The interrelationship of nutrition and pulmonary function in patients with cystic fibrosis.

This paper reviews recent publications on the interrelationship of nutrition and pulmonary function in patients with cystic fibrosis. It is unclear whether low weight is a cause or an effect of declining pulmonary status in patients with cystic fibrosis. Epidemiologic studies suggest that low weight may be an independent predictor of mortality. Elevations in energy expenditure are not seen in presymptomatic infants. The elevations in energy expenditure seen in those with lung disease are not totally explained by increased oxygen cost of breathing and can be decreased by improving lung function. Although circulating levels of natural antioxidants and inflammation-modulating nutrients are low in patients with cystic fibrosis and can be increased with supplements, there are no recent data on their clinical effects. Nutritional intervention for patients with chronic illness needs to take into account psychosocial and adherence factors as well as nutritional prescriptions. Pancreatic enzyme supplementation should be limited to no greater than 2500 lipase units per kilogram per meal to decrease the risk of developing dose-related fibrosing colonopathy.