Acute consumption of dietary nitrate (as beetroot juice) has been shown to increase exercise and decrease systemic blood pressure in multiple populations, including COPD. The chronic effect of dietary nitrate in obstructive sleep apnea syndrome (OSAS) has not been reported.

Acute consumption of dietary nitrate (as beetroot juice) has been shown to increase exercise and decrease systemic blood pressure in multiple populations, including COPD. The chronic effect of dietary nitrate in OSAS has not been reported.

The investigators hypothesize that chronic nitrate consumption might increase exercise tolerance, and exhaled NO but decrease blood pressure and have little impact on quality of life and pulmonary function.

This study is a randomized, double-blind placebo-controlled, crossover trial. At baseline, mid-point and endpoint exercise tolerance, pulmonary function, quality of life and ambulatory blood pressure will be assessed in conjunction with demographics and blood draw. After baseline measures, each subject will be randomized to consume nitrate rich beetroot juice for 14 consecutive nights when assessments will be repeated followed by 14 nights of placebo and endpoint assessments or the converse.

Inclusion Criteria:

• Clinically stable,
• Diagnosed with COPD
• Ambulatory out-patients

Exclusion Criteria:

• Long term oxygen therapy
• Pulmonary hypertension
• Active cardiovascular disease
• Active skeletal conditions
• Taking vasodilators
• Diabetes mellitus