Effect of tesamorelin on visceral fat and liver fat in HIV-infected patients with abdominal fat accumulation: a randomized clinical trial

MAVMET trial: maraviroc and/or metformin for metabolic dysfunction associated fatty liver disease in adults with suppressed HIV

OBJECTIVE

Metabolic dysfunction associated fatty liver disease (MAFLD) is over-represented in people with HIV (PWH). Maraviroc (MVC) and/or metformin (MET) may reduce MAFLD by influencing inflammatory pathways and fatty acid metabolism.

DESIGN

Open-label, 48-week randomized trial with a 2 x 2 factorial design.

SETTING

Multicenter HIV clinics.

PARTICIPANTS

Nondiabetic, virologically suppressed PLWH, aged at least 35 years, with confirmed/suspected MAFLD (≥1 biochemical/anthropometric/radiological/histological features).

INTERVENTION

Adjunctive MVC; MET; MVC+MET vs. antiretroviral therapy (ART) alone.

PRIMARY OUTCOME

Change in liver fat fraction (LFF) between baseline and week-48 using magnetic resonance proton density fat fraction (MR PDFF).

RESULTS

Six sites enrolled 90 participants (93% male; 81% white; median age 52 [interquartile range, IQR 47-57] years) between March 19, 2018, and November 11, 2019. Seventy percent had imaging/biopsy and at least one 1 MAFLD criteria. The analysis included 82/90 with week-0 and week-48 scans. Median baseline MR PDFF was 8.9 (4.6-17.1); 40, 38, 8, and 14% had grade zero, one, two, and three steatosis, respectively. Mean LFF increased slightly between baseline and follow-up scans: 2.22% MVC, 1.26% MET, 0.81% MVC+MET, and 1.39% ART alone. Prolonged intervention exposure (delayed week-48 scans) exhibited greater increases in MR PDFF (estimated difference 4.23% [95% confidence interval, 95% CI 2.97-5.48], P  < 0.001). There were no differences in predicted change for any intervention compared to ART alone: MVC (-0.42% [95% CI -1.53 to 0.68, P  = 0.45]), MET (-0.62 [-1.81 to 0.56, P  = 0.30]), and MVC+MET (-1.04 [-2.74 to 0.65, P  = 0.23]). Steatosis grade remained unchanged in 55% and increased in 24%.

CONCLUSION

Baseline levels of liver fat were lower than predicted. Contrary to our hypothesis, neither MVC, MET, or the combination significantly reduced liver fat as measured by MRPDFF compared to ART alone.

Mechanisms underlying HIV-associated cognitive impairment and emerging therapies for its management

People living with HIV are affected by the chronic consequences of neurocognitive impairment (NCI) despite antiretroviral therapies that suppress viral replication, improve health and extend life. Furthermore, viral suppression does not eliminate the virus, and remaining infected cells may continue to produce viral proteins that trigger neurodegeneration. Comorbidities such as diabetes mellitus are likely to contribute substantially to CNS injury in people living with HIV, and some components of antiretroviral therapy exert undesirable side effects on the nervous system. No treatment for HIV-associated NCI has been approved by the European Medicines Agency or the US Food and Drug Administration. Historically, roadblocks to developing effective treatments have included a limited understanding of the pathophysiology of HIV-associated NCI and heterogeneity in its clinical manifestations. This heterogeneity might reflect multiple underlying causes that differ among individuals, rather than a single unifying neuropathogenesis. Despite these complexities, accelerating discoveries in HIV neuropathogenesis are yielding potentially druggable targets, including excessive immune activation, metabolic alterations culminating in mitochondrial dysfunction, dysregulation of metal ion homeostasis and lysosomal function, and microbiome alterations. In addition to drug treatments, we also highlight the importance of non-pharmacological interventions. By revisiting mechanisms implicated in NCI and potential interventions addressing these mechanisms, we hope to supply reasons for optimism in people living with HIV affected by NCI and their care providers.

Growth hormone and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a prevalent cause of liver disease and metabolic comorbidities. Obesity is strongly associated with NAFLD and is also a state of relative deficiency of growth hormone (GH). Evidence supports a role of reduced GH and insulin-like growth factor-1 (IGF-1) in NAFLD pathogenesis. Physiological actions of GH in the liver include suppression of de novo lipogenesis (DNL) and promotion of lipid beta-oxidation, and GH also appears to have anti-inflammatory actions. Physiologic actions of IGF-1 include suppression of inflammatory and fibrogenic pathways important in the evolution from steatosis to steatohepatitis and fibrosis. Rodent models of impaired hepatic GH signaling show the development of steatosis, sometimes accompanied by inflammation, hepatocellular damage, and fibrosis, and these changes are ameliorated by treatment with GH and/or IGF-1. In humans, individuals with GH deficiency and GH resistance demonstrate an increased prevalence of NAFLD compared to controls, with improvement in hepatic lipid, steatohepatitis, and fibrosis following GH replacement. As a corollary, individuals with GH excess demonstrate lower hepatic lipid compared to controls along with increased hepatic lipid following treatment to normalize GH levels. Clinical trials demonstrate that augmentation of GH reduces hepatic lipid content in individuals with NAFLD and may also ameliorate steatohepatitis and fibrosis. Taken together, evidence supports an important role for perturbations in the GH/IGF-1 axis as one of the pathogenic mechanisms of NAFLD and suggests that further study is needed to assess whether augmentation of GH and/or IGF-1 may be a safe and effective therapeutic strategy for NAFLD.

BMI-adjusted adipose tissue volumes exhibit depot-specific and divergent associations with cardiometabolic diseases

For any given body mass index (BMI), individuals vary substantially in fat distribution, and this variation may have important implications for cardiometabolic risk. Here, we study disease associations with BMI-independent variation in visceral (VAT), abdominal subcutaneous (ASAT), and gluteofemoral (GFAT) fat depots in 40,032 individuals of the UK Biobank with body MRI. We apply deep learning models based on two-dimensional body MRI projections to enable near-perfect estimation of fat depot volumes (R2 in heldout dataset = 0.978-0.991 for VAT, ASAT, and GFAT). Next, we derive BMI-adjusted metrics for each fat depot (e.g. VAT adjusted for BMI, VATadjBMI) to quantify local adiposity burden. VATadjBMI is associated with increased risk of type 2 diabetes and coronary artery disease, ASATadjBMI is largely neutral, and GFATadjBMI is associated with reduced risk. These results - describing three metabolically distinct fat depots at scale - clarify the cardiometabolic impact of BMI-independent differences in body fat distribution.

Silhouette images enable estimation of body fat distribution and associated cardiometabolic risk

Inter-individual variation in fat distribution is increasingly recognized as clinically important but is not routinely assessed in clinical practice, in part because medical imaging has not been practical to deploy at scale for this task. Here, we report a deep learning model trained on an individual’s body shape outline—or “silhouette” —that enables accurate estimation of specific fat depots of interest, including visceral (VAT), abdominal subcutaneous (ASAT), and gluteofemoral (GFAT) adipose tissue volumes, and VAT/ASAT ratio. Two-dimensional coronal and sagittal silhouettes are constructed from whole-body magnetic resonance images in 40,032 participants of the UK Biobank and used as inputs for a convolutional neural network to predict each of these quantities. Mean age of the study participants is 65 years and 51% are female. A cross-validated deep learning model trained on silhouettes enables accurate estimation of VAT, ASAT, and GFAT volumes (R²: 0.88, 0.93, and 0.93, respectively), outperforming a comparator model combining anthropometric and bioimpedance measures (ΔR² = 0.05–0.13). Next, we study VAT/ASAT ratio, a nearly body-mass index (BMI)—and waist circumference-independent marker of metabolically unhealthy fat distribution. While the comparator model poorly predicts VAT/ASAT ratio (R²: 0.17–0.26), a silhouette-based model enables significant improvement (R²: 0.50–0.55). Increased silhouette-predicted VAT/ASAT ratio is associated with increased risk of prevalent and incident type 2 diabetes and coronary artery disease independent of BMI and waist circumference. These results demonstrate that body silhouette images can estimate important measures of fat distribution, laying the scientific foundation for scalable population-based assessment.

