July 9, 2002
Four oral presentations were presented in this afternoon session on metabolic disturbances associated with HIV disease and treatment. I will summarize the first three, which dealt with some basic science and observational data, a review of clinical syndromes and possible treatments of these disorders, and finally a patient's perspective on experiencing many of the side effects of HIV medications.
Carl Grunfeld from the University of California at San Francisco and the San Francisco VA Medical Center reviewed some preliminary data from the Fat Redistribution and Metabolic Changes in HIV Infection (FRAM) study. This study attempts to determine what the HIV and HIV treatment-related fat changes are compared to a HIV-negative control group that has comparative demographics (i.e., age, race and sex).
The study has recruited 800 men and 350 women from several HIV clinics across the country (mean age = 40) and included a HIV-negative control group from the CARDIA study. This was a one time, cross-section study of patients selected from each clinic database. Dr. Grunfeld presented preliminary data on 357 men. No women's data was presented today. In this group of men, 53 percent were Caucasian, 33 percent African American and 77 percent had as their risk factor for HIV infection having sex with men. The group had a mean CD4 count of 394/mm3, and a mean viral load of 35,700/ml; 14 percent had not received HIV treatment and 83 percent had received nucleoside reverse transcriptase inhibitors (NRTI). A lower percentage had received protease inhibitors (PI). Patients were asked to self-report on a questionnaire whether they had bodily changes suggestive of lipodystrophy and were also given an exam by a trained observer. Bodily areas examined and surveyed included peripheral areas (cheeks, face, buttocks, legs and arms) and central areas (waist, abdomen, neck, back, and chest). Lipodystrophy was rated as mild, moderate or severe.
Dr. Grunfeld then presented a large number of results showing various associations or lack of associations. Some definitions are required before the results can be reviewed and discussed. First, he distinguished between peripheral versus central lipoatrophy (loss of fat in the areas described above) and lipohypertrophy (gain of fat). He defined HIV-associated lipoatrophy as being LA+. Finally, visceral adipose tissue (VAT) is that fat associated with internal organs. The significant findings follow. It was commonly thought that you loose fat in your extremities and gain it in your belly. However, central fat lipohypertrophy was not associated with peripheral lipoatrophy in this study. In addition, central lipoatrophy is/was associated with peripheral lipoatrophy. This means that most people who lose fat in their extremities also lose it in their belly. This study also found that there was less limb fat in HIV-positive people versus uninfected controls and in those HIV-infected patients with clinical lipoatrophy versus those without LA. There was less lower abdominal trunk and chest subcutaneous fat in HIV-positive patients versus controls and in those HIV-infected patients with clinical lipoatrophy versus those without LA.
When fat in various body depots was considered, the legs were most affected. Subcutaneous lipoatrophy at all sites was greater peripherally then centrally. The upper trunk was least affected. Another interesting finding related to buffalo humps (fat growth in the back of the neck and upper back) was that the prevalence of buffalo humps in HIV-negative controls was unknown before this study. In this study, a buffalo hump was not more common in HIV-positive men. The data in this study do not support a hump as a diagnostic criterion for lipodystrophy. Also, visceral adipose tissue (VAT) was lower in HIV-positive patients versus controls and not higher in those with clinical lipoatrophy. Finally, age was found to be an important determinant of VAT in HIV-positive men. In other words the older an HIV patient was, the greater the amount of VAT. However, lipoatrophy was not associated with increased VAT. These are complicated findings and are only preliminary. However, as the data gets further analyzed, we should have better information as to what fat-related changes are occurring as a result of HIV infection and in addition, what added effect HIV treatment will have on fat loss and redistribution.
|Please note: Knowledge about HIV changes rapidly. Note the date of this summary's publication, and before treating patients or employing any therapies described in these materials, verify all information independently. If you are a patient, please consult a doctor or other medical professional before acting on any of the information presented in this summary. For a complete listing of our most recent conference coverage, click here.|