Clinical review 159: Human immunodeficiency virus/highly active antiretroviral therapy-associated metabolic syndrome: clinical presentation, pathophysiology, and therapeutic strategies

Biological Depiction of Lipodystrophy and Its Associated Challenges Among HIV AIDS Patients: Literature Review

Lipodystrophy syndrome is a medical condition characterized by the absence of adipose tissue without any underlying starvation or macromolecule breakdown. In HIV AIDS patients, the use of highly active antiretroviral therapy (HAART) can lead to an acquired form of lipodystrophy, with a prevalence ranging from 10% to 83% among HIV AIDS patients. It was aimed to review the current understanding of biological depiction and challenges related to lipodystrophy in AIDS patients. Relevant articles published in the English language were searched in PubMed, Google Scholar, and Google. Keywords used for the search were: lipodystrophy, lipodystrophy and HIV, ART and lipodystrophy, HIV treatment, metabolic syndrome and HIV. Articles with full abstract information were read for those that met the objective criteria of the review, then full text of the articles was accessed and used. It was revealed by the literature that patients who developed lipodystrophy are characterized by insulin abnormality, obesity, diabetes mellitus, dyslipidemia, fatty liver disease, and ovarian dysfunction. Anthropometric measurements have been known to change significantly with lipodystrophy. HIV patients suffering from hepatitis C virus, hepatitis B virus, who take a protease inhibitor, are changing treatment or duration of treatment, and are women are the common risk factors for lipodystrophy. The metabolic syndrome seen in HIV patients associated with lipodystrophy can further be complicated to different adverse health effects and can result in increased morbidity and mortality rate if not treated. Existing studies have successfully identified several challenges faced by HIV AIDS patients due to lipodystrophy, including low self-esteem, compromised quality of life, and poor treatment adherence. However, it is crucial to acknowledge that there may be numerous other challenges that have yet to be discovered, emphasizing the need for further studies. It is recommended that managing dyslipidemia, treating diabetes mellitus, modifying lifestyle, and improving the anthropometric measurements have crucial roles to halt further complications associated with lipodystrophy.

Lanthanum nitrate inhibits adipogenesis in 3T3-L1 preadipocytes with a disorder of mitotic clonal expansion process

Lanthanum (La) as a rare earth element is widely used in agriculture, industry, and medicine. It has been suggested in several studies that La might influence glycolipid metabolism in vivo. In this study, we used 3T3-L1 preadipocytes as in vitro cell model to elucidate the effects of La(NO₃ )₃ on adipogenesis and the underlying mechanisms. The results showed that La(NO₃ )₃ could inhibit the adipogenic differentiation of 3T3-L1 preadipocytes, which showed a decrease in lipid accumulation and the downregulation of specific adipogenic transcription factors. La(NO₃ )₃ exerted its inhibitory effect mainly at the early differentiation stage. Furthermore, La(NO₃ )₃ influenced the S-phase entry and cell cycle process during the mitotic clonal expansion and regulated the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and expressions of the proteins in phosphatidylinositol 3-kinase (PI3K)/Akt pathway at the early stage of differentiation. Besides, La(NO₃ )₃ upregulated the expressions of wnt10b mRNA and β-catenin protein and promoted the nucleus translocation of β-catenin. Additionally, we found that La(NO₃ )₃ could promote the growth of 3T3-L1 preadipocytes both with and without MDI (3-isobutyl-1-methylxanthine [IBMX], dexamethasone [Dex], and insulin) stimulation. Collectively, these results indicated that La(NO₃ )₃ could inhibit adipogenesis in 3T3-L1 preadipocytes and influence cell proliferation.

Temporal Trend and Clinical Outcomes in HIV and Non-HIV Patients following Liposuction: A Propensity-Matched Analysis

BACKGROUND

Because of the availability of highly active antiretroviral therapy, individuals infected with human immunodeficiency virus (HIV) are enjoying greater longevity with chronic conditions including abnormal adipose distribution. However, prior data on postoperative outcomes of liposuction in HIV-positive patients were limited by small sample size. Therefore, the authors aimed to compare differences in temporary trend, clinical characteristics, and outcomes between patients with and without HIV who underwent liposuction.

METHODS

The National Inpatient Sample database from 2010 to 2017 was queried to identify patients who underwent liposuction. Univariate, multivariate logistic regression and 1:4 propensity score-matched analyses were used to assess the primary outcomes (i.e., in-hospital mortality and postoperative outcomes) and secondary outcomes (i.e., discharge disposition, prolonged length of stay, and total cost).

RESULTS

Overall, 19,936 patients who underwent liposuction were identified, among whom 61 patients (0.31%) were infected with HIV. Patients with HIV were more likely to be male, insured by Medicare, and had more comorbidities and lower income. Unadjusted length of stay was longer among patients with HIV (OR, 1.81; 95% CI, 1.09 to 2.99; P = 0.020); nevertheless, multivariable models and propensity score-matched analysis demonstrated that patients with HIV were no more likely to have complications than the general population. This was also the case for length of stay and total costs.

CONCLUSIONS

The authors' findings indicated that patients with HIV who underwent liposuction did not experience an increased risk of major complication or mortality. Liposuction could be safely considered as a surgical treatment for HIV-positive patients with local fat deposition.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Vaspin Mediates the Intraorgan Crosstalk Between Heart and Adipose Tissue in Lipoatrophic Mice

Lipoatrophy is characterized as selective loss of adipose tissues, leading to the severity of cardiovascular disorders. Therefore, there was close intraorgan crosstalk between adipose tissue and cardiovascular in lipoatrophy. A-ZIP/F-1 mouse, a well-established lipoatrophic model, and primary cardiomyocytes were used for investigating the pathophysiological changes and molecular mechanisms. A-ZIP/F-1 mice had severe fat loss and impaired ventricular function during growth, but closely associated with the reduction of circulating vaspin levels. Administration of recombinant vaspin protein improved cardiac structural disorders, left ventricular dysfunction, and inflammatory response in lipoatrophic mice. In detail, vaspin decreased cardiac lipid deposits, but enhanced mitochondrial biogenesis and activities. Interestingly, A-ZIP/F-1 mice transplanted with normal visceral adipose tissues exhibited improvement in cardiac structural remodeling and mitochondrial function. Mechanistically, vaspin increased cardiac AKT activity, which guaranteed the mitochondrial benefits of vaspin in lipoatrophic mice and primary mouse cardiomyocytes. The present study suggested that vaspin possessed biological benefits in attenuating lipoatrophy-induced cardiomyopathy onset, and targeting vaspin/AKT signaling was a potential strategy to maintain heart metabolism.

Bioenergetic adaptations to HIV infection. Could modulation of energy substrate utilization improve brain health in people living with HIV-1?

The human brain consumes more energy than any other organ in the body and it relies on an uninterrupted supply of energy in the form of adenosine triphosphate (ATP) to maintain normal cognitive function. This constant supply of energy is made available through an interdependent system of metabolic pathways in neurons, glia and endothelial cells that each have specialized roles in the delivery and metabolism of multiple energetic substrates. Perturbations in brain energy metabolism is associated with a number of different neurodegenerative conditions including impairments in cognition associated with infection by the Human Immunodeficiency Type 1 Virus (HIV-1). Adaptive changes in brain energy metabolism are apparent early following infection, do not fully normalize with the initiation of antiretroviral therapy (ART), and often worsen with length of infection and duration of anti-retroviral therapeutic use. There is now a considerable amount of cumulative evidence that suggests mild forms of cognitive impairments in people living with HIV-1 (PLWH) may be reversible and are associated with specific modifications in brain energy metabolism. In this review we discuss brain energy metabolism with an emphasis on adaptations that occur in response to HIV-1 infection. The potential for interventions that target brain energy metabolism to preserve or restore cognition in PLWH are also discussed.

