Association of the polymorphisms of the genes APOC3 (rs2854116), ESR2 (rs3020450), HFE (rs1799945), MMP1 (rs1799750) and PPARG (rs1801282) with lipodystrophy in people living with HIV on antiretroviral therapy: a systematic review.

The aim of this study was to perform a systematic review to identify data reported in the literature concerning the association of APOC3 (rs2854116), ESR2 (rs3020450), HFE (rs1799945), MMP1 (rs1799750) and PPARG (rs1801282) polymorphisms with lipodystrophy in people living with HIV (PLWHIV) on antirretroviral therapy. The research was conducted in six databases and the studies were selected in two steps. First, a search was undertaken in the following electronic databases: PubMed, Science Direct, Medline, World Wide Science, Directory of Open Access Journals, Scielo, Lilacs and Medcarib. The titles and abstracts of 24,859 articles were read to select those that match the elegibilty criteria. Five papers that addressed the association of HAART, lipodystrophy and polymorphisms were selected for the review. There was no association between the polymorphisms of the genes APOC3 and PPARG and lipodystrophy. Another study described an association between the variant allele (G) of HFE and protection concerning the development of lipoatrophy (0.02) when compared with the reference allele (C). On the other hand, the variant allele (T) of the ESR2 gene was associated with the development of lipoatrophy (p = 0.007) when compared with the reference allele (C). In addition, the genotype and the variant allele of the gene MMP1 (2G) were associated with lipodystrophy in PLWHIV on HAART (p = 0.0002 and p = 0.0008, respectively). Therefore, further studies with other populations, involving PLWHIV on HAART are necessary to better understand the role of genetic markers, which may be involved in a predisposition to lipodystrophy.

Subcutaneous Adipocyte Adenosine Triphosphate Levels in HIV Infected Patients.

Lipoatrophy, or fat wasting, remains a syndrome plaguing HIV+ patients receiving antiretroviral (ARV) therapy. Both HIV infection per se and certain ARV are associated with lowered adipose tissue mitochondrial deoxyribonucleic acid (mtDNA) and mitochondrial ribonucleic acid (mtRNA) levels, but effects on adenosine triphosphate (ATP) production are unclear. We hypothesized that such alterations would accompany lowering of ATP levels in fat of HIV+ patients and would be worse in those displaying lipoatrophy. Gluteal-fold, subcutaneous adipose tissue was obtained from HIV seronegative control patients, from HIV+ ARV-naive patients, and those on ARV with or without lipoatrophy. Cellular ATP was measured in isolated adipocytes and preadipocyte fraction cells by bioluminescence. mtDNA copies/cell and oxidative phosphorylation (OXPHOS) mtRNA transcripts were evaluated by quantitative polymerase chain reactions. ATP levels were consistently higher in preadipocyte fraction cells than adipocytes, but values strongly correlated with each other (r = 0.66, p < .001). ATP levels in adipocytes were higher in both ARV-naive and nonlipoatrophic HIV+ patients compared to seronegative controls, but significantly lower in adipocytes and preadipocytes of lipoatrophic versus other HIV+ patients. Fat mtDNA copies/cell and OXPHOS mtRNA transcripts were lower in lipoatrophic patient samples compared to HIV seronegative. The ratio of specific OXPHOS transcripts to each other was significantly higher in nonlipoatrophic patients versus all groups, and this ratio correlated significantly with ATP levels in adipocytes. Thus, HIV infection is associated with an increase in adipose tissue ATP stores. Decreases in adipose mtDNA and OXPHOS mtRNA are found in those with HIV on ARV; however, ATP level is effected only in patients displaying lipoatrophy.

CT Fat Density Accurately Reflects Histologic Fat Quality in Adults With HIV On and Off Antiretroviral Therapy.