Inherited basis of visceral, abdominal subcutaneous and gluteofemoral fat depots

For any given level of overall adiposity, individuals vary considerably in fat distribution. The inherited basis of fat distribution in the general population is not fully understood. Here, we study up to 38,965 UK Biobank participants with MRI-derived visceral (VAT), abdominal subcutaneous (ASAT), and gluteofemoral (GFAT) adipose tissue volumes. Because these fat depot volumes are highly correlated with BMI, we additionally study six local adiposity traits: VAT adjusted for BMI and height (VATadj), ASATadj, GFATadj, VAT/ASAT, VAT/GFAT, and ASAT/GFAT. We identify 250 independent common variants (39 newly-identified) associated with at least one trait, with many associations more pronounced in female participants. Rare variant association studies extend prior evidence for PDE3B as an important modulator of fat distribution. Local adiposity traits (1) highlight depot-specific genetic architecture and (2) enable construction of depot-specific polygenic scores that have divergent associations with type 2 diabetes and coronary artery disease. These results - using MRI-derived, BMI-independent measures of local adiposity - confirm fat distribution as a highly heritable trait with important implications for cardiometabolic health outcomes.

Growth Hormone and Insulin-Like Growth Factor 1 Regulation of Nonalcoholic Fatty Liver Disease

Patients with obesity have a high prevalence of nonalcoholic fatty liver disease (NAFLD), representing a spectrum of simple steatosis to nonalcoholic steatohepatitis (NASH), without and with fibrosis. Understanding the etiology of NAFLD is clinically relevant since NAFLD is an independent risk factor for diabetes and cardiovascular disease. In addition, NASH predisposes patients to the development of cirrhosis and hepatocellular carcinoma, and NASH cirrhosis represents the fastest growing indication for liver transplantation in the United States. It is appreciated that multiple factors are involved in the development and progression of NAFLD. Growth hormone (GH) and insulin-like growth factor 1 (IGF1) regulate metabolic, immune, and hepatic stellate cell function, and alterations in the production and function of GH is associated with obesity and NAFLD/NASH. Therefore, this review will focus on the potential role of GH and IGF1 in the regulation of hepatic steatosis, inflammation, and fibrosis.

Approach to the Patient With Lipodystrophy

Lipodystrophy constitutes a spectrum of diseases characterized by a generalized or partial absence of adipose tissue. Underscoring the role of healthy fat in maintenance of metabolic homeostasis, fat deficiency in lipodystrophy typically leads to profound metabolic disturbances including insulin resistance, hypertriglyceridemia, and ectopic fat accumulation. While rare, recent genetic studies indicate that lipodystrophy is more prevalent than has been previously thought, suggesting considerable underdiagnosis in clinical practice. In this article, we provide an overview of the etiology and management of generalized and partial lipodystrophy disorders. We bring together the latest scientific evidence and clinical guidelines and expose key gaps in knowledge. Through improved recognition of the lipodystrophy disorders, patients (and their affected family members) can be appropriately screened for cardiometabolic, noncardiometabolic, and syndromic abnormalities and undergo treatment with targeted interventions. Notably, insights gained through the study of this rare and extreme phenotype can inform our knowledge of more common disorders of adipose tissue overload, including generalized obesity.

Synthesis of potent antagonists of receptors for growth hormone-releasing hormone with antitumor and anti-inflammatory activity

The syntheses and biological evaluation of GHRH antagonists of AVR series with high anticancer and anti-inflammatory activities are described. Compared to our previously reported GHRH antagonist 602 of MIAMI series, AVR analogs contain additional modifications at positions 0, 6, 8, 10, 11, 12, 20, 21, 29 and 30, which induce greater antitumor activities. Five of nineteen tested AVR analogs presented binding affinities to the membrane GHRH receptors on human pituitary, 2-4-fold better than MIA-602. The antineoplastic properties of these analogs were evaluated in vitro using proliferation assays and in vivo in nude mice xenografted with various human cancer cell lines including lung (NSCLC-ADC HCC827 and NSCLC H460), gastric (NCI-N87), pancreatic (PANC-1 and CFPAC-1), colorectal (HT-29), breast (MX-1), glioblastoma (U87), ovarian (SK-OV-3 and OVCAR-3) and prostatic (PC3) cancers. In vitro AVR analogs showed inhibition of cell viability equal to or greater than MIA-602. After subcutaneous administration at 5 μg/day doses, some AVR antagonists demonstrated better inhibition of tumor growth in nude mice bearing various human cancers, with analog AVR-353 inducing stronger suppression than MIA-602 in lung, gastric, pancreatic and colorectal cancers and AVR-352 in ovarian cancers and glioblastoma. Both antagonists induced greater inhibition of GH release than MIA-602 in vitro in cultured rat pituitary cells and in vivo in rats. AVR-352 also demonstrated stronger anti-inflammatory effects in lung granulomas from mice with lung inflammation. Our studies demonstrate the merit of further investigation of AVR GHRH antagonists and support their potential use for clinical therapy of human cancers and other diseases.

Adipose tissue is a predictor of 30-days mortality in patients with bloodstream infection caused by carbapenem-resistant Klebsiella pneumoniae

Background

Prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP) bloodstream infection with high mortality has attached physicians' attention. High visceral adipose tissue (VAT) and high subcutaneous adipose tissue (SAT) were confirmed by previous studies that were closely related to increased pneumonia severity, more complications, and higher mortality in COVID-19. Thus, we speculate that CT-quantified body composition may also be connected to all-cause mortality and bacterial clearance in patients with CRKP bloodstream infection (BSI).

Methods

We investigated the associations of CT-quantified body composition with the mortality of CRKP bloodstream infectious patients. All CT images were obtained at the level of the L3/4 spinal level. The prognostic value of the body composition was analyzed using the Cox regression model, and precise clinical nomograms were established.

Results

72 eligible patients both suffered from CRKP bloodstream infection and performed abdominopelvic CT were included. Factors associated with 30-day all-in hospital mortality included total adipose tissue (TAT) [adjusted hazard ratio (HR) = 1.028, 95% confidence interval (CI), 1.003–1.053; P = 0.025], age [HR = 1.030, 95% CI, 1.000–1.061; P = 0.047] and SOFA scores [HR = 1.138, 95% CI 1.049–1.263; P = 0.002]. Compared with low-VAT, patients with high-VAT show a strikingly poor prognosis in both 30-day all-cause mortality (P = 0.0108, Fig. 2A) and 30-day CRKP BSI mortality (P = 0.0049, Fig. 2C). The results of TAT were similar to VAT.

Conclusions

Our study suggested that CT-derived body composition could be a credible and effective alternative to assess the prognosis of patients with BSI owing to CRKP. CT-quantified TAT, age, and SOFA scores were independently associated with 30-day all-cause mortality in these severe infectious patients, while skeletal muscle did not have obvious statistical significance.

Expert Panel Review on Nonalcoholic Fatty Liver Disease in Persons With Human Immunodeficiency Virus

Nonalcoholic fatty liver disease (NAFLD) affects 25% of adults in the general population and is a disease spectrum ranging from steatosis to nonalcoholic steatohepatitis (NASH) to end-stage liver disease. NAFLD is an independent risk factor for cardiovascular disease, diabetes mellitus, and all-cause mortality, and NASH cirrhosis is a frequent indication for liver transplantation. In persons with human immunodeficiency virus (PWH), chronic liver disease is the second leading cause of non-human immunodeficiency virus-related mortality. Between 20% and 63% of PWH have NASH, and 14% to 63% have NASH with fibrosis. However, little is known about the optimal diagnostic strategies, risk factors for, and treatment of NAFLD in PWH. Here, we review current data on and identify knowledge gaps in the epidemiology, pathophysiology, diagnosis, and management of NAFLD in PWH and highlight priorities for research.

