Difficulties in understanding the metabolic complications of acquired immune deficiency syndrome.

With the introduction of combination antiretroviral therapy, changes in fat distribution and serum metabolites were reported. These included increased central fat ("buffalo hump," abdominal, and visceral); decreased peripheral fat (in the face, legs, and arms); increased levels of triglycerides, low-density lipoprotein and total cholesterol, glucose, and insulin; and low levels of high-density lipoprotein cholesterol. Many of these changes predict increased atherosclerosis. It has been proposed that these findings are part of a single syndrome, much like metabolic syndrome. Our data indicate that many of these changes are independent. Some changes are antiretroviral drug (but not necessarily class)-specific, some represent the restoration to health, and others are due to effects of the host response to human immunodeficiency virus itself.