This study is being discontinued based on data suggesting that none of the doses tested demonstrated both glycemic & body fluid benefits vs. the comparitor

A study to evaluate the effectiveness and tolerability of MK0533 and pioglitazone in patients with type 2 diabetes mellitus.

Inclusion Criteria:

• Patients between the ages of 18 to 70 years with Type 2 diabetes who have not been able to adequately control their blood glucose levels
• Note: Only patients who have not been taking any antihyperglycemic medicine for 3 months will be screened

Exclusion Criteria:

• Patients taking any medicines that affect body fluid level such as a diuretic or water pill
• Patients taking niacin or other certain medications
• Patients with any of the following conditions: liver or kidney disease, poorly controlled high blood pressure, heart disease or certain blood disorders
• Patients with abnormal laboratory results from a blood test that will be given before each patient starts the study