CONTEXT: Microscopic measurement of adipocyte size is the gold standard for determining adipose tissue (AT) quality. AT density on CT may also reflect adipocyte quality (lower density = poorer quality). OBJECTIVE: We used abdominal subcutaneous AT (SAT) specimens and CT scans to validate CT SAT density as a marker of SAT quality in adults living with HIV. SETTING AND DESIGN: Secondary data analysis from completed trial of antiretroviral therapy (ART) initiation (ACTG A5224s). CT abdominal SAT density was measured in HU. SAT specimens were digitally scanned for calculation of mean adipocyte area. PARTICIPANTS: Participants had SAT biopsy and CT data at baseline (n = 54) and HIV-1 RNA <50 copies per milliliter on ART and biopsy or CT data at week 96 (n = 30). OUTCOME MEASURES: Spearman correlations and linear regression models adjusting for participant characteristics examined associations between SAT density and adipocyte area. RESULTS: Baseline median age was 40 years, CD4+ T lymphocyte count 219 cells per cubic millimeter, and body mass index 26.0 kg/m2; 89% were male and 67% white. Median SAT area and density were 199 cm2 and -100 HU. Over 96 weeks, SAT area increased (+18%) and SAT density decreased (-3%). Mean SAT adipocyte area correlated with SAT density (P < 0.01) off and on ART after adjustment for SAT area, age, race, sex, CD4+ T lymphocyte count, and HIV-1 RNA. CONCLUSIONS: CT SAT density correlates with biopsy-quantified SAT adipocyte size in adults with HIV on and off ART, suggesting that CT is a useful tool for noninvasive assessment of SAT quality.

Doubly Labeled Water Method and Accelerometer for the Measurement of Energy Expenditure in Human Immunodeficiency Virus-Infected Patients.

BACKGROUND: Several studies have reported increased resting energy expenditure (REE) in human immunodeficiency virus (HIV)-infected patients with HIV-associated lipodystrophy syndrome (HALS). However, limited data exist on the total energy expenditure (TEE). This study was aimed at evaluating the REE and TEE of HIV-infected patients with and without HALS by using the doubly labeled water (DLW) technique and the activity monitor based on accelerometry system (AM), and comparing the results obtained using both methods. METHODS: Evaluated total of 45 HIV+ men undergoing antiretroviral therapy, including 18 LIPO- (without lipodystrophy) and 27 LIPO+ (with lipodystrophy) individuals were evaluated. Habitual physical activity patterns were measured by using the ActivPAL™ AM system, REE by indirect calorimetry, and TEE by DLW and AM. RESULTS: No significant differences were found between LIPO- and LIPO+ in REE (1,433 ± 196 vs. 1,510 ± 203 kcal), TEE-DLW (2,691 ± 856 vs. 2,618 ± 415 kcal) and TEE-AM (2,560 ± 458 vs. 2,594 ± 456 kcal), respectively. RQ was a predictor of REE in LIPO+. TEE estimated by the AM had a moderate correlation with DLW, but there was a wide variance in the intra-subject results. CONCLUSIONS: TEE is not increased in HIV-infected patients with HALS. AM should be used with caution for TEE evaluation during clinical practice.

A pilot study of brisk walking in sedentary combination antiretroviral treatement (cART)- treated patients: benefit on soluble and cell inflammatory markers.

