Contribution of metabolic and anthropometric abnormalities to cardiovascular disease risk factors

Home-based interventions to promote physical activity for people living with HIV - a systematic review

Although physical activity (PA) improves the physical, mental, and social outcomes of people living with HIV (PLH), multiple barriers prevent them from exercising. In this systematic review, we investigated the effect of home-based interventions to promote physical activity (HBI) among PLH. Randomised trials and quasi-experimental studies published in English until March 2020 were sought in five databases. Independent reviewers performed data extraction, risk of bias assessment and pragmatic-explanatory (PRECIS-2) evaluation of study characteristics. Outcomes included engagement in PA, body composition, cardiorespiratory fitness, strength, metabolic disturbances, and quality of life (QoL). Out of 480 retrieved references, six studies met inclusion criteria. Interventions lasted 12-48 weeks and involved 400 individuals (57.8% women). Ninety-eight (24.5%) participants completed interventions, but dropout rates varied considerably (5.0-54.5%). Resulted showed increased PA (two studies) and improved cardiorespiratory fitness or strength (three and two studies, respectively). Four studies demonstrated reduction of waist circumference and increase in lean body mass. QoL improved in two of three studies. We conclude HBI (aerobic and/or resistance exercises) may contribute to improve PA and/or cardiorespiratory fitness, body composition, strength and QoL of PLH. Further investigation using multi-centre standardised protocols is warranted to provide stronger evidence of their effectiveness in health promotion for PLH.

Association of Lower Adiponectin Plasma Levels, Increased Age and Smoking with Subclinical Atherosclerosis in Patients with HIV-1 Infection

BACKGROUND

The association between subclinical atherosclerosis and traditional cardiovascular disease (CVD) risk factors, inflammatory and metabolic biomarkers has been demonstrated around the world and specifically Brazilian human immunodeficiency virus type 1 (HIV-1)- infected individuals. However, the association between subclinical atherosclerosis and these aforementioned factors combined with anti-inflammatory biomarkers has not been examined in these populations.

OBJECTIVES

To evaluate the association of the carotid intima-media thickness (cIMT) with CVD risk factors, inflammatory, metabolic and HIV-1 infection markers combined with adiponectin and interleukin (IL)-10 as anti-inflammatory variables.

METHODS

In this case-control study, 49 HIV-1-infected patients on combined antiretroviral therapy (cART) and 85 controls were compared for traditional CVD risk factors, inflammatory, metabolic, and anti-inflammatory variables. Further, we compared HIV-1-infected patients according to their cIMT (as continuous and categorized <0.9 or ≥0.9 mm variable) visualized by carotid ultrasonography doppler (USGD).

RESULTS

Twenty-four (48.9%) HIV-1-infected patients showed cIMT ≥0.9 mm. The patients had higher levels of C reactive protein on high sensitivity assay (hsCRP), tumor necrosis factor α, IL-6, IL-10, triglycerides, and insulin, and lower levels of adiponectin, total cholesterol and low-density lipoprotein cholesterol than controls (all p<0.05). Low levels of adiponectin were negatively associated with cIMT ≥0.9 mm (p=0.019), and explained 18.7% of the cIMT variance. Age (p=0.033) and current smoking (p=0.028) were positively associated with cIMT values, while adiponectin levels (p=0.008) were negatively associated with cIMT values; together, these three variables explained 27.3% of cIMT variance.

CONCLUSION

Low adiponectin was associated with higher cIMT in HIV-1-infected patients on cART. Low adiponectin levels in combination with age and smoking could explain, in part, the increased subclinical atherosclerosis observed in these patients. Adiponectin may be a good candidate for predicting subclinical atherosclerosis in the management of HIV-1-infected patients in public health care, especially where USGD is not available.

Coronary artery disease in patients with human immunodeficiency virus infection

The life expectancy of people infected with human immunodeficiency virus (HIV) is rising due to better access to combination anti-retroviral therapy (ART). Although ART has reduced acquired immune deficiency syndrome (AIDS) related mortality and morbidity, there has been an increase in non-AIDS defining illnesses such as diabetes mellitus, hypercholesterolemia and coronary artery disease (CAD). HIV is a disease marked by inflammation which has been associated with specific biological vascular processes increasing the risk of premature atherosclerosis. The combination of pre-existing risk factors, atherosclerosis, ART, opportunistic infections and coagulopathy contributes to rising CAD incidence. The prevalence of CAD has emerged as a major contributor of morbidity in these patients due to longer life expectancy. However, ART has been associated with lipodystrophy, dyslipidemia, insulin resistance, diabetes mellitus and CAD. These adverse effects, along with drug-drug interactions when ART is combined with cardiovascular drugs, result in significant challenges in the care of this group of patients. Exercise tolerance testing, echocardiography, myocardial perfusion imaging, coronary computed tomography angiography and magnetic resonance imaging help in the diagnosis of CAD and heart failure and help predict cardiovascular outcomes in a manner similar to non-infected individuals. This review will highlight the pathogenesis and factors that link HIV to CAD, presentation and treatment of HIV-patients presenting with CAD and review briefly the cardiac imaging modalities used to identify this entity and help prognosticate future outcomes.

Dyslipidemia and Associated Factors Among Adult Patients on Antiretroviral Therapy in Armed Force Comprehensive and Specialized Hospital, Addis Ababa, Ethiopia

BACKGROUND

The development of antiretroviral drugs and subsequent access to combined antiretroviral therapy contributed to the decline in morbidity and mortality rates associated with acquired immune deficiency syndrome, resulting in an increased life expectancy and improved quality of life for people living with human immunodeficiency virus. However, a cluster of metabolic derangements such as dyslipidemia is increasing, especially for those on antiretroviral therapy. Limited studies were done on the prevalence of dyslipidemia and its associated factors among adult patients on antiretroviral therapy in Ethiopia which demand the conduct of the present investigation entitled on the prevalence of dyslipidemia and its associated factors among adult patients on antiretroviral therapy in Armed Force Comprehensive and Specialized Hospital Addis Ababa, Ethiopia, 2018.

