Effects of discontinuing stavudine or protease inhibitor therapy on human immunodeficiency virus-related fat redistribution evaluated by dual-energy x-ray absorptiometry

Adipose Tissue in HIV Infection

HIV infection and antiretroviral therapy (ART) treatment exert diverse effects on adipocytes and stromal-vascular fraction cells, leading to changes in adipose tissue quantity, distribution, and energy storage. A HIV-associated lipodystrophic condition was recognized early in the epidemic, characterized by clinically apparent changes in subcutaneous, visceral, and dorsocervical adipose depots. Underlying these changes is altered adipose tissue morphology and expression of genes central to adipocyte maturation, regulation, metabolism, and cytokine signaling. HIV viral proteins persist in circulation and locally within adipose tissue despite suppression of plasma viremia on ART, and exposure to these proteins impairs preadipocyte maturation and reduces adipocyte expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) and other genes involved in cell regulation. Several early nucleoside reverse transcriptase inhibitor and protease inhibitor antiretroviral drugs demonstrated substantial adipocyte toxicity, including reduced mitochondrial DNA content and respiratory chain enzymes, reduced PPAR-γ and other regulatory gene expression, and increased proinflammatory cytokine production. Newer-generation agents, such as integrase inhibitors, appear to have fewer adverse effects. HIV infection also alters the balance of CD4+ and CD8+ T cells in adipose tissue, with effects on macrophage activation and local inflammation, while the presence of latently infected CD4+ T cells in adipose tissue may constitute a protected viral reservoir. This review provides a synthesis of the literature on how HIV virus, ART treatment, and host characteristics interact to affect adipose tissue distribution, immunology, and contribution to metabolic health, and adipocyte maturation, cellular regulation, and energy storage. © 2017 American Physiological Society. Compr Physiol 7:1339-1357, 2017.

An update on the pharmacological strategies in the treatment of HIV-1-associated adipose redistribution syndromes

INTRODUCTION

With the introduction of combination antiretroviral therapy (ART) for HIV infection in the mid-1990s, descriptions of morphological changes and metabolic disturbances in treated patients began to emerge. HIV-1/highly active ART-associated lipodystrophy syndrome (HALS) involves metabolic abnormalities and diverse forms of anomalous fat distribution. The current review focuses on the pathophysiological basis and the clinical evidence for the use of several medical strategies in the management of HALS.

AREAS COVERED

We have covered the most relevant studies related to the pharmacological strategies in the treatment of HALS, with attention to the current and novel antiretroviral agents.

EXPERT OPINION

The most commonly used strategies for HALS reversion have included modification of host-dependent factors, including those related to HIV-1 infection and those associated with ART. Preventive and medical strategies have been associated with moderate success. The only intervention that offers an immediate aesthetical improvement for patients with HALS so far has been plastic surgery.

Regional adipose tissue measured by MRI over 5 years in HIV-infected and control participants indicates persistence of HIV-associated lipoatrophy

OBJECTIVE

Peripheral fat loss and visceral fat gain have been reported in HIV infection. There are limited data on long-term change in adipose tissue in HIV-infected patients vs. controls. Therefore, we determined change in regional adipose tissue from baseline examination to 5 years later among participants in the study of Fat Redistribution and Metabolic Change in HIV Infection.

METHODS

Regional adipose tissue volume was measured using MRI at both examinations in 477 HIV-infected and 214 control men and women. Lipoatrophy was defined as leg subcutaneous adipose tissue (SAT) below the cutoff point marking the lowest decile (10%) of controls at each examination.

RESULTS

HIV-infected and control participants showed similar adipose tissue gains. In men, all SAT depots and visceral adipose tissue started lower and remained lower on average in HIV-infected vs. controls. In women, leg and arm SAT also started lower and remained lower in HIV-infected vs. controls. Mean leg SAT of HIV-infected men was 67% of control men at baseline and 65% at follow-up; for women 83% and 77%. At baseline, 48% of HIV-infected participants had lipoatrophy; on average those with baseline lipoatrophy gained 0.96L of leg SAT compared with 1.23L gain for controls in the lowest decile (P = 0.16). At follow-up, 53% of HIV-infected participants had lipoatrophy. In multivariable models, discontinuation of stavudine appeared to produce little gain in leg SAT ( approximately 1.1%/year).

