The purpose of this study is to compare the efficacy of Amaryl®M 1/500 mg twice daily versus Amaryl® 4 mg both in combination with Lantus® once-daily regimen in type 2 Diabetes Mellitus patients with inadequate glycemic control.

There are several kinds of oral antidiabetic drugs (OADs) that are used in the treatment of patients with type 2 DM. Among them, sulfonylurea and metformin are well-established first-line OADs. However, as the beta cell dysfunction progresses over time, patients fail to achieve good glycemic control with OADs alone and need further treatment intensification, usually involving the introduction of insulin either alone or in combination with OADs. Now, an OAD combined with bedtime insulin is one of the recommended treatment options for patients with type 2 DM and OAD failure. But, it still remains unclear which OADs are the most effective in combination with insulin for the treatment of type 2 DM.

so, this study we will be able to verify which OADs are the most effective in combination with insulin for the treatment of type 2 DM.

Inclusion Criteria:

• Patients over 20 years old with type 2 DM
• Patients with inadequate glycemic control despite continuous use of tolerable or maximal doses of one or more OADs for 3months or more.
• 7%<HbA1c<11 % at screening
• 21 kg/m2 ≤ BMI ≤ 30 kg/m2
• Patents who need insulin add-on therapy based on investigator's discretion
• Patients who would give the informed consent
• Patients who can perform SMBG and record the data on the patient's diary

Exclusion Criteria:

• History of acute metabolic complications such as diabetic ketoacidosis or hyperosmolar nonketotic coma within 3 months before screening
• Pregnant or lactating females
• History of drug or alcohol abuse
• Patients with known hypersensitivity to glimepiride, metformin HCL or insulin
• Night-shift workers
• Patients who are under insulin therapy at screening
• Treatment with any investigational products in the last 3 months before screening
• Clinically significant laboratory abnormality on screening labs or any medical condition that would affect the completion or outcome of the study based on investigator's decision
• Patients with serum creatinine level > 1.5 mg/dl in male and > 1.4 mg/dl in female
• Patients with ALT or AST > 3x ULN