Sex differences in the associations of HIV disease characteristics and body composition in antiretroviral-naive persons

Changes in body mass index, weight, and waist-to-hip ratio over five years in HIV-positive individuals in the HIV Heart Aging Study compared to the general population

PURPOSE

Overweight and obesity have increased in people living with HIV (PLH). Our study evaluated weight, body-mass-index (BMI), and waist-to-hip ratio (WHR) change over 5 years of follow-up in PLH compared to the general population.

METHODS

HIV-positive participants in the HIV Heart Aging (HIVH) study were matched 1:2 by age and sex with HIV-negative controls of the population-based Heinz Nixdorf Recall (HNR) study. Both studies were recruited in the German Ruhr area. The association between HIV and weight, BMI, and WHR changes was examined using linear regression. Regression models were adjusted for parameters potentially affecting weight gain.

RESULTS

The matched HIVH and HNR participants (N = 585 and N = 1170, respectively; 14.7% females) had a mean age of 55 years at baseline. Despite the lower baseline weight (- 6 kg, 95% CI - 7.46 to - 4.59), the linear regression showed greater absolute and relative weight and BMI increases after 5 years in HIVH compared to HNR. Adjusting the linear regression models for smoking amplified that HIVH had a higher absolute and relative weight difference of 0.7 kg or ~ 1% compared to HNR after 5 years (95% Cl 0.1 to 1.3 and 0.2 to 1.6, respectively). Adjusting for HDL, LDL, systolic blood pressure, and diabetes mellitus did not affect the results.

CONCLUSIONS

PLH had lower weight than the general population at baseline and after 5 years, but experienced greater increases in body weight after 5 years. WHR change after 5 years was lower in PLH compared to the general population, despite a higher WHR at baseline.

Chronic Exposure to HIV-Derived Protein Tat Impairs Endothelial Function via Indirect Alteration in Fat Mass and Nox1-Mediated Mechanisms in Mice

People living with human immunodeficiency virus (HIV) (PLWH) have increased risk for atherosclerosis-related cardiovascular disease (CVD), the main cause of death in this population. Notwithstanding, the mechanisms of HIV-associated vascular pathogenesis are not fully elucidated. Therefore, we sought to determine whether HIV-regulatory protein Tat mediates HIV-induced endothelial dysfunction via NADPH oxidase 1 (Nox1)-dependent mechanisms. Body weight, fat mass, leptin levels, expression of reactive oxygen species (ROS)-producing enzymes and vascular function were assessed in C57BL/6 male mice treated with Tat for 3 days and 4 weeks. Aortic rings and human endothelial cells were also treated with Tat for 2–24 h in ex vivo and in vitro settings. Chronic (4 weeks) but not acute (3 days and 2–24 h) treatment with Tat decreased body weight, fat mass, and leptin levels and increased the expression of Nox1 and its coactivator NADPH oxidase Activator 1 (NoxA1). This was associated with impaired endothelium-dependent vasorelaxation. Importantly, specific inhibition of Nox1 with GKT771 and chronic leptin infusion restored endothelial function in Tat-treated mice. These data rule out direct effects of HIV-Tat on endothelial function and imply the contribution of reductions in adipose mass and leptin production which likely explain upregulated expression of Nox1 and NoxA1. The Nox1 and leptin system may provide potential targets to improve vascular function in HIV infection-associated CVD.

HIV and antiretroviral therapy-related fat alterations

Early in the HIV epidemic, lipodystrophy, characterized by subcutaneous fat loss (lipoatrophy), with or without central fat accumulation (lipohypertrophy), was recognized as a frequent condition among people living with HIV (PLWH) receiving combination antiretroviral therapy. The subsequent identification of thymidine analogue nucleoside reverse transcriptase inhibitors as the cause of lipoatrophy led to the development of newer antiretroviral agents; however, studies have demonstrated continued abnormalities in fat and/or lipid storage in PLWH treated with newer drugs (including integrase inhibitor-based regimens), with fat gain due to restoration to health in antiretroviral therapy-naive PLWH, which is compounded by the rising rates of obesity. The mechanisms of fat alterations in PLWH are complex, multifactorial and not fully understood, although they are known to result in part from the direct effects of HIV proteins and antiretroviral agents on adipocyte health, genetic factors, increased microbial translocation, changes in the adaptive immune milieu after infection, increased tissue inflammation and accelerated fibrosis. Management includes classical lifestyle alterations with a role for pharmacological therapies and surgery in some patients. Continued fat alterations in PLWH will have an important effect on lifespan, healthspan and quality of life as patients age worldwide, highlighting the need to investigate the critical uncertainties regarding pathophysiology, risk factors and management.