METHODS

Institution-based cross-sectional study design was employed between March and April 2018. Systematic sampling method was used to select 353 study participants. Pretested stepwise approach of the World Health Organization questionnaire (WHO Stepwise), document review, anthropometric measurements, and laboratory analysis were used to collect data on different variables under the study. Collected data were entered in Epidata version 3 and analyzed by SPSS version 21.

RESULTS

The prevalence of dyslipidemia among study participants was 74.8%. Female participants were twice and half at risk of developing dyslipidemia compared to males (AOR= 2.38; 95% CI: 1.15, 3.66). Similarly, compared to those attended college level of education, not attended formal education (AOR=0.19; 95% CI: 0.05, 0.66), and having primary/secondary educational level (AOR= 0.33; 95% CI: 0.16, 0.66) showed lower odds to develop dyslipidemia. Furthermore, WHO clinical stage II (AOR= 0.35; 95% CI: 0.14,0.92), stage III (AOR=0.25; 95% CI:0.10,0.64), duration on ART (AOR= 1.01; 95% CI: 1.001,1.02), and BMI (AOR =1.13; 95% CI: 1.06,1.23) were significantly associated with dyslipidemia.

CONCLUSION

There exists a high prevalence of dyslipidemia among study participants. Sex, educational status, WHO clinical stage, duration on ART, and BMI were significantly associated factors for dyslipidemia. Intervention strategies including the identified factors are demanded in the setting.

Metabolic and Cardiac Adaptation to Chronic Pharmacologic Blockade of Facilitative Glucose Transport in Murine Dilated Cardiomyopathy and Myocardial Ischemia

GLUT transgenic and knockout mice have provided valuable insight into the role of facilitative glucose transporters (GLUTs) in cardiovascular and metabolic disease, but compensatory physiological changes can hinder interpretation of these models. To determine whether adaptations occur in response to GLUT inhibition in the failing adult heart, we chronically treated TG9 mice, a transgenic model of dilated cardiomyopathy and heart failure, with the GLUT inhibitor ritonavir. Glucose tolerance was significantly improved with chronic treatment and correlated with decreased adipose tissue retinol binding protein 4 (RBP4) and resistin. A modest improvement in lifespan was associated with decreased cardiomyocyte brain natriuretic peptide (BNP) expression, a marker of heart failure severity. GLUT1 and -12 protein expression was significantly increased in left ventricular (LV) myocardium in ritonavir-treated animals. Supporting a switch from fatty acid to glucose utilization in these tissues, fatty acid transporter CD36 and fatty acid transcriptional regulator peroxisome proliferator-activated receptor α (PPARα) mRNA were also decreased in LV and soleus muscle. Chronic ritonavir also increased cardiac output and dV/dt-d in C57Bl/6 mice following ischemia-reperfusion injury. Taken together, these data demonstrate compensatory metabolic adaptation in response to chronic GLUT blockade as a means to evade deleterious changes in the failing heart.

CHA2DS2-VASc Score, Warfarin Use, and Risk for Thromboembolic Events Among HIV-Infected Persons With Atrial Fibrillation

BACKGROUND

The prevalence of atrial fibrillation in the HIV-infected population is growing, but the ability of the CHA2DS2-VASc score to predict thromboembolic (TE) risk is unknown in this population.

SETTING

Within the Veterans Affairs HIV Clinical Case Registry, 914 patients had an atrial fibrillation diagnosis between 1997 and 2011 and no previous TE events.

METHODS

We compared TE incidence by CHA2DS2-VASc scores and stratified by warfarin use. Using Cox proportional hazards regression with adjustment for competing risks, we modeled associations of CHA2DS2-VASc scores and warfarin use with TE risk.

RESULTS

At baseline, the distribution of CHA2DS2-VASc scores was 0 (n = 208), 1 (n = 285), and 2+ (n = 421); 34 patients developed 38 TE events during a median of 3.8 years follow-up. Event rates by CHA2DS2-VASc scores of 0, 1, and 2+ were 5.4, 9.3, and 8.1 per 1000 person years, respectively; multivariate-adjusted hazards ratios (HRs) were 1.70 (95% confidence interval: 0.65 to 4.45) for CHA2DS2-VASc score 1 (P = 0.28) and HR = 1.34 (0.51, 3.48) for score 2+ versus 0 (P = 0.55). Baseline warfarin use was associated with increased TE risk, although not statistically significant [HR 2.06 (0.86, 4.93), P = 0.11] with similar results when modeled as time-updated use and duration of use.

CONCLUSION

In this national registry of HIV-infected veterans with atrial fibrillation, CHA2DS2-VASc scores were only weakly associated with TE risk. Furthermore, warfarin did not seem to be effective at preventing TE events. These results should raise concerns about the optimal strategy for TE prevention among HIV-infected persons with atrial fibrillation.

Shortcuts to a functional adipose tissue: The role of small non-coding RNAs

Metabolic diseases such as type 2 diabetes are a major public health issue worldwide. These diseases are often linked to a dysfunctional adipose tissue. Fat is a large, heterogenic, pleiotropic and rather complex tissue. It is found in virtually all cavities of the human body, shows unique plasticity among tissues, and harbors many cell types in addition to its main functional unit - the adipocyte. Adipose tissue function varies depending on the localization of the fat depot, the cell composition of the tissue and the energy status of the organism. While the white adipose tissue (WAT) serves as the main site for triglyceride storage and acts as an important endocrine organ, the brown adipose tissue (BAT) is responsible for thermogenesis. Beige adipocytes can also appear in WAT depots to sustain heat production upon certain conditions, and it is becoming clear that adipose tissue depots can switch phenotypes depending on cell autonomous and non-autonomous stimuli. To maintain such degree of plasticity and respond adequately to changes in the energy balance, three basic processes need to be properly functioning in the adipose tissue: i) adipogenesis and adipocyte turnover, ii) metabolism, and iii) signaling. Here we review the fundamental role of small non-coding RNAs (sncRNAs) in these processes, with focus on microRNAs, and demonstrate their importance in adipose tissue function and whole body metabolic control in mammals.

