A 48-Week Study of Fat Molecular Alterations in HIV Naive Patients Starting Tenofovir/Emtricitabine With Lopinavir/Ritonavir or Efavirenz

Increased Circulating Levels of Growth Differentiation Factor 15 in Association with Metabolic Disorders in People Living with HIV Receiving Combined Antiretroviral Therapy

Objective: People living with HIV (PLWH) have an increased cardiovascular risk (CVR) owing to dyslipidemia, insulin resistance, metabolic syndrome, and HIV/combination antiretroviral therapy (cART)-associated lipodystrophy (HALS). Atherosclerosis and inflammation are related to growth differentiation factor-15 (GDF15). The relationship between metabolic disturbances, HALS, and CVR with GDF15 in PLWH is not known. Research design and methods: Circulating GDF15 levels in 152 PLWH (with HALS = 60, without HALS = 43, cART-naïve = 49) and 34 healthy controls were assessed in a cross-sectional study. Correlations with lipids, glucose homeostasis, fat distribution, and CVR were explored. Results: PLWH had increased circulating GDF15 levels relative to controls. The increase was the largest in cART-treated PLWH. Age, homeostatic model assessment of insulin resistance 1 (HOMA1-IR), HALS, dyslipidemia, C-reactive protein, and CVR estimated with the Framingham score correlated with GDF15 levels. The GDF15-Framingham correlation was lost after age adjustment. No correlation was found between GDF15 and the D:A:D Data Collection on Adverse Effects of Anti-HIV Drugs (D:A:D) score estimated CVR. CVR independent predictors were patient group (naïve, HALS−, and HALS+) and cumulated protease inhibitor or nucleoside reverse transcriptase inhibitor exposure. Conclusions: PLWH, especially when cART-treated, has increased GDF15 levels—this increase is associated with dyslipidemia, insulin resistance, metabolic syndrome, HALS, and inflammation-related parameters. GDF15 is unassociated with CVR when age-adjusted.

Switch to Efavirenz Attenuates Lipoatrophy in Girls With Perinatal HIV

OBJECTIVES

Children with HIV (CHIV) have lifetime exposure to antiretrovirals (ART); therefore, optimizing their regimens to have the least impact on fat redistribution is a priority.

METHODS

This is a cross-sectional study of 219 perinatally infected CHIV and 219 HIV-uninfected controls from similar socioeconomic backgrounds in Johannesburg, South Africa. We compared total body and regional fat distribution in CHIV on suppressive ART regimens with controls and, among CHIV, between ritonavir-boosted lopinavir (LPV/r)-based and efavirenz (EFV)-based regimens.

RESULTS

The mean age of the 219 uninfected children (45% girls) and the 219 CHIV (48% girls) was 7.0 and 6.4 years, respectively. CHIV had lower adjusted total body fat (P = 0.005) and lower percentage fat at the trunk (P = 0.020), arms (P = 0.001), and legs (P < 0.001) than uninfected children. CHIV on LPV/r had similar body composition as those on EFV, except for arm fat mass (P = 0.030). When stratified by sex, girls with HIV on LPV/r had lower adjusted total (P = 0.007), trunk (P = 0.002), arms (P = 0.008), legs (P = 0.048) fat mass; trunk-to-total body fat (P = 0.044); and higher legs-to-total body fat (P = 0.011) than those on EFV.

CONCLUSIONS

South African CHIV receiving ART had lower global and partial fat mass and percentage fat than healthy controls. In girls with HIV with sustained virologic suppression on ART, switching from LPV/r to EFV could attenuate fat mass loss, indicating that EFV-based regimen may be a better option in this group of individuals.

HIV Protease Inhibitor Ritonavir Impairs Endothelial Function Via Reduction in Adipose Mass and Endothelial Leptin Receptor-Dependent Increases in NADPH Oxidase 1 (Nox1), C-C Chemokine Receptor Type 5 (CCR5), and Inflammation

