The use of HAART has reduced the viral load and prolonged the lives of many HIV patients but they are not without side-effects. These include

• osteopenia

• lactic acidosis

• impaired glucose metabolism, insulin resistance, diabetes mellitus

• dyslipidemia

One of the more obvious and distressing side effects of these drugs is loss of fat (lipoatrophy) from the arms and legs, face and buttocks and the gain of fat on the abdomen, breasts and neck. The latter gives rise to the characteristic dorsocervical fat pad known as “buffalo hump”. This syndrome occurs in between one third and one half of patients receiving HAART and is known as HIV-associated lipodystrophy. It is particularly evident in older Caucasian patients. The cause is unknown and although this side effect arose at the time of the introduction of protease inhibitors, it is not associated with the use of these drugs in monotherapy. Non-nucleoside reverse transcriptase inhibitors also have not been associated with lipodystrophy when used alone. Lipodystrophy does occur, however, in patients treated with nucleoside reverse transcriptase inhibitors and the risk increased with duration of treatment. There is evidence that fat accumulation results from the effects of nucleoside reverse transcriptase inhibitors on mitochondrial function, particularly the depletion of the enzymes in oxidative phosphorylation and beta oxidation.