Ischemic Heart Disease in HIV: An In-depth Look at Cardiovascular Risk

Although the incidence of cardiovascular diseases classically associated with human immunodeficiency virus (HIV) has decreased considerably with antiretroviral therapy, cardiovascular risk, and especially ischemic heart disease, are higher in HIV-infected patients than in uninfected individuals. This is due to the interaction of patient-dependent factors with virus-dependent factors, as well as factors associated with antiretroviral therapy. With increasing of life expectancy and the chronicity of HIV infection, cardiovascular disease has emerged as an important cause of morbidity and mortality in HIV patients. In developed countries, the most common cardiovascular manifestation of HIV is ischemic heart disease. Currently, it is not uncommon to find HIV patients with acute coronary syndrome and, given the important pharmacokinetic interactions of antiretroviral drugs, it is important to know which cardiovascular treatments are safe in this group of patients. The ideal approach would be to mitigate the cardiovascular risk in HIV patients with specific primary prevention measures. All these issues are discussed in this review, which aims to aid clinical cardiologists faced with HIV patients with ischemic heart disease or with high cardiovascular risk in daily clinical practice.

Diabetes in HIV-infected persons in Cameroon?

In the past, the increased prevalence of diabetes in HIV infection has been attributed to antiretroviral drugs. In this study, Cameroonians with HIV infection were shown in a paper in this issue of the Journal to be more likely to have diabetes if they were not on therapy. Future research should examine if the diabetes is related to the host response to infection or to socioeconomic factors that might both contribute to not being on anti-retroviral therapy and predispose to diabetes. Copyright © 2016 John Wiley & Sons, Ltd.

Baseline cardiovascular risk in the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial

OBJECTIVES

The Strategic Timing of AntiRetroviral Treatment (START) trial has recruited antiretroviral-naïve individuals with high CD4 cell counts from all regions of the world. We describe the distribution of cardiovascular disease (CVD) risk factors, overall and by geographical region, at study baseline.

METHODS

The distribution of CVD risk factors was assessed and compared by geographical region among START participants who had a baseline electrocardiogram (n = 4019; North America, 11%; Europe/Australia/Israel, 36%; South America, 26%; Asia, 4%; Africa, 23%; median age 36 years; 26% female).

RESULTS

About 58.3% (n = 2344) of the participants had at least one CVD risk factor and 18.9% (n = 761) had two or more. The most common CVD risk factors were current smoking (32%), hypertension (19.3%) and obesity (16.5%). There were significant differences in the prevalence of CVD risk factors among geographical regions. The prevalence of at least one risk factor across regions was as follows: North America, 70.0%; Europe/Australia/Israel, 65.1%; South America, 49.4%; Asia, 37.0%; Africa, 55.8% (P-value < 0.001). Significant regional differences were also observed when risk factors were used as part of the Framingham and Data Collection on Adverse events of Anti-HIV Drugs (D:A:D) risk scores or used to define a favourable risk profile.

CONCLUSIONS

CVD risk factors are common among START participants, and their distribution varies by geographical region. Better understanding of how and why CVD risk factors develop in people with HIV infection and their geographical distributions could shed light on appropriate strategies for CVD prevention and may inform the interpretation of the results of START, as CVD is expected to be a major fraction of the primary endpoints observed.

The Glucose Transporter PfHT1 Is an Antimalarial Target of the HIV Protease Inhibitor Lopinavir

Malaria and HIV infection are coendemic in a large portion of the world and remain a major cause of morbidity and mortality. Growing resistance of Plasmodium species to existing therapies has increased the need for new therapeutic approaches. The Plasmodium glucose transporter PfHT is known to be essential for parasite growth and survival. We have previously shown that HIV protease inhibitors (PIs) act as antagonists of mammalian glucose transporters. While the PI lopinavir is known to have antimalarial activity, the mechanism of action is unknown. We report here that lopinavir blocks glucose uptake into isolated malaria parasites at therapeutically relevant drug levels. Malaria parasites depend on a constant supply of glucose as their primary source of energy, and decreasing the available concentration of glucose leads to parasite death. We identified the malarial glucose transporter PfHT as a target for inhibition by lopinavir that leads to parasite death. This discovery provides a mechanistic basis for the antimalarial effect of lopinavir and provides a direct target for novel drug design with utility beyond the HIV-infected population.

Exploration of the Effect of Tobacco Smoking on Metabolic Measures in Young People Living with HIV

We conducted cross-sectional, multicenter studies in HIV-positive young women and men to assess metabolic and morphologic complications from tobacco smoking in 372 behaviorally infected HIV-positive youth, aged 14–25 years. Measurements included self-reported tobacco use, fasting lipids, glucose, fat distribution, and bone mineral density (BMD; dual-energy X-ray absorptiometry scans). Overall, 144 (38.7%) self-reported smoking tobacco and 69 (47.9%) of these reported smoking greater than five cigarettes per day. Smokers versus nonsmokers had lower mean total cholesterol (146.0 versus 156.1 mg/dL; P < 0.01) and lower mean total body fat percent (24.1% versus 27.2%, P = 0.03). There was no difference between smokers and nonsmokers in fasting glucose or BMD. There appear to be only minimal effects from tobacco smoking on markers of cardiac risk and bone health in this population of HIV-positive youth. While these smokers may not have had sufficient exposure to tobacco to detect changes in the outcome measures, given the long-term risks associated with smoking and HIV, it is critical that we encourage HIV-positive youth smokers to quit before the deleterious effects become apparent.