Background Cardiovascular disease is currently the leading cause of death in patients with human immunodeficiency virus on combination antiretroviral therapy. Although the use of the protease inhibitor ritonavir has been associated with increased prevalence of cardiovascular disease, the underlying mechanisms remain ill-defined. Herein, we tested the hypothesis that ritonavir-mediated lipoatrophy causes endothelial dysfunction via reducing endothelial leptin signaling. Methods and Results Long-term (4 weeks) but not short-term (3 days) treatment with ritonavir reduced body weight, fat mass, and leptin levels and induced endothelial dysfunction in mice. Moreover, ritonavir increased vascular NADPH oxidase 1, aortic H₂O₂ levels as well as interleukin-1β, GATA3 (GATA binding protein 3), the macrophage marker (F4/80), and C-C chemokine receptor type 5 (CCR5) expression. Reactive oxygen species scavenging with tempol restored endothelial function, and both NADPH oxidase 1 and CCR5 deletion in mice protected from ritonavir-mediated endothelial dysfunction and vascular inflammation. Remarkably, leptin infusion markedly improved endothelial function and significantly reduced vascular NADPH oxidase 1, interleukin-1β, GATA3, F4/80, and CCR5 levels in ritonavir-treated animals. Selective deficiency in endothelial leptin receptor abolished the protective effects of leptin infusion on endothelial function. Conversely, selective increases in endothelial leptin signaling with protein tyrosine phosphatase deletion blunted ritonavir-induced endothelial dysfunction. Conclusions All together, these data indicate that ritonavir-associated endothelial dysfunction is a direct consequence of a reduction in adiposity and leptin secretion, which decreases endothelial leptin signaling and leads to a NADPH oxidase 1-induced, CCR5-mediated reduction in NO bioavailability. These latter data also introduce leptin deficiency as an additional contributor to cardiovascular disease and leptin as a negative regulator of CCR5 expression, which may provide beneficial avenues for limiting human immunodeficiency virus infection.

Potential role of the melanocortin signaling system interference in the excess weight gain associated to some antiretroviral drugs in people living with HIV

Exposure to some antiretroviral drugs, especially integrase strand transfer inhibitors (INsTI)-based combination antiretroviral therapy (cART) has been associated with weight gain in people living with HIV (PLWH) exceeding what would be a "return to health" phenomenon. Notwithstanding the fact that weight gain and obesity are multifactorial, the common epidemiological link in PLWH is INsTI-based cART. Here, we postulate that interference with the melanocortin system (MCS) functioning by INsTI plays an essential role in excess weight gain and obesity in PLWH, similar to disturbances caused by melanocortin receptor (MCR) mutations in the general population and by antipsychotic therapy in psychiatric patients.

CT Fat Density Accurately Reflects Histologic Fat Quality in Adults With HIV On and Off Antiretroviral Therapy

CONTEXT

Microscopic measurement of adipocyte size is the gold standard for determining adipose tissue (AT) quality. AT density on CT may also reflect adipocyte quality (lower density = poorer quality).

OBJECTIVE

We used abdominal subcutaneous AT (SAT) specimens and CT scans to validate CT SAT density as a marker of SAT quality in adults living with HIV.

SETTING AND DESIGN

Secondary data analysis from completed trial of antiretroviral therapy (ART) initiation (ACTG A5224s). CT abdominal SAT density was measured in HU. SAT specimens were digitally scanned for calculation of mean adipocyte area.

PARTICIPANTS

Participants had SAT biopsy and CT data at baseline (n = 54) and HIV-1 RNA <50 copies per milliliter on ART and biopsy or CT data at week 96 (n = 30).

OUTCOME MEASURES

Spearman correlations and linear regression models adjusting for participant characteristics examined associations between SAT density and adipocyte area.

RESULTS

Baseline median age was 40 years, CD4+ T lymphocyte count 219 cells per cubic millimeter, and body mass index 26.0 kg/m2; 89% were male and 67% white. Median SAT area and density were 199 cm2 and -100 HU. Over 96 weeks, SAT area increased (+18%) and SAT density decreased (-3%). Mean SAT adipocyte area correlated with SAT density (P < 0.01) off and on ART after adjustment for SAT area, age, race, sex, CD4+ T lymphocyte count, and HIV-1 RNA.

CONCLUSIONS

CT SAT density correlates with biopsy-quantified SAT adipocyte size in adults with HIV on and off ART, suggesting that CT is a useful tool for noninvasive assessment of SAT quality.

Does choice of antiretroviral drugs matter for inflammation?

