The purpose of this study is to evaluate the safety and efficacy of YJP-14 capsules for the treatment of endothelial dysfunction in patients with diabetes mellitus.

The primary purpose of this study is to demonstrate superior effect of YJP-14 three doses, 25, 50 and 100 mg t.i.d on endothelial dysfunction in diabetes mellitus indicated as mean change difference of flow-mediated dilation (FMD), compared to placebo group after treatment of 12 weeks.

The secondary purposes of this study are divided into three as follows;

• Clinically significant effect of YJP-14 three doses, 25, 50 and 100 mg t.i.d on endothelial dysfunction in diabetes mellitus indicated as mean change difference of FMD, compared to placebo group after treatment of 8 weeks.
• Clinically significant effect of YJP-14 three doses, 25, 50 and 100 mg t.i.d on insulin resistance in diabetes mellitus indicated as mean change difference of Homeostasis Model Assessment-Insulin Resistance (HOMA-IR), compared to placebo group after treatment of 4, 8 and 12 weeks.
• Clinically significant effect of YJP-14 three doses, 25, 50 and 100 mg t.i.d on mean change difference of blood pressure in diabetes mellitus, compared to placebo group after treatment of 4, 8 and 12 weeks.

The exploratory purposes of this study are divided into two as follows;

• Clinically significant effect of YJP-14 three doses, 25, 50 and 100 mg t.i.d on blood glucose level in diabetes mellitus indicated as mean change difference of HbA1c, compared to placebo group after treatment of 12 weeks.
• Clinically significant effect of YJP-14 three doses, 25, 50 and 100 mg t.i.d on vascular stiffness in diabetes mellitus indicated as mean change difference of blood lipids (LDL, HDL and TG), compared to placebo group after treatment of 12 weeks.

Inclusion Criteria:

Adult-onset DM (defined as fasting glucose greater than 125 mg/dl or by ongoing treatment with an oral hypoglycemic agent), Endothelial dysfunction: FMD below 6.7%, LDL cholesterol level less than 140 mg/dl, Patients agreed to Informed Consent Form

Exclusion Criteria: (Key exclusion criteria) Uncontrolled arterial hypertension (above 139/90 mmHg) or hypotension (below 80/50 mmHg), Severe diabetic complication: diabetic nephropathy, diabetic neuropathy, diabetic retinopathy, diabetic vascular complications