Urinary eicosanoid metabolites in HIV-infected women with central obesity switching to raltegravir: an analysis from the women, integrase, and fat accumulation trial

Chronic inflammation is a hallmark of HIV infection. Eicosanoids reflect inflammation, oxidant stress, and vascular health and vary by sex and metabolic parameters. Raltegravir (RAL) is an HIV-1 integrase inhibitor that may have limited metabolic effects. We assessed urinary F₂-isoprostanes (F₂-IsoPs), prostaglandin E₂ (PGE-M), prostacyclin (PGI-M), and thromboxane B₂ (TxB₂) in HIV-infected women switching to RAL-containing antiretroviral therapy (ART). Thirty-seven women (RAL = 17; PI/NNRTI = 20) with a median age of 43 years and BMI 32 kg/m² completed week 24. TxB₂ increased in the RAL versus PI/NNRTI arm (+0.09 versus −0.02; P = 0.06). Baseline PGI-M was lower in the RAL arm (P = 0.005); no other between-arm cross-sectional differences were observed. In the PI/NNRTI arm, 24-week visceral adipose tissue change correlated with PGI-M (rho = 0.45; P = 0.04) and TxB₂ (rho = 0.44; P = 0.005) changes, with a trend seen for PGE-M (rho = 0.41; P = 0.07). In an adjusted model, age ≥ 50 years (N = 8) was associated with increased PGE-M (P = 0.04). In this randomized trial, a switch to RAL did not significantly affect urinary eicosanoids over 24 weeks. In women continuing PI/NNRTI, increased visceral adipose tissue correlated with increased PGI-M and PGE-M. Older age (≥50) was associated with increased PGE-M. Relationships between aging, adiposity, ART, and eicosanoids during HIV-infection require further study.

Cardiovascular disease risk factors in HIV-infected women after initiation of lopinavir/ritonavir- and nevirapine-based antiretroviral therapy in Sub-Saharan Africa: A5208 (OCTANE)

BACKGROUND

Limited comparative, prospective data exist regarding cardiovascular risk factors in HIV-infected women starting antiretroviral therapy in Africa.

METHODS

In 7 African countries, 741 women with CD4 <200 cells/mm were randomized to tenofovir/emtricitabine (TDF/FTC) plus either nevirapine (NVP, n = 370) or lopinavir/ritonavir (LPV/r, n = 371). Lipids and blood pressure (BP) were evaluated at entry, 48, 96, and 144 weeks. Multivariable linear and logistic regression models were used to evaluate mean risk factor changes and clinically relevant risk factor changes.

RESULTS

At entry, both NVP and LPV/r groups were similar regarding age [mean = 33.5 (SD = 7.1) years], CD4 [129 (67) cells/mm], and HIV-1 RNA [5.1 (0.6) log10 copies/mL]. Nearly, all women had normal lipids and BP except for high-density lipoprotein (HDL)-cholesterol. Over 144 weeks, the LPV/r compared with NVP group had significantly greater mean lipid increases (eg, non-HDL: +29 vs. +13 mg/dL) and smaller HDL increases (+12 vs. +21 mg/dL). In contrast, the NVP compared with LPV/r group had greater mean increases in BP (eg, diastolic BP: +5 vs. -0.5 mm Hg). Significantly, more women assigned LPV/r had week 144 "abnormal" lipid levels (eg, HDL 29.7% vs. 14.8% and triglycerides 28.6% vs. 8.2%), and significantly, more women assigned NVP had "abnormal" BP (eg, diastolic BP 22.7% vs. 6.5%). Most differences remained significant when adjusted for baseline risk factor, age, CD4, and HIV-1 RNA.

CONCLUSIONS

In HIV-infected women initiating antiretroviral therapy in Africa, LPV/r + TDF/FTC was associated with less favorable changes in lipids, and use of NVP + TDF/FTC was associated with less favorable changes in BP.

Lipodystrophy Is Common Among Ethiopian Patients on Highly Active Antiretroviral Therapy but Is Not Associated With Quality of Life or Medication Adherence

Clinical experience suggests that lipodystrophy (LD) can have a profound impact on quality of life (QOL) and medication adherence (MA). Thus, a hospital-based, cross-sectional study was conducted to determine the prevalence of LD and its association with QOL and MA. A total of 405 participants were included in the study. The majority of participants were female (64.5%), with a mean age of 35.69 years (SD = 9.63 years). The prevalence of LD was 30.9%. Multiple logistic regression analysis showed that type of regimen initially used is an independent predictor of severity of LD (adjusted odds ratio, 44.16; 95% confidence interval, 10.56-184.59; P = .001). Quality of life was assessed with the World Health Organization Quality of Life short form instrument (WHOQOL-BREF), and medication adherence was assessed by self-report. The mean WHOQOL-BREF score of the participants was 53.48; the highest mean value was in the domain of physical health (68.56) and the lowest was in the social relationships domain (47.09). The majority of the patients scored lower (ie, in the lowest 5 deciles) in the domains of psychological health, social relationships, and environment compared with physical health. No differences in the WHOQOL-BREF measurements were observed, except in the environment domain, between patients with moderate LD and severe LD ( P = .02). The LD severity was not associated with self-reported MA ( P = .42). With the exception of the psychological health domain ( P = .044), participants' WHOQOL-BREF scores were not significantly associated with MA. Lipodystrophy was not associated with QOL or MA. The prevalence of LD in the present study was within the range of previous reports; however, the mean WHOQOL-BREF score of Ethiopian patients in this study is lower compared with reports from developed countries.

HIV, inflammation, and calcium in atherosclerosis

Atherosclerosis is consistently higher among the HIV-positive patients, with or without treatment, than among the HIV-negative population. Risk factors linked to atherosclerotic cardiovascular disease in HIV infection are both traditional and HIV specific although the underlying mechanisms are not fully delineated. Three key sequential biological processes are postulated to accelerate progression of atherosclerosis in the context of HIV: (1) inflammation, (2) transformation of monocytes to macrophages and then foam cells, and (3) apoptosis of foam cells leading to plaque development through Ca(2+)-dependent endoplasmic reticulum stress. These proatherogenic mechanisms are further affected when HIV interacts with the genes involved in various phases within this network.