Physical Activity is Associated with Metabolic Health in Men Living with HIV

Metabolic health is a cause for concern among those living with HIV, especially those on antiretroviral therapy. Physical activity (PA) is known to benefit metabolic health, however, few studies have objectively measured PA or investigated the relationship between PA and metabolic health among those living with HIV. In this study, PA and indices of metabolic health among twenty men living with HIV and twenty age matched HIV-negative men were measured. PA was measured using Actigraph accelerometers. Components of the metabolic syndrome and insulin resistance were measured using routine laboratory methods. Men living with HIV were significantly more physically active than HIV-negative men, and were reaching public PA guidelines. Significant inverse correlations between moderate PA and both insulin resistance (ρ -0.847; p < 0.001) and triglycerides (ρ -0.575; p = 0.013) were seen in those living with HIV. Results of this study emphasize the importance of an active lifestyle for those living with HIV.

High Prevalence of Lipid Abnormalities and Insulin Resistance Among Antiretroviral Naïve HIV-infected Children in India

BACKGROUND

As large numbers of children are accessing antiretroviral therapy (ART) in India, we evaluated the dietary intake, growth pattern and risk of metabolic complications like dyslipidemia and insulin resistance among ART-naïve HIV-infected children (CLHIV).

METHODS

CLHIV 2-12 years of age, at the time of initiating ART in Chennai and Bangalore, were assessed for their dietary intake, anthropometry, blood CD4 cell count, HIV-1 viral load, fasting serum lipids, glucose and insulin. Homeostatic model assessment-insulin resistance was derived.

RESULTS

Three hundred and ninety CLHIV (mean age [SD]: 8 [3] yrs; median viral load: 141,000 [25,876-436,000] copies/mL) were started on non-nucleoside reverse transcriptase inhibitor-based ART. Perinatal infection was documented among 97%. Sixty percent of children were in stage 3 or 4 of World Health Organization clinical staging of HIV/AIDS. Food insecurity was seen in 40% of households. A total of 204 children (52.4%) were stunted and 224 (57.6%) were underweight. Stunting seemed to be more prevalent with increasing age (0-4 years: 48%; >9 years: 60%). Mean intakes of calories, iron, folate and calcium were significantly less than recommended dietary allowances across all age groups. Dyslipidemia, in terms of any abnormal triglycerides or total cholesterol or low-density lipoprotein cholesterol (excluding high-density lipoprotein cholesterol), was seen in approximately 40% of children; insulin resistance in 17%; and C-reactive protein in risk range of metabolic syndrome in 24% of children.

CONCLUSIONS

In the background of high food insecurity and malnutrition, cardiometabolic abnormalities were seen in 20%-35% of ART-naïve CLHIV in India emphasizing close monitoring of these children for long-term cardiovascular morbidities after initiation of ART.

Metabolic syndrome and cardiovascular disease risk assessment among human immunodeficiency virus-infected individuals on antiretroviral therapy

Background:

The association of cardiovascular risk with first-line antiretroviral therapy (ART) in Indians has been a matter of concern with the background of a high risk in South Asians.

Aims:

This study aimed to compare metabolic syndrome and its components, dyslipidemia, insulin resistance, and cardiovascular risk among patients on first-line ART (Group 1) with age-matched, ART-naïve human immunodeficiency virus (HIV)-infected patients (Group 2) and normal controls (Group 3).

Methods:

Patients attending a tertiary care center in Mysore were enrolled in the study after obtaining informed consent and controls were chosen from relatives of patients.

Results:

The total number of patients enrolled in the study was 217 (males 111; females 106), and the mean age of these patients was 34.1 ± 7.4 years. The number of patients in Group 1 (HIV+, ART experienced) was 76; in Group 2 (HIV+, ART naïve) was 71, and in Group 3 (HIV−) was 70. There was no statistically significant difference in the prevalence of metabolic syndrome between the three groups. On comparing the components of metabolic syndrome, serum triglycerides (mg/dl) were significantly higher in the ART group (Group 1: 149.5 [interquartile range (IQR): 84–187], Group 2: 108 [IQR: 74–152], and Group 3: 141.5 [IQR: 89–192]; P = 0.014) and serum high-density lipoprotein cholesterol was higher in HIV-uninfected individuals (Group 1: 37.5 ± 11.83, Group 2: 31.5 ± 12.23, and Group 3: 40.1 ± 12.09; P = 0.0002). There was no association between metabolic syndrome, duration of HIV, and type of first-line ART. Total and low-density lipoprotein (LDL) cholesterol were significantly higher in the ART group. Homeostatic model assessment and Framingham scores did not reveal any significant difference across the three groups.

Conclusion:

HIV-infected individuals on ART had higher levels of triglycerides, LDL, and total cholesterol, but no increased cardiovascular risk compared to other groups.

Plasma levels of lipopolysaccharide correlate with insulin resistance in HIV patients

BACKGROUND

In HIV patients using HAART insulin resistance is a central pathophysiological condition that can contribute to the development of diabetes and cardiovascular complications. To examine the role of adipocyte hormones and LPS in insulin resistance in HIV patients, we investigated the role of adiponectin, leptin, visfatin and LPS levels in the insulin resistance of HIV-infected patients treated with HAART.

METHODS

This study included 67 HIV positive individuals on HAART and ten healthy controls. All participants performed plasma or serum levels of glucose; insulin; lipids, visfatin, leptin, adiponectin, and LPS. The homeostasis model assessment (HOMA-IR), was used to estimate insulin resistance.

RESULTS

The levels of visfatin, leptin and adiponectin were similar between controls and HIV patients. However, circulating levels of LPS were higher in HIV patients on HAART than in controls. There was a positive correlation between LPS and TG (r = 0.49, p = 0.0001), between LPS and TG/HDL (r = 0.50, p = 0.0001), between LPS and insulin (r = 0.52, p = 0.0003), and between LPS and HOMA-IR (r = 0.52, p = 0.0005), in HIV patients.

CONCLUSIONS

Our results showed a clear correlation between plasma LPS and markers of insulin resistance, suggesting a relationship between LPS levels and metabolic alterations, particularly affecting lipids and insulin resistance in HIV patients.

Liver test abnormalities in patients with HIV mono-infection: assessment with simple noninvasive fibrosis markers

Background

Patients with HIV mono-infection may develop chronic liver disease due to a number of factors including hepatic steatosis. We estimated the prevalence and predictors of hepatic steatosis and fibrosis in a cohort of HIV-mono-infected patients with persistently deranged liver function tests.

Methods

Of 2398 consecutive patients at one UK clinical center, 156 (6.5%) had persistently abnormal transaminases in at least two measurements six months apart. We used APRI and FIB4 scores to determine the presence of significant and/or advanced fibrosis in this group as well as its potential associations.

