Randomized controlled trial of single‐agent glimepiride and pioglitazone in Japanese patients with type 2 diabetes: A comparative study

Aims/Introduction: To compare first‐line, single‐agent glimepiride and pioglitazone in Japanese patients with type 2 diabetes uncontrolled by diet and exercise with respect to glycemic control, safety and metabolic changes. Materials and Methods: Patients with previously untreated type 2 diabetes were enrolled in a multicenter, randomized, non‐blind, parallel‐group trial of glimepiride (0.5–6 mg/day) or pioglitazone (15–45 mg/day) for 6 months. Results: A total of 191 patients aged 30–75 years were randomized. Similar percentages of patients attained the primary end‐point, with glycated hemoglobin < 6.9% at month 6 with glimepiride and pioglitazone, respectively (61.2 vs 56.8%, P = 0.64). At month 6, the following significant (P < 0.05) intragroup changes in mean plasma lipid concentrations were noted as compared with baseline: total cholesterol decreased from 203.5 to 195.5 mg/dL and low‐density lipoprotein (LDL)‐cholesterol decreased from 124.5 to 116.3 mg/dL in the glimepiride group, whereas high‐density lipoprotein (HDL)‐cholesterol increased from 51.6 to 56.0 mg/dL and triglycerides decreased from 167.6 to 143.6 mg/dL in the pioglitazone group. The only symptomatic adverse events were mild‐to‐moderate in four patients receiving pioglitazone, and constipation in one patient receiving glimepiride. Similar numbers of patients experienced asymptomatic hypoglycemia (<60 mg/dL) in the glimepiride and pioglitazone groups (n = 7 and 5, respectively). Conclusions: There was no statistically significant difference between glimepiride and pioglitazone with respect to glycemic control, and both agents were well tolerated. Glimepiride significantly lowered total cholesterol and LDL‐cholesterol, whereas pioglitazone increased HDL‐cholesterol. This trial was registered with University Hospital Medical Information Network (UMIN), Japan, UMIN000004582. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00115.x, 2011)