Fat loss in all body regions most common form of lipodystrophy in women

Women with HIV are more likely to experience overall body fat loss, rather than peripheral fat loss combined with central fat gain, according to an American study published in the December 15^th edition of the Journal of Acquired Immune Deficiency Syndromes.

Researchers from the University of California at San Francisco analysed body shape changes amongst participants in the Women’s Interagency HIV Study (WIHS), a natural history study of HIV-positive women and women at risk for HIV.

Noting that prior research has been hampered by the lack of a rigourous definition of lipodystrophy syndrome, the researchers classified body shape changes into four categories: fat loss (lipoatrophy) or fat gain (lipohypertrophy) in the peripheral (arms, legs, and buttocks) or central (chest, abdomen, and upper back) regions of the body. Rather than relying solely on subjective reports by participants or clinicians, reported changes were confirmed by anthropometric measurements including circumference and skinfold thickness. In addition, body shape changes in HIV-positive women were compared with those in a control group of uninfected women.

The researchers analyzed the incidence of body shape changes in 605 HIV-positive and 210 HIV-negative women over 30 months. Body shape changes were included in the analysis if self-reported changes occurring between semiannual study visits were confirmed by at least a 0.7 cm change in circumference of the chest, waist, hips, thigh, or triceps, or at least a 0.2 cm change in skinfold measurement of the upper back. Only about half the self-reported changes were confirmed by objective measurements.

The HIV-positive and HIV-negative groups were similar in terms of race and age (average about 40 years). At study entry the HIV-positive women had a lower body weight (mean 73 vs 78 kg) and a lower percentage of body fat (26% vs 31%). Among the HIV-positive women, the median CD4 cell count was 366 cells/mm3 and the median viral load was 3.3 log10 copies/mL.

During the study period overall weight and body fat percentage increased among the HIV-negative participants—as would be expected in middle-aged women—but remained stable in the HIV-positive subjects. In total, 311 of the HIV-positive women (49%) and 89 of the HIV-negative women (42%) experienced some body shape change, but the types of changes differed markedly between the two groups.

After adjusting for age and race, the HIV-positive women had about twice the cumulative incidence of both peripheral lipoatrophy (27% vs 13%; relative hazard [RH]=2.1, 95% CI 1.4-3.2) and central lipoatrophy (23% vs 13%; RH =1.8, 95% CI 1.2-2.8) compared with the HIV-negative women. The HIV-positive women had a slightly lower rate of peripheral lipohypertrophy (18% vs 25%; RH=0.8, 95% CI 0.6-1.1), and there was no significant difference in central lipohypertrophy (28% vs 31%; RH=1.0, 95% CI 0.7-1.3).

About one-third of both the HIV-positive and the HIV-negative women who experienced any shape changes (33.7% and 35.9%, respectively) developed only one of the four types. About one-half the subjects in both groups (49.7% and 53.9%, respectively) developed two types of change, whilst the remainder developed three or all four types at different times during the study.

Amongst those who experienced two types of changes, 81% of the HIV-positive and 94% of the HIV-negative women developed either combined peripheral and central lipoatrophy or combined peripheral and central lipohypertrophy. Only 14% of the HIV-positive women and 4% of the HIV-negative women developed both peripheral fat loss and central fat gain. According the authors, these findings suggest that “an HIV-associated lipoatrophy syndrome affecting both peripheral and central sites may predominate in women.”

Previous research has suggested that HIV-positive individuals with lipodystrophy syndrome lose fat in the peripheral regions of the body whilst gaining fat in the central regions. Such a mixed pattern was uncommon in this study, however, supporting the view that peripheral lipoatrophy and central lipohypertrophy are two distinct phenomena.

“[L]ipoatrophy and lipohypertrophy should be assessed separately when describing the prevalence or incidence, or exploring the etiology of lipodystrophy syndrome,” the authors recommended. “In addition, both fat loss and fat gain should be assessed in both peripheral and central sites.”

Because this research was aimed at describing the overall incidence of lipodystrophy in HIV-positive women compared with HIV-negative controls, the effect of antiretroviral therapy was not analyzed. However, the results of this study — and its more rigourous methodology — should help guide future research into how anti-HIV treatment influences body shape changes in individuals with HIV.