Please assess the completion status of the following clinical trial:

Trial Title: Nitric Oxide Bioavailability in Chronic Obstructive Pulmonary Disease (COPD)

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

Eligibility Criteria:
Inclusion Criteria:~* Patients with COPD (GOLD stages II-IV) and matched healthy controls~* Caucasian or African American~* Both men and women~* Current and former smokers~Exclusion Criteria:~* GOLD Stage I~* Clinical diagnosis of heart disease, hypertension, or metabolic disease~* Vasoactive medications (i.e. nitrates, beta-blockers, ACE inhibitors, Viagra, etc.)~* Pulmonary hypertension~* Hypothyroidism~* Hyper-homocysteinemia~* Interstitial lung disease~* Phenylketonuria~* Pregnancy~* Sleep apnea~* Anemia~* Raynod's phenomenon~* Gangrene of the digits~* History of low platelets or coagulopathies~* Aspirin sensitivity or allergy

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: t

Study Arms:
- COPD Patients (Type: EXPERIMENTAL): Patients with COPD~AOC protocol: Brachial artery flow-mediated dilation, direct assessment of oxidative stress via EPR spectroscopy (O2-) and biomarkers of oxidative stress (8-isoprostane, LH, SOD) will be assessed at baseline and 2 hours following ingestion of a single oral antioxidant cocktail (1g of vitamin C, 600 IU of vitamin E, and 600 mg of alpha-lipoic acid.) Antioxidant Cocktail: 1g of vitamin C, 600 IU of vitamin E, and 600 mg of alpha-lipoic acid~BH4 protocol: Brachial artery flow-mediated dilation (FMD), markers of inflammation, and markers of oxidative stress will be assessed at baseline and following an increase in nitric oxide bioavailability after administering a single dose = 5 mg/kg of Tetrahydrobiopterin (BH4)
- Controls (Type: EXPERIMENTAL): Healthy age- and sex- matched controls~AOC protocol: Brachial artery flow-mediated dilation, direct assessment of oxidative stress via EPR spectroscopy (O2-) and biomarkers of oxidative stress (8-isoprostane, LH, SOD) will be assessed at baseline and 2 hours following ingestion of a single oral antioxidant cocktail (1g of vitamin C, 600 IU of vitamin E, and 600 mg of alpha-lipoic acid.) Antioxidant Cocktail: 1g of vitamin C, 600 IU of vitamin E, and 600 mg of alpha-lipoic acid~BH4 protocol: Brachial artery flow-mediated dilation (FMD), markers of inflammation, and markers of oxidative stress will be assessed at baseline and following an increase in nitric oxide bioavailability after administering a single dose = 5 mg/kg of Tetrahydrobiopterin (BH4)

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