To evaluate the efficacy and predictive factors of Dipeptidyl peptidase-4 (DPP-4) inhibitors in type 2 diabetes mellitus (T2DM) patients who were not well controlled with other oral antidiabetic drugs or insulin in real clinical practice.

From December 2012 to January 2014, retrospective longitudinal observation study was conducted for patients with T2DM who were not reached a glycemic target (glycated hemoglobin [HbA1c] > 6.5%) with other oral antidiabetic drugs or insulins. Type 1 diabetes or other types of diabetes were excluded. Responders were eligible with decreased HbA1c from baseline for more than 5% during follow up period.

Of total 135 T2DM patients having an average 9.0 months follow-up period, 84 (62.2%) of patients were responder to DPP-4 inhibitors. After concomitant treatment with DPP-4 inhibitors, patients had a mean decrease in HbA1c of 0.69 ± 1.3%, fasting plasma glucose of 13 ± 52 ㎎/㎗, and postprandial plasma glucose of 29 ± 85 ㎎/㎗ from baseline (all P< 0.05). Independent predictive factor for an improvement of glycemic control with DPP-4 inhibitors was higher baseline HbA1c (odds ratio 2.07 with 95% confidence interval 1.15–3.72) compared with non-responders.

A clinical meaningful improvement in glycemic control was seen when DPP-4 inhibitors were added to other anti-diabetic medications in patients with T2DM regardless of age, duration of T2DM, type of combination treatment regimen. Patients who had higher HbA1c were more easily respond to DPP-4 inhibitors treatment in short-term follow-up period.