BACKGROUND: Chronic HIV infection is associated with low-level inflammation and increased risk of chronic diseases and mortality. The objective was to assess the effects of moderate intensity exercise on metabolic and inflammatory markers in HIV-infected treated persons. METHODS: This was a pilot study enrolling cART-treated, sedentary persons with metabolic complications in a 12-week protocol, consisting of three sessions per week of 60 min brisk walking with (strength-walk group) or without (walk group) 30 min circuit-training. Assessments at baseline and week 12 (W12) included body morphometrics and total body dual-energy X-ray absorptiometry; lipid and glucose blood profile; plasma level of high sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), D-dimer, interleukin-18 (IL-18), soluble CD14, and CD38 and HLA-DR expression on CD4+ and CD8+ T-cells. RESULTS: Forty-nine patients were included and 35 (71%) completed the program: 21 in the walk and 14 in the strength-walk group. At W12, significant improvements were observed of body mass index, waist and hip circumference, and total cholesterol both overall and in the walk group, and of LDL cholesterol in both training groups. In the whole group, significant reductions were observed in hsCRP, IL-6, D-dimer, IL-18, and of CD8+/CD38+/HLA-DR+ cell frequencies. HsCRP and CD8+/CD38+/HLA-DR+ frequency decreased significantly in both training groups when examined separately whereas IL-6 and D-dimer in the walk group only. CONCLUSIONS: Brisk walking, with or without strength exercise, could improve lipid profile and inflammatory markers in chronic HIV infection. TRIAL REGISTRATION: ACTRN12615001258549, registered 17 November 2015, "retrospectively registered" Web address of trial: http://www.ANZCTR.org.au/ACTRN12615001258549.aspx.

IL-4 and IL-6 levels and adipose tissue distribution in HIV-1 patients under antiretroviral therapy.

PURPOSE: Combined antiretroviral therapy (cART) for the treatment of HIV-1 infection has been associated with complications, including lipodystrophy. Several interleukins have been implicated in the pathology and physiology of lipodystrophy. The present study aimed to compare the levels of IL-4 and IL-6 in HIV-1 patients under cART with and without, clinically and fat mass ratio defined, lipodystrophy and in four different groups of fat distribution: (1) no lipodystrophy; (2) isolated central fat accumulation; (3) isolated lipoatrophy and (4) mixed forms of lipodystrophy. METHODS: In the present cross-sectional study we evaluated IL-4 and IL-6 levels, insulin resistance and insulin sensitivity indexes in 86 HIV-infected adults under cART. RESULTS: No significant differences in IL-4 and IL-6 levels between the four groups of body composition were observed. Patients with HOMA-IR >4 presented higher levels of IL-6 and lower levels of IL-4, although without statistical significance. No correlation between IL-6, or IL-4, HOMA-IR and quantitative body fat mass distribution was found. CONCLUSION: Although there was a tendency for patients with isolated lipoatrophy and isolated fat accumulation to present higher IL-6 levels, these differences were not statistically significant. No differences were found relating IL-4 levels.

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.

Lipid metabolism and lipodystrophy in HIV-1-infected patients: the role played by nonnucleoside reverse transcriptase inhibitors.

Dyslipidemia and lipodystrophy represent significant healthcare concerns in HIV-infected patients due to their association with diabetes mellitus and increased cardiovascular disease risk. Since the lipid effects of the nonnucleoside reverse transcriptase inhibitors are not well characterized, we systematically summarized the effects of nonnucleoside reverse transcriptase inhibitor treatment on dyslipidemia and lipodystrophy in HIV-1 infection. As with other classes of antiretroviral agents, the nonnucleoside reverse transcriptase inhibitors are associated with lipid changes, although individual agents exhibit differing effects on lipid profiles. Comparative trials have shown that the risk for hypertriglyceridemia is lower with efavirenz than with the use of ritonavir-boosted lopinavir, but there is a greater likelihood of hypercholesterolemia compared to ritonavir-boosted atazanavir. Data also suggest that efavirenz results in greater increases in plasma lipid levels than integrase inhibitors and CC-chemokine-receptor-5 antagonists. Lipid disturbances are less frequent with the newer nonnucleoside reverse transcriptase inhibitors than with efavirenz. However, in most cases, no change in the total:high-density lipoprotein-cholesterol ratio was seen between the efavirenz and comparator groups. Switching from efavirenz to etravirine or rilpivirine, or the integrase inhibitors raltegravir or elvitegravir, resulted in significant reductions in lipid levels. There appears to be minimal potential for efavirenz or rilpivirine to result in development of lipodystrophy. Overall, nonnucleoside reverse transcriptase inhibitors have a smaller impact on plasma lipids than ritonavir-boosted protease inhibitors, with the newer agents exhibiting more favorable lipid profiles than efavirenz. When considering antiretroviral regimens, awareness of the different lipid effect profiles of the third agent is important, without forgetting the critical contribution of the background antiretrovirals.