Specific Biological Features of Adipose Tissue, and Their Impact on HIV Persistence

Although white AT can contribute to anti-infectious immune responses, it can also be targeted and perturbed by pathogens. The AT's immune involvement is primarily due to strong pro-inflammatory responses (with both local and paracrine effects), and the large number of fat-resident macrophages. Adipocytes also exert direct antimicrobial responses. In recent years, it has been found that memory T cells accumulate in AT, where they provide efficient secondary responses against viral pathogens. These observations have prompted researchers to re-evaluate the links between obesity and susceptibility to infections. In contrast, AT serves as a reservoir for several persistence pathogens, such as human adenovirus Ad-36, Trypanosoma gondii, Mycobacterium tuberculosis, influenza A virus, and cytomegalovirus (CMV). The presence and persistence of bacterial DNA in AT has led to the concept of a tissue-specific microbiota. The unexpected coexistence of immune cells and pathogens within the specific AT environment is intriguing, and its impact on anti-infectious immune responses requires further evaluation. AT has been recently identified as a site of HIV persistence. In the context of HIV infection, AT is targeted by both the virus and the antiretroviral drugs. AT's intrinsic metabolic features, large overall mass, and wide distribution make it a major tissue reservoir, and one that may contribute to the pathophysiology of chronic HIV infections. Here, we review the immune, metabolic, viral, and pharmacological aspects that contribute to HIV persistence in AT. We also evaluate the respective impacts of both intrinsic and HIV-induced factors on AT's involvement as a viral reservoir. Lastly, we examine the potential consequences of HIV persistence on the metabolic and immune activities of AT.

Muscle strength is impaired in men but not in women living with HIV taking antiretroviral therapy

BACKGROUND

There is evidence that HIV antiretroviral therapy adverse effects may be sex-dependent, but data examining these sex differences in muscle strength is scarce. Our aim was to compare dynamic and isokinetic parameters of muscle strength between HIV-infected men and women to HIV-uninfected subjects.

METHODS

In this cross-sectional study, muscle strength was evaluated in 44 HIV-infected (20 men, 24 women) and 25 age-, race- and body mass index-matched HIV-uninfected subjects (11 men, 14 women). We assessed knee flexion and extension efforts in isokinetic dynamometer at angular velocities of 60° and 180°/s, and 1 repetition maximum test (1RM) for bench press, leg press and arm curl exercises, respectively. Lean body mass (LBM) was measured using bioelectrical impedance.

RESULTS

HIV-infected men had significantly less dynamic muscle strength for 1RM total (262.5 versus 357.2 kg), bench press (48.6 versus 60.3 kg), leg press (182.7 versus 261 kg) and arm curl (31.2 versus 36.5 kg) compared to HIV-uninfected men (P≤0.05); no differences were found among women. Men had lower values for peak torque in extension and flexion movements at 60°/s and 180°/s, while HIV-infected women presented higher peak torque in extension movement at 60°/s compared to controls. No differences were found in LBM. Moreover, isokinetic evaluation demonstrated that HIV-infected subjects showed greater acceleration and deceleration time in some variables, compared to controls, related to difficulty in activating motor units.

CONCLUSIONS

HIV infection is associated with impaired dynamic and isokinetic strength in men compared to HIV-uninfected controls, but not in women.

Impact of HIV/simian immunodeficiency virus infection and viral proteins on adipose tissue fibrosis and adipogenesis

OBJECTIVE

HIV-infected patients receiving antiretroviral treatment (ART) often present adipose tissue accumulation and/or redistribution. adipose tissue has been shown to be an HIV/SIV reservoir and viral proteins as Tat or Nef can be released by infected immune cells and exert a bystander effect on adipocytes or precursors. Our aim was to demonstrate that SIV/HIV infection per se could alter adipose tissue structure and/or function.