Results

Mean age was 47.5±8.5 years and 91% (142/156) were males. Diabetes mellitus was present in 11% of patients; hypertension in 18%; and dyslipidemia in 52%. Almost all were on antiretroviral therapy (ART) (97%) and most were virologically suppressed (94%). Steatosis was detected by ultrasound in 71% of patients. The prevalence of FIB4≤1.45, 1.46-3.24 and >3.25 was 67%, 29% and 4%, respectively, and that of APRI≤0.5, 0.51-1.49 and >1.5 was 52%, 45% and 3% respectively. In multivariate analysis, only cumulative ART exposure was associated with FIB4>1.45 (odds ratio [OR] 1.008, 95% confidence interval [CI] 1.000-1.016), while APRI>0.5 was associated with higher alanine aminotransferase levels (OR 1.033, 95%CI 1.015-1.510). Twenty patients had a liver biopsy, of whom 13 had non-alcoholic fatty liver disease (NAFLD).

Conclusions

Elevated transaminases are often present in HIV-mono-infected patients and this may be associated with NAFLD and/or ART. Non-invasive screening for the presence of NAFLD and fibrosis in all HIV-mono-infected patients as part of their routine clinical management should be further explored.

Prevalence and predictors of liver steatosis and fibrosis in unselected patients with HIV mono-infection

OBJECTIVES

Significant liver disease may develop in HIV mono-infected patients, usually associated with fatty liver and/or cART exposure. We estimated the prevalence and predictors of hepatic steatosis and fibrosis as assessed by ultrasound and transient elastography (TE).

METHODS

We enrolled 125 consecutive HIV mono-infected patients who underwent ultrasound and TE. Clinical, biochemical, immunological, virological features and medication history were analysed.

RESULTS

Mean age was 39.5±10.3years and 91% were male. Metabolic syndrome (MS) was present in 9.8%, diabetes in 5.6%, hypertension in 9.7%, dyslipidemia in 32.8%. Increased AST and ALT were found in 5.6% and 16.8% respectively. Eighty-five (68%) patients were on cART (median length of treatment of 3 years, IQR 0-17). Hepatic steatosis was detected in 61 (55%) patients and was independently associated with male sex (OR 14.6, 95% CI 1.44-148.17), age (OR 1.082, 95% CI 1.01-1.16), HOMA (OR 2.56, 95% CI 1.101-5.96) and GGT (OR 1.037, 95% CI 1.007-1.075). Significant fibrosis (stiffness>7.4kPa) was present in 22 patients (17.6%) and was significantly associated with MS (OR 3.99, 95% CI 1.001-16.09).

CONCLUSIONS

Liver fibrosis can develop in asymptomatic HIV mono-infected patients. This is likely associated with NAFLD and usually manifests with normal transaminases. Non-invasive screening for the presence of NAFLD and fibrosis should be considered in the routine care of such patients.

Adiponectin administration prevents weight gain and glycemic profile changes in diet-induced obese immune deficient Rag1-/- mice lacking mature lymphocytes

BACKGROUND

Obesity is associated with chronic low-grade inflammation leading to insulin resistance and diabetes. Adiponectin is an adipokine that regulates inflammatory responses. The aim of our study was to investigate whether any effects of adiponectin against obesity and insulin-resistance may depend on the adaptive immune system.

METHODS

We treated high-fat-diet fed Rag1-/- mice lacking mature lymphocytes with adiponectin over 7weeks and investigated alterations in their metabolic outcome and inflammatory state.

RESULTS

Adiponectin protects from weight gain despite a small compensatory stimulation of energy intake in mice lacking an adaptive immune system. Additionally, adiponectin protects from dysglycemia. Minor alterations in the macrophage phenotype, but not in the circulating cytokine levels, may contribute to the protective role of adiponectin against hyperglycemia and diabetes.

CONCLUSION

Adiponectin or agents increasing adiponectin may be a promising therapeutic option against obesity and hyperglycemia in immune-deficient populations.

Adiposity influences airway wall thickness and the asthma phenotype of HIV-associated obstructive lung disease: a cross-sectional study

Background

Airflow obstruction, which encompasses several phenotypes, is common among HIV-infected individuals. Obesity and adipose-related inflammation are associated with both COPD (fixed airflow obstruction) and asthma (reversible airflow obstruction) in HIV-uninfected persons, but the relationship to airway inflammation and airflow obstruction in HIV-infected persons is unknown. The objective of this study was to determine if adiposity and adipose-associated inflammation are associated with airway obstruction phenotypes in HIV-infected persons.

Methods

We performed a cross-sectional analysis of 121 HIV-infected individuals assessed with pulmonary function testing, chest CT scans for measures of airway wall thickness (wall area percent [WA%]) and adipose tissue volumes (mediastinal and subcutaneous), as well as HIV- and adipose-related inflammatory markers. Participants were defined as COPD phenotype (post-bronchodilator FEV₁/FVC < lower limit of normal) or asthma phenotype (doctor-diagnosed asthma or bronchodilator response). Pearson correlation coefficients were calculated between adipose measurements, WA%, and pulmonary function. Multivariable logistic and linear regression models were used to determine associations of airflow obstruction and airway remodeling (WA%) with adipose measurements and participant characteristics.

Results

Twenty-three (19 %) participants were classified as the COPD phenotype and 33 (27 %) were classified as the asthma phenotype. Body mass index (BMI) was similar between those with and without COPD, but higher in those with asthma compared to those without (mean [SD] 30.7 kg/m² [8.1] vs. 26.5 kg/m² [5.3], p = 0.008). WA% correlated with greater BMI (r = 0.55, p < 0.001) and volume of adipose tissue (subcutaneous, r = 0.40; p < 0.001; mediastinal, r = 0.25; p = 0.005). Multivariable regression found the COPD phenotype associated with greater age and pack-years smoking; the asthma phenotype with younger age, female gender, smoking history, and lower adiponectin levels; and greater WA% with greater BMI, younger age, higher soluble CD163, and higher CD4 counts.

Conclusions

Adiposity and adipose-related inflammation are associated with an asthma phenotype, but not a COPD phenotype, of obstructive lung disease in HIV-infected persons. Airway wall thickness is associated with adiposity and inflammation. Adipose-related inflammation may play a role in HIV-associated asthma.

Adverse Effects Associated With Antiretroviral Therapy and Potential Management Strategies

A variety of adverse drug reactions (ADRs) affecting many organ systems may be observed with antiretroviral therapy (ARV), and they can be differentiated into short- and long- term effects, class effects, or individual drug effects. Commonly seen ADRs include dermatological reactions, associated with nonnucleoside reverse transcriptase inhibitors (NNRTIs) and some protease inhibitors (PIs), and gastrointestinal problems, a major side effect of PIs and of some nucleoside reverse transcriptase inhibitors (NRTIs). Metabolic complications are frequently reported in HIV-infected patients on ARV and often coexist. Lipodystrophy, hyperinsulinemia/hyperglycemia, and bone disorders (osteoporosis, osteonecrosis) are mainly associated with PIs, while lactic acidemia/acidosis are primarily a problem of NRTIs. Hyperlipidemia may be caused by almost all PIs, few NRTIs, and NNRTIs. All antiretroviral drug classes may cause both asymptomatic and symptomatic hepatotoxicity, although nevirapine is the agent most implicated in hepatic events. More drug-specific ADRs include nephrotoxicity (indinavir and tenofovir), central nervous system problems (efavirenz), hematological disturbances (zidovudine), and hypersensitivity reactions (abacavir). Anticipation of ADRs may influence a patient’s decision to delay ARV or to choose specific and potentially less active agents. Occurrence of ADRs may significantly impact a patient’s quality of life and drug adherence. Pharmacists counseling HIV-infected patients should be aware of common ADRs with ARV and potential management strategies.

