Cachexia: pathophysiology and clinical relevance.

Cachexia causes weight loss and increased mortality. It affects more than 5 million persons in the United States. Other causes of weight loss include anorexia, sarcopenia, and dehydration. The pathophysiology of cachexia is reviewed in this article. The major cause appears to be cytokine excess. Other potential mediators include testosterone and insulin-like growth factor I deficiency, excess myostatin, and excess glucocorticoids. Numerous diseases can result in cachexia, each by a slightly different mechanism. Both nutritional support and orexigenic agents play a role in the management of cachexia.