DESIGN

Morphological and functional alterations of subcutaneous (SCAT) and visceral adipose tissue (VAT) were studied in SIV-infected macaques and HIV-infected ART-controlled patients. To analyze the effect of Tat or Nef, we used human adipose stem cells (ASCs) issued from healthy donors, and analyzed adipogenesis and extracellular matrix component production using two dimensional (2D) and three-dimensional (3D) culture models.

METHODS

Adipocyte size and index of fibrosis were determined on Sirius red-stained adipose tissue samples. Proliferating and adipocyte 2D-differentiating or 3D-differentiating ASCs were treated chronically with Tat or Nef. mRNA, protein expression and secretion were examined by RT-PCR, western-blot and ELISA.

RESULTS

SCAT and VAT from SIV-infected macaques displayed small adipocytes, decreased adipogenesis and severe fibrosis with collagen deposition. SCAT and VAT from HIV-infected ART-controlled patients presented similar alterations. In vitro, Tat and/or Nef induced a profibrotic phenotype in undifferentiated ASCs and altered adipogenesis and collagen production in adipocyte-differentiating ASCs.

CONCLUSION

We demonstrate here a specific role for HIV/SIV infection per se on adipose tissue fibrosis and adipogenesis, probably through the release of viral proteins, which could be involved in adipose tissue dysfunction contributing to cardiometabolic alterations of HIV-infected individuals.

The association between cytomegalovirus infection, obesity, and metabolic syndrome in U.S. adult females

OBJECTIVE

The purpose of this analysis was to determine whether cytomegalovirus (CMV) infection is associated with the prevalence of metabolic syndrome (MetS) and whether this relationship differs by BMI.

METHODS

Data from the 1999-2004 National Health and Nutrition Examination Survey (NHANES) were pooled (N = 2,532). Logistic regression was used for assessing the association between CMV and MetS, stratified by gender and BMI, categorized as normal weight, overweight, obesity, and extreme obesity, and adjusted for age, race/ethnicity, and poverty level.

RESULTS

In unadjusted analyses, CMV infection was significantly associated with MetS in females (OR: 1.50; 95% CI: 1.1-2.1) but not males. After adjusting for confounders, the odds of MetS were higher in CMV+ normal-weight females (aOR: 65.31; 95% CI: 6.8-625.6) but lower in CMV+ females with extreme obesity (aOR: 0.25; 95% CI: 0.1-0.9). CMV infection was associated with higher high-density lipoprotein cholesterol (HDL-C) and lower triglycerides in females with extreme obesity but lower HDL-C in normal-weight females.

CONCLUSIONS

CMV infection was found to be associated with unique MetS phenotypes that differ between BMI categories and gender. Seropositive normal-weight females had a higher prevalence of MetS and dyslipidemia, while infection in females with extreme obesity was associated with a more metabolically benign profile.

Change in serum 25-hydroxyvitamin D with antiretroviral treatment initiation and nutritional intervention in HIV-positive adults

Low vitamin D level in HIV-positive persons has been associated with disease progression. We compared the levels of serum 25-hydroxyvitamin D (25(OH)D) in HIV-positive and HIV-negative persons, and investigated the role of nutritional supplementation and antiretroviral treatment (ART) on serum 25(OH)D levels. A randomised nutritional supplementation trial was conducted at Jimma University Specialized Hospital, Ethiopia. The trial compared 200 g/d of lipid-based nutrient supplement (LNS) with no supplementation during the first 3 months of ART. The supplement provided twice the recommended daily allowance of vitamin D (10 μg/200 g). The level of serum 25(OH)D before nutritional intervention and ART initiation was compared with serum 25(OH)D of HIV-negative individuals. A total of 348 HIV-positive and 100 HIV-negative persons were recruited. The median baseline serum 25(OH)D level was higher in HIV-positive than in HIV-negative persons (42·5 v. 35·3 nmol/l, P17 kg/m2 were randomised to either LNS supplementation (n 189) or no supplementation (n 93) during the first 3 months of ART. The supplemented group had a 4·1 (95 % CI 1·7, 6·4) nmol/l increase in serum 25(OH)D, whereas the non-supplemented group had a 10·8 (95 % CI 7·8, 13·9) nmol/l decrease in serum 25(OH)D level after 3 months of ART. Nutritional supplementation that contained vitamin D prevented a reduction in serum 25(OH)D levels in HIV-positive persons initiating ART. Vitamin D replenishment may be needed to prevent reduction in serum 25(OH)D levels during ART.