The Effect of a Community-Based Exercise Program on Inflammation, Metabolic Risk, and Fitness Levels Among Persons Living with HIV/AIDS

The human immunodeficiency virus (HIV) pandemic remains a top national health priority. Chronic inflammation may be a critical component in the disease course of HIV as C-reactive protein (CRP) is elevated and associated with increased mortality. This study examined the effect of 3 months of combined aerobic and resistance exercise training among a diverse cohort of HIV-infected men and women. The fixed effect of time for CRP was found to be non-significant (F[1,57.3] = 1.7, p = 0.19). There was a significant fixed effect for time for upper body (F[1,51.6] = 18.1, p < 0.05) and lower body strength (F[1,48.0] = 15.7, p < 0.05) and significant declines in diastolic blood pressure (p = 0.002) and waist circumference (p = 0.027). Though levels of CRP were not impacted after 3 months training, participants demonstrated a significant increase in muscular strength as well as beneficial changes in metabolic risk factors. Future studies should focus on determining the optimal exercise intervention length and mode to reduce inflammation among individuals living with HIV.

Polymorphisms in adiponectin receptor genes are associated with lipodystrophy-related phenotypes in HIV-infected patients receiving antiretroviral therapy

OBJECTIVES

Adiponectin is a circulating peptide secreted by mature adipocytes that may act as a regulator of glucose and lipid metabolism. This study aimed to investigate the association between genetic variability in the adiponectin receptor genes ADIPOR1 (adiponectin receptor 1) and ADIPOR2 and lipodystrophy and its related anthropometric and metabolic phenotypes in HIV-infected patients on highly active antiretroviral therapy (HAART).

METHODS

We studied six single nucleotide polymorphisms (SNPs) in the adiponectin receptor genes ADIPOR1 (rs1342387 and rs10920533) and ADIPOR2 (rs11061925, rs10773983, rs929434 and rs767870) and their association with adiponectin plasma levels, lipodystrophy subtypes and other parameters linked to glucose and lipid metabolism involved in the lipodystrophic syndrome. The genotypes of 407 HIV-infected patients receiving HAART were investigated using real-time polymerase chain reaction. Mean biochemical and anthropometrical parameters were compared between the different genotypes using analysis of variance.

RESULTS

Two ADIPOR2 SNPs (rs11061925 and rs929434) were associated with fasting plasma triglyceride concentrations in the entire sample. Stronger significant associations were found between these SNPs and biochemical parameters (levels of triglycerides, total cholesterol, adiponectin and glucose) in men. We did not find any significant associations with ADIPOR1 gene variants.

CONCLUSIONS

SNPs in the ADIPOR2 gene appear to be involved in the metabolic alterations in HIV-infected men receiving HAART.

Leptin in congenital and HIV-associated lipodystrophy

Leptin is a hormone secreted by adipocytes that regulates energy metabolism via peripheral action on glucose synthesis and utilization as well as through central regulation of food intake. Patients with decreased amounts of fat in their adipose tissue (lipoatrophy) will have low leptin levels, and hypoleptinemic states have been associated with a variety of metabolic dysfunctions. Pronounced complications of insulin resistance, dyslipidemia and fatty liver are observed in patients suffering from congenital or acquired generalized lipodystrophy while somewhat less pronounced abnormalities are associated with human immunodeficiency virus (HIV) and the use of highly active antiretroviral therapy, the so-called HIV-associated lipodystrophy. Previous uncontrolled open-label studies have demonstrated that physiological doses of leptin repletion have corrected many of the metabolic derangements observed in subjects with rare fat maldistribution syndromes such as generalized lipodystrophy. In the much more commonly encountered HIV-associated lipodystrophy, leptin replacement has been shown to decrease central fat mass and to improve insulin sensitivity, dyslipidemia, and glucose levels. The United States Food and Drug Administration has recently granted approval for recombinant leptin therapy for congenital and acquired generalized lipodystrophy, however large, well-designed, placebo-controlled studies are needed to assess long-term efficacy, safety and adverse effects of leptin replacement. In this review, we present the role of leptin in the metabolic complications of congenital and acquired lipodystrophy and discuss current and emerging clinical therapeutic uses of leptin in humans with lipodystrophy.

Association between risk factors for vascular dementia and adiponectin

Vascular dementia is caused by various factors, including increased age, diabetes, hypertension, atherosclerosis, and stroke. Adiponectin is an adipokine secreted by adipose tissue. Adiponectin is widely known as a regulating factor related to cardiovascular disease and diabetes. Adiponectin plasma levels decrease with age. Decreased adiponectin increases the risk of cardiovascular disease and diabetes. Adiponectin improves hypertension and atherosclerosis by acting as a vasodilator and antiatherogenic factor. Moreover, adiponectin is involved in cognitive dysfunction via modulation of insulin signal transduction in the brain. Case-control studies demonstrate the association between low adiponectin and increased risk of stroke, hypertension, and diabetes. This review summarizes the recent findings on the association between risk factors for vascular dementia and adiponectin. To emphasize this relationship, we will discuss the importance of research regarding the role of adiponectin in vascular dementia.

Non-traditional adipokines in pediatric HIV-related lipodystrophy: a-FABP as a biomarker of central fat accumulation

BACKGROUND

Lipodystrophy characterized by adipose tissue redistribution and lipid and glucose metabolism abnormalities, is common among HIV-infected adults and children on highly-active-antiretroviral-therapy (HAART). In a previous study of HIV-infected children, we did not detect insulin resistance, despite a high percentage of body fat redistribution abnormalities.

AIM OF THE STUDY

To investigate the non-traditional adipokines Retinol-binding-Protein-4 (RBP4), neutrophil-gelatinase-associated-lipocalin (NGAL), a-Fatty-Acid-Binding-Protein (a-FABP) and YKL-40 in HIV-infected children on highly-active-antiretroviral-therapy and evaluate their possible association to lipodystrophic changes or insulin resistance.

METHODS

Seventeen vertically HIV-infected children (mean age: 12.5 years, mean duration of HAART: 5.2 years) and 20 age- and BMI-matched controls were recruited. The HIV-children were re-evaluated after 12 months. RBP4, NGAL, a-FABP and YKL-40 were assessed at study entry and 12 months later and were correlated to body fat content and insulin resistance.

RESULTS

RBP4 values were similar at study entry and 12 months later in HIV-children and controls and showed no correlation to body fat or insulin resistance. NGAL was lower in HIV children at study entry but normalized after 12 months with no positive correlation to insulin resistance. a-FABP was positively correlated to body fat content, especially to trunk fat, both at initial evaluation and at follow-up in HIV children and, after prolonged highly-active-antiretroviral-therapy, it was also positively correlated to insulin resistance.

CONCLUSIONS

This study is the first one to demonstrate that a-FABP could be a useful marker in unraveling central fat accumulation in HIV-infected children on highly-active-antiretroviral-therapy. Large prospective studies are needed to confirm these results.

The role of Nrf2: adipocyte differentiation, obesity, and insulin resistance

Metabolic diseases, such as type 2 diabetes and obesity, are increasing globally, and much work has been performed to elucidate the regulatory mechanisms of these diseases. Nuclear factor E2-related factor 2 (Nrf2) is a basic leucine zipper transcription factor that serves as a primary cellular defense against the cytotoxic effects of oxidative stress. Recent studies have proposed a close relationship between oxidative stress and energy metabolism-associated disease. The Nrf2 pathway, as a master regulator of cellular defense against oxidative stress, has emerged as a critical target of energy metabolism; however, its effects are controversial. This review examines the current state of research on the role of Nrf2 on energy metabolism, specifically with respect to its participation in adipocyte differentiation, obesity, and insulin resistance, and discusses the possibility of using Nrf2 as a therapeutic target in the clinic.

