Impact of Insulin Glargine compared to Insulin Detemir in combination with Metformin (BOT) on prandial beta cell function and overall metabolic control in type 2 diabetic patients with insufficient metabolic control during OAD Treatment

INTERVENTION: Trade Name: Lantus Pharmaceutical Form: Solution for injection Trade Name: Levemir Pharmaceutical Form: Solution for injection Trade Name: Metformin‐ratiopharm Pharmaceutical Form: Film‐coated tablet CONDITION: Diabetes mellitus Type 2 ; MedDRA version: 9.1 Level: LLT Classification code 10045242 Term: Type II diabetes mellitus PRIMARY OUTCOME: Main Objective: The primary objective of the study is to evaluate beta‐cell‐function and beta‐cell‐stress as measured by the postprandial dynamics of intact proinsulin secretion after standardized test meals during standardized 12 hours inpatient treatment days Primary end point(s): intact proinsulin secretion Secondary Objective: The secondary objectives are to evaluate the ratio of exogenous insulin vs. endogenous insulin, the postprandial increase in hs CRP, ADMA, glucose after treatment with insulin glargine compared with insulin detemir. Further secondary objectives are changes in fasting blood glucose, changes in 8‐Point‐ blood glucose profiles, percentage of patients reaching the treatment goal and the insulin dosage per kg body weight to reach treatment goal. INCLUSION CRITERIA: 1. Type 2 Diabetes mellitus according to the ADA criteria 2. HbA1c between 6.5 % and 8.5 % 3. Monotherapy with metformin or combined with sulfonylurea in a stable dosage within the last 3 months 4. Age between 40 and 75 years 5. Fasting intact proinsulin level > 7 pmol/L Are the trial subjects under 18? no Number of subjects for this age range: F.1.2 Adults (18‐64 years) yes F.1.2.1 Number of subjects for this age range F.1.3 Elderly (>=65 years) yes F.1.3.1 Number of subjects for this age range