Switching to darunavir/ritonavir monotherapy vs. triple-therapy on body fat redistribution and bone mass in HIV-infected adults: the Monarch randomized controlled trial

Changes in body fat distribution and bone mass in HIV-infected patients may be associated with long-term use of nucleoside reverse transcriptase inhibitors (NRTIs). The Monarch trial recruited 30 patients receiving non-nucleoside reverse transcriptase inhibitor or protease inhibitor-based highly active antiretroviral therapy, with HIV RNA <40 copies/mL. Patients were randomized to either darunavir/ritonavir 800/100 mg once daily monotherapy or darunavir/ritonavir 800/100 mg once daily + two NRTIs. Bone mass, peripheral lipoatrophy and central fat accumulation were assessed using dual-energy X-ray absorptiometry scanning, supplemented by computed tomography scans. Median age was 43 years, 77% were men. Visceral adipose tissue remained stable from baseline to Week 48 in the whole group (p = 0.261) with no significant difference between arms (p = 0.56). There was a significant reduction in insulin resistance (HOMA-IR, p = 0.013) over 48 weeks in the whole group, but not of body mass index (p = 0.24). In the darunavir/ritonavir monotherapy arm, there was a small but significant increase in both lumbar and femur bone mineral density at 48 weeks and was observed after correction for baseline values. The absolute change in lumbar bone mineral density at 48 weeks was more pronounced in the darunavir/ritonavir arm compared with the darunavir/ritonavir + 2NRTIs arm. In this study, discontinuing nucleoside analogues and switching to darunavir/ritonavir monotherapy was associated with a small but statistically significant increase in bone mineral density, but stable levels of limb fat and visceral adipose tissue.

Markers of microbial translocation predict hypertension in HIV-infected individuals

OBJECTIVES

The aim of the study was to test the hypothesis that microbial translocation, quantified by levels of lipopolysaccharide (LPS) and subsequent monocyte activation [soluble (sCD14)], is associated with hypertension in HIV-infected individuals.

METHODS

In this exploratory substudy, 42 patients were recruited from a larger, longitudinal HIV-infected cohort study on blood pressure. LPS and sCD14 levels were measured retrospectively at the time of nadir CD4 cell count, selecting untreated HIV-infected patients with both advanced immunodeficiency and preserved immunocompetence at the time of nadir. Patients with later sustained hypertension (n = 16) or normotension (n = 26) throughout the study were identified. LPS was analysed using the Limulus Amebocyte Lysate colorimetric assay (Lonza, Walkersville, MD) and sCD14 using an enzyme-linked immunosorbent assay (ELISA). Nonparametric statistical tests were applied.

RESULTS

In the HIV-infected patients [median (interquartile range) age 42 (32-46) years; 79% male and 81% Caucasian], LPS and sCD14 levels were both negatively correlated with nadir CD4 cell count. Plasma levels of LPS (P < 0.001) and sCD14 (P = 0.024) were elevated in patients with later hypertension compared with patients with normotension. There was a stepwise increase in the number of patients with hypertension across tertiles of LPS (P = 0.001) and sCD14 (P = 0.007). Both LPS and sCD14 were independent predictors of elevated blood pressure after adjustment for age and gender. For each 10-unit increase in LPS (range 66-272 pg/ml), the increment in mean blood pressure in the first period of blood pressure recording was 0.86 (95% confidence interval 0.31-1.41) mmHg (P = 0.003).

CONCLUSIONS

As LPS and sCD14 were both independently associated with elevated blood pressure, microbial translocation may be linked to the development of hypertension.

The role of insulin resistance in HIV/hepatitis C virus-coinfected patients

PURPOSE OF REVIEW

Insulin resistance, HIV, antiviral drugs and hepatitis C virus (HCV) infection contribute to a complex interaction involving the metabolic syndrome. The objective of this review was to explore the meaning of insulin resistance in HIV-HCV-coinfected patients and how it may impact on sustained virological response (SVR) and disease progression.

RECENT FINDINGS

In the HIV/HCV coinfection setting, insulin resistance seems to be associated with a reduction in rapid virological response and SVR to pegylated interferon and ribavirin, both in naive and treatment experienced patients. A recent meta-analysis demonstrated insulin resistance impairs SVR rate with an odds ratio 0.47 (95% confidence interval 0.31-0.71). However, many confounding factors may promote contradictory results. Prevalence of insulin resistance depends on surrogate markers of insulin resistance and the threshold for defining impaired insulin sensitivity. For example, homeostasis model for the assessment of insulin resistance may be influenced by both methods of insulin measurement and interpretation. Insulin sensitizers, lifestyle changes and improvement in the use of protease inhibitors should be evaluated in the management of coinfected patients.

SUMMARY

Insulin resistance is common finding in patients with HIV/HCV coinfection, with wide clinical consequences including progression of hepatic fibrosis and reduction in the response to antiviral treatment. Our understanding of this relationship continues to improve. More prospective studies are required to improve future management.

Left ventricular remodelling in asymptomatic HIV infection on chronic HAART: comparison between hypertensive and normotensive subjects with and without HIV infection

The high cardiovascular risk of HIV infected (HIV+) patients is still partly unexplained. We aimed to evaluate if HIV infection and highly active antiretroviral therapy (HAART) are linked per se to left ventricular (LV) remodelling, independently of blood pressure (BP) values. We enrolled 4 groups of patients matched by gender, age, body mass index and smoking habit: 30 HIV+ hypertensives, 30 HIV+ normotensives, 30 not-infected (HIV-) hypertensives and 30 HIV- normotensives. HIV+ patients were on chronic HAART. Hypertension was newly diagnosed (≤6 months) and never treated. Each patient underwent blood tests, 24-h BP monitoring and LV echocardiogram. The 4 groups had similar fasting glucose and cholesterol; triglycerides, HOMA index and prevalence of metabolic syndrome were higher in the HIV+ groups. Despite similar 24-h BP values, HIV+ hypertensives had greater LV mass and higher prevalence of preclinical diastolic dysfunction than HIV- hypertensives. Compared to HIV- normotensives, HIV+ normotensives had similar 24-h BP values, but greater LV mass and lower LV diastolic indices, similar to HIV- hypertensives, whose 24-h BP values were higher. Asymptomatic HIV infection and chronic HAART are associated with myocardial hypertrophy and preclinical diastolic dysfunction, independently of BP values.

