Predictors of the Efficacy of Dipeptidyl Peptidase-4 Inhibitors in Taiwanese Patients with Type 2 Diabetes Mellitus

BACKGROUND/PURPOSE: Dipeptidyl peptidase-4 (DPP-4) inhibitors are the most popular oral antidiabetic drugs (OADs) in recent 20 years because of the low risk of hypoglycemia, intermediate efficacy to lower glycated hemoglobin (△HbA1c): 0.5–0.9%, neutral effect on body weight change, convenience for usage (mostly once daily), and rare occurrence of major side effects. The purpose of this study was to determine the important predictors of the efficacy of naïve use of DPP-4 inhibitors in Taiwanese patients with type 2 diabetes mellitus (T2D). METHODS: A retrospective observational study was conducted. Of the T2D patients, 193 (122 men) naïve DPP-4 inhibitor users with an age of 58.0 ± 12.6 years, disease duration 5.4 ± 4.7 years, body mass index (BMI) 26.1 ± 4.3 kg/m(2), and estimated glomerular filtration rate 95.9 ± 27.0 mL/min/1.73M(2) were assessed for △HbA1c in 6 months. RESULTS: After 6 months of DPP-4 inhibitors use, mostly second or third line of OADs (2.8 ± 0.7 kinds of OADs), 193 T2D patients (mean baseline HbA1c: 8.4 ± 1.4%) had △HbA1c 1.1 ± 1.2% on average (P < 0.01). The group with a higher baseline HbA1c level had more effective efficacy (△HbA1c ≥0.5%) in lowering HbA1c. Single regression analysis showed that the change in HbA1c after 6 months of treatment was positively associated with the baseline HbA1c level (R = 0.71, P < 0.001). In addition, multiple regression analysis showed that contributors to decrease HbA1c level after 6 months were high baseline HbA1c level, low BMI, short T2D duration, and fewer kinds of OADs. CONCLUSION: Our study suggested that high baseline HbA1c level, low BMI, short T2D duration, and fewer kinds of OADs are the predictors of the efficacy of DPP-4 inhibitors in Taiwanese patients with T2D. The baseline HbA1c level, in particular, played the most important role in effective efficacy (△HbA1c ≥0.5%).