August 9, 2006 (AIDSmeds)—New data from a large study indicates that a loss of fat (lipoatrophy) is a common occurrence in HIV positive women. The women-only results from the Fat Redistribution and Metabolic Change
in HIV Infection (FRAM) study, much like the FRAM study data involving
men published in 2005, also indicate that increased fat
(lipohypertrophy) is not more likely to occur in HIV-positive women
compared to HIV-negative women.
For several years,
beginning with the widespread use of HIV combination therapy, different
types of body-shape changes – notably lipoatrophy of the face, arms,
and legs, and lipohypertrophy of the abdominal area – have been
reported by numerous HIV-positive people and their healthcare
providers. In turn, they were both unofficially lumped together as a
single syndrome called "lipodystrohy," likely caused by anti-HIV drug treatment.
Researchers,
however, have long questioned if these two different types of
body-shape changes are related. Some HIV-positive people don't have any
signs of lipoatrophy or lipohypertrophy, some experience one or the
other, whereas others experience both. Because different HIV-positive
people seem to experience different problems, it has been difficult to
determine if either of these body-shape changes is truly a unique
complication caused by HIV or its treatment.
For
researchers to understand the cause(s), prevention, and treatment of
these complications, studies to determine if these body-shape changes
are unique among HIV-positive people – and how these body-shape changes
relate to each other – have been needed.
FRAM is one
such study. It is headed by Dr. Carl Grunfeld of the University of
California, San Francisco. Between June 2000 and September 2002, FRAM
enrolled 1,480 volunteers, including 1,183 HIV-positive people and 297
HIV-negative people. HIV-negative study volunteers were included for
comparison purposes. Of 1,480 enrolled, there were 350 HIV-positive
women and 142 HIV-negative women.
The study results involving women were reported in the August 15 issue of the Journal of Acquired Immune Deficiency Syndromes.
Much
like the comparison between HIV-positive and HIV-negative men in FRAM,
lipoatrophy was more common among the HIV-positive women compared to
the HIV-negative women. Approximately 28% of the HIV-positive women had
"clinical" lipoatrophy of at least one part of the body – fat loss that
was reported by the study participants and confirmed by the researchers
during a physical examination – compared to 4% of the HIV-negative
women.
More HIV-positive women, compared to HIV-negative
women, reported loss of fat in the cheeks, face, arms, buttocks, and
legs. HIV-positive women were also more likely to report a decrease in
their waist size compared to their HIV-negative counterparts.
The
study also demonstrated that HIV-positive women do experience
lipohypertrophy. However, clinical lipohypertrophy was just as likely
to be seen in the HIV-negative women. Approximately 62% of the
HIV-positive women had lipohypertrophy of at least one part of the
body, compared to 63% of the HIV-negative women.
HIV-negative
women were more likely to have lipohypertrophy of the cheeks, face,
arms, buttocks, legs, neck, chest, and upper back. There was no
statistically significant differences between lipohypertrophy of the
waist or the abdomen in the two groups of women.
Magnetic
resonance imaging (MRI) data were also reported. The amount, or volume,
of visceral fat – fat deep within the body that can cause the abdominal
area to appear enlarged – was significantly lower among women with
clinical lipoatrophy compared to the HIV-positive women without
lipoatrophy.
Just like the FRAM data involving men,
these results indicate that for women too, lipoatrophy is a unique
complication caused by HIV and/or HIV medications. Similarly, FRAM
suggests that lipohypertrophy is not a unique complication of HIV
infection or HIV treatment, given that visceral fat increases were seen
in a large percentage of HIV-negative women as well.
The
one major difference between the men and women in FRAM involves fat
accumulation in the upper trunk (the chest and back). The women without
clinical lipoatrophy had greater amounts of visceral fat and
subcutaneous fat – fat under the skin – in the upper trunk than the
HIV-negative women. With the men, the volume of visceral and
subcutaneous fat in the upper trunk was no different in those without
lipoatrophy compared to the HIV-negative men.
The
study also suggested that lipoatrophy and lipohypertrophy are not
linked – women who had increased visceral fat were more likely to have
increased (not decreased) subcutaneous fat. In other words, FRAM
suggests that visceral fat and subcutaneous fat either increase
together or decrease together; one doesn't go up while the other goes
down.
As is reviewed in our lipodystrophy lesson, the
FRAM results involving the male volunteers have been frustrating to a
number of people. It is likely that the newest results involving the
female volunteers will cause equal consternation.
A
common misperception of the FRAM study is that lipohypertrophy is not a
problem for HIV-positive men or women. However, neither the male or
female data support this.
FRAM concludes that abnormal
fat increases can and do occur in HIV-positive people, but not
necessarily to a greater extent than HIV-negative people. Nor does the
FRAM study suggest that these fat increases are "healthy," given that
they are also seen in HIV-negative people. Numerous experts, including
those associated with the FRAM study, stress that enlarged visceral fat
deposits are not healthy. They can cause serious problems for both
HIV-positive and HIV-negative people.
It is also
important to recognize that FRAM is not a perfect study. For starters,
it is a cross-sectional study. This means that the study relied on a
one-time "snapshot" of all patients enrolled. Because it didn't follow
the study volunteers over time, it's impossible to know how their body
shapes changed since starting HIV drug treatment or how their body
shapes will continue to change in the future.
While FRAM
suggests that lipoatrophy, and not lipohypertrophy, is the primary
concern facing HIV-positive people, the cross-sectional study design
doesn't really permit this conclusion. Without knowing when the
HIV-positive people experienced lipohypertrophy – perhaps after HIV
drug treatment was started – it cannot be concluded that anti-HIV
treatment doesn't cause a syndrome (lipodystrophy) that can result in
lipohypertrophy and lipoatrophy (even if it is much more likely to
cause lipoatrophy).
What's more, FRAM did not compare
HIV-positive people on anti-HIV treatment to HIV-positive people not
taking any anti-HIV medications. In turn, it can be very difficult to
come up with a real understanding of the body-shape changes caused by
HIV or its medications, based on a study that includes only
HIV-positive people on drug treatment to HIV-negative people not on HIV
medications.
