Chronic obstructive lung disease and respiratory muscle function: the role of nutrition and exercise training in cystic fibrosis.

Malnutrition may be an extremely important complicating factor in patients with a variety of chronic lung diseases. The impact of malnutrition on lung disease and respiratory muscle function has been extensively studied in patients with chronic lung disease due to cystic fibrosis (CF). In patients with CF it appears that malnutrition and deterioration of lung function are closely interrelated and interdependent, with each affecting the other, leading to a spiral decline in both. The occurrence of malnutrition during childhood seems to be associated with impaired growth and repair of the airway walls. Therefore, in children, when growth in body-length may be expected, prevention of malnutrition is associated with better lung function and improved survival. Nutritional intervention in adults, when no further growth may be expected, will only lead to an increase of body fat. However, when combined with a physical training programme it may lead to an improvement in bodyweight, respiratory muscle function, lung function and exercise tolerance. In addition, this approach will lead to an increase in both respiratory and other muscle mass.