Intermuscular adipose tissue and metabolic associations in HIV infection

Intermuscular adipose tissue (IMAT) is associated with metabolic abnormalities similar to those associated with visceral adipose tissue (VAT). Increased IMAT has been found in obese human immunodeficiency virus (HIV)-infected women. We hypothesized that IMAT, like VAT, would be similar or increased in HIV-infected persons compared with healthy controls, despite decreases in subcutaneous adipose tissue (SAT) found in HIV infection. In the second FRAM (Study of Fat Redistribution and Metabolic Change in HIV infection) exam, we studied 425 HIV-infected subjects and 211 controls (from the Coronary Artery Risk Development in Young Adults study) who had regional AT and skeletal muscle (SM) measured by magnetic resonance imaging (MRI). Multivariable linear regression identified factors associated with IMAT and its association with metabolites. Total IMAT was 51% lower in HIV-infected participants compared with controls (P = 0.003). The HIV effect was attenuated after multivariable adjustment (to -28%, P < 0.0001 in men and -3.6%, P = 0.70 in women). Higher quantities of leg SAT, upper-trunk SAT, and VAT were associated with higher IMAT in HIV-infected participants, with weaker associations in controls. Stavudine use was associated with lower IMAT and SAT, but showed little relationship with VAT. In multivariable analyses, regional IMAT was associated with insulin resistance and triglycerides (TGs). Contrary to expectation, IMAT is not increased in HIV infection; after controlling for demographics, lifestyle, VAT, SAT, and SM, HIV(+) men have lower IMAT compared with controls, whereas values for women are similar. Stavudine exposure is associated with both decreased IMAT and SAT, suggesting that IMAT shares cellular origins with SAT.

Effects of the HIV protease inhibitor ritonavir on GLUT4 knock-out mice

HIV protease inhibitors acutely block glucose transporters (GLUTs) in vitro, and this may contribute to altered glucose homeostasis in vivo. However, several GLUT-independent mechanisms have been postulated. To determine the contribution of GLUT blockade to protease inhibitor-mediated glucose dysregulation, the effects of ritonavir were investigated in mice lacking the insulin-sensitive glucose transporter GLUT4 (G4KO). G4KO and control C57BL/6J mice were administered ritonavir or vehicle at the start of an intraperitoneal glucose tolerance test and during hyperinsulinemic-euglycemic clamps. G4KO mice exhibited elevated fasting blood glucose compared with C57BL/6J mice. Ritonavir impaired glucose tolerance in control mice but did not exacerbate glucose intolerance in G4KO mice. Similarly, ritonavir reduced peripheral insulin sensitivity in control mice but not in G4KO mice. Serum insulin levels were reduced in vivo in ritonavir-treated mice. Ritonavir reduced serum leptin levels in C57BL/6J mice but had no effect on serum adiponectin. No change in these adipokines was observed following ritonavir treatment of G4KO mice. These data confirm that a primary effect of ritonavir on peripheral glucose disposal is mediated through direct inhibition of GLUT4 activity in vivo. The ability of GLUT4 blockade to contribute to derangements in the other molecular pathways that influence insulin sensitivity remains to be determined.

HIV Infection, Antiretroviral Therapy and Cardiovascular Risk

In the last 15 years, highly active antiretroviral therapy (HAART) has determined a dramatic reduction of both morbidity and mortality in human immunodeficiency virus (HIV)-infected subjects, transforming this infection in a chronic and manageable disease. Patients surviving with HIV in the developed world, in larger number men, are becoming aged. As it would be expected for a population of comparable age, many HIV-infected individuals report a family history of cardiovascular disease, a small proportion have already experienced a cardiovascular event and an increasing proportion has diabetes mellitus. Smoking rate is very high while an increasing proportion of HIV-infected individuals have dyslipidaemia. Studies suggest that these traditional risk factors could play an important role in the development of cardiovascular disease in these patients as they do in the general population. Thus, whilst the predicted 10-year cardiovascular disease risk remains relatively low at present, it will likely increase in relation to the progressive aging of this patient population. Thus, the long-term follow-up of HIV infected patients has to include co-morbidity management such as cardiovascular disease prevention and treatment. Two intriguing aspects related to the cardiovascular risk in patients with HIV infection are the matter of current investigation: 1) while these subjects share many cardiovascular risk factors with the general population, HIV infection itself increases cardiovascular risk; 2) some HAART regimens too influence atherosclerotic profile, partly due to lipid changes. Although the mechanisms involved in the development of cardiovascular complications in HIV-infected patients remain to be fully elucidated, treatment guidelines recommending interventions to prevent cardiovascular disease in these individuals are already available; however, their application is still limited.

Premature onset of cardiovascular disease in HIV-infected individuals: the drugs and the virus

Life expectancy in HIV-infected individuals has been greatly enhanced through immunologic restoration and virologic suppression resulting from antiretroviral therapy. Current clinical HIV care in Western countries focuses on treatment of drug toxicities and prevention of comorbidities. These non-AIDS HIV-related comorbidities, such as cardiovascular disease, occur even in individuals with virologic suppression and manifest at an earlier age than when normally presenting in the general population. While traditional risk factors are present in many HIV-infected individuals who develop cardiovascular disease, the additional roles of HIV-related chronic inflammation and immune activation as well as chronic HIV viremia may be significant. This review provides current evidence for the contributions of the virus, in terms of both chronic viremia and its contribution via chronic low-level inflammation, immune activation, premature immune senescence and dyslipidemia, to the pathogenesis of HIV-related cardiovascular disease, and balances this against the propensity of specific antiretroviral therapies to cause cardiovascular disease, in particular through altered cholesterol metabolism.