Altered miRNA processing disrupts brown/white adipocyte determination and associates with lipodystrophy.

miRNAs are important regulators of biological processes in many tissues, including the differentiation and function of brown and white adipocytes. The endoribonuclease dicer is a major component of the miRNA-processing pathway, and in adipose tissue, levels of dicer have been shown to decrease with age, increase with caloric restriction, and influence stress resistance. Here, we demonstrated that mice with a fat-specific KO of dicer develop a form of lipodystrophy that is characterized by loss of intra-abdominal and subcutaneous white fat, severe insulin resistance, and enlargement and "whitening" of interscapular brown fat. Additionally, KO of dicer in cultured brown preadipocytes promoted a white adipocyte-like phenotype and reduced expression of several miRNAs. Brown preadipocyte whitening was partially reversed by expression of miR-365, a miRNA known to promote brown fat differentiation; however, introduction of other miRNAs, including miR-346 and miR-362, also contributed to reversal of the loss of the dicer phenotype. Interestingly, fat samples from patients with HIV-related lipodystrophy exhibited a substantial downregulation of dicer mRNA expression. Together, these findings indicate the importance of miRNA processing in white and brown adipose tissue determination and provide a potential link between this process and HIV-related lipodystrophy.

Adipokines, hormones related to body composition, and insulin resistance in HIV fat redistribution syndrome.

BACKGROUND: Lipodystrophies are characterized by adipose tissue redistribution, insulin resistance (IR) and metabolic complications. Adipokines and hormones related to body composition may play an important role linking these alterations. Our aim was to evaluate adipocyte-derived hormones (adiponectin, leptin, resistin, TNF-α, PAI-1) and ghrelin plasma levels and their relationship with IR in HIV-infected patients according to the presence of lipodystrophy and fat redistribution. METHODS: Anthropometric and metabolic parameters, HOMA-IR, body composition by DXA and CT, and adipokines were evaluated in 217 HIV-infected patients on cART and 74 controls. Fat mass ratio defined lipodystrophy (L-FMR) was defined as the ratio of the percentage of the trunk fat mass to the percentage of the lower limb fat mass by DXA. Patient's fat redistribution was classified into 4 different groups according the presence or absence of either clinical lipoatrophy or abdominal prominence: no lipodystrophy, isolated central fat accumulation (ICFA), isolated lipoatrophy and mixed forms (MXF). The associations between adipokines levels and anthropometric, metabolic and body composition were estimated by Spearman correlation. RESULTS: Leptin levels were lower in patients with FMR-L and isolated lipoatrophy, and higher in those with ICFA and MXF. Positive correlations were found between leptin and body fat (total, trunk, leg, arm fat evaluated by DXA, and total, visceral (VAT), subcutaneous adipose tissue (SAT), and VAT/SAT ratio evaluated by CT) regardless of FMR-L, and with HOMA-IR only in patients with FMR-L. Adiponectin correlated negatively with VAT, and its mean levels were lower in patients with ICFA and higher in those with no lipodystrophy. Resistin was not correlated with adipose tissue but positively correlated with HOMA-IR in FMR-L patients. PAI-1 levels were higher in MXF-patients and their levels were positively correlated with VAT in those with FMR-L. Ghrelin was higher in HIV-infected patients than controls despite BMI-matching. CONCLUSION: The overall body fat reduction in HIV lipoatrophy was associated with low leptin plasma levels, and visceral fat accumulation was mainly associated with decreased plasma levels of adiponectin.

A 48-week study of fat molecular alterations in HIV naive patients starting tenofovir/emtricitabine with lopinavir/ritonavir or efavirenz.

