Therapeutic approaches to combating lipoatrophy: do they work?

Adipose Tissue Dysfunction and Energy Balance Paradigms in People Living With HIV

Over the past 4 decades, the clinical care of people living with HIV (PLWH) evolved from treatment of acute opportunistic infections to the management of chronic, noncommunicable comorbidities. Concurrently, our understanding of adipose tissue function matured to acknowledge its important endocrine contributions to energy balance. PLWH experience changes in the mass and composition of adipose tissue depots before and after initiating antiretroviral therapy, including regional loss (lipoatrophy), gain (lipohypertrophy), or mixed lipodystrophy. These conditions may coexist with generalized obesity in PLWH and reflect disturbances of energy balance regulation caused by HIV persistence and antiretroviral therapy drugs. Adipocyte hypertrophy characterizes visceral and subcutaneous adipose tissue depot expansion, as well as ectopic lipid deposition that occurs diffusely in the liver, skeletal muscle, and heart. PLWH with excess visceral adipose tissue exhibit adipokine dysregulation coupled with increased insulin resistance, heightening their risk for cardiovascular disease above that of the HIV-negative population. However, conventional therapies are ineffective for the management of cardiometabolic risk in this patient population. Although the knowledge of complex cardiometabolic comorbidities in PLWH continues to expand, significant knowledge gaps remain. Ongoing studies aimed at understanding interorgan communication and energy balance provide insights into metabolic observations in PLWH and reveal potential therapeutic targets. Our review focuses on current knowledge and recent advances in HIV-associated adipose tissue dysfunction, highlights emerging adipokine paradigms, and describes critical mechanistic and clinical insights.

Contribution of Adipose Tissue to the Chronic Immune Activation and Inflammation Associated With HIV Infection and Its Treatment

White adipose tissue (AT) contributes significantly to inflammation – especially in the context of obesity. Several of AT’s intrinsic features favor its key role in local and systemic inflammation: (i) large distribution throughout the body, (ii) major endocrine activity, and (iii) presence of metabolic and immune cells in close proximity. In obesity, the concomitant pro-inflammatory signals produced by immune cells, adipocytes and adipose stem cells help to drive local inflammation in a vicious circle. Although the secretion of adipokines by AT is a prime contributor to systemic inflammation, the lipotoxicity associated with AT dysfunction might also be involved and could affect distant organs. In HIV-infected patients, the AT is targeted by both HIV infection and antiretroviral therapy (ART). During the primary phase of infection, the virus targets AT directly (by infecting AT CD4 T cells) and indirectly (via viral protein release, inflammatory signals, and gut disruption). The initiation of ART drastically changes the picture: ART reduces viral load, restores (at least partially) the CD4 T cell count, and dampens inflammatory processes on the whole-body level but also within the AT. However, ART induces AT dysfunction and metabolic side effects, which are highly dependent on the individual molecules and the combination used. First generation thymidine reverse transcriptase inhibitors predominantly target mitochondrial DNA and induce oxidative stress and adipocyte death. Protease inhibitors predominantly affect metabolic pathways (affecting adipogenesis and adipocyte homeostasis) resulting in insulin resistance. Recently marketed integrase strand transfer inhibitors induce both adipocyte adipogenesis, hypertrophy and fibrosis. It is challenging to distinguish between the respective effects of viral persistence, persistent immune defects and ART toxicity on the inflammatory profile present in ART-controlled HIV-infected patients. The host metabolic status, the size of the pre-established viral reservoir, the quality of the immune restoration, and the natural ageing with associated comorbidities may mitigate and/or reinforce the contribution of antiretrovirals (ARVs) toxicity to the development of low-grade inflammation in HIV-infected patients. Protecting AT functions appears highly relevant in ART-controlled HIV-infected patients. It requires lifestyle habits improvement in the absence of effective anti-inflammatory treatment. Besides, reducing ART toxicities remains a crucial therapeutic goal.

HIV and antiretroviral therapy-related fat alterations

Early in the HIV epidemic, lipodystrophy, characterized by subcutaneous fat loss (lipoatrophy), with or without central fat accumulation (lipohypertrophy), was recognized as a frequent condition among people living with HIV (PLWH) receiving combination antiretroviral therapy. The subsequent identification of thymidine analogue nucleoside reverse transcriptase inhibitors as the cause of lipoatrophy led to the development of newer antiretroviral agents; however, studies have demonstrated continued abnormalities in fat and/or lipid storage in PLWH treated with newer drugs (including integrase inhibitor-based regimens), with fat gain due to restoration to health in antiretroviral therapy-naive PLWH, which is compounded by the rising rates of obesity. The mechanisms of fat alterations in PLWH are complex, multifactorial and not fully understood, although they are known to result in part from the direct effects of HIV proteins and antiretroviral agents on adipocyte health, genetic factors, increased microbial translocation, changes in the adaptive immune milieu after infection, increased tissue inflammation and accelerated fibrosis. Management includes classical lifestyle alterations with a role for pharmacological therapies and surgery in some patients. Continued fat alterations in PLWH will have an important effect on lifespan, healthspan and quality of life as patients age worldwide, highlighting the need to investigate the critical uncertainties regarding pathophysiology, risk factors and management.

