Oral β-Alanine Supplementation in Patients With COPD

Oral β-Alanine Supplementation in Patients With COPD: Structural, Metabolic and Functional Adaptations

Preliminary evidence suggest that patients with chronic obstructive pulmonary disease (COPD) suffer from lower-limb muscle dysfunction. This may, at least in part, be due to a combination of physical inactivity and muscle oxidative stress. Pilot data (not published) clearly show that patients with COPD have significantly lower carnosine, which is a pH (acidity-basicity level) buffer and antioxidant, levels in the m. vastus lateralis compared to healthy subjects. Beta-alanine supplementation has shown to increase muscle carnosine in trained and untrained healthy subjects. This study will assess if muscle carnosine can be augmented by beta-alanine supplementation in 40 COPD patients (20 patients receive beta-alanine, 20 patients receive placebo). 10 healthy elderly controls will also be assessed to compare baseline muscle carnosine levels.

The aims of this study are to:

1. Investigate baseline muscle carnosine levels to confirm the pilot data in a larger sample of patients with COPD compared with healthy elderly subjects
2. Investigate if beta-alanine supplementation augments muscle carnosine in COPD patients and whether it has an influence on exercise capacity, lower-limb muscle function and quality of life
3. To investigate baseline and post supplementation structural and metabolic muscle characteristics and markers of oxidative stress and inflammation in COPD patients and it's association with muscle carnosine levels

Inclusion Criteria:

• COPD: diagnosis of moderate to very severe COPD according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines
• Healthy controls: forced expiratory volume at one second/forced vital capacity (FEV1/FVC) > 0.7, matched for age and gender

Exclusion Criteria:

• The presence of known instable cardiac disease
• neurological disease and/or musculoskeletal disease that preclude safe participation in an exercise test
• a history of drugs/alcohol abuse
• vegetarianism
• inability to understand the Flemish language.

COPD-specific exclusion criteria:

• COPD exacerbation and/or hospitalization in the last 6 weeks
• participation in pulmonary rehabilitation in the previous 12 months.