Please assess the completion status of the following clinical trial:

Trial Title: A Study of the Effects of Sitagliptin (MK0431) and Metformin on Incretin Hormone Concentrations (0431-050)(COMPLETED)

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: CROSSOVER
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: DOUBLE
- Phase: PHASE1
- Number of Arms: 4.0

Eligibility Criteria:
Inclusion Criteria:~* Subject is in good health~* Subject has been a nonsmoker for at least 6 months~* Subject is willing to avoid strenuous activity from the screening visit until the end of the study~* Subject agrees not to consume grapefruit products during the study and to avoid all fruit juices 24 hours before and after study drug administration~Exclusion Criteria:~* Any history of stroke or neurological disorder~* Subject has a history of cardiovascular, blood, endocrine or liver diseases~* Subject has a history of cancer

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 55 Years
- Healthy Volunteers: t

Study Arms:
- A (Type: ACTIVE_COMPARATOR): Sitagliptin alone
- B (Type: ACTIVE_COMPARATOR): Metformin alone
- C (Type: EXPERIMENTAL): Sitagliptin and metformin concomitantly
- D (Type: PLACEBO_COMPARATOR): Placebo

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