Novel Antidiabetic Strategies and Diabetologists' Views in Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide with high prevalence, especially in individuals with obesity and type 2 diabetes. Among individuals with type 2 diabetes, the severe insulin resistant subgroup has the greatest risk of NAFLD, likely due to dysfunctional adipose tissue mass but also genetic factors, and may progress earlier to inflammatory and profibrotic nonalcoholic steatohepatitis (NASH). NASH has been associated with increased liver-related as well as cardiovascular morbidity and mortality. International diabetes associations recommend certain screening and treatment strategies for NASH in type 2 diabetes, which, however, bear several limitations such as lack of accurate noninvasive diagnostic tools and targeted treatments. Currently, antihyperglycemic drug concepts based on glucagon-like peptide-1 receptor agonists and sodium glucose cotransporter 2 inhibitors offer metabolic as well as cardiorenal benefits and provide treatment options for both hyperglycemia and NASH in type 2 diabetes.

Pharmacotherapy for Non-Alcoholic Fatty Liver Disease: Emerging Targets and Drug Candidates

Non-alcoholic fatty liver disease (NAFLD), or metabolic (dysfunction)-associated fatty liver disease (MAFLD), is characterized by high global incidence and prevalence, a tight association with common metabolic comorbidities, and a substantial risk of progression and associated mortality. Despite the increasingly high medical and socioeconomic burden of NAFLD, the lack of approved pharmacotherapy regimens remains an unsolved issue. In this paper, we aimed to provide an update on the rapidly changing therapeutic landscape and highlight the major novel approaches to the treatment of this disease. In addition to describing the biomolecules and pathways identified as upcoming pharmacological targets for NAFLD, we reviewed the current status of drug discovery and development pipeline with a special focus on recent evidence from clinical trials.

Towards Understanding the Direct and Indirect Actions of Growth Hormone in Controlling Hepatocyte Carbohydrate and Lipid Metabolism

Growth hormone (GH) is critical for achieving normal structural growth. In addition, GH plays an important role in regulating metabolic function. GH acts through its GH receptor (GHR) to modulate the production and function of insulin-like growth factor 1 (IGF1) and insulin. GH, IGF1, and insulin act on multiple tissues to coordinate metabolic control in a context-specific manner. This review will specifically focus on our current understanding of the direct and indirect actions of GH to control liver (hepatocyte) carbohydrate and lipid metabolism in the context of normal fasting (sleep) and feeding (wake) cycles and in response to prolonged nutrient deprivation and excess. Caveats and challenges related to the model systems used and areas that require further investigation towards a clearer understanding of the role GH plays in metabolic health and disease are discussed.

Altered pattern of circulating miRNAs in HIV lipodystrophy perturb key adipose differentiation and inflammation pathways

We identified a microRNA (miRNA) profile characterizing HIV lipodystrophy and explored the downstream mechanistic implications with respect to adipocyte biology and the associated clinical phenotype. miRNA profiles were extracted from small extracellular vesicles (sEVs) of HIV-infected individuals with and without lipodystrophic changes and individuals without HIV, among whom we previously showed significant reductions in adipose Dicer expression related to HIV. miR-20a-3p was increased and miR-324-5p and miR-186 were reduced in sEVs from HIV lipodystrophic individuals. Changes in these miRNAs correlated with adipose Dicer expression and clinical markers of lipodystrophy, including fat redistribution, insulin resistance, and hypertriglyceridemia. Human preadipocytes transfected with mimic miR-20a-3p, anti–miR-324-5p, or anti–miR-186 induced consistent changes in latent transforming growth factor beta binding protein 2 (Ltbp2), Wisp2, and Nebl expression. Knockdown of Ltbp2 downregulated markers of adipocyte differentiation (Fabp4, Pparγ, C/ebpa, Fasn, adiponectin, Glut4, CD36), and Lamin C, and increased expression of genes involved in inflammation (IL1β, IL6, and Ccl20). Our studies suggest a likely unique sEV miRNA signature related to dysregulation of Dicer in adipose tissue in HIV. Enhanced miR-20a-3p or depletion of miR-186 and miR-324-5p may downregulate Ltbp2 in HIV, leading to dysregulation in adipose differentiation and inflammation, which could contribute to acquired HIV lipodystrophy and associated metabolic and inflammatory perturbations.

Estimated visceral adiposity is associated with risk of cardiometabolic conditions in a population based study

Visceral adiposity is a major risk factor of cardiometabolic diseases. Visceral adipose tissue (VAT) is usually measured with expensive imaging techniques which present financial and practical challenges to population-based studies. We assessed whether cardiometabolic conditions were associated with VAT by using a new and easily measurable anthropometric index previously published and validated. Data (1529 participants) came from the European Health Examination Survey in Luxembourg (2013–2015). Logistic regressions were used to study associations between VAT and cardiometabolic conditions. We observed an increased risk of all conditions associated with VAT. The total adjusted odds ratio (AOR, [95% CI]) for hypertension, prediabetes/diabetes, hypercholesterolemia, and hypertriglyceridemia for the fourth quartile of VAT compared to the lowest were 10.22 [6.75, 15.47]), (5.90 [4.02, 8.67]), (3.60 [2.47, 5.25]) and (7.67 [5.04, 11.67]. We observed higher odds in women than in men for all outcomes with the exception of hypertension. Future studies should investigate the impact of VAT changes on cardiometabolic health and the use of anthropometrically predicted VAT as an accurate outcome when no biomedical imaging is available.

Immunomodulatory and Anti-Inflammatory Strategies to Reduce Comorbidity Risk in People with HIV

PURPOSE OF REVIEW

In this review, we will discuss treatment interventions targeting drivers of immune activation and chronic inflammation in PWH.

RECENT FINDINGS

Potential treatment strategies to prevent the progression of comorbidities in PWH have been identified. These studies include, among others, the use of statins to modulate lipid alterations and subsequent innate immune receptor activation, probiotics to restore healthy gut microbiota and reduce microbial translocation, hydroxychloroquine to reduce immune activation by altering Toll-like receptors function and expression, and canakinumab to block the action of a major pro-inflammatory cytokine IL-1β. Although many of the treatment strategies discussed here show promise, due to the complex nature of chronic inflammation and comorbidities in PWH, larger clinical studies are needed to understand and target the prominent drivers and inflammatory cascades underlying these end-organ diseases.

Quantitative Imaging of Body Composition

Body composition refers to the amount and distribution of lean tissue, adipose tissue, and bone in the human body. Lean tissue primarily consists of skeletal muscle; adipose tissue comprises mostly abdominal visceral adipose tissue and abdominal and nonabdominal subcutaneous adipose tissue. Hepatocellular and myocellular lipids are also fat pools with important metabolic implications. Importantly, body composition reflects generalized processes such as increased adiposity in obesity and age-related loss of muscle mass known as sarcopenia.In recent years, body composition has been extensively studied quantitatively to predict overall health. Multiple imaging methods have allowed precise estimates of tissue types and provided insights showing the relationship of body composition to varied pathologic conditions. In this review article, we discuss different imaging methods used to quantify body composition and describe important anatomical locations where target tissues can be measured.

Carotid Intima-Media Thickness Progression as Surrogate Marker for Cardiovascular Risk: Meta-Analysis of 119 Clinical Trials Involving 100 667 Patients

BACKGROUND

To quantify the association between effects of interventions on carotid intima-media thickness (cIMT) progression and their effects on cardiovascular disease (CVD) risk.