Poly-L-lactic Acid for Facial Lipoatrophy in HIV

Objective:

To review the clinical data for poly-L-lactic acid, a synthetic polymer used as an intradermal injection for the treatment of HIV associated facial fat loss (lipoatrophy).

Data Sources:

A literature search was performed using MEDLINE (1966–August 2006). The search was limited to articles published in English and used the key words polylactic acid, polylactides, degradation, lipodystrophy, lipoatrophy, and HIV/AIDS. Dermik Laboratories was contacted to obtain unpublished information. Additional articles were retrieved from citations of selected references.

Study Selection and Data Extraction:

Relevant information on the pharmacology, pharmacokinetics, safety, and efficacy of poly-L-lactic acid from clinical trials were selected.

Data Synthesis:

Poly-L-lactic acid (Sculptra) is a biocompatible, biodegradable, synthetic polymer able to be tailored into various desired morphologic features. It is approved by the Food and Drug Administration for the correction of facial lipoatrophy in people with HIV. Six clinical trials have evaluated the use of intradermal injections of poly-L-lactic acid. Results showed that cutaneous thickness is improved in patients receiving poly-L-lactic acid. Adverse effects included nodule and hematoma formation, as well as pain at the injection site.

Conclusions:

Poly-L-lactic acid offers a treatment alternative for patients with HIV-associated lipoatrophy. Further research is required in nonwhite populations.

Anthropometric and Nutritional Profile of People Living with HIV and AIDS in India: an Assessment

BACKGROUND

Importance of nutrition in human immunodeficiency virus (HIV) is well-established; however, the information regarding the diet quality of people living with HIV (PLHIV) especially in India is lacking.

OBJECTIVES

The objective of this study is to assess the anthropometric and nutritional profile of Indian PLHIV.

MATERIAL AND METHODS

The study was performed on 400 adult PLHIV registered at the Antiretroviral Center (ART) center in New Delhi, India. Anthropometric data including height, weight, waist, hip, mid arm, and calf circumferences, were collected; 1-day 24-h dietary recall was done to gather nutrient intake from which nutrient adequacy ratios were computed. Mini Nutritional Assessment (MNA) was also conducted.

RESULTS

The mean body mass index (BMI) of the sample was 19.73 ± 3.55 kg/m(2) with around 40% having BMI <18.5 kg/m(2) . All anthropometric measurements were found to correlate positively and significantly with CD4 count (P < 0.05). The sample consumed poor quality of diet as they could not meet even the 2/3(rd) of the Indian Council of Medical Research (2010) requirements for energy, protein, calcium, iron, riboflavin, niacin, folic acid, B12, copper, and zinc. Classification of subjects according to MNA indicated that more than 50% of the sample was at-risk of malnutrition and 34% were malnourished. With 40% of sample having BMI less than normal, 50% at risk of malnutrition together with poor nutrient intakes over a long period of time could contribute to further worsening of the nutritional status.

CONCLUSION

There is a need to develop a database on nutritional profile of PLHIV in India which reinforces the need for development of effective strategies to improve their nutritional status.

HIV-associated lipodystrophy: impact of antiretroviral therapy

In the late 1990s, reports of unusual changes in body fat distribution named 'lipodystrophy' (LD) began to appear in HIV patients mitigating the enormous enthusiasm about improvement of survival and quality of life provided by the combinations of antiretroviral (ARV) drug classes, the so-called highly active antiretroviral therapy (HAART), which had just become available at that time. The objective of this paper is to critically review the literature on LD and to discuss the impact of newer ARV agents, namely atazanavir, darunavir and raltegravir, as well as strategies of the late HAART era, including single-tablet regimens and nucleoside-sparing regimens. Studies in which LD was measured by dual-energy x-ray absorptiometry or by abdominal computed tomography or magnetic resonance imaging scan only, were included. We were unable to identify studies depicting a negative impact of drugs or ARV regimens on limb fat loss. On the contrary, a few studies identified a negative impact of atazanavir/ritonavir or darunavir/ritonavir on trunk fat increase. It should be noted that this anthropometric measure is a poor instrument since it cannot distinguish between subcutaneous and visceral fat. We conclude that presumably the body fat changes currently observed in HIV-infected patients is the net result of competing phenomena: on one side the natural history of lipohypertrophy as a result of HIV and HAART impact, and on the other side the physiological body fat changes observed in the aging population.