Short communication: contribution of the immunovirological state and traditional cardiovascular risk factors to low HDL-cholesterol in HIV patients

The prevalence of low HDL-C levels in an HIV population and its related factors was investigated. We undertook a multicenter, cross-sectional study of all HIV patients on regular follow-up in five hospitals (Southern Spain). A physical examination and fasting laboratory analysis were performed and a questionnaire about cardiovascular risk factors was provided. One thousand and seventy-two patients were included, 43.8% of whom had low HDL-C levels. The prevalence of low HDL-C was higher among patients diagnosed with AIDS, those not on antiretroviral therapy, those with a detectable HIV viral load, those with CD4 cell counts ≤350 cells/μl, smokers, and those with hypertriglyceridemia. For patients on antiretroviral therapy, the prevalence of low HDL-C was higher for those on protease inhibitors than those taking nonnucleoside reverse transcriptase inhibitors. In the multivariate analysis, low HDL-C levels were associated with tobacco use (OR 1.37, 95% CI 1.04-1.8; p = 0.04), hypertriglyceridemia (OR 2.94, 95% CI 2.2-3.8; p < 0.00001), CD4 cells count ≤350 cells/μl (OR 1.74, 95% CI 1.2-2.3; p < 0.0001), and a detectable HIV viral load (OR 1.85, 95% CI 1.3-2.5; p < 0.0001). The immunological and virological conditions, in addition to traditional cardiovascular risk factors such as tobacco use and hypertriglyceridemia, affect HDL-C levels in HIV-infected patients. For patients on antiretroviral therapy, the use of protease inhibitors is associated with a higher probability of low levels of HDL-C. Although it is not clear if the higher HDL-C levels associated with antiretroviral use are surrogates for decreased cardiovascular disease risk, this may be another reason to start antiretroviral therapy earlier.

HIV protease inhibitors and obesity

PURPOSE OF REVIEW

To review the current scientific literature and recent clinical trials on HIV protease inhibitors and their potential role in the pathogenesis of lipodystrophy and metabolic disorders.

RECENT FINDINGS

HIV protease inhibitor treatment may affect the normal stimulatory effect of insulin on glucose and fat storage. Further, chronic inflammation from HIV infection and protease inhibitor treatment trigger cellular homeostatic stress responses with adverse effects on intermediary metabolism. The physiologic outcome is such that total adipocyte storage capacity is decreased, and the remaining adipocytes resist further fat storage. This process leads to a pathologic cycle of lipodystrophy and lipotoxicity, a proatherogenic lipid profile, and a clinical phenotype of increased central body fat distribution similar to the metabolic syndrome.

SUMMARY

Protease inhibitors are a key component of antiretroviral therapy and have dramatically improved the life expectancy of HIV-infected individuals. However, they are also associated with abnormalities in glucose/lipid metabolism and body fat distribution. Further studies are needed to better define the pathogenesis of protease inhibitor-associated metabolic and body fat changes and their potential treatment.

Associations of antiretroviral drug use and HIV-specific risk factors with carotid intima-media thickness

BACKGROUND

Previous research has demonstrated an increase in carotid intima-media thickness (cIMT) in HIV-infected individuals compared to controls. However, the reason for this increased level of subclinical vascular disease is unknown.

OBJECTIVE

To identify HIV-related risk factors for increased cIMT.

METHODS

We evaluated the relationship between HIV-related characteristics (including markers of HIV disease severity and use of antiretroviral therapy) and cIMT measurements in the internal/bulb and common carotid regions among 538 HIV-infected participants from the Study of Fat Redistribution and Metabolic Change in HIV Infection (FRAM). We used Bayesian model averaging to estimate the posterior probability of candidate HIV and non-HIV-related risk factors being true predictors of increased cIMT. Variables with a posterior probability of more than 50% were used to develop a selected regression model for each of the anatomic regions.

RESULTS

For common cIMT, the Bayesian model selection process identified age, African-American race, and systolic and diastolic blood pressure with probability more than 95%, HDL cholesterol with probability 85% and Hispanic ethnicity with probability 51%. Among the HIV-related factors included in the analysis, only tenofovir use was selected (51% probability). In the selected model, duration of tenofovir use was associated with lower common cIMT (-0.0094 mm/year of use; 95% confidence interval: -0.0177 to -0.0010). For internal cIMT, no HIV-related risk factors were above the 50% posterior probability threshold.

CONCLUSION

We observed an inverse association between duration of tenofovir use and common carotid cIMT. Whether this association is causal or due to confounding by indication needs further investigation.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Obesity and dyslipidemia in behaviorally HIV-infected young women: Adolescent Trials Network study 021

BACKGROUND

The goal of this study was to determine the nature and prevalence of abnormalities in lipids, glucose metabolism, and body composition in behaviorally human immunodeficiency virus (HIV)-infected young women and the relationship of these abnormalities to different classes of antiretroviral therapy regimens.

METHODS

We conducted a cross-sectional, multicenter study involving 173 behaviorally HIV-infected women aged 14-24 years and 61 HIV-seronegative control subjects. HIV-infected women were categorized as follows: antiretroviral therapy naive (n=85), receiving a regimen containing a nonnucleoside reverse-transcriptase inhibitor (NNRTI; n=33), receiving a regimen containing a protease inhibitor (PI; n=36), or receiving a regimen not containing an NNRTI or a PI (n=19). Measurements included fasting lipid levels, glucose and insulin levels before and 2 hours after an oral glucose challenge, high-sensitivity C-reactive protein (hsCRP) levels, anthropometry, fat distribution (measured by dual energy X-ray absorptiometry), and antiretroviral therapy and medical histories. Race-adjusted results were compared across groups and within HIV-infected groups.

RESULTS

The median age of participants was 20 years. Of HIV-infected subjects, 77% were African American, 35% smoked cigarettes, and 32% reported exercising regularly. More than 40% had a body mass index > or =25. Triglycerides; total, high-density lipoprotein (HDL), and non-HDL cholesterol; and hsCRP levels differed significantly among groups, with higher levels being most common among those receiving antiretroviral therapy. Indices of glucose metabolism did not differ among groups. In general, cholesterol levels, hsCRP levels, and indices of glucose metabolism worsened as body mass index increased.

CONCLUSIONS

Obesity, dyslipidemia, and inflammation were prominent among HIV-infected adolescent women and, coupled with other risk factors, may accelerate the lifetime risk of cardiovascular disease and other adverse events. These results underscore the need for a multifaceted approach to addressing risk reduction in this population.