METHODS

We systematically collated data from randomized, controlled trials. cIMT was assessed as the mean value at the common-carotid-artery; if unavailable, the maximum value at the common-carotid-artery or other cIMT measures were used. The primary outcome was a combined CVD end point defined as myocardial infarction, stroke, revascularization procedures, or fatal CVD. We estimated intervention effects on cIMT progression and incident CVD for each trial, before relating the 2 using a Bayesian meta-regression approach.

RESULTS

We analyzed data of 119 randomized, controlled trials involving 100 667 patients (mean age 62 years, 42% female). Over an average follow-up of 3.7 years, 12 038 patients developed the combined CVD end point. Across all interventions, each 10 μm/y reduction of cIMT progression resulted in a relative risk for CVD of 0.91 (95% Credible Interval, 0.87-0.94), with an additional relative risk for CVD of 0.92 (0.87-0.97) being achieved independent of cIMT progression. Taken together, we estimated that interventions reducing cIMT progression by 10, 20, 30, or 40 μm/y would yield relative risks of 0.84 (0.75-0.93), 0.76 (0.67-0.85), 0.69 (0.59-0.79), or 0.63 (0.52-0.74), respectively. Results were similar when grouping trials by type of intervention, time of conduct, time to ultrasound follow-up, availability of individual-participant data, primary versus secondary prevention trials, type of cIMT measurement, and proportion of female patients.

CONCLUSIONS

The extent of intervention effects on cIMT progression predicted the degree of CVD risk reduction. This provides a missing link supporting the usefulness of cIMT progression as a surrogate marker for CVD risk in clinical trials.

Causes, consequences, and treatment of metabolically unhealthy fat distribution

An increase in fat mass is considered to be an important risk factor for the worldwide increase in type 2 diabetes and cardiovascular disease. However, for a given fat mass, there is a large variability in the risk prediction of these cardiometabolic diseases. For example, some lean people unexpectedly have a risk of type 2 diabetes and cardiovascular disease that is similar to the increased risk that is observed in most people who have obesity. What both of these phenotypes have in common is a very characteristic fat distribution. As a result, much focus has been given on the strong predictive power of increased visceral fat mass. However, an analysis of the causes of type 2 diabetes and cardiovascular disease, as well as comparisons to rare diseases such as lipodystrophy and studying genetically determined fat distribution in the general population, suggest that an impaired ability to expand subcutaneous fat in the lower part of the body is also important for predicting the incidence of these cardiometabolic diseases. This Review, first, addresses the identification of distinct fat distribution phenotypes and their risk of cardiometabolic diseases by discussing findings from published studies that have applied precise quantification of different fat depots. Second, this Review provides support for the theory that a lower amount of lower-body fat mass is equally important to a high amount of visceral fat mass as a determinant of cardiometabolic diseases. Third, this Review discusses the genetic and lifestyle-related causes of metabolically healthy and unhealthy fat distribution. Finally, this Review summarises and appraises the effectiveness of lifestyle-related interventions and pharmacological interventions for reducing visceral adiposity and maintaining lower-body fat mass to prevent and treat cardiometabolic diseases.

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.

Obesity and Weight Gain in Persons with HIV

PURPOSE OF REVIEW

The proportion of overweight and obese persons with HIV (PWH) has increased since the introduction of antiretroviral therapy (ART). We aim to summarize recent literature on risks of weight gain, discuss adipose tissue changes in HIV and obesity, and synthesize current understanding of how excess adiposity and HIV contribute to metabolic complications.

RECENT FINDINGS

Recent studies have implicated contemporary ART regimens, including use of integrase strand transfer inhibitors and tenofovir alafenamide, as a contributor to weight gain, though the mechanisms are unclear. Metabolic dysregulation is linked to ectopic fat and alterations in adipose immune cell populations that accompany HIV and obesity. These factors contribute to an increasing burden of metabolic diseases in the aging HIV population. Obesity compounds an increasing burden of metabolic disease among PWH, and understanding the role of fat partitioning and HIV- and ART-related adipose tissue dysfunction may guide prevention and treatment strategies.

Effects of tesamorelin on non-alcoholic fatty liver disease in HIV: a randomised, double-blind, multicentre trial

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a substantial cause of comorbidity in people with HIV and there are no proven pharmacological treatments for the disease in this population. We assessed the effects of tesamorelin on liver fat and histology in people with HIV and NAFLD.

METHODS

This randomised, double-blind, multicentre study with identical placebo as a comparator was done in a hospital and a medical research centre in the USA. People with HIV infection and a hepatic fat fraction (HFF) of 5% or more by proton magnetic resonance spectroscopy were eligible. Participants were randomly assigned (1:1) to receive either tesamorelin 2 mg once daily or placebo once daily for 12 months, followed by a 6-month open-label phase during which all participants received tesamorelin 2 mg daily. The randomisation list was prepared by the study statistician using a permuted block algorithm within each stratum with randomly varying block sizes. The primary endpoint was change in HFF between baseline and 12 months. The primary safety endpoint was glucose. Analysis was by intention to treat using all available data. This trial is registered with ClinicalTrials.gov, number NCT02196831.

FINDINGS

61 patients were enrolled between Aug 20, 2015, and Jan 16, 2019, of whom 30 received tesamorelin and 30 received placebo. Patients receiving tesamorelin had a greater reduction of HFF than did patients receiving placebo, with an absolute effect size of -4·1% (95% CI -7·6 to -0·7, p=0·018), corresponding to a -37% (95% CI -67 to -7, p=0·016) relative reduction from baseline. After 12 months, 35% of individuals receiving tesamorelin and 4% receiving placebo had a HFF of less than 5% (p=0·0069). Changes in fasting glucose and glycated haemoglobin were not different between groups at 12 months. Individuals in the tesamorelin group experienced more localised injection site complaints than those in the placebo group, though none were judged to be serious.

INTERPRETATION

Tesamorelin might be beneficial in people with HIV and NAFLD. Further studies are needed to determine the long-term effects of tesamorelin on liver histology.

FUNDING

National Institutes of Health and National Institute of Allergy and Infectious Diseases.

Practice Paper of the Academy of Nutrition and Dietetics: Nutrition Intervention and Human Immunodeficiency Virus Infection

Nutrition is an integral component of medical care for people living with human immunodeficiency virus (HIV)/autoimmune deficiency syndrome (AIDS) (PLWHA). The Academy of Nutrition and Dietetics supports integration of medical nutrition therapy into routine care for this population. Fewer PLWHA experience wasting and undernutrition, while the prevalence of obesity and other chronic diseases has increased significantly. Improved understanding of HIV infection's impact on metabolism and chronic inflammation has only increased the complexity of managing chronic HIV infection. Nutrition assessment should encompass food insecurity risk, changes in body composition, biochemical indices, and clinical indicators of comorbid disease. Side effects from current antiretroviral therapy regimens are less prevalent than with previous generations of therapy. However, micronutrient deficiencies and chronic anemia also remain significant nutritional risks for PLWHA, making vitamin and mineral supplementation necessary in cases of acute deficiency or food insecurity. Additional factors can impact HIV-related nutrition care among the pediatric population, older adults, minority groups, those co-infected with tuberculosis or hepatitis, and PLWHA in rural or underserved areas. Registered dietitian nutritionists and nutrition and dietetic technicians, registered should participate in multidisciplinary care to incorporate nutrition into the medical management of PLWHA.

The Growth Hormone Releasing Hormone Analogue, Tesamorelin, Decreases Muscle Fat and Increases Muscle Area in Adults with HIV

BACKGROUND

Tesamorelin, a growth hormone-releasing hormone analogue, decreases visceral adipose tissue in people living with HIV, however, the effects on skeletal muscle fat and area are unknown.