Effect of BMI and fat mass on HIV disease progression in HIV-infected, antiretroviral treatment-naïve adults in Botswana

An obesity paradox has been proposed in many conditions including HIV. Studies conducted to investigate obesity and its effect on HIV disease progression have been inconclusive and are lacking for African settings. This study investigated the relationship between overweight/obesity (BMI≥25 kg/m2) and HIV disease progression in HIV+ asymptomatic adults not on antiretroviral treatment (ART) in Botswana over 18 months. A cohort study in asymptomatic, ART-naïve, HIV+ adults included 217 participants, 139 with BMI of 18·0-24·9 kg/m2 and seventy-eight participants with BMI≥25 kg/m2. The primary outcome was time to event (≥25 % decrease in cluster of differentiation 4 (CD4) cell count) during 18 months of follow-up; secondary outcomes were time to event of CD4 cell count<250 cells/µl and AIDS-defining conditions. Proportional survival hazard models were used to compare hazard ratios (HR) on time to events of HIV disease progression over 18 months. Higher baseline BMI was associated with significantly lower risk of an AIDS-defining condition during the follow-up (HR 0·218; 95 % CI 0·068, 0·701; P=0·011). Higher fat mass at baseline was also significantly associated with decreased risk of AIDS-defining conditions during the follow-up (HR 0·855; 95 % CI 0·741, 0·987; P=0·033) and the combined outcome of having CD4 cell count≤250/µl and AIDS-defining conditions, whichever occurred earlier (HR 0·918; 95 % CI 0·847, 0·994; P=0·036). All models were adjusted for covariates. Higher BMI and fat mass among the HIV-infected, ART-naïve participants were associated with slower disease progression. Mechanistic research is needed to evaluate the association between BMI, fat mass and HIV disease progression.

Effects of HIV Infection on Body Composition Changes Among Men of Different Racial/Ethnic Origins

PURPOSE

To compare racial/ethnic differences and effects of HIV on body composition among antiretroviral (ART)-naïve HIV seropositive (HIV+) men to a representative sample of HIV seronegative (HIV-) men. We hypothesized that the effect of HIV infection will be uniform across all racial/ethnic groups.

METHOD

A cross-sectional analysis was performed comparing HIV- (NHANES 1999-2002) and ART-naïve HIV+ men (CPCRA 061). Regional subcutaneous fat area was estimated by skinfold caliper. Total body fat (TBF), fat-free mass (FFM), and body fat index (BFI) were derived by Durnin-Womersley formula (TBF-DW, FFM-DW, BFI [TBF-DW/height(2)]). Bioelectric impedance analyses (BIA) was used to assess TBF-BIA, FFM-BIA, and body cell mass (BCM). Multivariate regression modeling adjusted for age, smoking, and hepatitis C for each measurement was performed.

RESULTS

HIV+ men (n = 321) were older and more likely to be smokers than HIV- men (n = 1,996). The HIV- men were heavier in weight (+17.8 kg, p < .001) and had higher BMI (+4.3 kg/m(2), p < .001), BCM (+2.4 kg, p = .02), FFM (+5.9 kg, p < .001), TBF-DW (+5.95 kg, p < .001), BFI (+1.6 kg/m(2), p < .001), and regional fat mass than the HIV+ men. In the multivariate model, there were significant percentage differences between HIV- and HIV+ African American men for all body composition measurements (weight +15.3%; BMI +14.5%; BCM +5.2%; TBF-DW +15%; BFI 13.9%; FFM-DW 7.9%) and all circumference and skinfold measurements; all ps < .05. For Caucasian men, the following differences were significant between HIV- and HIV+: weight +14.4%; BMI +14.0%; BCM +6.0%; TBF-DW +17.7%; BFI 17.1%; FFM-DW 8.7%; and all circumference and skinfold measurements. Similarly, among Latino men the following differences were significant: weight +10.1%; BMI +12.3%; FFM-DW +7.7%; and arm, waist, and thigh circumferences and mid-arm skinfold fat area. The interaction terms for race/ethnicity were not significant across the three racial groups for weight, BMI, BCM, TBF-BIA, and BFI.

