HIV/hepatitis C coinfected may have less risk of lipodystrophy and diabetes

This article is more than 17 years old. Click here for more recent articles on this topic

Coinfection of HIV and hepatitis C virus (HCV) has been associated with metabolic changes, in particular lipodystrophy and diabetes, which are also linked with antiretroviral therapy. Now, two studies have failed to find a significant link between HIV/HCV coinfection and diabetes or lipodystrophy.

One-third of HIV-positive Americans are thought to be coinfected with HCV: coinfection has been linked previously with fat distribution changes, particularly lipoatrophy, and with diabetes. However, both these metabolic changes are also linked with HIV therapy. Moreover, previous studies have had various limitations. The May 1st edition of the Journal of the Acquired Immune Deficiency Syndromes reports two new US studies that help to clarify previous findings.

Phyllis Tien (University of California, San Francisco) and colleagues measured body composition using magnetic resonance imaging in 1,183 HIV-positive people, from the study of Fat Redistribution and Metabolic Change in HIV Infection (FRAM). Multivariate modelling was used to detect associations between various factors, including HIV/HCV coinfection and antiretroviral therapy with body fat at various sites, particularly in the leg.

Glossary

diabetes

A group of diseases characterized by high levels of blood sugar (glucose). Type 1 diabetes occurs when the body fails to produce insulin, which is a hormone that regulates blood sugar. Type 2 diabetes occurs when the body either does not produce enough insulin or does not use insulin normally (insulin resistance). Common symptoms of diabetes include frequent urination, unusual thirst and extreme hunger. Some antiretroviral drugs may increase the risk of type 2 diabetes.

lipodystrophy

A disruption to the way the body produces, uses and distributes fat. Different forms of lipodystrophy include lipoatrophy (loss of subcutaneous fat from an area) and lipohypertrophy (accumulation of fat in an area), which may occur in the same person.

multivariate analysis

An extension of multivariable analysis that is used to model two or more outcomes at the same time.

metabolism

The physical and chemical reactions that produce energy for the body. Metabolism also refers to the breakdown of drugs or other substances within the body, which may occur during digestion or elimination.

naive

In HIV, an individual who is ‘treatment naive’ has never taken anti-HIV treatment before.

Investigators from Detroit studied the prevalence of diabetes and associated factors in an antiretroviral - naïve population of 2,565 adults from the Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA). Diabetes was diagnosed by self-report, while a subset of participants had fasting blood glucose measurements: findings did not substantially differ when diabetes was confirmed. These findings were compared with those from 6,585 participants in the National Health and Nutrition Examination Survey.

One-fifth of the men and around a quarter of the women in the lipodystrophy study had HIV/HCV coinfection, while 17% of CPCRA participants in the diabetes study also had HCV. CPCRA participants had a significantly lower rate of diabetes than the general population (3.3% versus 4.8%), but the known risk factors of black race, older age, and higher body-mass index were independently associated with diabetes in both cohorts. In univariate analyses, HIV/HCV coinfection was associated with diabetes but multivariate analyses failed to demonstrate an independent association, except possibly among black people. These findings suggest that the linkage between HIV/HCV coinfection and diabetes, in the absence of antiretroviral therapy, “is at best a weak one,” note Brar and colleagues.

In the lipodystrophy study, overall coinfection was not linked with body composition changes when compared with men and women infected with HIV alone. Coinfected men had more leg fat and coinfected women had more visceral fat than people solely infected with HIV, in a multivariate analysis. Stavudine (d4T) in particular (p

Coinfected men had about a 2% loss of leg fat per year of stavudine use compared with 7% in monoinfected men, and there was no significant association between the use of any individual antiretroviral drugs and fat loss. Coinfected women also had slightly smaller decreases in leg fat with increasing duration of stavudine use. “These data suggest that the presence of HCV infection may, in fact, mitigate the leg fat loss that occurs as a result of HIV infection and stavudine use”, the authors note.

The changes in body composition found in the lipodystrophy study are unlikely to have clinical implications, since they would not have been visibly noticeable. However, the findings suggest that “the mechanisms by which HIV, antiretroviral drugs, and HCV may affect fat changes may be more complex than previously hypothesized and warrant further investigation in men and women”. In the diabetes study, “the relatively low prevalence [of diabetes] in the CPCRA cohort contrasts sharply with reports of other investigators”, Brar and colleagues write. Previous studies have found diabetes prevalence varied from 2.8% to 12% of HIV-positive participants, but none of these studies evaluated antiretroviral-naïve patients. The current findings do not preclude the need to screen co-infected patients for diabetes when protease inhibitor therapy is being contemplated. But “the results of the present study emphasize the need to screen patients with classic risk factors . . . Further studies are needed to elucidate the interaction between antiretroviral therapy, especially protease inhibitor therapy, and these other factors”, the authors conclude.

References

Brar I et al. A comparison of factors associated with prevalent diabetes mellitus among HIV-infected antiretroviral-naïve individuals versus individuals in the National Health and Nutritional Examination Survey Cohort. J Acquir Immune Defic Syndr 45: 66–71, 2007.

Tien PC et al. Association between hepatitis C virus coinfection and regional adipose tissue volume in HIV-infected men and women. J Acquir Immune Defic Syndr 45: 60–65, 2007.