For many patients the weight loss is profound and contributes substantially to early death. Multiple factors contribute to weight loss in patients with HIV infection, including anorexia ascribed to medications or depression, oral lesions, esophagitis, malabsorption, and active infection. There is also an alteration of intermediary metabolism with reduced carbohydrate oxidation, increased triglyceride concentrations and accelerated protein turnover. The result is that ingested substrates are directed to fat instead of lean tissue. It is commonly thought that wasting in AIDS reflects increased energy expenditure, but rapid weight loss usually results from intercurrent opportunistic infections that reduce intake rather than increase catabolism.
Infections can cause fatigue which is a compensatory mechanism to maintain weight.
Gradual weight loss is more likely to reflect anorexia or malabsorption. There have been numerous therapeutic approaches to the treatment and prevention of wasting, many of which are summarized in the table on page 9. There is no clear consensus on an optimal approach, so choices must be tailored to individual needs. In general, a major goal is to increase lean body mass rather than fat, to reduce fatigue, and improve functional performance. Many patients also receive supplemental feedings, but studies demonstrate only modest improvement with this method, and the cost is often high.