CONCLUSION

Compared to HIV uninfected men, among HIV-infected ART-naïve men there was a significant effect of HIV infection itself on body composition among all racial/ethnic groups.

Viral mechanisms of adipose dysfunction: lessons from HIV-1 Vpr

HIV-associated lipodystrophy is a heterogeneous, evolving condition associated with fundamental defects in adipose tissue differentiation, turnover and function. Although many antiretroviral drugs can affect adipose tissues adversely, clinical evidence suggests that factors associated with the virus per se could play a role. We have focused on the possibility that an HIV accessory protein, viral protein R (Vpr) could dysregulate metabolically critical transcription factors to cause the adipose dysfunction. In a recent study published in Science Translational Medicine, we utilized 2 animal models to show that Vpr, produced in tissues that sequester HIV after antiretroviral therapy, can act in a paracrine or endocrine fashion to disrupt adipocyte differentiation and function by inhibiting PPARγ target gene expression and activating glucocorticoid target gene expression. The phenotypic consequences included many features typical of the human syndrome, including accelerated lipolysis, increased macrophage infiltration in adipose tissue, diminished size of white adipose depots and hepatic steatosis. In this commentary, we summarize the background, results, and implications of these studies, and raise important questions for future investigation. More broadly, these studies suggest that chronic viral infections may be a causative factor in the pathogenesis of some forms of lipid metabolic disease, insulin resistance, and diabetes.

HIV-1 Vpr induces adipose dysfunction in vivo through reciprocal effects on PPAR/GR co-regulation

Viral infections, such as HIV, have been linked to obesity, but mechanistic evidence that they cause adipose dysfunction in vivo is lacking. We investigated a pathogenic role for the HIV-1 accessory protein viral protein R (Vpr), which can coactivate the glucocorticoid receptor (GR) and co-repress peroxisome proliferator-activated receptor γ (PPARγ) in vitro, in HIV-associated adipose dysfunction. Vpr circulated in the blood of most HIV-infected patients tested, including those on antiretroviral therapy (ART) with undetectable viral load. Vpr-mediated mechanisms were dissected in vivo using mouse models expressing the Vpr transgene in adipose tissues and liver (Vpr-Tg) or infused with synthetic Vpr. Both models demonstrated accelerated whole-body lipolysis, hyperglycemia and hypertriglyceridemia, and tissue-specific findings. Fat depots in these mice had diminished mass, macrophage infiltration, and blunted PPARγ target gene expression but increased GR target gene expression. In liver, we observed blunted PPARα target gene expression, steatosis with decreased adenosine monophosphate-activated protein kinase activity, and insulin resistance. Similar to human HIV-infected patients, Vpr circulated in the serum of Vpr-Tg mice. Vpr blocked differentiation in preadipocytes through cell cycle arrest, whereas in mature adipocytes, it increased lipolysis with reciprocally altered association of PPARγ and GR with their target promoters. These results delineate a distinct pathogenic sequence: Vpr, released from HIV-1 in tissue reservoirs after ART, can disrupt PPAR/GR co-regulation and cell cycle control to produce adipose dysfunction and hepatosteatosis. Confirmation of these mechanisms in HIV patients could lead to targeted treatment of the metabolic complications with Vpr inhibitors, GR antagonists, or PPARγ/PPARα agonists.

Physical activity and capacity at initiation of antiretroviral treatment in HIV patients in Ethiopia

SUMMARY We described levels of habitual physical activity and physical capacity in HIV patients initiating antiretroviral treatment in Ethiopia and assessed the role of HIV and nutritional indicators on these outcomes. Physical activity energy expenditure (PAEE) and activity levels were measured with combined heart rate and movement sensors. Physical capacity was assessed by grip strength, sleeping heart rate and heart rate economy. Grip strength data was also available from a sex- and age-matched HIV-negative reference group. Median PAEE was 27.9 (interquartile range 17.4-39.8) kJ/kg per day and mean ± s.d. grip strength was 23.6 ± 6.7 kg. Advanced HIV disease predicted reduced levels of both physical activity and capacity; e.g. each unit viral load [log(1+copies/ml)] was associated with -15% PAEE (P < 0.001) and -1.0 kg grip strength (P < 0.001). Grip strength was 4.2 kg lower in patients compared to HIV-negative individuals (P < 0.001). Low body mass index (BMI) predicted poor physical activity and capacity independently of HIV status, e.g. BMI <16 was associated with -42% PAEE (P < 0.001) and -6.8 kg grip strength (P < 0.001) compared to BMI ≥18.5. The study shows that advanced HIV and malnutrition are associated with considerably lower levels of physical activity and capacity in patients at initiation of antiretroviral treatment.