INTRODUCTION

The massive implementation of combination antiretroviral therapy (cART) has forever changed the landscape of HIV infection. This unprecedented success has turned HIV infection into a manageable chronic disease. The increased survival of people living with HIV is, however, shadowed by a high burden of aging-related comorbidities. The pathogenic basis underlying this excess of co-morbid conditions is most likely a persistent inflammatory and immune activation state, despite an optimal control of HIV replication, which in turn has largely been attributed to bacterial or bacterial products translocation from the gut. Area covered: This review is focused on the relationship between cART and the chronic inflammatory and immune activation status in otherwise virologically well-controlled people living with HIV (PLWH). Particular focus will be placed on the differences, if any, between distinct cART modalities, with emphasis on less-drug cART regimens, and especially on dual therapies. Expert opinion: Research to address the increased inflammatory and immune activation status of cART-treated, HIV-infected patients, should focus on adjuvant means of therapy, rather than on the cART regime itself. With current antiretrovirals, no difference between dual and triple regimens has been demonstrated, provided that virological and immunological outcomes be non-inferior.

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.

Fat Matters: Understanding the Role of Adipose Tissue in Health in HIV Infection

More than one-third of adults in the USA are obese and obesity-related disease accounts for some of the leading causes of preventable death. Mid-life obesity may be a strong predictor of physical function impairment later in life regardless of body mass index (BMI) in older age, highlighting the benefits of obesity prevention on health throughout the lifespan. Adipose tissue disturbances including lipodystrophy and obesity are prevalent in the setting of treated and untreated HIV infection. This article will review current knowledge on fat disturbances in HIV-infected persons, including therapeutic options and future directions.

Improvement of lipoatrophy by switching from efavirenz to lopinavir/ritonavir

OBJECTIVE

To assess whether changes in antiretroviral drugs other than thymidine nucleoside reverse transcriptase inhibitors (NRTI) may have a body fat impact in HIV-infected patients with lipoatrophy.

METHODS

Ninety-six-week phase IV, open-label, multicentre, pilot randomized trial. HIV-infected patients with moderate/severe lipoatrophy at one or more body sites despite long-term thymidine NRTI-free therapy were randomized to continue their efavirenz (EFV)-based antiretroviral regimen or to switch from EFV to lopinavir/ritonavir (LPV/r). The primary endpoint was the absolute change in limb fat mass measured by dual X-ray absorptiometry from baseline to 96 weeks. Changes in other body fat measurements, subjective perception of lipoatrophy, subcutaneous fat gene expression and plasma lipids were also assessed.

RESULTS

Thirty-three patients (73% men, median age 52 years) were recruited. At 96 weeks, absolute limb fat mass increased in the LPV/r arm vs. the EFV arm (estimated difference +1082.1 g; 95% CI +63.7 to +2103.5; P = 0.04); this difference remained significant after adjustment by gender, age, fat mass, body mass index and CD4 cell count at baseline. Subjective lipoatrophy perception scores also improved in the LPV/r arm relative to the EFV arm. Adipogenesis, glucose and lipid metabolism, and mitochondrial gene expression increased in the LPV/r arm compared with the EFV arm at 96 weeks. HDL cholesterol decreased in the LPV/r arm relative to the EFV arm.

CONCLUSIONS

Switching from EFV to LPV/r in HIV-infected patients with lipoatrophy may offer further limb fat gain beyond thymidine NRTI discontinuation, although this strategy decreased plasma HDL cholesterol and caused changes in subcutaneous fat gene expression that may be associated with increased insulin resistance.

Circulating fibroblast growth factor 23 (FGF23) levels are associated with metabolic disturbances and fat distribution but not cardiovascular risk in HIV-infected patients

OBJECTIVES

Dyslipidaemia, insulin resistance, metabolic syndrome and HIV/HAART-associated lipodystrophy syndrome (HALS) are common comorbidities in HIV-1-infected patients, which may increase cardiovascular risk. Fibroblast growth factor 23 (FGF23) is a bone-derived hormone with effects on metabolism and phosphate homeostasis. The aim of this study was to determine the relationship between FGF23 levels, metabolic alterations, fat distribution and cardiovascular risk.

METHODS

This was a cross-sectional study. Serum FGF23 levels were analysed in 152 patients and 34 healthy control individuals. Patients belonged to three groups: HIV-1-infected, antiretroviral-treated patients who have developed HALS (n = 60); HIV-1-infected, antiretroviral-treated patients without HALS (n = 43); and untreated (naive) HIV-1-infected patients (n = 49). Serum FGF23 levels were compared with lipid and glucose homeostasis parameters, fat distribution and cardiovascular risk.