OBJECTIVES

The goals of this exploratory secondary analysis were to determine the effects of tesamorelin on muscle quality (density) and quantity (area).

DESIGN

Secondary, exploratory analysis of two previously completed randomized (2:1), clinical trials.

SETTING

U.S. and Canadian sites.

PARTICIPANTS

People living with HIV and with abdominal obesity. Tesamorelin participants were restricted to responders (visceral adipose tissue decrease ≥8%).

INTERVENTION

Tesamorelin or placebo.

MEASUREMENTS

Computed tomography scans (at L4-L5) were used to quantify total and lean density (Hounsfield Units, HU) and area (centimeters2) of four trunk muscle groups using a semi-automatic segmentation image analysis program. Differences between muscle area and density before and after 26 weeks of tesamorelin or placebo treatment were compared and linear regression models were adjusted for baseline and treatment arm.

RESULTS

Tesamorelin responders (n=193) and placebo (n=148) participants with available images were similar at baseline; most were Caucasian (83%) and male (87%). In models adjusted for baseline differences and treatment arm, tesamorelin was associated with significantly greater increases in density of four truncal muscle groups (coefficient 1.56-4.86 Hounsfield units; all p<0.005), and the lean anterolateral/abdominal and rectus muscles (1.39 and 1.78 Hounsfield units; both p<0.005) compared to placebo. Significant increases were also seen in total area of the rectus and psoas muscles (0.44 and 0.46 centimeters2; p<0.005), and in the lean muscle area of all four truncal muscle groups (0.64-1.08 centimeters2; p<0.005).

CONCLUSIONS

Among those with clinically significant decrease in visceral adipose tissue on treatment, tesamorelin was effective in increasing skeletal muscle area and density. Long term effectiveness of tesamorelin among people with and without HIV, and the impact of these changes in daily life should be further studied.

Actions and Potential Therapeutic Applications of Growth Hormone-Releasing Hormone Agonists

In this article, we briefly review the identification of GHRH, provide an abridged overview of GHRH antagonists, and focus on studies with GHRH agonists. Potent GHRH agonists of JI and MR class were synthesized and evaluated biologically. Besides the induction of the release of pituitary GH, GHRH analogs promote cell proliferation and exert stimulatory effects on various tissues, which express GHRH receptors (GHRH-Rs). A large body of work shows that GHRH agonists, such as MR-409, improve pancreatic β-cell proliferation and metabolic functions and facilitate engraftment of islets after transplantation in rodents. Accordingly, GHRH agonists offer a new therapeutic approach to treating diabetes. Various studies demonstrate that GHRH agonists promote repair of cardiac tissue, producing improvement of ejection fraction and reduction of infarct size in rats, reduction of infarct scar in swine, and attenuation of cardiac hypertrophy in mice, suggesting clinical applications. The presence of GHRH-Rs in ocular tissues and neuroprotective effects of GHRH analogs in experimental diabetic retinopathy indicates their possible therapeutic applications for eye diseases. Other effects of GHRH agonists, include acceleration of wound healing, activation of immune cells, and action on the central nervous system. As GHRH might function as a growth factor, we examined effects of GHRH agonists on tumors. In vitro, GHRH agonists stimulate growth of human cancer cells and upregulate GHRH-Rs. However, in vivo, GHRH agonists inhibit growth of human cancers xenografted into nude mice and downregulate pituitary and tumoral GHRH-Rs. Therapeutic applications of GHRH analogs are discussed. The development of GHRH analogs should lead to their clinical use.

Inflammation and Metabolic Complications in HIV

PURPOSE OF REVIEW

We aim to provide an in-depth review of recent literature highlighting the role of inflammation involving the adipose tissue, liver, skeletal muscles, and gastrointestinal tract in the development of metabolic complications among persons living with HIV (PLWH).

RECENT FINDINGS

Recent studies in PLWH have demonstrated a significant association between circulating inflammatory markers and development of insulin resistance and metabolic complications. In adipose tissue, pro-inflammatory cytokine expression inhibits adipocyte insulin signaling, which alters lipid and glucose homeostasis. Increased lipolysis and lipogenesis elevate levels of circulating free fatty acids and promote ectopic fat deposition in liver and skeletal muscles. This leads to lipotoxicity characterized by a pro-inflammatory response with worsening insulin resistance. Finally, HIV is associated with gastrointestinal tract inflammation and changes in the gut microbiome resulting in reduced diversity, which is an additional risk factor for diabetes. Metabolic complications in PLWH are in part due to chronic, multisite tissue inflammation resulting in dysregulation of glucose and lipid trafficking, utilization, and storage.

Fatty liver disease in persons with HIV infection

The leading cause of non-HIV-related mortality is liver disease. Fatty liver disease can be characterized as alcoholic or nonalcoholic in nature. Alcohol use is prevalent among individuals with HIV infection and can lead to medication nonadherence, lower CD4+ cell count, inadequate viral suppression, and disease progression. The pathogenesis of nonalcoholic fatty liver disease (NAFLD) in individuals with HIV infection includes metabolic syndrome, hyperuricemia, HIV-related lipodystrophy, genetic polymorphisms, medications, HIV itself, and the gut microbiome. The prevalence of NAFLD in persons with HIV infection ranges from 30% to 65% depending on the modality of diagnosis. Individuals with HIV infection and NAFLD are at higher risk of cardiovascular disease; however, there is a dearth of longitudinal outcomes studies on this topic. Current therapies for NAFLD, such as vitamin E and pioglitazone, have not been studied in persons with HIV infection. There are several drugs in phase II and III clinical trials that specifically target NAFLD in HIV, including CC chemokine receptor 5 inhibitors, growth hormone-releasing factor agonists, and stearoyl-CoA desaturase inhibitors. Persons with HIV should be screened for NAFLD while pursuing aggressive risk factor modification and lifestyle changes, given the increased risk of cardiovascular mortality.

A Review of Non-Alcoholic Fatty Liver Disease in HIV-Infected Patients: The Next Big Thing?

The burden of liver-related morbidity remains high among HIV-infected patients, despite advances in the treatment of HIV and viral hepatitis. Especially, the impact of non-alcoholic fatty liver disease (NAFLD) is significant with a prevalence of up to 50%. The pathogenesis of NAFLD and the reasons for progression to non-alcoholic steatohepatitis (NASH) are still not fully elucidated, but insulin resistance, mitochondrial dysfunction and dyslipidemia seem to be the main drivers. Both HIV-infection itself and combination antiretroviral therapy (cART) can contribute to the development of NAFLD/NASH in various ways. As ongoing HIV-related immune activation is associated with insulin resistance, early initiation of cART is needed to limit its duration. In addition, the use of early-generation nucleoside reverse transcriptase inhibitors and protease inhibitors is also associated with the development of NAFLD/NASH. Patients at risk should therefore receive antiretroviral drugs with a more favorable metabolic profile. Only weight reduction is considered to be an effective therapy for all patients with NAFLD/NASH, although certain drugs are available for specific subgroups. Since patients with NASH are at risk of developing liver cirrhosis and hepatocellular carcinoma, several non-antifibrotic and antifibrotic drugs are under investigation in clinical trials to broaden the therapeutic options. The epidemiology and etiology of NAFLD/NASH in HIV-positive patients is likely to change in the near future. Current guidelines recommend early initiation of cART that is less likely to induce insulin resistance, mitochondrial dysfunction and dyslipidemia. In contrast, as a result of increasing life expectancy in good health, this population will adopt the more traditional risk factors for NAFLD/NASH. HIV-treating physicians should be aware of the etiology, pathogenesis and treatment of NAFLD/NASH in order to identify and treat the patients at risk.

