60, 120 min during standard meal test in 81 patients with type 2 diabetes. Insulin sensitivity index (ISI) and insulin secretion index (?I 30 /?G 30 ) were calculated for evaluating the insulin sensitivity. Contributions of basal and early insulin secretion to plasma glucose level were evaluated by multivariate regression analysis with SAS software. Results ISI and ?I 30 /?G 30 showed nearly equal effects on plasma glucose levels by multivariate regression analysis. Among insulin levels of different time points during standard meal test, basal and postprandial 60 min insulin levels played important roles in changes of plasma glucose levels. The effect of fasting insulin on the area under plasma glucose curve was stronger than that of ?I 30 /?G 30 . Conclusion Both basal and early insulin secretions greatly contribute to glycemic control.