At the recent San Diego conference on body composition changes and metabolic processes (called lipodystrophy), Dr. Garg of the University of Texas Southwestern Medical Center presented an overview of non-HIV related lipodystrophy syndromes. He provided participants with a broader context for looking at inherited and acquired lipodystrophy, what is known about them and how they develop. Interestingly, while these conditions are very rare, acquired lipodystrophy in people who are not HIV-positive appears more common in women -- affecting only one man for every three women. The reason for this gender difference is unknown.
In a large study, known as the SALSA study, which specifically looked at lipodystrophy, 55% of 140 men and 33% of 30 women reported changes in body composition after starting anti-HIV therapy. The kinds of changes differed between men and women. Men more frequently noted only loss of body fat, whereas women more commonly reported only gaining fat. Moreover, women maintained normal lipid levels (a laboratory marker of circulating fat) while men typically showed abnormal lipid levels. Another observation from this study was that only a few people on highly active antiretroviral therapy (HAART) for less than a year reported changes in body composition whereas about 50% of the participants who were on HAART for one to three years reported changes.
Another study from Milan, Italy included 92 men and 96 women, none of whom received a protease inhibitor or NNRTI. In this study 26% of women and about 7% of men experienced changes in body composition, demonstrating that these changes do not strictly relate to the use of protease inhibitors. Women had a five times higher risk of developing fat redistribution, with the largest differences being breast enlargement (14.6% women, 0% men) and loss of weight in legs.
A French study that included 624 people (84% men) also showed evidence of gender differences in body changes. All participants received triple-drug therapy (HAART). Breast enlargement was observed in 49% of women and only 15% of men, and central obesity was observed in 67% of women and 48% of men.
These studies suggest that gender differences may exist in the incidence and prevalence of body composition changes associated with HIV disease and/or anti-HIV therapies. Moreover, the types of changes that occur may differ between men and women. Women may be more likely to experience breast enlargement, for example, while men may be more likely to experience fat loss and laboratory abnormalities (i.e. abnormal lipid levels). If fat accumulation proves more common among women, then risks associated with certain kinds of fat accumulation, such as diabetes, may also be more common among women. However, it very important to recognize that these studies, like all studies of lipodystrophy so far, may be hampered by imprecise definitions, inconsistent measurement methods and the relatively small number of women who were followed. There may indeed be real differences between men and women in this regard, but the current round of studies should not be seen as conclusive proof of this. Prospective, controlled studies with adequate numbers of men and women must be conducted under a single definition of lipodystrophy before hard conclusions can be reached.