CONCLUSION

HIV-infected participants did not substantially recover SAT compared with controls, although both showed average gains. HIV-associated lipoatrophy persisted after 5 years of follow-up.

Longitudinal study of body composition of 101 HIV men with lipodystrophy: dual-energy X-ray criteria for lipodystrophy evolution

The aim of this study was to define evolution profiles of body composition among human immunodeficiency virus (HIV)-infected men with lipodystrophy. The design is a retrospective analysis using observational data collected longitudinally. We included 101 HIV-infected men with lipodystrophy managed in routine practice and who had 2 dual energy X-ray absorptiometry scans within a minimum interval of 18 mo. Lipodystrophy was defined as a fat mass ratio (FMR, defined as the ratio of the percentage of the trunk fat mass over the percentage of the lower limbs fat mass) equal or superior to 1.5. Patients were classified in "improved" group (IG: increase of lower limbs fat mass >/= 10%) or "nonimproved" group (NIG). Body composition, immunovirological and epidemiological data were collected and compared between the 2 groups. In the whole population, over a 4-yr period, a significant increase was observed for total fat mass, trunk fat mass, and lower limbs fat mass, whereas total lean mass was stable. Total body mineral density decreased. Fifty-nine patients (IG), less exposed to zidovudine than the NIG, had an increase of lower limbs fat mass higher than 10%. But only 13 (22%) regained a normal distribution of fat mass (FMR < 1.5), showing that lipodystrophy was slowly reversible. Among the NIG, 5 patients (11.9%), less exposed to zidovudine and with a higher mean of viral load, reached an FMR below 1.5. It was mainly because of a loss of trunk fat mass, which could be the sign of a lipodystrophy worsening. Lipodystrophy improved for 58.4% of men. The improvement was very slow. Recovery was observed only in patients with an earlier intervention. No correlation was observed between lipodystrophy and total body bone mineral density. The loss of trunk fat mass without gain of lower limbs fat mass may indicate a worsening of HIV disease.

Strategies in the treatment of HIV-1-associated adipose redistribution syndromes

HIV-1/highly active antiretroviral therapy-associated lipodystrophy syndrome (HALS) is presently the most common long-term adverse effect limiting the doubtless efficacy of antiretroviral therapy. It has a great impact on the quality of life of patients, it is stigmatising and its psychologically devastating consequences may ultimately impact on the adherence to treatment of patients, eventually leading to treatment failure. Despite considerable advances in recent times, the pathogenesis of HALS remains elusive. Factors involved belong to three categories: those intrinsic to the host, some of them modifiable and some not, those associated with antiretroviral therapy, that are sometimes modifiable as well, and finally those related to HIV-1 infection and its consequences, most often not modifiable. The most commonly used strategies for HALS reversion have included host-dependent factors such as lifestyle and dietary modifications and antiretroviral-dependent factors such as switching or avoiding the use of drugs more prone to promote HALS. Lifestyle modifications and switching thymidine analogues have been associated with moderate success. Pharmacological interventions have included the use of insulin-sensitising agents and hormone therapy with disappointing results, whereas treatment with pravastatin or pioglitazone, and uridine supplementation seem to be associated with fat gain in preliminary studies. The only interventions with almost immediate results that may render a patient's appearance similar to his past one have included filling techniques for facial lipoatrophy and ultrasound-assisted liposuction for cervical fat pad hypertrophy. Among the filling options, semipermanent reabsorbable materials and autologous fat transfer have been associated with acceptable outcomes. As of now, the best hope should rely on the use of drugs friendly for fat, on defining the appropriate timing for starting antiretroviral and on continuing the research effort to understand the basic mechanisms underlying HALS pathogenesis. Only through this effort can the best chances for preventing or reverting established HALS be recognised.