Vitamin D status among pulmonary TB patients and non-TB controls: a cross-sectional study from Mwanza, Tanzania

BACKGROUND

Little is known about vitamin D status in low-income populations burdened with infectious diseases. Hence, there is a need for data on correlates of serum 25-hydroxy vitamin D (S-25(OH)D) and its validity during infections.

OBJECTIVE

To assess the role of pulmonary TB (PTB) and HIV as correlates of S-25(OH)D.

DESIGN

Age-sex-matched cross-sectional study among PTB patients and non-TB controls.

METHODS

PTB patients were categorized as sputum negative (PTB-) and positive (PTB+) by culture. Non-TB controls were randomly selected among age-sex-matched neighbours to PTB+ patients. Height, weight, arm circumference and triceps skinfold were measured, and body mass index (BMI), arm fat (AFA) and muscle area (AMA) computed. HIV status, and S-25(OH)D, C-reactive protein (S-CRP) and α1-acid glycoprotein (S-AGP) were determined. Linear regression analysis with controls and PTB patients combined was used to identify correlates of S-25(OH)D.

RESULTS

S-25(OH)D data were available on 97.8% (1570) of 1605 participants. Mean (SD) S-25(OH)D was 84.4 (25.6) nmol/L with 39.6% <75 nmol/L among 347 non-TB controls. Time of recruitment, sex, PTB and HIV, and elevated S-AGP were correlates of S-25(OH)D. S-25(OH)D was 24.8 (95% CI 18.6;30.9) nmol/L higher in PTB compared to controls among females, but only 9.8 (95% CI:4.5;15.2) nmol/L among males (interaction p<0.0001). Females had 13.8 (95% CI:8.2;21.9) nmol/L lower S-25(OH)D than males, and HIV infected individuals had 8.5 (95% CI:4.9;12.1) higher S-25(OH)D compared to uninfected. Elevated S-AGP was a positive correlate of S-25(OH)D. Low BMI was associated with S-25(OH)D, but not with infections or S-AGP in the model.

CONCLUSION

While S-25(OH)D may decline transiently during a mild acute phase response, it may increase if the acute phase response leads to loss of fat. The validity of S-25(OH)D as a marker of vitamin D status may be affected by infections.

High Prevalence of Low Skeletal Muscle Mass Associated with Male Gender in Midlife and Older HIV-Infected Persons Despite CD4 Cell Reconstitution and Viral Suppression

Therapeutic goals for HIV-infected patients receiving antiretroviral therapy include minimizing risk of future physical disability. Presarcopenia and sarcopenia precede age-associated physical disability. We investigated their prevalence and the predictive value of patient mid-upper arm circumference (MUAC) for them. Eighty community-dwelling patients ≥45 years old demonstrating durable viral suppression were evaluated. Sarcopenia was defined as low skeletal muscle index (SMI, skeletal muscle kg/height m2) and either low strength or poor performance by handgrip dynamometry and gait speed, respectively. Presarcopenia was defined as low SMI only. MUAC was interpreted according to National Health Statistics percentile. Prevalence of sarcopenia and presarcopenia was 5.0% and 20.0%, respectively. Male gender (odds ratio [OR] 10.72; P < .026), recreational psychoactive substance use (OR 5.13; P < .037), and intravenous drug use transmission category (OR 6.94; P <.0327) were associated with presarcopenia. Higher body mass index (OR 0.80; P < .0007), MUAC (OR 0.83; P < .024), and large skeletal frame (OR 0.09; P < .003) were negatively associated with presarcopenia. Finding that a participant did not have a MUAC <25th percentile on physical examination had a 90.4% negative predictive value for presarcopenia. Although sarcopenia was uncommon, presarcopenia was highly prevalent in midlife and older HIV-infected males. Determination of MUAC percentile may identify those least likely to demonstrate skeletal muscle deficit and improve patient selection for mass and function testing.

