Please assess the completion status of the following clinical trial:

Trial Title: Efficacy of Metformin in Preventing Diabetes in China

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: PREVENTION
- Time Perspective: None
- Masking: NONE
- Phase: PHASE4
- Number of Arms: 2.0

Eligibility Criteria:
Main Inclusion Criteria:~1. Diagnosis of IGR before the randomization based on the 1999 WHO diagnostic and classification criteria.~2. Age: 18 ≤age≤70 years old.~3. Not on a treatment of anti-diabetic agents, including Chinese traditional herbs lowering blood glucose for at least 6 months before screening.~4. Male or non-pregnant, non-breastfeeding females, females without birthing plan in next three years.~5. Body mass index (BMI) ：21 kg/m2 ≤BMI\<32 kg/m2.~6. Written informed consent given before any trial-related activities are carried out.~Main exclusion Criteria:~1. Administration with medications for pre-existed diseases affect glucose metabolism (except thiazide diuretics when its daily dose≤12.5mg).~2. Administration with anti-obesity agents (including Chinese traditional medicine) within 6 months of enrolment and during intervention.~3. Administration with three or more than three types antihypertensive drugs.~4. Diabetes patients (subjects with prior history of gestational Diabetes will not be excluded).~5. Have any of the following cardiovascular conditions within 3 months prior to the screening visit: acute myocardial infarction, congestive heart failure defined as New York Heart Association class III/IV or left ventricular ejection fraction ≤40%,) or cerebrovascular accident.~6. Persistent uncontrolled hypertension (systolic blood pressure ≥160mmHg, or diastolic blood pressure ≥100 mmHg).~7. Impaired liver function, have obvious clinical signs or symptoms of liver disease, acute or chronic hepatitis, ALT or AST levels ≥3 times the upper limit of the reference range at the screening visit.~8. Renal dysfunction (eGFR\<45ml/min）.~9. Patients ventilated by ventilator.~10. Hypersensitivity to metformin or to any of the excipients such as povidone K 30, magnesium stearate and hypromellose.~11. Disease which may cause tissue hypoxia (especially acute disease, or worsening of chronic respiratory disease).~12. Acute alcohol intoxication, alcoholism.~13. Severe chronic gastrointestinal disease.~14. Severe psychiatric illness.~15. Cancer requiring treatment in past 5 years.~16. Uncontrolled thyroid diseases.~17. Women who are pregnant or breastfeeding .~18. Participation in another clinical trial within the past 30 days .~19. Other significant disease that in the Investigator's opinion would exclude the subject from the trial.

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 70 Years
- Healthy Volunteers: f

Study Arms:
- metformin plus standard lifestyle intervention (Type: EXPERIMENTAL): Metformin starting dose is 850mg/d, it will be titrated to 850mg twice daily after 2 weeks and maintained until the last subject completes 2 years' intervention.
- Standard lifestyle intervention (Type: OTHER): Standard lifestyle advice will be united for all subjects by providing special booklet.

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

Answer: outcome: complete