Estrogen and progesterone hormones in birth control do not influence the effectiveness of highly active antiretroviral therapy (HAART), which is used to treat HIV infection, according to researchers from the Johns Hopkins Bloomberg School of Public Health and other institutions. The study is published in the May 1, 2005, issue of the American Journal of Epidemiology.
"Since the introduction of HAART in 1996, many studies have proven the effectiveness of these regimens in reducing mortality and HIV-associated morbidity. However, not all patients respond equally well and determining the factors that could affect response is an important area of research. Our research group set out to investigate whether hormonal contraception influenced response to HAART,” said Stephen J. Gange , PhD, corresponding author of the study and an associate professor in the Bloomberg School of Public Health's Department of Epidemiology .
Data from the Women's Interagency HIV Study (WIHS), the largest, ongoing study of HIV-infected and high-risk HIV-negative women in the United States, were examined. The study authors matched hormonal contraceptive users with nonusers, according to age, race/ethnicity, pre-HAART CD4+ T-lymphocyte counts and viral load. They investigated whether there were any effects on the two main markers of HIV disease progression, which are CD4 cell count and viral load. The researchers did not find an association between hormonal contraceptive use and changes in CD4+ cell count or time to viral load suppression after initiation of HAART. There was also no relationship between those outcomes and the duration of hormonal contraception use before HAART initiation.
The study results also reinforce the strong effects of HAART on HIV disease progression. The researchers found that women who used HAART continuously were almost 3 times more likely to experience a CD4+ cell-count increase of 50 cells/mm3, over 3.5 times more likely to achieve a CD4+ cell-count increase of 100 cells/mm3 and approximately 2.7 times more likely to achieve an undetectable viral load than nonusers.