BACKGROUND: Conflicting reports on the effects of efavirenz (EFV) and lopinavir/ritonavir (LPV/r) on subcutaneous adipose tissue (SAT) have been described. OBJECTIVE: The aim was to assess the 48-week molecular and clinical effects of LPV/r and EFV, combined with tenofovir/emtricitabine (TDF/FTC), on SAT of HIV-infected, antiretroviral-naive patients. METHODS: Forty-four adults were started on LPV/r or EFV combined with TDF/FTC. Fasting metabolic tests, HIV RNA, CD4 cell count, and fat measured by dual x-ray absorptiometry scans were obtained at study entry and week 48. Mitochondrial DNA (mtDNA) and transcripts for mtDNA-encoded proteins and genes involved in inflammation, adipocyte differentiation, and metabolism were assessed in paired SAT biopsies. RESULTS: Whole-body fat and limb fat mass increased in the LPV/r and EFV groups. MtDNA and cytochrome oxidase subunit II did not change, and cytochrome b increased significantly in EFV-treated patients. Tumor necrosis factor alpha and monocyte chemotactic protein-1 gene expression did not change in the LPV/r group, but these significantly increased in the EFV group. Interleukin 18 decreased in the LPV/r group, whereas it increased in the EFV group. CONCLUSIONS: Starting TDF/FTC plus EFV was associated with an increased expression of genes encoding for inflammatory cytokines in SAT in naive patients. Therapy with TDF/FTC plus LPV/r or EFV was associated with an increase in subcutaneous fat mass.

Immunohistochemical analysis of the expression of TNF-alpha, TGF-beta, and caspase-3 in subcutaneous tissue of patients with HIV lipodystrophy syndrome.

INTRODUCTION: HIV Lipodystrophy Syndrome (HIVLS) is a multifactorial clinical expression that presents alterations in the metabolism and distribution pattern of body fat via immunological changes capable of disrupting homeostasis. This study aimed to analyze the degree of inflammatory, anti-inflammatory, and apoptosis activity in the subcutaneous tissue of patients, based on the expression of Tumor Necrosis Factor-α (TNF-α), Transforming Growth Factor-ß (TGF-ß), and caspase-3, respectively, and correlate them with clinical data and with each other. METHODS: This is a cross-analytical study. The biopsy of subcutaneous cellular tissue was performed on the right thigh of 19 patients with HIVLS who were attended to at a university hospital, and four people without HIV and lipodystrophy, for comparison. The type of lipodystrophy and the estimation of body fat were obtained during the consultation or obtained from medical charts. The cytokine expression was observed in the adipose tissue through the streptavidin-biotin peroxidase method, and analyzed by optical microscopy. RESULTS: Despite the mixed clinical form having been prevalent in both genders, men were more lipoatrophic and women were more lipohypertrophic. Men showed higher expression of TNF-α and caspase-3 than women. Patients with lipodystrophy had higher expression of TNF-α and caspase-3 and lower TGF-ß, compared to the control group. The percentage of body fat was negatively correlated with the expression of TNF-α and caspase-3. Longer durations of infection and use of antiretroviral therapy (ARVT) were positively associated with the levels of TNF-α. The expression of caspase-3 and TGF-ß was associated with higher levels of TNF-α. CONCLUSION: Regardless of the clinical form, HIVLS is characterized by a chronic inflammatory process associated with the male gender, the percentage of body fat, and lipoatrophy manifestations. There is increased apoptotic activity in more inflamed tissues and there is correlation between TNF-α and TGF-ß, which suggests a possible negative feedback mechanism between the inflammatory and anti-inflammatory activity.

Involvement of the LPS-LPB-CD14-MD2-TLR4 inflammation pathway in HIV-1/HAART-associated lipodystrophy syndrome (HALS).