Anthropometric differences between HIV-infected individuals prior to antiretroviral treatment and the general population from 1998-2007: the AIDS Clinical Trials Group Longitudinal Linked Randomized Trials (ALLRT) cohort and NHANES

OBJECTIVE

To assess differences in body circumferences and body mass index (BMI, kg/m(2)) between antiretroviral treatment (ART) naïve HIV-infected and HIV-uninfected persons.

METHODS

Waist, arm, and thigh circumferences and BMI were measured within the ALLRT and NHANES cohorts between 1998 and 2007. ALLRT is a prospective, longitudinal study of U.S. participants enrolled in randomized HIV treatment studies conducted by the AIDS Clinical Trials Group (ACTG). NHANES is a representative group of the US population. The cohorts were analyzed in two time periods, to account for trends towards increased adiposity. Anthropometrics were displayed in percentiles by age and sex. Multiple linear regression models examined differences between cohorts.

RESULTS

ALLRT had more males (82% versus 48%, p<0.0001), more black participants (32% versus 23%, p<0.0001), and less Hispanics (21% versus 30%, p<0.0001) than NHANES. Mean BMI was smaller in ALLRT males and females compared to NHANES by 1.6-2.4 kg/m(2) (p<0.0001). Mean waist and arm circumferences in both sexes and time periods were significantly smaller in ALLRT than in NHANES (p<0.0001). Mean thigh circumference in ALLRT was also smaller than NHANES among males (p<0.0001 in both time periods) and females (p = 0.01 in the early time period).

CONCLUSIONS

Differences in anthropometrics existed prior to ART initiation, in this large national cohort of HIV-infected individuals, compared to a representative HIV-uninfected cohort, indicating that HIV and its complications have important effects on body shape. Further longitudinal examination of anthropometrics in this HIV-infected cohort may provide additional insight into disease risk.

TRIAL REGISTRATION

NCT00001137 at www.clinicaltrials.gov.

HIV type-1 transgene expression in mice alters adipose tissue and adipokine levels: towards a rodent model of HIV type-1 lipodystrophy

BACKGROUND

Lipodystrophy in HIV type-1 (HIV-1)-infected patients is the consequence of effects originating from antiretroviral treatment and HIV-1 infection. We have studied adipose tissues and circulating parameters in mice bearing the HIV-1 transgene as a model to provide insight into the role of HIV-1-infection-related events in fat alterations.

METHODS

Heterozygous transgenic mice expressing a 7.7 kb HIV-1 construct (Tg26+/-) were used. Cytokine and adipokine levels were quantified using multiplex procedures. Gene expression and mitochondrial DNA abundance in visceral and subcutaneous white adipose tissues and in brown fat were determined using quantitative real-time PCR.

RESULTS

The amount of visceral, but not subcutaneous, adipose depot was lower in Tg26+/- mice. Serum proinflammatory cytokine levels were increased in Tg26+/- mice, whereas adiponectin and leptin levels were reduced. Gene expression of monocyte chemoattractant protein-1 was induced in visceral and subcutaneous fat, whereas tumour necrosis factor-α and interleukin-6 were induced in visceral and subcutaneous white adipose tissues, respectively. Adiponectin and leptin gene expression was repressed in all white fat depots, in concert with reduced expression of peroxisome proliferator-activated receptor γ, a master controller of adipogenesis. In brown fat, a coordinate induction in the expression of thermogenesis marker genes was observed.

CONCLUSIONS

HIV-1 transgene expression in mice causes changes in adipose tissue reminiscent of those in patients with HIV-1 lipodystrophy, particularly early pretreatment changes. These data support a role for HIV-1-infection-related events in eliciting adipose tissue dysfunction. The Tg26+/- mouse appears as a promising model to assess the effects of HIV-1 infection on adipose tissue and for determining the effects of antiretroviral drugs on an HIV-1-infected background.