RESULTS

Serum FGF23 levels were increased in HIV-1-infected patients, but the increase was most marked in those with HALS. FGF23 levels showed a strong positive correlation with age, indicators of dyslipidaemia (LDL cholesterol, polyunsaturated fatty acids and monounsaturated fatty acids), HALS parameters (trunk/appendicular fat ratio), insulin resistance (fasting insulin and homeostasis model assessment of insulin resistance) and C-reactive protein. FGF23 levels correlated with cardiovascular risk but correlation was lost after age adjustment.

CONCLUSIONS

FGF23 levels are increased in HIV-1-infected patients, especially in those with HALS, and this increase is associated with dyslipidaemia, insulin resistance, metabolic syndrome, fat distribution and parameters of inflammation. FGF23 is not associated with cardiovascular risk when age is taken into account.

Efficacy and pharmacokinetics of the combination of etravirine plus raltegravir as novel dual antiretroviral maintenance regimen in HIV-infected patients

Novel combination antiretroviral regimens may be needed for selected HIV-infected patients with toxicity or resistance. We evaluated prospectively 25 virologically suppressed patients, largely pretreated (15.6 years on therapy) with antiretroviral drug toxicity (n=19) or interactions (n=9, mainly with chemotherapy against non-Hodgkin lymphoma or anti-HCV therapy), who switched to a dual therapy with etravirine (ETR) plus raltegravir (RAL). Patients were required not to have prior virological failure or resistance to both drugs. After a median follow up of 722 days (473-1088: 53.3 patients-year), there were no cases of transient virological replication or failure. Only 1 patient left therapy at day 10 due to a grade 2 rash, and therefore efficacy by intent-to-treat analysis was 96% at 48 weeks. There were no cases of liver toxicity grade 3-4, and total cholesterol (TC) and triglycerides (TG) levels decrease significantly after initiation (TC, -17 mg/dl; p=0.01; TG, -42 mg/dl; p=0.01), as well as the TC/High density lipoprotein-cholesterol ratio (from 4.35 to 4.28). Geometric mean plasma trough level of RAL was 166 ng/ml (IQR, 40-249), well above the inhibitory concentration 90 (IC(90)). In conclusion, a novel dual therapy with ETR plus RAL is effective and well tolerated, and it could be an option to maintain durable viral suppression in hard-to-treat HIV-infected patients.

Differential subcutaneous adipose tissue gene expression patterns in a randomized clinical trial of efavirenz or lopinavir-ritonavir in antiretroviral-naive patients

Gene expression studies of subcutaneous adipose tissue may help to better understand the mechanisms behind body fat changes in HIV-infected patients who initiate antiretroviral therapy (ART). Here, we evaluated early changes in adipose tissue gene expression and their relationship to fat changes in ART-naive HIV-infected patients randomly assigned to initiate therapy with emtricitabine/tenofovir plus efavirenz (EFV) or ritonavir-boosted lopinavir (LPV/r). Patients had abdominal subcutaneous adipose tissue biopsies at baseline and week 16 and dual-energy-X-ray absorptiometry at baseline and weeks 16 and 48. mRNA changes of 11 genes involved in adipogenesis, lipid and glucose metabolism, mitochondrial energy, and inflammation were assessed through reverse transcription-quantitative PCR (RT-qPCR). Additionally, correlations between gene expression changes and fat changes were evaluated. Fat increased preferentially in the trunk with EFV and in the limbs with LPV/r (P < 0.05). After 16 weeks of exposure to the drug regimen, transcripts of CEBP/A, ADIPOQ, GLUT4, LPL, and COXIV were significantly down-regulated in the EFV arm compared to the LPV/r arm (P < 0.05). Significant correlations were observed between LPL expression change and trunk fat change at week 16 in both arms and between CEBP/A or COXIV change and trunk fat change at the same time point only in the EFV arm and not in the LPV/r arm. When combined with emtricitabine/tenofovir as standard backbone therapy, EFV and LPV/r induced differential early expression of genes involved in adipogenesis and energy metabolism. Moreover, these mRNA expression changes correlated with trunk fat change in the EFV arm. (This was a substudy of a randomized clinical trial [LIPOTAR study] registered at ClinicalTrials.gov under identifier NCT00759070.).