Adipokines in the HIV/HAART-associated lipodystrophy syndrome

The use of highly active antiretroviral therapy (HAART) in the treatment of human immunodeficiency virus has dramatically altered both the landscape of this disease and the prognosis for those affected. With more patients now receiving HAART, adverse effects such as lipodystrophy and metabolic syndrome have emerged. In HIV/HAART-associated lipodystrophy syndrome (HALS), patients demonstrate fat maldistribution with dyslipidemia, insulin resistance, and other metabolic complications. Recent studies have contributed to the elucidation of the pathophysiological abnormalities seen in this syndrome and have provided guidance for the study and use of potential treatments for these patients, but widely accepted guidelines have not yet been established. Two adipokines, leptin and adiponectin, are decreased in patients with HALS and lipoatrophy or lipodystrophy. Further, recent proof-of-concept clinical trials have proven the efficacy of leptin replacement and medications that increase circulating adiponectin levels in improving the metabolic profile of HALS patients. This review article highlights recent evidence on leptin replacement and compares leptin's efficacy to that of other treatments, including metformin and thiazolidinediones, on metabolic abnormalities such as impaired insulin-glucose homeostasis associated with lipodystrophy in patients receiving HAART. It is hoped that forthcoming large phase III clinical trials will allow the addition of leptin to our therapeutic armamentarium for use in patients suffering from this disease state.

Leptin's role in lipodystrophic and nonlipodystrophic insulin-resistant and diabetic individuals

Leptin is an adipocyte-secreted hormone that has been proposed to regulate energy homeostasis as well as metabolic, reproductive, neuroendocrine, and immune functions. In the context of open-label uncontrolled studies, leptin administration has demonstrated insulin-sensitizing effects in patients with congenital lipodystrophy associated with relative leptin deficiency. Leptin administration has also been shown to decrease central fat mass and improve insulin sensitivity and fasting insulin and glucose levels in HIV-infected patients with highly active antiretroviral therapy (HAART)-induced lipodystrophy, insulin resistance, and leptin deficiency. On the contrary, the effects of leptin treatment in leptin-replete or hyperleptinemic obese individuals with glucose intolerance and diabetes mellitus have been minimal or null, presumably due to leptin tolerance or resistance that impairs leptin action. Similarly, experimental evidence suggests a null or a possibly adverse role of leptin treatment in nonlipodystrophic patients with nonalcoholic fatty liver disease. In this review, we present a description of leptin biology and signaling; we summarize leptin's contribution to glucose metabolism in animals and humans in vitro, ex vivo, and in vivo; and we provide insights into the emerging clinical applications and therapeutic uses of leptin in humans with lipodystrophy and/or diabetes.

Selective capacity of metreleptin administration to reconstitute CD4+ T-cell number in females with acquired hypoleptinemia

Leptin is an adipocyte-derived hormone that controls food intake and reproductive and immune functions in rodents. In uncontrolled human studies, low leptin levels are associated with impaired immune responses and reduced T-cell counts; however, the effects of leptin replacement on the adaptive immune system have not yet been reported in the context of randomized, controlled studies and/or in conditions of chronic acquired leptin deficiency. To address these questions, we performed a randomized, double-blinded, placebo-controlled trial of recombinant methionyl-human leptin (metreleptin) administration in replacement doses in women experiencing the female triad (hypothalamic amenorrhea) with acquired chronic hypoleptinemia induced by negative energy balance. Metreleptin restored both CD4(+) T-cell counts and their in vitro proliferative responses in these women. These changes were accompanied by a transcriptional signature in which genes relevant to cell survival and hormonal response were up-regulated, and apoptosis genes were down-regulated in circulating immune cells. We also observed that signaling pathways involved in cell growth/survival/proliferation, such as the STAT3, AMPK, mTOR, ERK1/2, and Akt pathways, were activated directly by acute in vivo metreleptin administration in peripheral blood mononuclear cells and CD4(+) T-cells both from subjects with chronic hypoleptinemia and from normoleptinemic, lean female subjects. Our data show that metreleptin administration, in doses that normalize circulating leptin levels, induces transcriptional changes, activates intracellular signaling pathways, and restores CD4(+) T-cell counts. Thus, metreleptin may prove to be a safe and effective therapy for selective CD4(+) T-cell immune reconstitution in hypoleptinemic states such as tuberculosis and HIV infection in which CD4(+) T cells are reduced.

Benefits of leptin therapy in HIV patients

Leptin therapy in human recombinant form has recently been used in HIV-associated lipodystrophy syndrome on experimental basis in some small short-term clinical trials. It has shown its beneficial effects only in hypoleptinemic HIV-infected patients by causing definite improvement in their insulin sensitivity, glucose tolerance, lipid status, and truncal obesity. Leptin prevents lipotoxicity and activates insulin signaling pathways through several postulated mechanisms. Central leptin insufficiency with peripheral hyperleptinemia has come out to be a significant contributor to the development of obesity and metabolic syndrome. In this article, we will review the basis of leptin therapy in HIV patients, with its promises. However, further larger clinical trials are needed to prove its long-term efficacy in the control of metabolic complications related to HIV therapy.

Leptin in relation to the lipodystrophy-associated metabolic syndrome

Leptin, an adipocyte-secreted hormone, regulates energy homeostasis as well as reproductive, neuroendocrine, immune and metabolic functions. Subjects with decreased amounts of fat in their adipose tissue, i.e., lipoatrophy, have low leptin levels. In the context of open-label, uncontrolled studies leptin administration, in physiological replacement doses, has been shown to have metabolically salutary effects in the rare patients with the syndrome of congenital lipodystrophy accompanied by leptin deficiency. Much more patients with lipodystrophy suffer from lipodystrophy and the metabolic syndrome associated with the use of highly active antiretroviral therapy. In this so called highly active antiretroviral therapy (HAART)-associated lipodystrophy and metabolic syndrome, patients demonstrate fat maldistribution with dyslipidemia, insulin resistance, and other metabolic complications. Leptin administration has been shown to decrease central fat mass and to improve fasting insulin/glucose levels and insulin sensitivity in human immunodeficiency virus-infected hypoleptinemic patients with HAART induced lipodystrophy and the metabolic syndrome. By contrast, the results of leptin treatment in leptin replete or hyperleptinemic obese individuals with glucose intolerance and diabetes mellitus have been minimal or null, presumably due to leptin tolerance or resistance that impairs leptin action. In this review, we present the emerging clinical applications and potential therapeutic uses of leptin in humans with lipodystrophy and the metabolic syndrome.

Secreted factors from adipose tissue increase adipogenic differentiation of mesenchymal stem cells

OBJECTIVES

Adipose tissue engineering is one of the hottest topics in the field of regenerative medicine. Fat tissue has been considered as an abundant and accessible source of adult stem cells by tissue engineers, since it gives rise to adipose stem cells. However, recent reports have pointed out that adipose tissue, as a secretory and endocrine organ, might secrete cytokines that regulate body functions such as metabolism, infammation and more. In this study, we aim to investigate the adipogenic-inducing factors secreted by fat tissue.