OBJECTIVES: A relationship between obesity and intestinal bacterial translocation has been reported. Very little information is available with respect to the involvement of the bacterial translocation mechanistic pathway in HIV-1/highly active antiretroviral therapy (HAART)-associated lipodystrophy syndrome (HALS). We determined whether lipopolysaccharide (LPS)-binding protein (LBP), cluster of differentiation 14 (CD14), myeloid differentiation protein 2 (MD2) and toll-like receptor 4 (TLR4) single-nucleotide polymorphisms and LPS, LBP and soluble CD14 (sCD14) plasma levels are involved in HALS. PATIENTS AND METHODS: This cross-sectional multicentre study involved 558 treated HIV-1-infected patients, 240 with overt HALS and 318 without HALS. Anthropometric, clinical, immunovirological and metabolic variables were determined. Polymorphisms were assessed by genotyping. Plasma levels were determined by ELISA in 163 patients (81 with HALS and 82 without HALS) whose stored plasma samples were available. Student's t-test, one-way ANOVA, two-way repeated measures ANOVA, the χ(2) test and Pearson and Spearman correlation analyses were carried out for statistical analysis. RESULTS: LBP rs2232582 T→C polymorphism was significantly associated with HALS (P = 0.01 and P = 0.048 for genotype and allele analyses, respectively). Plasma levels of LPS (P = 0.009) and LBP (P < 0.001) were significantly higher and sCD14 significantly lower (P < 0.001) in patients with HALS compared with subjects without HALS. LPS levels were independently predicted by triglycerides (P < 0.001) and hepatitis C virus (P = 0.038), LBP levels by HALS (P < 0.001) and sCD14 levels by age (P = 0.008), current HIV-1 viral load (P = 0.001) and protease inhibitor use (P = 0.018). CONCLUSIONS: HALS is associated with LBP polymorphism and with higher bacterial translocation.

Investigating the effects of metabolic dysregulation on hair follicles: a comparison of HIV-infected women with and without central lipohypertrophy.

BACKGROUND: Normal lipid metabolism and functioning of the peroxisome proliferator-activated receptor gamma (PPAR-gamma) in the sebaceous gland is critical to maintaining a normal hair follicle. Human immunodeficiency virus (HIV) infection affects lipid metabolism; some have hypothesized a link between PPAR-gamma function and lipodystrophy in HIV infection. Our objective was to determine whether lipodystrophy is associated with altered hair characteristics in HIV-infected women from the Women's Interagency HIV Study. METHODS: Hair characteristics and scalp inflammation were assessed by an interviewer-administered questionnaire. Central lipohypertrophy and peripheral lipoatrophy were defined by self-report of moderate to severe fat gain in central body sites and fat loss in peripheral body sites, respectively confirmed by clinical examination. Additional covariates considered in the analyses included demographics, behavioral characteristics, medical history, and HIV-related factors. RESULTS: There were 1037 women with data on all study variables; 76 women reported central lipohypertrophy, while only four women reported lipoatrophy. Women with central lipohypertrophy were more likely to be older, had a self-reported history of injection drug use, statin medication use, diabetes, elevated cholesterol, and have self-reported less hair and shorter eyelashes. After adjustment for age, central lipohypertrophy was associated with shorter eyelashes (OR 2.3; 95% CI 1.4-3.8). CONCLUSIONS: Central lipohypertrophy was not associated with change in scalp hair texture or scalp inflammation in this cohort. Rather, we found an association between central lipohypertrophy and shorter eyelash length. This finding may be explained by an influence of prostaglandin E2 mediators on eyelash follicles.

CD8 T-cell activation is associated with lipodystrophy and visceral fat accumulation in antiretroviral therapy-treated virologically suppressed HIV-infected patients.

