The pulmonary cachexia syndrome: aspects of energy balance

The present paper reviews current knowledge of the pulmonary cachexia syndr ome with reference to chronic obstructive pulmonary disease (COPD). Aspects of incidence, aetiology and management are discussed. Malnutrition occurs in approximately one-quarter to one-third of patients with moderate to seve re COPD. Both fat mass and fat-free mass become depleted. Loss of fat-free mass is the more important and appears to be due to a depression of protein synthesis. Weight loss is an independent prognostic indicator of mortality , and is associated with increased morbidity and decreased health-related q uality of life. The aetiology of malnutrition in CORD is not well understoo d. Reduced food intake does not seem to be the primary cause. Resting energ y expenditure (REE) is elevated in a proportion of patients and probably co ntributes to negative energy balance. Measurement of actual REE is helpful when considering the adequacy of nutritional supplementation. The underlyin g reason for a hypermetabolic state is not known. Although weight-losing CO RD patients are not catabolic, nutritional supplementation alone does not a ppear to reverse the loss of fat-free mass. Strategies involving nutritiona l supplementation in combination with a second intervention are being explo red, and there are some encouraging results using anabolic hormones.