MATERIALS AND METHODS

Conditioned medium were collected by culturing fat tissue fragments in plastic flasks. Mesenchymal stem cells (MSCs) cultured in conditioned medium (CM) to test the adipogenic-inducing factors. Oil red O staining, reverse transcription/polymerase chain reaction and immunocytofluorescent staining were performed to examine the differentiation of MSCs in CM.

RESULTS

MSCs cultured in CM of adipose tissue spontaneously differentiated into adipocytes. Furthermore, supplementation of insulin or dexamethasone to CM accelerated the process of lipid accumulation of differentiated MSCs.

DISCUSSION

Results from this study demonstrated that fat tissues secrete small molecules, which induce adipogenic differentiation of MSCs.

CONCLUSIONS

Our study provides clues for improving adipose tissue engineering by using fragmented adipose tissue as sources of fat-inducing factors.

The pathophysiology of HIV-/HAART-related metabolic syndrome leading to cardiovascular disorders: the emerging role of adipokines

Individuals infected with human immunodeficiency virus (HIV) frequently demonstrate metabolic syndrome (MS) associated with increased incidence of cardiovascular disorders. Characteristics of HIV infection, such as immunodeficiency, viral load, and duration of the disease, in addition to the highly active antiretroviral therapy (HAART) have been suggested to induce MS in these patients. It is well documented that MS involves a number of traditional cardiovascular risk factors, like glucose, lipids, and arterial blood pressure abnormalities, leading to extensive atherogenic arterial wall changes. Nevertheless, the above traditional cardiovascular risk factors merely explain the exacerbated cardiovascular risk in MS. Nowadays, the adipose-tissue derivatives, known as adipokines, have been suggested to contribute to chronic inflammation and the MS-related cardiovascular disease. In view of a novel understanding on how adipokines affect the pathogenesis of HIV/HAART-related MS and cardiovascular complications, this paper focuses on the interaction of the metabolic pathways and the potential cardiovascular consequences. Based on the current literature, we suggest adipokines to have a role in the pathogenesis of the HIV/HAART-related MS. It is crucial to understand the pathophysiology of the HIV/HAART-related MS and apply therapeutic strategies in order to reduce cardiovascular risk in HIV patients.

Brown fat activity is not apparent in subjects with HIV lipodystrophy and increased resting energy expenditure

The HIV lipodystrophy (LD) syndrome is associated with increased resting energy expenditure (REE), but the basis of this hypermetabolism has not been determined. The objective of this pilot study was to determine if brown fat is activated in subjects with HIV LD and increased REE. In this descriptive study of four subjects with HIV LD and marked hypermetabolism, REE was measured by indirect calorimetry and brown fat activity was determined by (18)F-fluorodeoxyglucose (FDG) positron-emission tomography (PET) combined with anatomic computed tomography (CT). Brown fat activity was not apparent in any subject with HIV LD and resting hypermetabolism. Therefore, brown fat activation is unlikely to be the principal cause of the increased REE associated with the HIV LD syndrome. Evidence of adaptive thermogenesis has been demonstrated in this syndrome, but this study suggests that tissues other than brown adipose tissue (BAT) are responsible. Further understanding of the chronic hypermetabolism associated with HIV LD could provide new insights into the regulation of energy balance.

Effect of extended-release niacin on hormone-sensitive lipase and lipoprotein lipase in patients with HIV-associated lipodystrophy syndrome

BACKGROUND

HIV-associated lipodystrophy syndrome is strongly associated with antiretroviral treatment in patients with human immunodeficiency virus (HIV). Niacin is thought to affect hormone-sensitive lipase (HSL) and lipoprotein lipase (LPL) expression in peripheral and intra-abdominal fat (IAF).

OBJECTIVE

This study investigated the effect of extended-release niacin (ERN) on adipose HSL and LPL expression in patients with HIV-associated lipodystrophy syndrome.

METHODS

Changes in IAF and peripheral fat content and HSL and LPL expression were examined in 4 HIV-infected patients recruited from a prospective study treated with ERN. Patients underwent limited 8 slice computerized tomography abdominal scans, dual-energy X-ray absorptiometry scans, and skin punch biopsies of the mid-thigh at baseline and after 12 weeks of ERN. All subjects were on stable highly active antiretroviral therapy prior to and during the study. Changes in body habitus were self-reported.

RESULTS

Normalized HSL expression decreased in 3 patients and normalized LPL expression increased in all 4 patients when comparing pre- and post-ERN treated samples. All subjects showed a decrease in total cholesterol (TC) and triglyceride (TG) levels.

CONCLUSIONS

Preliminary analysis suggests ERN may induce changes in HSL and LPL expression. This method is a feasible approach to identify changes in adipose RNA expression involved with lipolysis.

Leptin replacement improves postprandial glycemia and insulin sensitivity in human immunodeficiency virus-infected lipoatrophic men treated with pioglitazone: a pilot study

Highly active antiretroviral therapy (HAART)-induced lipoatrophy is characterized by hypoleptinemia and insulin resistance. Evidence suggests that pioglitazone and recombinant methionyl human leptin (metreleptin) administration has beneficial effects in human immunodeficiency virus (HIV)-infected lipoatrophic patients. This proof-of-concept study aimed at evaluating whether the combination of metreleptin and pioglitazone has favorable effects, above and beyond pioglitazone alone, on both metabolic outcomes and peripheral lipoatrophy in HIV-infected patients on HAART. Nine HIV-positive men with at least 6 months of HAART exposure, clinical evidence of lipoatrophy, and low leptin concentrations (≤4 ng/mL) were placed on pioglitazone treatment (30 mg/d per os) and were randomized to receive either metreleptin (0.04 mg/kg subcutaneously once daily; n = 5) or placebo (n = 4) for 3 months in a double-blinded fashion. Compared with placebo, metreleptin reduced fasting serum insulin concentration, increased adiponectin concentration, reduced the homeostasis model assessment index of insulin resistance, and attenuated postprandial glycemia in response to a mixed meal (all P ≤ .02), but did not affect trunk and peripheral fat mass. HIV control was not affected, and no major adverse effects were observed. Metreleptin administration in HIV-positive, leptin-deficient patients with lipoatrophy treated with pioglitazone improves postprandial glycemia and insulin sensitivity. Results from this pilot study should be confirmed in larger clinical trials.

Lipodystrophy: pathophysiology and advances in treatment

Lipodystrophy is a medical condition characterized by complete or partial loss of adipose tissue. Not infrequently, lipodystrophy occurs in combination with pathological accumulation of adipose tissue at distinct anatomical sites. Patients with lipodystrophy exhibit numerous metabolic complications, which indicate the importance of adipose tissue as an active endocrine organ. Not only the total amount but also the appropriate distribution of adipose tissue depots contribute to the metabolic state. Genetic and molecular research has improved our understanding of the mechanisms underlying lipodystrophy. Circulating levels of hormones secreted by the adipose tissue, such as leptin and adiponectin, are greatly reduced in distinct subpopulations of patients with lipodystrophy. This finding rationalizes the use of these adipokines or of agents that increase their circulating levels, such as peroxisome proliferator-activated receptor γ (PPARγ) agonists, for therapeutic purposes. Other novel therapeutic approaches, including the use of growth hormone and growth-hormone-releasing factors, are also being studied as potential additions to the therapeutic armamentarium. New insights gained from research and clinical trials could potentially revolutionize the management of this difficult-to-treat condition.