Comparison of visceral fat measurement by dual-energy X-ray absorptiometry to computed tomography in HIV and non-HIV

Background/Objectives

Individuals with HIV are susceptible to visceral fat accumulation, which confers an increased risk of cardiometabolic disease. Advanced software to ascertain visceral fat content from dual-energy X-ray absorptiometry (DXA) has not been validated among this population. We sought to compare DXA with computed tomography (CT) in the measurement of visceral fat cross-sectional area (VAT) in HIV and non-HIV using Bland–Altman analyses.

Subjects/Methods

Data were combined from five previously conducted studies of individuals with HIV (n = 313) and controls without HIV (n = 144) in which paired DXA and CT scans were available. In cross-sectional analyses, DXA-VAT was compared with CT-VAT among participants with and without HIV. In longitudinal analyses, changes in VAT over time were compared between DXA and CT among participants with and without HIV receiving no intervention over 12 months and among individuals with HIV receiving tesamorelin—a medication known to reduce VAT—over 6 months.

Results

In HIV, DXA underestimated VAT compared with CT among individuals with increased visceral adiposity. The measurement bias was −9 ± 47 cm² overall, but became progressively larger with greater VAT (P < 0.0001), e.g., −61 ± 58 cm² among those with VAT ≥ 200 cm². Sex-stratified analyses revealed that the relationship between VAT and measurement bias was especially pronounced in men (P < 0.0001). Longitudinally, DXA underestimated changes in VAT, particularly among those at the extremes of VAT gain or loss (P < 0.0001). In contrast to the cross-sectional findings, the tendency for DXA to underestimate longitudinal changes in VAT was evident in both men and women. Analogous findings were seen among controls in cross-sectional and longitudinal analyses.

Conclusions

DXA underestimated VAT relative to CT in men with and without HIV, who had increased visceral adiposity. DXA also underestimated changes in VAT over time in men and women, irrespective of HIV status. DXA-VAT should be used with caution among both HIV and non-HIV-infected populations.

Adult-Onset Hepatocyte GH Resistance Promotes NASH in Male Mice, Without Severe Systemic Metabolic Dysfunction

Nonalcoholic fatty liver disease (NAFLD), which includes nonalcoholic steatohepatitis (NASH), is associated with reduced GH input/signaling, and GH therapy is effective in the reduction/resolution of NAFLD/NASH in selected patient populations. Our laboratory has focused on isolating the direct vs indirect effects of GH in preventing NAFLD/NASH. We reported that chow-fed, adult-onset, hepatocyte-specific, GH receptor knockdown (aHepGHRkd) mice rapidly (within 7 days) develop steatosis associated with increased hepatic de novo lipogenesis (DNL), independent of changes in systemic metabolic function. In this study, we report that 6 months after induction of aHepGHRkd early signs of NASH develop, which include hepatocyte ballooning, inflammation, signs of mild fibrosis, and elevated plasma alanine aminotransferase. These changes occur in the presence of enhanced systemic lipid utilization, without evidence of white adipose tissue lipolysis, indicating that the liver injury that develops after aHepGHRkd is due to hepatocyte-specific loss of GH signaling and not due to secondary defects in systemic metabolic function. Specifically, enhanced hepatic DNL is sustained with age in aHepGHRkd mice, associated with increased hepatic markers of lipid uptake/re-esterification. Because hepatic DNL is a hallmark of NAFLD/NASH, these studies suggest that enhancing hepatocyte GH signaling could represent an effective therapeutic target to reduce DNL and treat NASH.

Endocrinological aspects of HIV infection

PURPOSE

Patients with human immunodeficiency virus (HIV) are living longer with effective antiretroviral therapies and are enjoying near normal life span. Therefore, they are encountering endocrine issues faced by the general population along with those specific to HIV infection. The purpose of this article is to review the common endocrine aspects of HIV infection, and the early detection and management strategies for these complications.

METHODS

Recent literature on HIV and endocrine disease was reviewed.

RESULTS

HIV can influence endocrine glands at several levels. Endocrine glandular function may be altered by the direct effect of HIV viral proteins, through generation of systemic and local cytokines and the inflammatory response and via glandular involvement with opportunistic infections and HIV-related malignancies. Endocrine disorders seen in people with HIV include metabolic issues related to obesity such as diabetes, hyperlipidemia, lipohypertrophy, lipoatrophy and lipodystrophy and contribute significantly to quality of life, morbidity and mortality. In addition, hypogonadism, osteopenia and osteoporosis are also more prevalent in the patients with HIV. Although disorders of hypothalamic-pituitary-adrenal axis resulting in adrenal insufficiency can be life threatening, these along with thyroid dysfunction are being seen less commonly in the antiretroviral therapy (ART) era. ARTs have greatly improved life expectancy in people living with HIV but can also have adverse endocrine effects.

CONCLUSIONS

Clinicians need to have a high index of suspicion for endocrine abnormalities in people with HIV as they can be potentially life threatening if untreated. Endocrine evaluation should be pursued as in the general population, with focus on prevention, early detection and treatment to improve quality of life and longevity.

Future trends in the treatment of non-alcoholic steatohepatitis

With an estimated prevalence of ≈25% in Western and Asian countries, non alcoholic fatty liver disease (NAFLD), caused by chronic excessive caloric intake, is the emerging as the most prevalent liver disorder worldwide. NAFLD exists in two clinical entities, non-alcoholic fatty liver disease (NAFL), a relative benign disease that carry on minimal risk of liver-related morbidity but significant risk of cardiovascular complications, and non-alcoholic steatohepatitis (NASH), a progressive liver disorder with a significant risk for development of liver-related morbidities and mortality. While, liver injury in NASH is contributed by lipid overload in hepatocytes, lipotoxicity, the main determinant of disease progression is an inflammation-driven fibrotic response. Here, we review the landscape of emerging pharmacological interventions in the treatment of NAFL and NASH. A consensus exists that, while treating the liver component of NASH requires development of novel pharmacological approaches, the future therapy of NASH needs to be tailored to the single patient and most likely will be a combination of agents acting on specific pathogenic mechanisms at different disease stage.

NAFLD and HIV: Do Sex, Race, and Ethnicity Explain HIV-Related Risk?

PURPOSE OF REVIEW

Here, we review the epidemiology, diagnosis, and management of non-alcoholic fatty liver disease (NAFLD) in the general population, discuss HIV-specific differences in NAFLD pathogenesis, and summarize what is known regarding differences in NAFLD by race/ethnicity and sex.

RECENT FINDINGS

The reported prevalence of NAFLD among people living with HIV varies by age, body mass index, comorbidity, and method of NAFLD diagnosis, but is generally thought to be greater among HIV-infected compared to HIV-uninfected populations. Minorities and women tend to experience poorer HIV treatment outcomes (Meditz et al. J Infect Dis. 203(4):442-51, 2011; Beer et al. Medicine (Baltimore). 95(13):e 3171, 2016; Gant et al. MMWR Morb Mortal Wkly Rep. 66(40):1065-72, 2017; Millett et al. Lancet. 380(9839):341-8, 2012; Wejnert et al. J Infect Dis. 213(5):776-83, 2016), and are at the greatest risk for significant weight gain with HIV treatment (Erlandson et al. Medicine (Baltimore). 95(46):e 5399, 2016). Thus, women and minorities living with HIV may be at a higher risk of developing NAFLD and progressive liver disease. Disparities in the diagnosis, progression, and prognosis of NAFLD and HIV-associated NAFLD may be, in part, explained by genetic and sex differences; however, data is limited.

Heart fat in HIV: marker or mediator of risk?

PURPOSE OF REVIEW

The review aims to summarize the literature describing the clinical impact of cardiac fat depots in patients with HIV infection.

