Insulin Resistance and the Cardiometabolic Syndrome in HIV Infection

'Adipaging': ageing and obesity share biological hallmarks related to a dysfunctional adipose tissue

The increasing ageing of our societies is accompanied by a pandemic of obesity and related cardiometabolic disorders. Progressive dysfunction of the white adipose tissue is increasingly recognized as an important hallmark of the ageing process, which in turn contributes to metabolic alterations, multi-organ damage and a systemic pro-inflammatory state ('inflammageing'). On the other hand, obesity, the paradigm of adipose tissue dysfunction, shares numerous biological similarities with the normal ageing process such as chronic inflammation and multi-system alterations. Accordingly, understanding the interplay between accelerated ageing related to obesity and adipose tissue dysfunction is critical to gain insight into the ageing process in general as well as into the pathophysiology of obesity and other related conditions. Here we postulate the concept of 'adipaging' to illustrate the common links between ageing and obesity and the fact that, to a great extent, obese adults are prematurely aged individuals.

Exercise therapy for human immunodeficiency virus/AIDS patients: Guidelines for clinical exercise therapists

Human immunodeficiency virus (HIV) has infected > 60 million people since its discovery and 30 million people have died since the pandemic began. Antiretroviral therapy has transformed HIV infection from an acute to a chronic disease, increasing life expectancy but also adding to the potential side effects associated with drug therapy and the comorbidity accompanying longevity. Exercise can play a valuable role in the management of HIV/AIDS patients by addressing various symptoms and improving their quality of life, but the optimum mode, intensity, frequency, and duration of exercise that take the different clinical stages of the disease into consideration are inadequately known. Searches of Medline, Embase, Science Citation Index, CINAHL database, HealthSTAR, PsycINFO, Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews, Physiotherapy Evidence Database (PEDro), and SPORTDiscus were conducted between 2000 and January 2014. Searches of published and unpublished abstracts were conducted, as well as a hand search of reference lists and tables of contents of relevant journals and books. Identified studies were reviewed for methodological quality. A total of 33 studies met the inclusion criteria. Most studies failed to indicate the optimum type (mode), intensity, frequency, and duration of aerobic and progressive resistive exercise prescribed to HIV-infected individuals in relation to the different clinical stages of the disease. The purpose of this review is to provide evidence-based recommendations after revision of exercise guidelines for HIV patients, by highlighting practical guidelines that clinical exercise therapists should consider when prescribing exercise for patients in different stages of the disease.

Effect of darunavir on lipid profile in HIV-infected patients

Highly active antiretroviral therapy regimens, consisting of a ritonavir-boosted protease inhibitor (PI) and 2 nucleoside reverse transcriptase inhibitors, are established first-line regimens for HIV-infected patients. However, a common adverse effect in patients receiving PIs is dyslipidemia, characterized by increases in plasma levels of triglycerides, low-density lipoprotein cholesterol, and total cholesterol (TC). These lipid changes, as well as other well-described risk factors, may predispose patients to the development of cardiovascular disease, an important comorbidity, especially as the lifespan of HIV-infected patients has increased dramatically in recent years. Among PIs, ritonavir-boosted atazanavir (ATV/r) and, more recently, ritonavir-boosted darunavir (DRV/r) have demonstrated potent antiviral efficacy with more favorable lipid profiles than other PIs. This review provides an overview of the lipid effects of DRV/r. Studies with DRV/r in healthy volunteers and in both treatment-naïve and -experienced patients have demonstrated that changes in tri-glycerides and TC are comparable to those seen with ATV/r.

Metabolic disorders and cardiovascular consequences of HIV infection and antiretroviral therapy

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

Genes linked to energy metabolism and immunoregulatory mechanisms are associated with subcutaneous adipose tissue distribution in HIV-infected men

OBJECTIVE

Genetic studies may help explain abnormalities of fat distribution in HIV-infected patients treated with antiretroviral therapy (ARV).

METHODS

Subcutaneous adipose tissue (SAT) volume measured by MRI in the leg, the lower trunk, the upper trunk, and the arm was examined in 192 HIV-infected White men, ARV-treated from the Fat Redistribution and Metabolic Change in HIV infection study. Single-nucleotide polymorphisms were assayed using the Illumina Human CNV370-quad beadchip. Multivariate and univariate genome-wide association analyses of the four SAT depots were implemented in PLINK software adjusted for age and ARV duration. Functional annotation analysis using Ingenuity Systems Pathway Analysis tool was carried out for markers with P lower than 10(-3) near known genes identified by multivariate analysis.

RESULTS

Loci (rs10504906, rs13267998, rs921231) in or near the anion exchanger solute carrier family 26, member 7 isoform a (SLC26A7) were strongly associated with the upper trunk and the arm SAT (9.8×10(-7) ≤P<7.8×10(-6)). Loci (rs193139, rs7523050, rs1761621) in and near a gene-rich region including G-protein-signaling modulator 2 (GPSM2) and syntaxin-binding protein 3 (STXBP3) were significantly associated with the lower body SAT depots (9.9×10(-7) ≤P<9.5×10(-6)). GPSM2 is associated with cell division and cancer whereas STXBP3 is associated with glucose metabolism in adipoctyes. Ingenuity Systems Pathway Analysis identified atherosclerosis, mitochondrial function, and T-cell-mediated apoptosis as processes related to SAT volume in HIV-infected individuals (P<5×10(-3)).

CONCLUSION

Our results are limited by the small sample size and replication is needed; however, this genomic scan uncovered new genes associated with metabolism and inflammatory pathways that may affect SAT volume in ARV-treated HIV-infected patients.