[Metabolic disorders in emerging and neglected infectious diseases]

The gradual and progressive replacement of infectious and parasitic by chronic diseases as causes of morbidity and mortality, characterizing the process of epidemiological transition hasn't been observed in various populations, especially in underdeveloped or developing countries characterizing a superposition of these profiles (incomplete transition). Besides the increased prevalence of metabolic disorders, various infectious diseases remain endemic in several regions, such as leprosy, tuberculosis, leishmaniasis, viral hepatitis, among others, as well as emerging diseases in recent decades, as HIV infection/Aids. In this context, more attention has been given to the occurrence of metabolic disturbances in the recent years, mainly from the observation of a high incidence of metabolic disorders associated with HIV infection/Aids, and its therapy with antiretroviral drugs. This review addresses clinical and epidemiological aspects of metabolic disturbances reported in some infectious and parasitic diseases with worldwide and local (Brazil) relevance, as well as possible mechanisms and factors involved in these associations.

Diabetes mellitus, insulin resistance, and metabolic syndrome in HIV-positive patients in South India

Insulin resistance, diabetes mellitus, and metabolic syndrome in patients with human immunodeficiency virus (HIV) infection are increasingly being reported in the global medical literature. This cross-sectional study was done to describe the occurrence of metabolic syndrome, diabetes mellitus, and insulin resistance in HIV-positive patients in a tertiary referral center in South India. A total of 60 patients who had HIV infection for 12 months or more were enrolled in the study. Of these, 30 patients were antiretroviral therapy (ART)-naïve, and 30 were treated with ART. Biochemical estimations (fasting blood glucose, 75 g oral glucose tolerance test, lipid profile, and fasting insulin) and anthropometric measurements (height, weight, and waist circumference) were performed for each patient. Metabolic syndrome was diagnosed using National Cholesterol Education Program–Adult Treatment Plan III criteria, and insulin resistance was calculated applying the homeostasis model assessment method. Diabetes mellitus, impaired fasting glycemia, and impaired glucose tolerance were diagnosed based on American Diabetes Association criteria. A high prevalence of metabolic syndrome was observed in patients with HIV (16/60), and was more prevalent in the ART-treated group (13/30; P = 0.028). Similarly, insulin resistance was also noted to be high (24/60), and of these patients, 15 were on ART. Seventy-five percent of patients with metabolic syndrome had insulin resistance. Diabetes was diagnosed in one patient who was ART-naïve and in six patients who were on ART. Our observations suggest an increased prevalence of metabolic syndrome, insulin resistance, and diabetes mellitus in ART-treated patients. These warrant attention and substantiation with larger studies. While ART improves survival, it may lead on to cardiovascular morbidity and mortality, especially in the Indian subcontinent where there is a genetic predisposition to cardiovascular risk.

[The role of the hospital pharmacist in the prevention, treatment and management of the side effects associated with antiretroviral treatment]

At present, the side effects associated with antiretroviral treatment are the main reasons for discontinuation of this kind of therapy, both in clinical trials and in regular clinical practise. On the other hand, due to the change of direction that our profession has suffered in recent years, we face the need to establish a different relationship with the patient, achieving direct and effective Pharmaceutical Care within a framework of shared responsibility for therapeutic results. Pharmacist interventions should be aimed at improving the quality of life of patients, which can only be achieved with a multidisciplinary approach and individualised and adjusted to new patterns of toxicity of the drugs currently used. The pharmacist who does this work must know how to interpret these side effects, giving accurate information to the patient about both pharmacological and non-pharmacological treatment and correct pharmaceutical follow-up which clearly sets forth the criteria for referral to medical appointments. The aim of this paper is to establish baselines so that the hospital pharmacist can perform clearly and uniformly in the prevention, identification and management of major side effects: gastrointestinal, cardiovascular, dermatological, at the central nervous system and kidney level, associated with antiretroviral therapy.

Clinical classification and treatment of congenital and acquired lipodystrophy

OBJECTIVE

To review the initial clinical manifestations of congenital and acquired lipodystrophy syndromes, discuss novel classifications associated with genetic mutations, and assess currently available therapeutic options for patients with lipodystrophy.

METHODS

This review is the result of the authors' collective clinical experience and a comprehensive MEDLINE literature search on the English-language literature published between January 1966 and October 2009 on "lipodystrophy." This review focuses primarily on severe dystrophy not related to human immunodeficiency virus (HIV) infection, in light of the additional scope required to cover HIV-related lipodystrophy.

RESULTS

Congenital lipodystrophy syndromes are characterized by a paucity of adipose tissue and classified on the basis of the extent of fat loss and heritability Paradoxically, they are associated with metabolic abnormalities often found in obese patients, including insulin resistance, diabetes, and severe hypertriglyceridemia. Patients with severe forms of lipodystrophy are also deficient in adipokines such as leptin, which may contribute to metabolic abnormalities. The search for molecular defects has revealed a role for genes that affect adipocyte differentiation (for example, peroxisome proliferator-activated receptor gamma), lipid droplet morphology (seipin, caveolin-1), or lipid metabolism (AGPAT2). Others (lamin A/C) are known to be associated with completely different diseases. There are also acquired forms of lipodystrophy that are thought to occur primarily attributable to autoimmune mechanisms. Recently, recombinant leptin has emerged as a useful therapy.

CONCLUSION

Lipodystrophy syndromes have advanced our understanding of the physiologic role of adipose tissue and allowed identification of key molecular mechanisms involved in adipocyte differentiation. Novel therapeutic strategies are being developed on the basis of the pathophysiologic aspects of these syndromes.

Dual-energy X-ray absorptiometry modeling to explain the increased resting energy expenditure associated with the HIV lipoatrophy syndrome

BACKGROUND

The HIV lipoatrophy syndrome is characterized by loss of subcutaneous fat and is associated with increased resting energy expenditure (REE). Recently, dual-energy X-ray absorptiometry (DXA) modeling of organ-tissue mass combined with specific organ-tissue metabolic rates has been used to gain further insight into the relation of the lean body mass to REE and to better understand differences in REE between groups.

OBJECTIVE

This study examined the organ-tissue basis of the increased REE shown in HIV lipoatrophy.

DESIGN

REE was measured in 29 HIV-infected patients with lipoatrophy and in 29 HIV-infected and 19 healthy control subjects. Five organ-tissue mass components (brain, bone, skeletal muscle, adipose tissue, and residual mass) were calculated with the use of DXA modeling and body weight.

RESULTS

DXA modeling showed no significant differences in predicted REE between the 3 groups. However, measured REE was significantly greater in subjects with lipoatrophy than in control subjects. Measured REE remained significantly greater in lipoatrophy subjects after routine adjustment for lean body mass and after adjustment for each organ-tissue mass component. Finally, DXA and regression modeling of REE suggests that increased energy expenditure in skeletal muscle may account for the resting hypermetabolism of patients with HIV lipoatrophy.

CONCLUSIONS

Increased REE in subjects with HIV lipoatrophy cannot be explained by differences in organ-tissue mass as modeled by DXA. Instead, DXA and regression modeling of REE suggests that skeletal muscle is hypermetabolic in patients with HIV lipoatrophy. This may be a form of adaptive thermogenesis in response to an inability to store triglyceride fuel in a normal manner.

Lipodystrophy and metabolic complications of highly active antiretroviral therapy

OBJECTIVE

To assess the metabolic drug toxicities of first-line, World Health Organization (WHO)-recommended generic highly active antiretroviral therapy (HAART) regimens, to estimate the prevalence of body fat redistribution and to identify associated risk factors.