RECENT FINDINGS

People living with HIV (PLHIV) have accelerated rates of cardiovascular disease, and are prone to the development of ectopic fat deposition. Specifically, PLHIV have higher volumes of epicardial and intracardiac fat quantified by noninvasive imaging. Higher volumes of epicardial fat may be related to antiretroviral therapy duration and chronic inflammation, independently of other measures of body adiposity such as BMI. They have been associated with increased coronary artery calcium, myocardial perfusion defects, death, and myocardial infarction. The association with risk may be partly mediated through direct actions of cytokines and adipokines produced by the adipose tissue. Furthermore, HIV-infected patients have increased myocardial fat deposition that is also associated with antiretroviral therapy duration, and may be responsible for myocardial systolic and diastolic dysfunction.

SUMMARY

PLHIV have increased fat deposition surrounding and inside the heart that may serve as an important imaging marker of risk but may also directly mediate coronary artery disease and cardiac dysfunction. Although robust data of targeted therapies is lacking, some pharmacotherapies may be able to reduce cardiac fat volumes. In the meantime, as the evidence grows, physicians may consider intensifying preventive strategies and monitoring in patients with abnormal heart fat on noninvasive imaging.

The Fat of the Matter: Obesity and Visceral Adiposity in Treated HIV Infection

PURPOSE OF REVIEW

The aim of this review is to summarize knowledge of the prevalence, relevant physiology, and consequences of obesity and visceral adiposity in HIV-infected adults, including highlighting gaps in current knowledge and future research directions.

RECENT FINDINGS

Similar to the general population, obesity prevalence is increasing among HIV-infected persons, and obesity and visceral adiposity are associated with numerous metabolic and inflammatory sequelae. However, HIV- and antiretroviral therapy (ART)-specific factors may contribute to fat gain and fat quality in treated HIV infection, particularly to the development of visceral adiposity, and sex differences may exist. Obesity and visceral adiposity commonly occur in HIV-infected persons and have significant implications for morbidity and mortality. Future research should aim to better elucidate the HIV- and ART-specific contributors to obesity and visceral adiposity in treated HIV infection, with the goal of developing targeted therapies for the prevention and treatment of obesity and visceral adiposity in the modern ART era.

NOVEL MECHANISMS AND ANTI-INFLAMMATORY STRATEGIES TO REDUCE CARDIOVASCULAR RISK IN HUMAN IMMUNODEFICIENCY VIRUS

Cardiovascular disease (CVD) rates are 50% to 100% higher in human immunodeficiency virus (HIV) patients. Traditional risks account for only 25% of this excess risk. Excess CVD risk in HIV may relate in part to increases in ectopic adipose depots. CVD in HIV-infection is characterized by atypical highly vulnerable plaque lesions, which are inflamed, in tight relationship to immune, and monocyte activation pathways. Using ¹⁸fluorine-2-deoxy-D-glucose positron-emission tomography imaging techniques, we have shown increased arterial inflammation which persists even after effective antiretroviral therapy. More recent studies, using a novel macrophage specific imaging agent in humans, have shown highly increased inflammatory patterns in large vessels in HIV. In addition, statins may be uniquely valuable among HIV patients, not only lowering low-density lipoprotein, but also reducing monocyte chemo-attraction, and immune activation pathways. These data have led the National Institutes of Health to fund the Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE), the first large multicenter primary CVD prevention trial in HIV, aimed at assessing inflammatory mechanisms of CVD in HIV.

Fibroblast growth factor 21 decreases after liver fat reduction via growth hormone augmentation

OBJECTIVE

Fibroblast growth factor 21 (FGF21) ameliorates steatohepatitis but is increased in humans with fatty liver, potentially due to compensatory mechanisms and/or FGF21 resistance. Further, animal models suggest that GH increases serum FGF21. Tesamorelin, a growth hormone releasing hormone agonist, reduces liver fat in HIV-infected individuals. The objectives of this study were to investigate changes in FGF21 during tesamorelin treatment, to elucide the interplay between FGF21, GH augmentation, and liver fat reduction in humans.

METHODS

50 HIV-infected men and women with increased abdominal adiposity participated in this randomized, placebo-controlled trial of tesamorelin, 2mg vs. identical placebo daily for six months. Fasting laboratory measures, liver fat by 1H-magnetic resonance spectroscopy, and visceral adipose tissue (VAT) by computed tomography were obtained. Euglycemic hyperinsulinemic clamp was performed in a randomly selected subset.

RESULTS

At baseline, serum log10 FGF21 was significantly associated with log10 liver fat (r=0.32, p=0.03). Log10 FGF21 tended to decrease in the tesamorelin group compared to placebo (p=0.06). Among the entire cohort, reductions in FGF21 were significantly associated with reductions in liver fat (ρ=0.41, p=0.01), log10 gamma glutamyl tran speptidase (GGT, r=0.40, p=0.009), and FIB4 index (r=0.37, p=0.02).

CONCLUSIONS

In HIV-infected individuals, FGF21 is significantly positively associated with liver fat. FGF21 decreases in association with reductions in liver fat, GGT, and FIB4, suggesting that FGF21 is upregulated in the context of steatosis and steatohepatitis and is reduced when these conditions improve. Moreover, these data suggest that tesamorelin improves liver fat via pathways other than increasing serum FGF21.

TRIAL REGISTRATION

clinicaltrials.govNCT01263717.

Hepatic lipid metabolism and non-alcoholic fatty liver disease in aging

Aging is associated with dysregulation of glucose and lipid metabolism. Various factors that contribute to the dysregulation include both modifiable (e.g. obesity, insulin resistance) and non-modifiable risk factors (age-associated physiologic changes). Although there is no linear relationship between aging and prevalence of non-alcoholic fatty liver disease, current data strongly suggests that advanced age leads to more severe histological changes and poorer clinical outcomes. Hepatic lipid accumulation could lead to significant hepatic and systemic consequences including steatohepatitis, cirrhosis, impairment of systemic glucose metabolism and metabolic syndrome, thereby contributing to age-related diseases. Insulin, leptin and adiponectin are key regulators of the various physiologic processes that regulate hepatic lipid metabolism. Recent advances have expanded our understanding in this field, highlighting the role of novel mediators such as FGF 21, and mitochondria derived peptides. In this review, we will summarize the mediators of hepatic lipid metabolism and how they are altered in aging.

Visceral fat reduction with tesamorelin is associated with improved liver enzymes in HIV

OBJECTIVE

Tesamorelin reduces visceral adipose tissue (VAT) in HIV. We investigated whether reductions in VAT with tesamorelin are associated with changes in alanine aminotransferase (ALT) and aspartate aminotransferase (AST).

DESIGN AND METHODS

We utilized data from two multicenter Phase III trials of tesamorelin among 806 HIV-infected patients with abdominal obesity. These studies showed that the majority of patients treated with tesamorelin are 'responders', defined a priori by the Food and Drug Administration as achieving at least 8% reduction in VAT. In the current analysis, we sought to examine the impact of VAT reduction on ALT and AST among patients participating in the Phase III trials with baseline elevated ALT or AST. Within this group, we compared changes in ALT and AST in VAT responders vs. nonresponders after 26 weeks of treatment, and then assessed the effects of drug discontinuation on these endpoints over a subsequent 26-week period.

RESULTS

At baseline, VAT was positively associated with ALT (P = 0.01). In study participants assigned to tesamorelin with baseline ALT or AST more than 30 U/l, VAT responders experienced greater reductions in ALT (-8.9 ± 22.6 vs. 1.4 ± 34.7 U/l, P = 0.004) and AST (-3.8 ± 12.9 vs. 0.4 ± 22.4 U/l, P = 0.04) compared with nonresponders over 26 weeks. This improvement among VAT responders persisted over 52 weeks even in those switched to placebo despite a partial reaccumulation of VAT.

