Glycosylated hemoglobin level and number of oral antidiabetic drugs predict whether or not glycemic target is achieved in insulin-requiring type 2 diabetes.

Aims: Factors predicting success (glycosylated hemoglobin (A1C)<7%) with insulin therapy in patients with insulin-requiring type 2 diabetes need to be identified.

Methods: A retrospective, multi-center, observational study was conducted for outpatients with oral antidiabetic drug (OAD)-treated type 2 diabetes whose A1C levels remained above 7%. Patients were begun on basal insulin between January 2005 and December 2006. Biochemical variables and demographic data were collected before and after 52 weeks of insulin therapy.

Results: A total of 565 patients (age, 60.4±11.9 years; A1C levels, 10.11 ±1.81%; duration of diabetes, 11.5±6.8 years) were studied. By study end, 63 patients (11.2%) had achieved the glycemic goal (A1C<7%). The glycemic goal attainment rate was only 9.1% in patients with A1C>8.8% and who were taking >2 OADs at baseline. The highest rate (32.7%) of successful glycemic control was observed in the group of patients with A1C ≤ 8.8% and who used ≤ 2 OADs at baseline.

Conclusions: Insulin-naïve diabetic patients with A1C>8.8%, especially those who are taking >2 OADs, have small chance to achieve good glycemic control with adding only basal insulin therapy.