METHODS

Cross-sectional observational study. During 3 month period, 52 HIV infected children (25 on HAART; 27 not on HAART) were assessed. Their sociodemographic, clinical, and immunological data was recorded. Children were examined or the signs of fat redistribution (peripheral lipoatrophy and central lipohypertrophy). Liver function tests, fasting blood sugar, lipid profile, serum amylase, serum lactate, blood pH and bicarbonate levels were done in all patients.

RESULTS

Twenty-two patients were on stavudine and three on zidovudine based HAART. None of the patients ever received any protease inhibitor. There were no cases of clinical or immunological failure. Children on HAART had significantly lower weight for age and body mass index but the mean height for age was similar between study groups. Only two cases of peripheral lipoatrophy were observed. Hypercholesterolemia was observed in four children on HAART but none without therapy. Hypertriglyceridemia was observed in three children on HAART and seven without therapy. Four cases of asymptomatic mild hyperlactatemia were observed. No case of any hyperglycemia or liver impairment was observed.

CONCLUSION

Metabolic abnormalities and lipodystrophy are emerging complications of HAART in Indian children and needs very close follow up. Future studies with larger sample size and longitudinal model are recommended.

Genetic disruption of myostatin reduces the development of proatherogenic dyslipidemia and atherogenic lesions in Ldlr null mice

OBJECTIVE

Insulin-resistant states, such as obesity and type 2 diabetes, contribute substantially to accelerated atherogenesis. Null mutations of myostatin (Mstn) are associated with increased muscle mass and decreased fat mass. In this study, we determined whether Mstn disruption could prevent the development of insulin resistance, proatherogenic dyslipidemia, and atherogenesis.

RESEARCH DESIGN AND METHODS

C57BL/6 Ldlr(-/-) mice were cross-bred with C57BL/6 Mstn(-/-) mice for >10 generations to generate Mstn(-/-)/Ldlr(-/-) double-knockout mice. The effects of high-fat/high-cholesterol diet on body composition, plasma lipids, systemic and tissue-specific insulin sensitivity, hepatic steatosis, as well as aortic atheromatous lesion were characterized in Mstn(-/-)/Ldlr(-/-) mice in comparison with control Mstn(+/+)/Ldlr(-/-) mice.

RESULTS

Compared with Mstn(+/+)/Ldlr(-/-) controls, Mstn(-/-)/ Ldlr(-/-) mice were resistant to diet-induced obesity, and had greatly improved insulin sensitivity, as indicated by 42% higher glucose infusion rate and 90% greater muscle [(3)H]-2-deoxyglucose uptake during hyperinsulinemic-euglycemic clamp. Mstn(-/-)/Ldlr(-/-) mice were protected against diet-induced hepatic steatosis and had 56% higher rate of hepatic fatty acid beta-oxidation than controls. Mstn(-/-)/Ldlr(-/-) mice also had 36% lower VLDL secretion rate and were protected against diet-induced dyslipidemia, as indicated by 30-60% lower VLDL and LDL cholesterol, free fatty acids, and triglycerides. Magnetic resonance angiography and en face analyses demonstrated 41% reduction in aortic atheromatous lesions in Ldlr(-/-) mice with Mstn deletion.

CONCLUSIONS

Inactivation of Mstn protects against the development of insulin resistance, proatherogenic dyslipidemia, and aortic atherogenesis in Ldlr(-/-) mice. Myostatin may be a useful target for drug development for prevention and treatment of obesity and its associated type 2 diabetes and atherosclerosis.

[Prevalence of HIV-associated lipodystrophy in Brazilian outpatients: relation with metabolic syndrome and cardiovascular risk factors]

Lipodystrophy in HIV-infected patients (LDHIV) affects 40-50% of HIV-infected patients, but there are no data on its prevalence in Brazil. The aim of this study was to assess the LDHIV prevalence among HIV-infected adult Brazilian individuals, as well as to evaluate LDHIV association with cardiovascular risk factors and the metabolic syndrome (MS). It was included 180 adult HIV-infected outpatients consecutively seen in the Infectology Clinic of Universidade Estadual de Londrina. Anthropometric and clinical data (blood pressure, family and personal comorbidities, duration of HIV infection/AIDS, antiretroviral drugs used, CD4+ cells, viral load, fasting glycemia and plasma lipids) were obtained both from a clinical interview as well as from medical charts. LDHIV was defined as the presence of body changes self-reported by the patients and confirmed by clinical exam. MS was defined using the NCEP-ATPIII criteria, reviewed and modified by AHA/NHLBI. A 55% prevalence of LDHIV was found. Individuals with LDHIV presented a longer infected period since HIV infection, longer AIDS duration and longer use of antiretroviral drugs. In multivariate analysis, women (p=0.006) and AIDS duration >8 years (p<0.001) were independently associated with LDHIV. Concerning MS diagnostic criteria, high blood pressure was found in 32%, low HDL-cholesterol in 68%, hypertriglyceridemia in 55%, altered waist circumference in 17% and altered glycemia and/or diabetes in 23% of individuals. Abnormal waist and hypertriglyceridemia were more common in LDHIV-affected individuals. MS was diagnosed in 36%. In multivariate analysis, the factors associated with MS were: BMI >25 kg/m(2) (p<0.001), family history of obesity (p=0.01), indinavir (p=0.001) and age >40 years on HIV first detection (p=0.002). There was a trend to higher frequency of LDHIV among patients with MS (65% versus 50%, p=0.051). LDHIV prevalence among our patients (55%) was similar to previous reports from other countries. MS prevalence in these HIV-infected individuals seems to be similar to the prevalence reported on Brazilian non-HIV-infected adults.

Metabolic disorders induced by highly active antiretroviral therapy and their relationship with vascular remodeling of the brachial artery in a population of HIV-infected patients

Antiretroviral therapy has positively modified the natural history of HIV infection; but this treatment can induce metabolic abnormalities, including dyslipidemia, fat redistribution, high blood pressure, and insulin resistance. The metabolic syndrome, a clustering of the metabolic disorders, is frequently detected among HIV patients, especially those on antiretroviral treatment. All the arteries can modify their diameter in response to a chronic injury. This process, defined vascular remodeling, was demonstrated for the brachial artery. It is well known that the diameter of the brachial artery was correlated with the number of the elements of the metabolic syndrome and was associated with the severity of coronary artery disease. On this basis, we postulate that brachial arterial enlargement may be a process potentially correlated with the metabolic disorders induced by antiretroviral therapy. We tested this hypothesis in a large population of HIV-infected patients in which we measured brachial artery diameter, as an indicator of artery remodeling, by noninvasive, ultrasonographic technique. Our population consisted of 570 patients, with a mean age of 46.3 +/- 7.1 years. All the patients were chronically treated with highly active antiretroviral therapy. Brachial artery diameter was correlated with insulin resistance, evaluated by the homeostasis model assessment of insulin resistance index (r = 0.18, P < .0001). There was a significant linear increase in brachial artery diameter as the number of components of the metabolic syndrome increased: brachial artery diameter for those with 0, 1, 2, 3, or + characteristics was 39.3 +/- 7.2, 41.0 +/- 6.8, 42.0 +/- 7.3, and 43.8 +/- 7.9 mm, respectively (P < .001 for trend). In multivariable logistic regression analysis, brachial artery diameter was independently correlated with the presence of metabolic syndrome. Our results are in line with the hypothesis that, among HIV-infected patients chronically treated with antiretroviral therapy, those with a larger brachial artery diameter are at high risk for metabolic disorders, including a more severe insulin resistance and the presence of metabolic syndrome.