High prevalence of the metabolic syndrome in HIV-infected patients: impact of different definitions of the metabolic syndrome

Management of hepatitis C in HIV and/or HBV co-infected patients

Co-infection with either HIV or HBV in chronic hepatitis C patients is common, since all these viruses share transmission routes and geographical distribution. Interaction between these viruses generally amplifies liver damage, increasing the risk of developing end-stage liver disease and hepatocellular carcinoma. HIV-HCV co-infection is associated with poorer response to antiviral therapy. New antivirals against HCV are eagerly awaited for this population. HBV-HCV dual infections are less common. The principles guiding indication of therapy in monoinfected patients should be followed considering which virus replicates in persons with serological markers of dual HBV-HCV infection. Although there is growing evidence supporting the use of direct acting antivirals (DAA) in dually infected patients with active HCV replication, prospective trials should be conducted to demonstrate their benefit, assessing carefully the rate and clinical consequences of HBV rebounds.

Prevalence and clinical correlates of metabolic syndrome in Nigerians living with human immunodeficiency virus/acquired immunodeficiency syndrome

BACKGROUND

Sub-Saharan Africa bears an inordinate burden of human immunodeficiency virus (HIV) infection/acquired immune deficiency syndrome (AIDS). Reports have shown increased prevalence of clustering of cardiovascular risk factors referred to as metabolic syndrome in treatment-naïve patients and patients on highly active antiretroviral therapy (HAART). In view of the fact that metabolic syndrome is a heterogeneous disorder with substantial variability in the prevalence and component traits within and across populations and the dearth of publications on the prevalence and clinical correlates of metabolic syndrome in people living with HIV/AIDS (PLWHA) in Nigeria, this study was carried out to determine the prevalence and clinical correlates of metabolic syndrome among an HIV-infected outpatient population using the National Cholesterol Education Adult Treatment Panel III (NCEP ATP III), the International Diabetes Federation (IDF), and the Joint Interim Statement (JIS) definitions. We also sought to determine if HAART use and CD4 count level were associated with metabolic syndrome.

METHODS

This cross-sectional study involved 291 (95 men, 196 women) consecutive PLWHA. Anthropometry, blood pressure, fasting plasma glucose, and lipid profile values were determined.

RESULTS

The prevalence rates of metabolic syndrome according to the ATP III, IDF, and JIS criteria were 12.7%, 17.2%, and 21.0%, respectively. Metabolic syndrome was significantly associated with female gender (all definitions), body mass index (all definitions), increasing age, and CD4 count (IDF definition). There was no significant association between metabolic syndrome and HAART. The concordance [kappa coefficient (κ)] between the definitions of metabolic syndrome varied between 0.583 and 0.878.

CONCLUSIONS

The prevalence of metabolic syndrome varied with the criteria used and metabolic syndrome correlates with traditional cardiovascular risk factors rather than HAART-related factors.

Serum leptin level mediates the association of body composition and serum C-reactive protein in HIV-infected persons on antiretroviral therapy

Higher body mass index (BMI) is associated with increased serum C-reactive protein (CRP) levels in HIV-infected individuals on antiretroviral therapy (ART), but the relationship of adipose tissue mass to systemic inflammation is not well described in this population. We hypothesized that serum adipokine levels (i.e., hormones produced by adipocytes) are a superior predictor of CRP compared to anthropometric or radiographic measures of body composition in patients on effective, stable ART. We evaluated the relationship of serum leptin, adiponectin, and resistin, BMI, and dual energy x-ray absorptiometry (DEXA) measurements with serum highly sensitive CRP (hsCRP) in a cross-sectional cohort of 106 predominantly virologically suppressed, HIV-infected adults on ART for ≥24 weeks using multivariable linear regression and formal criteria to assess statistical mediation. Median BMI, hsCRP, and leptin values were 25.2 kg/m(2), 3.0 mg/liter, and 3.8 ng/ml, respectively. BMI and DEXA limb fat, body fat, and trunk fat measurements were significantly associated with both serum leptin and hsCRP levels (all p≤0.02). Leptin was also associated with hsCRP (p<0.01). The regression coefficient for the effect of BMI or DEXA measurements on hsCRP was reduced, and the relationship was no longer statistically significant, after adjusting for leptin, indicating leptin functioned as a mediating variable within these relationships. Adiponectin and resistin levels did not demonstrate similar effects. Serum leptin was a superior predictor of hsCRP compared to BMI and DEXA body fat measurements, which may reflect alterations in body composition in treated HIV infection and the important contribution of adipose tissue to inflammation in this population.

