Please assess the completion status of the following clinical trial:

Trial Title: Effect of Sitagliptin on Endothelial Progenitor Cells

Study Design Characteristics:
- Allocation: NON_RANDOMIZED
- Intervention Model: SINGLE_GROUP
- Observational Model: None
- Primary Purpose: BASIC_SCIENCE
- Time Perspective: None
- Masking: NONE
- Phase: PHASE4
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~* Type 2 diabetes;~* Both genders~* Age 40-80~* fasting c-peptide \>=1.0 ng/L~* Therapy with metformin or sulphonylureas~* HbA1c \>7.0%~* No contraindications to sitagliptin use~Exclusion Criteria:~* Type 1 diabetes~* Age \<40 or \>80~* fasting c-peptide \<1.0 ng/L~* Therapy with TZD~* HbA1c \<=7.0%~* Acute concomitant diseases~* Immunological disorders~* Recent (within 3 months) cardiovascular events or surgery~* Pregnancy and lactation~* Inability to provide informed consent

- Gender: ALL
- Minimum Age: 40 Years
- Maximum Age: 80 Years
- Healthy Volunteers: f

Study Arms:
- Treatment (Type: EXPERIMENTAL): Sitagliptin 100 mg once daily for 4 weeks
- Control (Type: NO_INTERVENTION): No change in anti-diabetic treatment regimen for at least 4 weeks.

Based on this trial design, predict the completion outcome and termination type (if applicable).