• HbA1c [ Time Frame: At end of treatment arm or 3 months. ]
• 2 hour plasma glucose excursions, plasma glucose AUC, and plasma glucose AUC excursions after the three main test meals combined [ Time Frame: At end of treatment arm or 3 months. ]
• Plasma glucose AUC excursions during a 24 hours when plasma glucose exceeds the following: greater than or equal to 7.5 mmol/L (135 mg/dL), greater than or equal to 7.8 mmol/L (140 mg/dL), and greater than or equal to 10.0 mmol/L (180 mg/dL) [ Time Frame: At end of treatment arm or 3 months. ]
• The number of patients with increased plasma glucose during the last 2 hours of each inpatient period [ Time Frame: At end of treatment arm or 3 months. ]
• The mean amplitude of glycemic excursion [ Time Frame: At end of treatment arm or 3 months. ]
• Concentration of plasma triglycerides and free fatty acids [ Time Frame: At end of treatment arm or 3 months. ]
• Self blood glucose monitoring parameters: fasting, premeal, 2 hour postprandial, 2 hour postprandial excursion, bedtime, and overall daily blood glucose value [ Time Frame: At end of treatment arm or 3 months. ]
• Insulin dose and body weight [ Time Frame: At end of treatment arm or 3 months. ]

The purpose of this study is to determine if twice-daily Lispro low mixture (75/25) will result in lower post prandial blood glucose readings versus once-daily glargine plus oral diabetic medications.

The primary objective of this study is to test the hypothesis that a twice daily insulin regimen consisting of insulin lispro (mix 75/25)plus OAMs will result in a lower 2 hour postprandial plasma glucose, averaged across the morning and evening meals, compared with once daily insulin glargine plus OAMs at bedtime following 12 weeks of treatment.

• Drug: Lispro mix 75/25
• Drug: Glargine

• Active Comparator: Lispro mixture 75/25 twice-daily, SC injection, given in conjunction with oral antidiabetic medications.
• Active Comparator: Glargine, once-daily, SC injection, given in conjunction with oral antidiabetic medications.

Inclusion Criteria:

• Have type 2 diabetes
• Have inadequate overall glycemic control (hemoglobin A1c greater than or equal to 7.0% and less than or equal to 12.0%) at or within 4 weeks prior to Visit 1

• Have used:

  • single or multiple OAMs for at least 3 months immediately prior to entering the study, including metformin, sulfonylurea, meglitinides (repaglinide, nateglinide), or alpha glucosidase inhibitors (acarbose, miglitol); or
  • insulin (once or twice daily) for at least 3 months immediately prior to entering the study; or
  • a combination of the above.
• Are greater than or equal to 21 and less than 80 years of age

• As determined by the investigator, are capable and willing to:

  • comply with their prescribed diet and medication regimen,
  • perform self blood glucose monitoring,
  • use the patient diary as required for this protocol,
  • participate in two 24 hour inpatient assessments

Exclusion Criteria:

• Have used a thiazolidinedione (pioglitazone or rosiglitazone) during the 3 months prior to entry into the study
• Are currently treated with a meglitinide without sulfonylurea
• Have a known allergy or intolerance to insulin lispro mix 75/25, insulin glargine, or metformin
• Have plasma creatinine greater than or equal to 1.5 mg/dL (for males) or greater than or equal to 1.4 mg/dL (for females) for patients who will be treated with metformin or; greater than 2 mg/dL for patients treated with other OAMs, as determined by a local laboratory
• Have received chronic (lasting longer than 2 weeks), systemic glucocorticoid therapy (excluding topical and inhaled preparations) within 4 weeks immediately prior to Visit 1