Adjunctive Therapy of Exenatide or Sitagliptin to Insulin Glargine in Type 2 Diabetes

insulin glargine once daily subcutaneously over 4 weeks, dose adjustment according to a treat-to-target algorithm, exenatide 5ug twice daily subcutaneously for 2 weeks, then 10ug twice daily for 2 weeks, continuation of preexisting metformin

insulin glargine once daily subcutaneously over 4 weeks, dose adjustment according to a treat-to-target algorithm, sitagliptin 100 mg once daily in the morning over 4 weeks, continuation of preexisting metformin

insulin glargine once daily subcutaneously over 4 weeks, continuation of preexisting metformin