Please assess the completion status of the following clinical trial:

Trial Title: Endothelial Damage and Atherosclerosis in Obstructive Sleep Apnea

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

Eligibility Criteria:
Inclusion Criteria:~* age 18-65 years old~* AHI \>= 15~* BMI \< 35~Exclusion Criteria:~* Known cardiovascular disease, including hypertension~* Diabetes~* Acute or unstable chronic disease~* Renal failure~* Major organ system failure, including liver, renal, cardiac and respiratory failure~* Taking long-term medications

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 65 Years
- Healthy Volunteers: t

Study Arms:
- no treatment (Type: NO_INTERVENTION): being observed at 4 weeks and 12 weeks
- CPAP treatment (Type: ACTIVE_COMPARATOR): a machine delivers positive airway pressure into the upper airway via nasal mask

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