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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.

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, β = 5.63, P = 0.005, and β = 4.19, P = 0.020). This was also the case for IL-7R expressing CD8⁺ T cells (CD127⁺) for lipoatrophy β = 12.8, P = 0.003, and for central fat accumulation β = 9.45, P = 0.016. CD8⁺ T-cell activation was also associated with VAT/total adipose tissue (β = 0.01, P = 0.002) and SAT/VAT ratios (β = -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.

Background: To determine the role of fibroblast growth factor (FGF)-19 and FGF21 and the endocrine FGFs receptor system in the metabolic alterations that manifest in HIV-1-infected patients undergoing highly active antiretroviral treatment (HAART)., Methods: Serum FGF19 and FGF21 levels were determined in 4 groups of individuals as follows: (1) HIV-1-infected HAART patients with lipodystrophy (n = 38); or (2) without lipodystrophy (n = 34); (3) untreated (naive) HIV-1-infected patients (n = 34); and (4) healthy controls (n = 31). Serum FGF19 levels were correlated with anthropometric, metabolic, HIV-1 infection-related, and HAART-related parameters and with FGF21 levels. The gene expression of FGF receptor 1 and the coreceptor β-Klotho was analyzed in adipose tissue from 10 individuals from each group., Results: Serum FGF19 levels were significantly reduced in all groups of HIV-1-infected patients, whereas FGF21 levels were increased. FGF19 levels were negatively correlated with insulin resistance and insulin levels and positively correlated with high-density lipoprotein cholesterol. FGF19 was inversely correlated with cumulative exposure to nucleoside reverse transcriptase inhibitor and nonnucleoside reverse transcriptase inhibitor drugs. The expression of FGF receptor 1 and coreceptor β-Klotho was reduced in adipose tissue from all groups of HIV-infected patients., Conclusions: FGF19 levels are reduced in HIV-1-infected patients, in contrast with FGF21 levels. Impaired expression of the corresponding receptor and coreceptor, which mediate the actions of endocrine FGFs in adipose tissue, suggests a resistance to the metabolic effects of FGF19 and FGF21 in HIV-1-infected patients. Considering the beneficial effects of endocrine FGFs on metabolism, the observed reduction in FGF19 levels and decreased sensitivity to endocrine FGFs in adipose tissue may contribute to metabolic alterations in HIV-1-infected patients.

Background: Long-term antiretroviral therapy dramatically reduces HIV-related morbidity and mortality but is also associated with metabolic and morphological changes and requires high levels of adherence., Methods: A randomized, 48-week, open-label, comparative study of continuation of twice-daily zidovudine/lamivudine or replacement with once-daily tenofovir disoproxil fumarate/emtricitabine in individuals on successful efavirenz-based antiretroviral therapy. Limb fat mass was assessed by dual x-ray absorptiometry in a subset of participants through week 48., Results: Two hundred thirty-four individuals were randomized and treated (117 each to continue or switch) with 206 subjects completing 48 weeks of study. Five percent subjects in the continue group and 3% subjects in the switch group discontinued due to adverse events. By intent-to-treat, missing = failure analysis, no differences in virological efficacy were observed at any time point (week 48 <50 copies/mL continue 85%, switch 88%). At week 24, switching was associated with significant increases in hemoglobin (mean difference 0.37 g/dL, 95% confidence interval: 0.15 to 0.58 g/dL, P < 0.001) and significant declines in total cholesterol and triglycerides. In the dual x-ray absorptiometry substudy (n = 100), fat was preserved or increased in the switch group but declined in the continue group (mean difference 448 g, 95% confidence interval: 57 to 839 g, P = 0.025). Individuals with longer exposure to zidovudine and lower baseline limb fat experienced less limb fat increase after switching. No differences in renal adverse events were observed between groups., Conclusions: Switching from zidovudine/lamivudine to tenofovir disoproxil fumarate/emtricitabine in persons on efavirenz therapy maintains virological control, establishes a once-daily regimen, results in improvements in hemoglobin and key lipid parameters, and preserves and restores limb fat relative to continuation of zidovudine/lamivudine.

