HIV-related cachexia: potential mechanisms and treatment.

Involuntary weight loss or wasting indicative of severe protein energy malnutrition is a frequent complication of acquired immune deficiency syndrome (AIDS). Malnutrition, with its associated adverse effects on immunocompetence, may contribute to the progression of AIDS itself. Since death from wasting is ultimately related to the magnitude of tissue depletion, restoration of body cell mass may enhance survival. The mechanism of weight loss in AIDS has not been clearly elucidated. The etiology is likely to be multifactorial, the result of interactions between decreased caloric intake, malabsorption, and alterations in energy expenditure secondary to hormonal and/or metabolic abnormalities. Although weight loss is occasionally reversible with treatment of underlying infections and/or easily identifiable and reversible causes, the majority of patients are not this fortunate. Enteral and parenteral nutrition, which are expensive, cumbersome, and potentially morbid, have been suggested by some as therapeutic options. Megestrol acetate, a synthetic, orally active progestational agent, has been reported to stimulate appetite and weight gain. Data regarding the use of megestrol acetate for the treatment of cachexia related to human immunodeficiency virus (HIV) infection demonstrate convincingly its effectiveness in treating many patients with HIV-related anorexia and cachexia.