CONCLUSION

A clinically significant VAT reduction with tesamorelin was associated with improved liver enzymes among HIV-infected patients with abdominal obesity and elevated baseline transaminases.

Safety and metabolic effects of tesamorelin, a growth hormone-releasing factor analogue, in patients with type 2 diabetes: A randomized, placebo-controlled trial

Objective

Use of growth hormone is associated with side effects, including insulin resistance. The objective of this study was to determine whether tesamorelin, a stabilized growth hormone-releasing hormone analogue, would alter insulin sensitivity or control of diabetes.

Design

A 12-week randomized, placebo-controlled study of 53 patients with type 2 diabetes. Three treatment groups: placebo, 1 and 2 mg tesamorelin.

Measurements

Fasting glucose, glucose and insulin from oral glucose tolerance test, glycosylated hemoglobin (HbA_1c), home blood glucose, insulin-like growth factor-1, and lipids.

Main outcome measure

Relative insulin response following oral ingestion of glucose.

Results

No significant differences were observed between groups in relative insulin response over the 12-week treatment period. At Week 12, fasting glucose, HbA_1c and overall diabetes control were not significantly different between groups. In addition, relevant modifications in diabetes medications were similar between groups. Total cholesterol (-0.3±0.6 mmol/L) and non-HDL cholesterol (-0.3±0.5 mmol/L) significantly decreased from baseline to Week 12 in the tesamorelin 2 mg group (p<0.05 vs. placebo). No patient discontinued the study due to loss of diabetes control.

Conclusions

Treatment of type 2 diabetic patients with tesamorelin for 12 weeks did not alter insulin response or glycemic control.

Trial registration

ClinicalTrials.gov NCT01264497.

Metabolic concerns in aging HIV-infected persons: from serum lipid phenotype to fatty liver

: Among HIV-infected persons, the assessment of nonalcoholic fatty liver disease (NAFLD) provides a window through which overall metabolic health can be evaluated. In this review, we summarize clinical data that support the roles of aging and metabolic dysregulation as factors contributing to fatty liver/NAFLD among HIV-infected persons.Age-related metabolic alterations include hepatic anatomic and functional changes, altered homeostasis of gastrointestinal microbiota and anthropometric changes (such as a shift of body fat depots from the subcutaneous to the visceral compartment) that are often associated with the development of insulin resistance and increased cardiovascular risk.Fatty changes in the liver occur not only with metabolic disruption but also with virus-induced injury. Chronic hepatitis C virus infection is commonly associated with fatty liver, and can be related to both hepatitis C virus genotype and host metabolic features. Similarly, HIV infection is associated with fatty liver as a result of multiple viral and host factors. Clearly, lipodystrophy, dysregulation of the gut-liver axis and HIV infection itself may each contribute simultaneously to NAFLD pathogenesis. Although lifestyle changes are the mainstay of treatment, to date no drug has specifically been approved for use in persons with NAFLD. Moreover, current guidelines provide no specific therapeutic recommendations for persons with NAFLD older than 65 years.Well-designed studies characterizing the epidemiology, pathogenesis, clinical outcomes and potential therapeutic interventions for liver disease and associated metabolic comorbidities in older HIV-infected patients are urgently needed.

Non-alcoholic fatty liver disease and non-alcoholic steatohepatitis in patients with HIV

Liver disease is a leading cause of morbidity and mortality among people with HIV, and in this era of safer and more effective hepatitis C therapy, non-alcoholic fatty liver disease (NAFLD) could soon emerge as the most common liver disease in this population. NAFLD is common among patients with HIV, and might be more likely to progress to non-alcoholic steatohepatitis (NASH) and NAFLD-related fibrosis or cirrhosis in these patients than in individuals without HIV. Several mechanisms of NAFLD pathogenesis are postulated to explain the disease severity in patients with HIV; these mechanisms include the influence of the gut microbiome, and also metabolic, genetic, and immunological factors. Although treatment strategies are currently based on modification of NAFLD risk factors, many new drugs are now in clinical trials, including trials specifically in patients with HIV. Thus, the identification and risk-stratification of patients with HIV and NAFLD are becoming increasingly important for accurately counselling of these patients regarding their prognosis and for establishing the most appropriate disease-altering therapy.

Current and upcoming pharmacotherapy for non-alcoholic fatty liver disease

Given the high prevalence and rising incidence of non-alcoholic fatty liver disease (NAFLD), the absence of approved therapies is striking. Although the mainstay of treatment of NAFLD is weight loss, it is hard to maintain, prompting the need for pharmacotherapy as well. A greater understanding of disease pathogenesis in recent years was followed by development of new classes of medications, as well as potential repurposing of currently available agents. NAFLD therapies target four main pathways. The dominant approach is targeting hepatic fat accumulation and the resultant metabolic stress. Medications in this group include peroxisome proliferator-activator receptor agonists (eg, pioglitazone, elafibranor, saroglitazar), medications targeting the bile acid-farnesoid X receptor axis (obeticholic acid), inhibitors of de novo lipogenesis (aramchol, NDI-010976), incretins (liraglutide) and fibroblast growth factor (FGF)-21 or FGF-19 analogues. A second approach is targeting the oxidative stress, inflammation and injury that follow the metabolic stress. Medications from this group include antioxidants (vitamin E), medications with a target in the tumour necrosis factor α pathway (emricasan, pentoxifylline) and immune modulators (amlexanox, cenicriviroc). A third group has a target in the gut, including antiobesity agents such as orlistat or gut microbiome modulators (IMM-124e, faecal microbial transplant, solithromycin). Finally, as the ongoing injury leads to fibrosis, the harbinger of liver-related morbidity and mortality, antifibrotics (simtuzumab and GR-MD-02) will be an important element of therapy. It is very likely that in the next few years several medications will be available to clinicians treating patients with NAFLD across the entire spectrum of disease.

Fatty liver is associated with an increased risk of diabetes and cardiovascular disease - Evidence from three different disease models: NAFLD, HCV and HIV

Fatty liver, which frequently coexists with necro-inflammatory and fibrotic changes, may occur in the setting of nonalcoholic fatty liver disease (NAFLD) and chronic infections due to either hepatitis C virus (HCV) or human immunodeficiency virus (HIV). These three pathologic conditions are associated with an increased prevalence and incidence of cardiovascular disease (CVD) and type 2 diabetes (T2D). In this multidisciplinary clinical review, we aim to discuss the ever-expanding wealth of clinical and epidemiological evidence supporting a key role of fatty liver in the development of T2D and CVD in patients with NAFLD and in those with HCV or HIV infections. For each of these three common diseases, the epidemiological features, pathophysiologic mechanisms and clinical implications of the presence of fatty liver in predicting the risk of incident T2D and CVD are examined in depth. Collectively, the data discussed in this updated review, which follows an innovative comparative approach, further reinforce the conclusion that the presence of fatty/inflamed/fibrotic liver might be a shared important determinant for the development of T2D and CVD in patients with NAFLD, HCV or HIV. This review may also open new avenues in the clinical and research arenas and paves the way for the planning of future, well-designed prospective and intervention studies.

Metabolic Complications and Glucose Metabolism in HIV Infection: A Review of the Evidence

HIV infection and antiretroviral therapy (ART) use are associated with perturbations in glucose and lipid metabolism. Increasing incidence of diabetes, cardiovascular disease, and obesity highlights the need for early identification and treatment of metabolic dysfunction. Newer ART regimens are less toxic for cellular function and metabolism but have failed to completely eliminate metabolic dysfunction with HIV infection. Additional factors, including viral-host interactions, diet, physical activity, non-ART medications, and aging may further contribute to metabolic disease risk in the HIV setting. We summarize the recent literature regarding the impact on metabolic function of HIV infection, ART, and pharmaceutical or lifestyle prescriptions.