Objective: To evaluate the efficacy and safety of add-on pioglitazone versus sitagliptin in patients with type 2 diabetes inadequately controlled on metformin and a sulfonylurea (SU).
Methods: This 24-week, randomized, open-label study compared pioglitazone (30 mg daily, n = 59) and sitagliptin (100 mg daily, n = 60) in patients with inadequate glycemic control (glycosylated hemoglobin [HbA1c] ≥7.0% to <11.0%) while receiving a stable dose of metformin (≥1,500 mg daily) and an SU (≥half-maximal dose).
Results: The mean changes in HbA1c from baseline was -0.94 ± 0.12% with pioglitazone and -0.71 ± 0.12% with sitagliptin, for a between-groups difference of -0.23 ± 0.16% (P = .16). The mean change in fasting plasma glucose (FPG) were -35.7 ± 4.0 mg/dL with pioglitazone and -22.8 ± 4.0 mg/dL with sitagliptin, for a between-groups difference of -12.9 ± 5.7 mg/dL (P = .02). Pioglitazone was associated with a significant decrease in high-sensitive C-reactive protein (hs-CRP), but sitagliptin did not. The mean weight gain was higher in the pioglitazone group, with a between-group difference of 1.6 kg (P<.01). Overall adverse events (AEs) were similar in both groups. However, the incidence of edema was higher with pioglitazone, and the incidence of gastrointestinal AEs was higher with sitagliptin.
Conclusion: Pioglitazone and sitagliptin achieved similar improvements in overall glycemic control in patients with type 2 diabetes inadequately controlled with metformin and an SU. However there were some differences in terms of FPG, hs-CRP, lipids, body-weight change, and AEs.