Estrogen and progesterone hormones in birth control do
not influence the effectiveness of highly active
antiretroviral therapy, or 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 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," says
Stephen J. Gange, 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, 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 three
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.
"From a public health perspective, our findings
alleviate concerns regarding suspected negative effects of
hormonal contraceptive use on the response to HAART.
However, sexually active HIV-infected women who wish to use
hormonal contraceptives to prevent pregnancy should also
continue using condoms to fight the spread of HIV," Gange
said.
The study authors recommend that follow-up data be
collected after a greater number of years in order to
assess the effects of long-term exposure to hormonal
contraceptives.
The study was supported by the National Institute of
Allergy and Infectious Diseases, with supplemental funding
from the National Cancer Institute, the National Institute
of Child Health and Human Development and the National
Institute on Drug Abuse.
Additional co-authors of the study were Jaclyn H. Chu,
Kathryn Anastos, Howard Minkoff, Helen Cejtin, Melanie
Bacon, Alexandra Levine and Ruth M. Greenblatt.