Primary, secondary, and tertiary prevention of cardiovascular disease in patients with HIV disease: a guide for nurse practitioners

HIV infection elevates a patient's risk for developing cardiovascular disease (CVD), due in part to direct effects of increased infection-producing inflammation and to drugs used to treat the infection, which can have untoward effects on serum lipid profiles. HIV-infected older adults often present with multiple comorbidities, including CVD, making disease management more challenging. Treatment paradigms are evolving, and nurse practitioners (NPs) are expected to play an ever-larger role in the management of HIV infection. Due to their accessibility and close patient contact, NPs are especially well suited to work with and educate patients to manage multiple risk factors. Appropriate use of primary, secondary, and tertiary CVD prevention strategies, including education to modify lifestyle risks, individualized antiretroviral treatment regimens to achieve serum lipid targets, and use of additional lipid-modifying strategies to minimize a patient's overall CVD risk profile will be important throughout the treatment lifecycle.

Efficacy of Tat-conjugated ritonavir-loaded nanoparticles in reducing HIV-1 replication in monocyte-derived macrophages and cytocompatibility with macrophages and human neurons

Human immunodeficiency virus (HIV)-1 targets mononuclear phagocytes (MP), which disseminate infection to organs such as brain, spleen and lymph. Thus MP, which include microglia, tissue macrophages and infiltrating monocyte-derived macrophages (MDM), are important target of anti-HIV-1 drug therapy. Most of the currently used antiretroviral drugs are effective in reducing viral loadin the periphery but cannot effectively eradicate infection from tissue reservoirs such as brain MP. HIV-1 infection of the central nervous system can lead to a wide variety of HIV-1-associated neurocognitive disorders. In this study, we demonstrate that ritonavir-loaded nanoparticles (RNPs) are effective in inhibiting HIV-1 infection of MDM. Reduced infection is observed in multiple read-out systems including reduction of cytopathic effects, HIV-1 p24 protein secretion and production of progeny virions. Furthermore, the RNPs retained antiretroviral efficacy after being removed from MDM cultures. As HIV-1-infected cells in the brain are likely to survive for a long period of time, both acute and chronic infection paradigms were evaluated. Tat-peptide-conjugated RNPs (Tat-RNP) were effective in both short-term and long-term HIV-1-infected MDM. Importantly, we confirm that delivery of RNPs, both with and without Tat-peptide conjugation, is toxic neither to MDM nor to neural cells, which may be bystander targets of the nanoformulations. In conclusion, Tat-NPs could be a safe and effective way of delivering anti-HIV-1 drugs for controlling viral replication occurring within brain MP.

The association between Helicobacter pylori infection and insulin resistance: a systematic review

BACKGROUND

Helicobacter pylori infection has been associated with diverse extradigestive morbidity, including insulin resistance (IR) syndrome. The aim of this systematic review was to summarize the epidemiologic evidence concerning the association between H. pylori infection and IR quantitative indexes.

MATERIALS AND METHODS

A computerized literature search in PubMed electronic databases and Cochrane Central Register of Controlled Trials was performed.

RESULTS

Nine studies reporting data on 2120 participants were finally eligible for this systematic review. Seven of them were cross-sectional studies and two were nonrandomized, open-label, controlled trials investigating the effect of H. pylori eradication on IR. Homeostatic model of assessment insulin resistance (HOMA-IR) was used in all studies to quantify IR. There seems to be a trend toward a positive association between H. pylori infection and HOMA-IR, strengthened by regression analysis in one study. However, there was significant heterogeneity between studies regarding the method(s) of H. pylori infection diagnosis based on and the study populations. The studies for the effect of H. pylori eradication on HOMA-IR revealed conflicting results.

CONCLUSIONS

Although data seem to indicate a potential association between H. pylori infection and IR, further studies are needed to strengthen this association and to clarify whether there is a causative link between them. If a causal link is confirmed in the future, this may have a major impact on the pathophysiology and management of IR syndrome, including type 2 diabetes mellitus and nonalcoholic fatty liver disease.

Fasting Triglyceride Concentrations are Associated with Early Mortality Following Antiretroviral Therapy in Zambia

BACKGROUND: In developing countries, 8 to 71% of patients initiating highly active antiretroviral therapy (HAART) die within the first year of treatment. Apart from baseline CD4 count, viral load, hemoglobin, BMI and stage of the disease, there may be other variables that contribute to AIDS-related mortality. We investigated the potential role of nutrition, lipids and insulin resistance-related phenotypes in predicting early mortality. METHODS: We recruited 210 HAART-naïve HIV/AIDS patients in Lusaka, Zambia. Dietary intake, anthropometric measurements, fasting serum insulin, glucose, and lipid profiles were assessed at baseline. Mortality was assessed after 90 days of follow-up. We used logistic regression models to identify variables associated with mortality. RESULTS: The mean±SD for age, BMI and CD4 count at baseline were 34±7.4 y, 20±3 kg/m(2) and 138±52 cells/μL, respectively. Sixteen patients (7.6%) died during follow-up. Triglyceride concentrations were associated with increased mortality [odds ratio (OR) for 1 mmol/L increase in triglyceride concentration=2.51; 95% CI: 1.34-4.71]. This association remained significant (OR=3.24; 95% CI: 1.51-6.95) after adjusting for age, gender, smoking, alcohol use, total cholesterol, BMI, CD4 count and n3 fatty acid intake. Apart from higher n3 fat intake which was inversely associated with mortality (survivors: 1.81±0.99% total energy/day vs. non-survivors 1.28±0.66% energy/day, P=0.04), there were no other macronutrients associated with mortality. CONCLUSION: Triglyceride concentrations at the time of initiating HAART are independently associated with increased risk for early mortality. If this association is confirmed in larger studies, assessment of triglycerides could become part of routine care of HIV patients initiating HAART in developing countries.