Nutrition:
Low body weight in COPD may be a marker of systemic disease. If weight loss is observed, it may be a consequence of reduced oral intake, increased energy expenditure and metabolic alterations due to low-grade systemic inflammation, and increased protein consumption [221]. Low body weight is associated with increased mortality and reduced health status, quality of life and exercise capacity. However, the magnitude of weight loss does not correlate with the severity of airflow limitation [39, 222–224].