OBJECTIVE: HIV-infected patients receiving antiretroviral treatment frequently accumulate fat at the abdominal level. It is unknown whether T-cell activation and immune phenotypes are associated with fat accumulation. Thus, the aim of the study was to search for an association between the presence of clinical lipodystrophy (LD), visceral and subcutaneous abdominal adipose tissue amount (VAT and SAT), and peripheral T-cell immune phenotypes. DESIGN: Cross-sectional study including 87 HIV-infected antiretroviral therapy-treated virologically suppressed and immune-reconstituted patients. METHODS: The patients were evaluated for clinical LD, VAT, SAT, homeostasis model of insulin resistance, and coronary artery calcium score (>10). T-cell activation (CD8/CD38), differentiation (CD4/CD8/CCR7/CD45RA), and expression/activation of the interleukin-7 (IL-7)/IL-7R system (CD4/CD8/CD127, IL-7, and CD4/CD8/pStat-5) were assessed by cytometry. RESULTS: In multivariable analyses, CD8 T-cell activation (CD38) was associated with lipoatrophy and central fat accumulation (respectively, ß = 5.63, P = 0.005, and ß = 4.19, P = 0.020). This was also the case for IL-7R expressing CD8⁺ T cells (CD127⁺) for lipoatrophy ß = 12.8, P = 0.003, and for central fat accumulation ß = 9.45, P = 0.016. CD8⁺ T-cell activation was also associated with VAT/total adipose tissue (ß = 0.01, P = 0.002) and SAT/VAT ratios (ß = -0.014, P = 0.015). As expected, VAT/total adipose tissue was an independent risk factor for homeostasis model of insulin resistance (r = 0.364, P = 0.028) and cardiovascular risk (coronary artery calcium, r = 0.406, P = 0.002). CONCLUSIONS: CD8⁺ T-cell activation was associated with LD and the relative amount of VAT in antiretroviral therapy-controlled, virologically suppressed, HIV-infected patients. We propose that CD8 activation may be involved in the accumulation of central fat frequently observed in these patients, with resulting increased cardiometabolic risk.

Thiazolidinediones in the treatment of HIV/HAART-associated lipodystrophy syndrome.

The treatment of HIV-1 infected patients with HAART has resulted in long-term suppression of viral replication and reduced progression to AIDS. However, the use of HAART has been associated with adverse effects, including metabolic dysregulation and changes in body fat deposition. This syndrome, known as HIV/HAART-associated lipodystrophy syndrome, is characterized by insulin resistance, dyslipidemia, lipodystrophy, and increased visceral adiposity, which contribute to an increased risk of cardiovascular disease amongst these patients. The thiazolidinediones are a class of agonists for the nuclear receptors, the peroxisome proliferator-activated receptor. Since peroxisome proliferator-activated receptor is critically involved in the regulation of insulin sensitivity and lipid metabolism, a number of clinical trials have analyzed whether thiazolidinediones could ameliorate the signs of HIV/HAART-associated lipodystrophy syndrome. Based on these trials, thiazolidinediones appear to up-regulate peroxisome proliferator-activated receptor-dependent genes such as adiponectin, an effect that could have important physiological benefits in the long-term for HIV/HAART-associated lipodystrophy syndrome patients. Critically, many of the studies were of short duration and thus the beneficial effects of thiazolidinediones might have been missed. In addition, the few studies on the thiazolidinedione pioglitazone showed a beneficial effect on limb fat mass that was not associated with a pro-atherogenic lipid profile. Based on these studies, a large-scale clinical trial of pioglitazone use in HIV/HAART-associated lipodystrophy syndrome patients is warranted.

HIV-associated lipodystrophy: impact of antiretroviral therapy.

In the late 1990s, reports of unusual changes in body fat distribution named 'lipodystrophy' (LD) began to appear in HIV patients mitigating the enormous enthusiasm about improvement of survival and quality of life provided by the combinations of antiretroviral (ARV) drug classes, the so-called highly active antiretroviral therapy (HAART), which had just become available at that time. The objective of this paper is to critically review the literature on LD and to discuss the impact of newer ARV agents, namely atazanavir, darunavir and raltegravir, as well as strategies of the late HAART era, including single-tablet regimens and nucleoside-sparing regimens. Studies in which LD was measured by dual-energy x-ray absorptiometry or by abdominal computed tomography or magnetic resonance imaging scan only, were included. We were unable to identify studies depicting a negative impact of drugs or ARV regimens on limb fat loss. On the contrary, a few studies identified a negative impact of atazanavir/ritonavir or darunavir/ritonavir on trunk fat increase. It should be noted that this anthropometric measure is a poor instrument since it cannot distinguish between subcutaneous and visceral fat. We conclude that presumably the body fat changes currently observed in HIV-infected patients is the net result of competing phenomena: on one side the natural history of lipohypertrophy as a result of HIV and HAART impact, and on the other side the physiological body fat changes observed in the aging population.