Abacavir, didanosine and tenofovir do not induce inflammatory, apoptotic or oxidative stress genes in coronary endothelial cells

BACKGROUND

The use of abacavir and didanosine in HAART has been associated with an increased risk of myocardial infarction in HIV-infected patients. The aim of this study was to address the development of endothelial dysfunction in cultivated coronary artery endothelial cells (HCAECs) in response to abacavir, didanosine and tenofovir. We examined the impact of these drugs on the expression levels of the proinflammatory, oxidative stress and apoptosis regulating genes in HCAECs.

METHODS

We tested gene and protein expression changes in HCAECs in response to abacavir, didanosine and tenofovir using quantitative real-time reverse transciptase PCR, FACS and ELISA. The assessed genes/proteins included the proinflammatory molecules VCAM-1, ICAM-1, MCP-1, RANTES and IL-6. In addition, we assessed the gene expression of the intracellular reactive oxygen producing NADPH oxidase subunit gp91(PHOX) and the apoptosis regulating molecules Bcl-2 and BAD.

RESULTS

Exposure of HCAECs to abacavir, didanosine and tenofovir resulted in no statistically significant changes in any of the tested genes/proteins at any time point or at any concentration.

CONCLUSIONS

We found no evidence that abacavir, didanosine or tenofovir had direct in vitro effects on coronary endothelial cell gene transcription and protein expression of the selected mediators. If abacavir or didanosine increase cardiovascular risk, it is likely not through the direct endothelial activation pathways tested in these experiments. However, further studies are needed to completely exclude the toxicity of abacavir or didanosine on endothelial cells.

Effects of lifestyle modification and metformin on atherosclerotic indices among HIV-infected patients with the metabolic syndrome

OBJECTIVE

Metabolic abnormalities including diabetes, dyslipidemia, hypertension, and abdominal obesity occur commonly in HIV patients, are associated with increased coronary artery calcification (CAC), and contribute to increased cardiovascular disease (CVD) in this population. We hypothesized that lifestyle modification (LSM) and metformin would improve CVD indices in HIV patients with metabolic syndrome.

DESIGN

A randomized, placebo-controlled trial to investigate LSM and metformin, alone and in combination, over 1 year, among 50 HIV-infected patients with metabolic syndrome.

METHODS

We assessed CAC, cardiovascular and metabolic indices.

RESULTS

Among the participants, duration of HIV-infection was 14 ± 1 year and duration of antiretroviral therapy was 6 ± 1 year. Metformin-treated patients demonstrated significantly less progression of CAC (-1 ± 2 vs. 33 ± 17, P = 0.004, metformin vs. placebo), whereas the effect of LSM on CAC progression was not significant (8 ± 6 vs. 21 ± 14, P =  0.82, LSM vs. no-LSM). Metformin had a significantly greater effect on CAC than LSM (P = 0.01). Metformin-treated patients also demonstrated less progression in calcified plaque volume (-0.4 ± 1.9 vs. 27.6 ± 13.8 μl, P = 0.008) and improved homeostatic model of assessment-insulin resistance (HOMA-IR) (P = 0.05) compared with placebo. Participants randomized to LSM vs. no-LSM showed significant improvement in HDL (P = 0.03), high-sensitivity C-reactive protein (hsCRP) (P = 0.05), and cardiorespiratory fitness. Changes in CAC among the four groups--no-LSM-placebo (43 ± 30); LSM-placebo (19 ± 7); no-LSM-metformin (1 ± 1) and LSM-metformin (-4 ± 6)--were different (P = 0.03 for ANOVA and linear trend across groups), and the majority of this effect was mediated by metformin. Results are mean ± SEM.

CONCLUSION

Metformin prevents plaque progression in HIV-infected patients with the metabolic syndrome.