Comparisons of body composition and metabolic changes among antiretroviral-naive patients randomly assigned to didanosine and stavudine- (ddI+d4T) vs. abacavir and lamivudine- (ABC+3TC) containing regimens were assessed in a nested substudy of an ongoing multicenter randomized trial. At baseline and every 4 months, body cell mass and total body fat were calculated, anthropometric measurements were performed, and fasting metabolic parameters were obtained. The rates of change (unit/mo) estimated using the slopes of regression lines and overall mean changes from baseline were compared by study assignment. Among 96 patients enrolled, 46 received ddI+d4T- and 50 received ABC+3TC-containing regimens with a median follow-up of 32.4 months. For both study arms, an overall increase in the rates of change was seen for body cell mass. For ddI+d4T, after an initial increase, the rates of change declined for regional fat and total body fat compared with an increase for ABC+3TC, with the 2 arms being significantly different (P<0.05). For high-density lipoprotein cholesterol rates of change, ddI+d4T decreased, while ABC+3TC increased. For both arms, low-density lipoprotein cholesterol decreased, while triglycerides increased. Early and sustained increases in insulin and insulin resistance were seen only for ddI+d4T. In this prospective study, metabolic and body composition changes varied according to whether subjects received ddI+d4T or ABC+3TC.

Ten HIV-infected nucleoside reverse transcriptase inhibitor-treated subjects with lipoatrophy or sustained hyperlactatemia were given antioxidants: vitamins C, E, and N-acetyl cysteine. After 24 weeks, anthropometrics did not change significantly, except for a modest decrease in the waist-to-hip ratio. Fasting low-density lipoprotein cholesterol trended toward lower values. Fasting glucose significantly increased along with a significant increase in homeostatic model assessment values, reflecting an increase in insulin resistance. Controlled trials are required to evaluate directly the effects of these agents on lipid and glucose metabolism.

Osteopenia and osteoporosis have recently been described as complications of antiretroviral therapy in HIV-infected patients. The advent of highly active antiretroviral therapy in conjunction with improved standard antiviral and antibiotic regimens has dramatically changed the clinical course of HIV infection, resulting in prolonged survival. The pathogenesis and role of each individual medication are poorly understood. Avascular necrosis has also been described in AIDS patients receiving or not receiving antiretroviral therapy. This article is a clinically focused review of the literature on osteopenia, osteoporosis, and mineral metabolism related to HIV infection. In patients with HIV infection, the risks of osteopenia and osteoporosis are not very clear. The suggested risk factors for the development of osteopenia are use of protease inhibitors, longer duration of HIV infection, high viral load, high lactate levels, low bicarbonate levels, raised alkaline phosphatase level, and lower body weight before antiretroviral therapy. There have also been a few case reports of pathologic fractures in AIDS patients with antiretroviral therapy-induced osteopenia and osteoporosis. The underlying mechanism triggering bone loss in HIV-infected patients is unknown. The proinflammatory cytokines tumor necrosis factor and interleukin-6 have been found to be constitutionally produced in increased amounts in HIV-positive individuals, and they may have a role in osteoclast activation and resorption. Serum markers of bone formation are decreased and resorption is increased in patients with advanced clinical disease. Hypocalcemia, hypercalcemia, and abnormalities of the parathyroid hormone axis have been described in HIV infection. Histomorphometric analyses have shown altered bone remodeling in HIV-infected patients when compared with controls. Patients with known risk factors for osteoporosis-advancing age, low body weight, and prolonged duration of HIV infection-and those receiving protease inhibitor treatment should be considered for dual x-ray absorptiometry imaging. If bone mineral density is osteopenic or osteoporotic, then the patient should also be screened for other known medical causes of osteoporosis and consider treatment with a bisphosphonate or, if hypogonadal, testosterone replacement under close monitoring.