Role of mitochondria in HIV infection and associated metabolic disorders: focus on nonalcoholic fatty liver disease and lipodystrophy syndrome.

Highly active antiretroviral therapy (HAART) has considerably improved the prognosis of HIV-infected patients. However, prolonged use of HAART has been related to long-term adverse events that can compromise patient health such as HIV-associated lipodystrophy syndrome (HALS) and nonalcoholic fatty liver disease (NAFLD). There is consistent evidence for a central role of mitochondrial dysfunction in these pathologies. Nucleotide reverse transcriptase inhibitors (NRTIs) have been described to be mainly responsible for mitochondrial dysfunction in adipose tissue and liver although nonnucleoside transcriptase inhibitors (NNRTIs) or protease inhibitors (PIs) have also showed mitochondrial toxicity, which is a major concern for the selection and the long-term adherence to a particular therapy. Several mechanisms explain these deleterious effects of HAART on mitochondria, and evidence points to other mechanisms beyond the "Pol- γ hypothesis." HIV infection has also direct effects on mitochondria. In addition to the negative effects described for HIV itself and/or HAART on mitochondria, HIV-infected patients are more prone to develop a premature aging and, therefore, to present an increased oxidative state that could lead to the development of these metabolic disturbances observed in HIV-infected patients.

In vitro and in vivo effects of IGF-I on adiposity in HIV-associated metabolic disease: a pilot study.

BACKGROUND AND AIMS: We tested the effects of recombinant insulin-like growth factor-I (IGF-I) in an adipocyte model of HIV lipodystrophy and in an open label study on body composition and metabolism in patients with HIV lipodystrophy. METHODS: The effects of IGF-I on ritonavir-induced adipocyte cell death were studied in vitro. We assessed lipid accumulation, IGF signaling, apoptosis, and gene expression. We conducted a 24-week open label trial of recombinant IGF-I in ten adults with HIV associated lipoatrophy. Laboratory assessments included glucose, insulin, lipids, and IGF-I. At weeks 0 and 24, body composition studies were performed including skinfold measurement, dual-energy x-ray absorptiometry, and computed tomography of the abdomen and thigh. RESULTS: In vitro, ritonavir increased delipidation and apoptosis of adipocytes, whereas co-treatment with IGF-I attenuated the effect. In the clinical study, subcutaneous adipose tissue did not increase in patients after treatment with IGF-I; however, there was a decrease in the proportion of abdominal fat (39.8 ± 7% vs. 34.6 ± 7%, p = 0.007). IGF-I levels increased with treatment (143 ± 28 µg/L at week 0 vs. 453 ± 212 µg/L at week 24, p = 0.002), whereas IGFBP-3 levels declined (3.554 ± 1.146 mg/L vs. 3.235 ± 1.151 mg/L, p = 0.02). Insulin at week 12 decreased significantly (90.1 ± 39.8 pmol/L vs. 33.2 ± 19.6 pmol/L, p = 0.002). There was a nonsignificant decrease in visceral adipose tissue (155.2 ± 68 cm² at week 0 vs. 140.6 ± 70 cm² at week 24, p = 0.08). CONCLUSIONS: Use of recombinant IGF-I may lower fasting insulin and abdominal fat in patients with lipoatrophy associated with HIV infection. Further evaluation of this agent for treatment of HIV-associated lipodystrophy may be warranted.