Metabolic disorders and cardiovascular consequences of HIV infection and antiretroviral therapy

Metabolic disturbances associated with HIV disease have become an important factor in patient management and have important implications for long-term outcomes, both in regards to mortality and healthcare burden. Recent research has implicated both HIV infection itself and specific antiretroviral therapies in the development of these disorders. This review examines recent findings from research into insulin and glucose dysregulation, serum lipid abnormalities, adipose tissue and derangements in bone metabolism. This review then describes the cardiovascular consequences and management of these metabolic disorders, and summarizes current thinking on the pathogenesis and effects of antiretroviral therapy. Finally, the review raises some questions regarding ongoing challenges and unmet needs in this field of research.

Four-year follow-up of polyalkylimide gel use for the treatment of HIV-associated lipoatrophy

PURPOSE

To evaluate polyalkylamide gel (PAIG) use in treating HIV-associated facial lipoatrophy (FLA) 4 years after its injection in an open-label, randomized controlled trial (RCT).

METHODS

Five patients were treated with PAIG in a pilot study, and 31 patients were subsequently enrolled in the RCT of immediate or delayed (12 weeks later) PAIG injections. Endpoints included proportion of participants with complications; changes in FLA severity score (FLSS); and quality of life (QoL), depression, anxiety, and satisfaction scores. Infections were classified as "confirmed" if purulent material was extracted and/or an organism cultured. Infections were classified as "possible" if only clinical signs were present without purulent discharge or microbiologic confirmation.

RESULTS

Year 4 results were available for 5 pilot and 27 full-scale study participants. Delayed complications included 5 confirmed infections (15.6%), 3 possible infections (9.4%), nodules (25%), and bleeding (3%). No significant changes were observed between years 2 to 4 in patient-graded FLSS, QoL, depression, and anxiety scores. Whereas 94% of participants were satisfied with their overall treatment, only 69% were satisfied with PAIG treatment specifically.

CONCLUSION

Even though PAIG treatment was associated with delayed complications including high rates of infection and nodules, most patients were satisfied with the treatment.

Long-term efficacy and safety of polyalkylimide gel for the treatment of HIV-associated lipoatrophy

The long-term safety and efficacy of products used in the correction of HIV-associated facial lipoatrophy (FLA) are largely unknown. The purpose of this study was to describe the long-term efficacy and safety of polyalkylimide gel (PAIG) in the treatment of HIV-associated FLA. In this open-label, randomized, single-center study, 31 HIV-positive individuals (median age 48 years (interquartile ranges (IQR) 45, 55, 97% male) with FLA were randomized to immediate (week 0 and six) or delayed (week 12 and 18) PAIG injections. Week 96 endpoints included change in FLA severity scores (FLSS) (five-point scale), proportion of patients with adverse events, and changes in quality of life, depression and anxiety using validated surveys. Results at week 96 were available for 28 patients. Adverse events, including swelling, redness, bruising and pain, were mild, and resolved after a median of three days following the injection. At week 96, median changes in physician and patient FLSS scores were -2 (IQR -3, -1; p<0.001 vs. baseline) and -2 (IQR -2, -1; p<0.001 vs. baseline), respectively. Physician and patient FLSS scores were not significantly different between the groups at week 96. Significant improvements in patient's anxiety (p<0.001), depression (p<0.001) and mental health (p=0.01) were observed from baseline to week 96. In conclusion, treatment with PAIG was associated with sustained improvements in both the physical and psychological components of FLA through 96 weeks of follow-up.

Lipodystrophy in HIV 1-infected patients: lessons for obesity research

Lipodystrophy is a common alteration in HIV 1-infected patients under anti-retroviral treatment. This syndrome is usually associated with peripheral lipoatrophy, central adiposity and, in some cases, lipomatosis, as well as systemic insulin resistance and hyperlipidemia. Research on the ethiopathogenesis of the disease revealed novel aspects of adipose tissue biology highly relevant to obesity research: the pivotal role of mitochondria in white adipose tissue function, the role that interference with master transcription factors of adipogenesis may have in human adipose tissue, the capacity of human white adipose tissue to acquire brown fat-like features, as well as the importance of apoptosis and the potential impact of viral infections in adipose tissue. The dramatic difference between subcutaneous adipose depots, prone to lipoatrophy, and the visceral adipose depots, prone to enlargement, has been further evidenced in the study of the lipodystrophy syndrome. The recognition of a local pro-inflammatory environment in lipoatrophic adipose tissue from affected patients, including macrophage infiltration and enhanced expression of chemokines and cytokines, points to events paradoxically similar to those in the hypertrophied adipose tissue in obesity. However, this also potentially provides an explanation for the existence of systemic alterations common to lipodystrophy and obese patients and reminiscent of the metabolic syndrome.

