Effect of Dipeptidyl Peptidase-IV Inhibitor and Sulfonylurea on Glucose Variability and Oxidative Stress

The Comparative Study of Dipeptidyl Peptidase-IV Inhibitor and Sulfonylurea on the Effect of Improving Glucose Variability and Oxidative Stress in Type 2 Diabetic Patients With Inadequate Glycemic Control on Metformin

This research will focus on the effect of Sitagliptin on 24 hour glycemic excursion and improvement of oxidative stress markers compared to long acting sulphonylurea Glimepiride in type 2 diabetic patients with inadequate glycemic control on metformin

Sitagliptin might improve not only the mean glycemic control during study period but also 24 hour glycemic fluctuation by restoring the physiologic pattern of insulin secretion. Furthermore decrease postprandial glycemic excursion should decrease the oxidative stress markers. Those effects might be amplified in Asian patients because of prominent early phase insulin secretory defects accompanied with relatively less degree of insulin resistance. Based on this assumption, this research will focus on the effect of Sitagliptin on 24 hour glycemic excursion and improvement of oxidative stress markers compared to long acting sulphonylurea Glimepiride in type 2 diabetic patients with inadequate glycemic control on metformin.

Inclusion Criteria:

• patients with type 2 diabetes
• duration of diabetes less than 10 years
• HbA1c 6.5-8.0%
• BMI 20-30
• on stable dose of metformin (more than 1000mg) for at least 2 months

Exclusion Criteria:

• having oral hypoglycemic agents other than metformin
• using insulin
• serum creatinin >= 1.5 mg/dL
• SGOT, SGPT >= 90
• ischemic heart disease
• congestive heart failure (NYHA class >=2)
• severe diabetic complication (PDR, CRF, CVA)
• on medication affecting glucose profile (such as steroid)
• infectious disease
• malignancy
• pregnant or breast-feeding woman