A Comparative Study of Insulin Secretagogue (SU Agent) and Insulin sensitizers (TZD)

INTERVENTION: [Step 1] The assigned study drug will be administered alone. Insulin secretagogue (SU agent) Treatment with the insulin secretagogue should be started at a half of the usual dose when the HbA1c level just before administration is &#61619; 6.5% to < 7.0%, and at the usual dose when the HbA1c level is &#61619; 7.0% to < 10.0%. Thereafter, the dose should be adjusted as necessary for achieving the morning FPG level of < 120 mg/dL. [Step 2] Combination therapy will be started or monotherapy will be continued according to the directions in Table 1 taking account of an evaluation of the HbA1c level at Month 6 and the dose level of the study drug. The treatment method is as follows: The maximum doses of the insulin secretagogue (SU agent) and insulin sensitizer (TZD) are the same as those specified for Step 1. (1)When monotherapy with the insulin secretagogue (SU agent) is continued The dose should be adjusted for achieving the morning FPG level of < 120 mg/dL. If the subjects do not achieve the HbA1c < 6.5% after reaching the maximum dose during the treatment period, coadministration with the insulin sensitizer (TZD) should be started as in Item (2). (2)When the insulin secretagogue (SU agent) is combined with the insulin sensitizer (TZD) The dose of the insulin sensitizer (TZD) should be adjusted for achieving the morning FPG level of < 120 mg/dL. [Step 1] The assigned study drug will be administered alone. Insulin sensitizer (TZD) The doses of pioglitazone should be as follows: 15 mg/day as the starting dose, 30 mg/day as the usual dose, 45 mg/day as the maximum dose for men, and 30 mg/day as the maximum dose for women. The dose should be adjusted for achieving the morning FPG level of < 120 mg/dL. [Step 2] Combination therapy will be started or monotherapy will be continued according to the directions in Table 1 taking account of an evaluation of the HbA1c level at Month 6 and the dose level of the study drug. The treatment method is as CONDITION: Type2 diabetes PRIMARY OUTCOME: The rate for achieving the HbA1c level of < 6.5% at Month 6 INCLUSION CRITERIA: At preliminary registration (1)Being treated only with dietary management and/or therapeutic exercise. (2)HbA1c >= 6.5% to < 10.0% at preliminary registration. (3)Age at treatment initiation: 30 to 73 years* (4)Sex: Male and female (5)Inpatient or outpatient (6)Being capable of providing informed consent to participate in the study, reading the informed consent document and understanding its contents. At formal registration (1)Being treated only with diet and exercise. (2)HbA1c >= 6.5% to < 10.0% at formal registration (3)A < 1.0% difference in HbA1c from the level at preliminary registration. SECONDARY OUTCOME: Secondary endpoints in Step 1; 1)Change in the HbA1c level at Month 6.; 2)Changes in the FPG level, fasting insulin level, lipid metabolism, body weight, BMI, blood pressure and BNP at Month 6.; Secondary endpoints in Step 2; 1)The rate for achieving the HbA1c level of 6.5% in the total subjects in each randomized group in Step 1.; 2)The rates for achieving the target HbA1c level in the monotherapy groups.; 3)Change in the HbA1c level in the monotherapy groups.; 4)Changes in the FPG level, fasting insulin level, lipid metabolism, body weight, BMI, blood pressure and BNP at Month 12.5.; 5)Changes in the dose of the drug and the HbA1c level.; 6)Medical economic evaluation (medical expenses, new expenses for treatment and tests/ examinations required at the onset of adverse reactions, drugs necessary for lowering the HbA1c level by 1%, and drugs and medical care necessary for improving the DTSQ score by 1 point).