Metabolic syndrome among HIV-infected Taiwanese patients in the era of highly active antiretroviral therapy: prevalence and associated factors

OBJECTIVES

Metabolic complications related to antiretroviral therapy are rarely investigated among HIV-infected patients in Asian countries. We investigated the prevalence of and factors associated with metabolic syndrome among HIV-infected patients who are ethnic Chinese in the era of highly active antiretroviral therapy (HAART).

METHODS

A cross-sectional survey was performed to collect information on the demographic and clinical characteristics and antiretroviral therapy prescribed in 877 HIV-infected patients at a university hospital in Taiwan from May 2008 to April 2009. The modified Adult Treatment Panel III criteria were used to define metabolic syndrome after adjusting for the waist circumference criteria for Asians.

RESULTS

Of the 877 patients, 75.3% were male homosexuals, 80.7% were receiving HAART and 88.7% had CD4 counts ≥ 200 cells/mm(3). Metabolic syndrome was diagnosed in 210 patients (26.2%). After adjusting for age, gender, smoking status, family history of diabetes mellitus, cardiovascular disease and hypertension, and baseline CD4 and plasma HIV RNA load, use of protease inhibitors (PIs) was significantly associated with the presence of metabolic syndrome (OR 1.63; 95% CI 1.10-2.43). In addition, exposure to PI for ≥ 3 years, to HAART for ≥ 6 years and to nucleoside reverse transcriptase inhibitor(s) for ≥ 6 years was significantly associated with the presence of metabolic syndrome with an adjusted OR of 1.96 (95% CI 1.13-3.42), 1.78 (95% CI 1.03-3.07), and 1.91 (95% CI 1.11-3.30), respectively.

CONCLUSIONS

Approximately one-fourth of HIV-infected Taiwanese patients developed metabolic syndrome in the HAART era. Receipt of HAART and prolonged exposure to PI and nucleoside reverse transcriptase inhibitor(s) were associated with metabolic syndrome.

Altered phosphate metabolism in HIV-1-infected patients with metabolic syndrome

BACKGROUND

Metabolic syndrome (MS) represents a cluster of cardiovascular risk factors that has become a serious problem for HIV-1-infected patients. It has been proposed that disturbance of phosphate metabolism may represent a key feature of MS. Thus, we undertook the present study to investigate the relationship between phosphate levels and the presence of the characteristics of MS.

METHODS

One hundred and twenty-one HIV-1-infected patients were consecutively enrolled in a prospective, cross-sectional, single-centre study. Kidney tubular function was examined using tubular resorption of phosphate and normalized renal threshold phosphate concentration.

RESULTS

Univariate analysis showed that serum phosphate levels correlated negatively with systolic and diastolic blood pressure, glucose values, waist circumference, insulin, and triglycerides. Moreover, there was a positive relationship between phosphate and high-density lipoprotein (HDL) cholesterol. Multivariate analysis showed that insulin levels were correlated with serum phosphate concentration (r = - 0.24, p = 0.01).

CONCLUSIONS

Our data show that HIV-1-infected patients with MS have lower phosphate levels.

Treatment for prevention of HIV transmission in a localised epidemic: the case for South Australia

BACKGROUND

Discussion is currently taking place among international HIV/AIDS groups around increasing HIV testing and initiating earlier use of antiretroviral therapy (ART) among people diagnosed with HIV as a method to reduce the spread of HIV. In this study, we explore the expected epidemiological impact of this strategy in a small population in which HIV transmission is predominantly confined to men who have sex with men (MSM).

METHODS

A deterministic mathematical transmission model was constructed to investigate the impacts of strategies that increase testing and treatment rates, and their likely potential to mitigate HIV epidemics among MSM. Our novel model distinguishes men in the population who are more easily accessible to prevention campaigns through engagement with the gay community from men who are not. This model is applied to the population of MSM in South Australia.

RESULTS

Our model-based findings suggest that increasing testing rates alone will have minimal impact on reducing the expected number of infections compared to current conditions. However, in combination with increases in treatment coverage, this strategy could lead to a 59-68% reduction in the number of HIV infections over the next 5 years. Targeting men who are socially engaged with the gay community would result in the majority of potential reductions in incidence, with only minor improvements possible by reaching all other MSM.

