Nutritional management of the patient with chronic obstructive pulmonary disease.

The prevalence and prognostic importance of malnutrition in chronic obstructive pulmonary disease (COPD), the factors that contribute to development of nutritional depletion, and the available evidence regarding effects of nutrition support in these patients are the subjects of this review. Nutritional depletion, as indicated by weight loss and loss of lean body mass, is a common complication of advanced COPD (particularly, but not limited to, the emphysematous type). Low body weight or recent weight loss and in particular depleted lean body mass in patients with COPD have been shown to be independent predictors of mortality, outcomes after acute exacerbations, hospital admission rates, and need for mechanical ventilation. The factors thought to contribute to nutritional depletion in these patients include elevated resting and activity-related energy expenditure, reduced dietary intake relative to resting energy expenditure, accelerated negative nitrogen balance, particularly during acute exacerbations of COPD, medication effects, and perhaps most importantly an elevated systemic inflammatory response. Studies to date suggest that, although it can help limit weight loss and negative energy balance in these patients, the effect of nutritional supplementation alone on clinically significant outcomes such as pulmonary function and exercise capacity is minimal. However, nutritional supplementation may have a role in the management of COPD when provided as part of an integrated rehabilitation program incorporating a structured exercise component as an anabolic stimulus.