HIV-associated adipose redistribution syndrome (HARS): definition, epidemiology and clinical impact

A segment of the HIV infected population develops abnormal and excessive accumulation of adipose tissue in the trunk, including accumulation of visceral (deep abdominal) adipose tissue. This condition, known as HIV-related adipose redistribution syndrome (HARS), may also be accompanied by fat accumulation in the upper back/neck (dorsocervical region) and/or depletion of subcutaneous adipose tissue from the abdomen, face, limbs, or buttocks. HARS is estimated to occur in up to 32% of patients and is associated with health risks similar to those of metabolic syndrome. Techniques to detect and measure HARS include physician and patient assessments and radiologic or anthropometric methods.

Long-term complications of antiretroviral therapy: lipoatrophy

The effective use of potent antiretroviral therapy has dramatically improved the life expectancy for HIV-infected individuals. Long-term complications of both HIV-infection and antiretroviral agents are therefore of increasing concern. Lipoatrophy (LA) or fat wasting is a complication most frequently associated with nucleoside reverse transcriptase inhibitors, thymidine analogues particularly. LA can be stigmatising and is associated with psychosocial complication. It can occur in isolation or as part of the 'metabolic' or 'lipodystrophy' syndrome, a triad of LA, fat accumulation and metabolic disturbance (insulin resistance and dyslipidaemia) with a subsequently increased risk of cardiovascular events. We aimed to review the definition, prevalence, pathogenesis, implications and treatment of HIV/highly active antiretroviral therapy-associated fat loss. We performed a review of PubMed, Medline and recent conference abstracts for information on LA. The current treatments available for treating LA are limited. Switching away from thymidine analogues can provide a small benefit but improvement is, at best, slow and partial. Specific medical therapies such as glitazones, metformin and stating have been disappointing to date. Surgical fillers can yield marked results but are costly, time consuming and only of value for facial LA, not other sites. Ultimately, prevention of this condition is the best approach by avoiding thymidine analogues wherever possible or careful monitoring with early switching away from these agents. New therapies to treat pre-existing fat loss are required.

Safety and Efficacy of Poly-l-lactic Acid Injections in Persons with HIV-Associated Lipoatrophy: The US Experience

BACKGROUND

With the introduction of highly active antiretroviral therapy (HAART), HIV/AIDS has become a more chronic disease. This increase in survival, however, has been accompanied by the occurrence of metabolic and morphologic changes known collectively as HIV-associated lipodystrophy.

OBJECTIVE

The objective was to evaluate the quantifiable improvement in facial wasting (lipoatrophy) after serial injections of poly-L-lactic acid (PLLA) as well as the long-term safety and durability of this material.

METHODS AND MATERIALS

A single-site, open-label study in which patients received up to six treatment sessions of injectable PLLA. Patients were followed for 12 months after treatment. Patients were evaluated for increase in total cutaneous thickness by skin calipers. Serial photographs and patient satisfaction and patient well-being questionnaires were undertaken throughout the study period.

RESULTS

Patients at the end of treatment exhibited a mean increase in skin thickness of 65.1% compared with baseline values. This correction was maintained throughout the 12-month follow-up period (68.8% at 6 months and 73% at 12 months). On a one to five scale, patient satisfaction was 4.5 at the end of treatment and increased to 4.8 at 12-month follow-up. No serious adverse events were reported.

CONCLUSION

PLLA is a safe and well-tolerated treatment option for HIV-associated lipoatrophy.

Use of tenofovir disoproxil fumarate and emtricitabine combination in HIV-infected patients

With the continuing spread of HIV infection, particularly in developing countries, cost-effective treatment for its management is a high priority. Truvada (Gilead Sciences) is a single combination pill of the nucleotide reverse transcriptase inhibitors tenofovir disoproxil fumarate and emtricitabine, which is used once daily. It is anticipated to be a clinically potent combination that is free of short-term irritating toxicity. The drug has recently been licensed but there are currently little clinical efficacy data regarding its use. The limited published data have indicated that emtricitabine and lamivudine have equivalent potency, and randomised controlled trials have produced evidence of the efficacy of lamivudine combined with tenofovir disoproxil fumarate in a regimen containing either the non-nucleoside reverse transcriptase inhibitor efavirenz or a protease inhibitor lopinavir/ritonavir. In these trials, long-term durability data are available for < or = 96 weeks.