CONCLUSIONS

Investing in strategies that will achieve higher coverage and earlier initiation of treatment to reduce infectiousness of HIV-infected individuals could be an effective strategy for reducing incidence in a population of MSM.

Hypertriglyceridemia, Metabolic Syndrome, and Cardiovascular Disease in HIV-Infected Patients: Effects of Antiretroviral Therapy and Adipose Tissue Distribution

The use of combination antiretroviral therapy (CART) in HIV-infected patients has resulted in a dramatic decline in AIDS-related mortality. However, mortality due to non-AIDS conditions, particularly cardiovascular disease (CVD) seems to increase in this population. CART has been associated with several metabolic risk factors, including insulin resistance, low HDL-cholesterol, hypertriglyceridemia and postprandial hyperlipidemia. In addition, HIV itself, as well as specific antiretroviral agents, may further increase cardiovascular risk by interfering with endothelial function. As the HIV population is aging, CVD may become an increasingly growing health problem in the future. Therefore, early diagnosis and treatment of cardiovascular risk factors is warranted in this population. This paper reviews the contribution of both, HIV infection and CART, to insulin resistance, postprandial hyperlipidemia and cardiovascular risk in HIV-infected patients. Strategies to reduce cardiovascular risk are also discussed.

Liver transplantation in human immunodeficiency virus-positive patients

With the successful introduction of combined antiretroviral therapy (cART), human immunodeficiency virus (HIV) is now regarded as a chronic illness with excellent long-term outcomes. However, chronic exposure to viral etiologies (ie, chronic hepatitis B and hepatitis C) and drug-induced toxicity secondary to cART have resulted in increasing rates of mortality and morbidity due to end-stage liver disease. HIV disease is no longer considered an absolute contraindication to liver transplantation (LT) by most transplant centers worldwide. Because the burden of liver disease in this cohort is likely to increase, this review addresses the key etiologies and the management strategies available for HIV-positive patients undergoing LT.

Increasing burden of liver disease in patients with HIV infection

Introduction of effective combined antiretroviral therapy has made HIV infection a chronic illness. Substantial reductions in the number of AIDS-related deaths have been accompanied by an increase in liver-related morbidity and mortality due to co-infection with chronic hepatitis B and C viruses. Increases in non-alcoholic fatty liver disease and drug-induced hepatotoxicity, together with development of hepatocellular carcinoma, also potentiate the burden of liver disease in individuals with HIV infection. We provide an overview of the key causes, disease mechanisms of pathogenesis, and recommendations for treatment options including the evolving role of liver transplantation.

The assessment of metabolic syndrome in UK patients with HIV using two different definitions: CREATE 2 study

OBJECTIVE

To determine the prevalence and clinical associations of the metabolic syndrome (M-IRS) in an HIV cohort.

METHODS AND DESIGN

Data was collected prospectively on demographics, anthropometry, HIV disease, drug regimens and cardiometabolic risk factors using a two-centre cross-sectional cohort study design. M-IRS was diagnosed by National Cholesterol Education Program (NCEP) and International Diabetes Federation (IDF) criteria.

RESULTS

The prevalence of M-IRS in 678 subjects was 14% by NCEP and 10% by IDF. One feature of the M-IRS was present in 68%, while 37% had two or more features. Increased waist circumference was found in 32% by NCEP or by IDF criteria, hypertriglyceridaemia in 32%, reduced HDL-C in 27%, 18% had raised systolic blood pressure and 13% had dysglycaemia. Protease inhibitor (PI) usage was similar in both M-IRS categories (43 vs. 38%; p = 0.38) but increased use of efavirenz was seen in M-IRS (47 vs. 36%; p = 0.07) and nevirapine in the non-M-IRS groups (10 vs. 20%; p = 0.05). Multiple drug therapies were associated with raised triglyceride levels while nevirapine therapy was associated with raised HDL-C and abacavir with dysglycaemia.

CONCLUSIONS

The prevalence of M-IRS in this HIV cohort was similar to the general population and independent of current or previous highly active antiretroviral therapy (HAART) or its duration. Given the relationship between individual drugs and features of M-IRS its significance must be interpreted in the light of probable accrual bias in prescribing. Prospective studies are required to ascertain the cardiometabolic risk factors to include in a prognostically useful HIV disease-specific definition of M-IRS.

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.