A genome-wide association study of carotid atherosclerosis in HIV-infected men

BACKGROUND

The role of host genetics in the development of subclinical atherosclerosis in the context of HIV-infected persons who are being treated with highly active antiretroviral therapy (HAART) is not well understood.

METHODS

The present genome-wide association study (GWAS) is based on 177 HIV-positive Caucasian males receiving HAART who participated in the Fat Redistribution and Metabolic Change in HIV Infection (FRAM) Study. Common and internal carotid intima-media thicknesses (cIMT) measured by B-mode ultrasound were used as a subclinical measure of atherosclerosis. Single nucleotide polymorphisms (SNPs) were assayed using the Illumina HumanCNV370-quad beadchip. Copy Number Variants (CNV) were inferred using a hidden Markov Model (PennCNV). Regression analyses were used to assess the association of common and internal cIMT with individual SNPs and CNVs, adjusting for age, duration of antiretroviral treatment, and principal components to account for potential population stratification.

RESULTS

Two SNPs in tight linkage disequilibrium, rs2229116 (a missense, nonsynonymous polymorphism (IIe to Val)) and rs7177922, located in the ryanodine receptor (RYR3) gene on chromosome 15 were significantly associated with common cIMT (P-value < 1.61 x 10). The RYR gene family has been known to play a role in the etiology of cardiovascular disease and has been shown to be regulated by HIV TAT protein.

CONCLUSION

These results suggest that in the context of HIV infection and HAART, a functional SNP in a biologically plausible candidate gene, RYR3, is associated with increased common carotid IMT, which is a surrogate for atherosclerosis.

Lipoprotein particle subclasses, cardiovascular disease and HIV infection

OBJECTIVE

To study the association of lipoprotein particles with CVD in a subgroup of HIV-infected patients who were enrolled in the Strategies for Management of Anti-Retroviral Therapy (SMART) study. SMART was a trial of intermittent use of ART (drug conservation [DC]) versus continuous of ART (viral suppression [VS]).

METHODS

In a nested case-control study, lipoprotein particles (p) by nuclear magnetic resonance were measured at baseline and at the visit prior to the CVD event (latest levels) for 248 patients who had a CVD event and for 480 matched controls. Odds ratios (ORs) were estimated using conditional logistic models.

RESULTS

Total, large and small HDL-p, but not VLDL-p nor LDL-p, were significantly and inversely associated with CVD and its major component, non-fatal coronary heart disease. The HDL-p associations with CVD were reduced after adjustment for high sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6) and D-dimer. Latest levels of total HDL-p were also significantly inversely associated with CVD; treatment interruption led to decrease of total HDL-p; adjusting for latest HDL-p did not explain the greater risk of CVD that was observed in the DC versus VS group.

CONCLUSIONS

Lipoprotein particles, especially lower levels of small and large HDL-p identify HIV-infected patients at increased risk of CVD independent of other CVD risk factors.

Preclinical atherosclerosis due to HIV infection: carotid intima-medial thickness measurements from the FRAM study

BACKGROUND

Cardiovascular disease (CVD) is an increasing cause of morbidity and mortality in HIV-infected patients. However, it is controversial whether HIV infection contributes to accelerated atherosclerosis independent of traditional CVD risk factors.

METHODS

Cross-sectional study of HIV-infected participants and controls without pre-existing CVD from the study of Fat Redistribution and Metabolic Change in HIV Infection (FRAM) and the Multi-Ethnic Study of Atherosclerosis (MESA). Preclinical atherosclerosis was assessed by carotid intima-medial thickness (cIMT) measurements in the internal/bulb and common regions in HIV-infected participants and controls after adjusting for traditional CVD risk factors.

RESULTS

For internal carotid, mean IMT was 1.17 +/- 0.50 mm for HIV-infected participants and 1.06 +/- 0.58 mm for controls (P < 0.0001). After multivariable adjustment for demographic characteristics, the mean difference of HIV-infected participants vs. controls was 0.188 mm [95% confidence interval (CI) 0.113-0.263, P < 0.0001]. Further adjustment for traditional CVD risk factors modestly attenuated the HIV association (0.148 mm, 95% CI 0.072-0.224, P = 0.0001). For the common carotid, HIV infection was independently associated with greater IMT (0.033 mm, 95% CI 0.010-0.056, P = 0.005). The association of HIV infection with IMT was similar to that of smoking, which was also associated with greater IMT (internal 0.173 mm, common 0.020 mm).

CONCLUSION

Even after adjustment for traditional CVD risk factors, HIV infection was accompanied by more extensive atherosclerosis measured by IMT. The stronger association of HIV infection with IMT in the internal/bulb region compared with the common carotid may explain previous discrepancies in the literature. The association of HIV infection with IMT was similar to that of traditional CVD risk factors, such as smoking.

Cardiovascular disease and HIV infection: host, virus, or drugs?

PURPOSE OF REVIEW

With effective antiretroviral therapy, cardiovascular disease has gained importance as a cause of morbidity and mortality in HIV-infected persons. We review the risk of cardiovascular disease in HIV-infected persons compared with that in uninfected persons and discuss the relative contributions of host, HIV, and antiretroviral therapy in the light of current knowledge.

RECENT FINDINGS

The incidence of cardiovascular disease in HIV-infected patients receiving antiretroviral therapy is low. However, the risk of cardiovascular disease increased compared with that in uninfected persons. This fact is substantially due to a higher prevalence of underlying traditional cardiovascular risk factors that are mostly host dependent. HIV may additionally contribute both directly through immune activation and inflammation, and indirectly through immunodeficiency. In a more modest way than that of HIV infection, the type of antiretroviral therapy may also contribute through its impact on metabolic and body fat parameters, and possibly through other factors that are currently unclear.

SUMMARY

Prevention of cardiovascular disease in HIV-infected patients should be standard of care. Traditional risk factors should be investigated and aggressively treated when possible. Antiretroviral therapy should be initiated earlier in patients with high cardiovascular risk. From a purely cardiovascular perspective, the benefits of antiretroviral therapy clearly outweigh any potential risk.