February 12, 2003
Dr. Kate Squires from University of Southern California presented an extensive overview of the association of gender with the outcomes and complications of antiretroviral therapy. First and foremost, there is no evidence that women respond less well than men to antiretroviral therapy. In other words, they reach an undetectable HIV viral load just as often as men and have a similar rise in CD4 T-cell counts when starting antiretroviral therapy. This was true whether the regimen studied used a protease inhibitor (PI), non-nucleoside reverse transcriptase inhibitor (NNRTI), or three nucleoside reverse transcriptase inhibitors (NRTIs). Other data from cohort studies also found no difference between men and women.
There does seem to be important gender differences in blood levels of antiretroviral medications. In general, women tend to have a lower body weight and a higher percentage of fat than men, which affects the way these medications circulate in the body.
In one study, women had higher levels of indinavir (IDV, Crixivan) than did men which leads to a higher rate of side effects. The side effects were improved by reducing the dose. In a study from the AIDS Clinical Trial Group, women required a reduction in the dose of ddI (didanosine, Videx) more often than did men. Interestingly, women have a lower rate of nelfinavir (NFV, Viracept)-associated diarrhea than do men. However, women have certain serious complications from antiretroviral therapy more often than men do, including nevirapine (NVP, Viramune)-associated hepatitis, NNRTI-associated rash, and pancreatitis. On the positive side, it seems that women have lower triglycerides than men. Dr. Squires also gave a very preliminary look at a review she is compiling on lactic acidosis -- she found a disproportionately high percentage of women with this complication. Lipodystrophy also seems to present differently in men and women, with men showing fat loss in the arms and legs and women experiencing fat accumulation in their breasts and trunk.
Dr. Squires ended with a call for more research that defines the optimal antiretroviral regimens for women. This symposium should help spur researchers to consider gender-specific issues in their clinical trials, and to be aware of gender differences in complications so that research will be applicable to all people infected with HIV.