HIV Wasting Syndrome in a Nigerian Failing Antiretroviral Therapy: A Case Report and Review of the Literature

The HIV wasting syndrome represented the face of HIV/AIDS before the advent of highly active antiretroviral therapy (HAART). Although the incidence of wasting has declined since the introduction of HAART, weight loss remains common in patients receiving HAART, especially in the setting of a failing HAART regimen. As we are not aware of any previous reports from Nigeria, we report a case of the classical wasting syndrome in a Nigerian female who had both virological and immunological HAART failure due to poor adherence. The influence of a failing HAART regimen, socioeconomic status, and other clinical variables in the wasting syndrome are discussed.

Validity of impedance-based predictions of total body water as measured by 2H dilution in African HIV/AIDS outpatients

Measurements of body composition are crucial in identifying HIV-infected patients at risk of malnutrition. No information is available on the validity of indirect body composition methods in African HIV-infected outpatients. Our first aim was to test the validity of fifteen published equations, developed in whites, African-Americans and/or Africans who were or not HIV-infected, for predicting total body water (TBW) from bioelectrical impedance analysis (BIA) in HIV-infected patients. The second aim was to develop specific predictive equations. Thirty-four HIV-infected patients without antiretroviral treatment and oedema at the beginning of the study (age 39 (SD 7) years, BMI 18.7 (SD3.7) kg/m2, TBW 30.4 (SD7.2) kg) were measured at inclusion then 3 and 6 months later. In the resulting eighty-eight measurements, we compared TBW values predicted from BIA to those measured by 2H dilution. Range of bias values was 0.1-4.3 kg, and errors showed acceptable values (2.2-3.4 kg) for fourteen equations and a high value (10.4) for one equation. Two equations developed in non-HIV-infected subjects showed non-significant bias and could be used in African HIV-infected patients. In the other cases, poor agreement indicated a lack of validity. Specific equations developed from our sample showed a higher precision of TBW prediction when using resistance at 1000 kHz (1.7 kg) than at 50 kHz (2.3 kg), this latter precision being similar to that of the valid published equations (2.3 and 2.8 kg). The valid published or developed predictive equations should be cross-validated in large independent samples of African HIV-infected patients.

Racial differences in changes of metabolic parameters and body composition in antiretroviral therapy-naive persons initiating antiretroviral therapy

OBJECTIVE

To assess by race/ethnicity long-term changes in metabolic parameters and body composition among treatment-naive persons initiating antiretroviral therapy (ART).

METHODS

We compared changes in 398 participants (African American n = 243, Latino n = 43, white n = 112) initiating ART. At baseline, 1-month (metabolic parameters only) and 4-month follow-up intervals (anthropometric measurements) were performed and fasting metabolic parameters measured. Rates of change over time and overall mean changes from baseline were compared.

RESULTS

Latinos had the greatest increase in glucose and insulin resistance and greatest loss of mid-arm and mid-thigh subcutaneous tissue areas. On average, mid-arm and mid-thigh nonsubcutaneous tissue areas increased in all races. Waist subcutaneous tissue area decreased only for Latinos. Visceral tissue area increased the most for Latinos and whites. For all groups, the initial increase in high-density lipoprotein cholesterol was sustained. The initial increase in low-density lipoprotein cholesterol was followed by a gradual decline in all groups. Triglycerides increased for all groups; the increase being the least for African Americans.

CONCLUSIONS

In this prospective long-term evaluation, changes in metabolic parameters and body composition varied across race groups. Latinos experienced the most unfavorable changes. Such changes should be monitored over time as the identified differences may impact ART selection.

HIV-1 infection and the PPARγ-dependent control of adipose tissue physiology

PPARγ is a ligand-dependent master transcription factor controlling adipocyte differentiation as well as multiple biological processes taking place in other cells present in adipose tissue depots such as macrophages. Recent research indicates that HIV-1 infection-related events may alter adipose tissue biology through several mechanisms involving PPARγ, ranging from direct effects of HIV-1-encoded proteins on adipocytes to the promotion of a proinflammatory environment that interferes with PPARγ actions. This effect of HIV-1 on adipose tissue cells can occur even in the absence of direct infection of adipocytes, as soluble HIV-1-encoded proteins such as Vpr may enter cells and inhibit PPARγ action. Moreover, repression of PPARγ actions may relieve inhibitory pathways of HIV-1 gene transcription, thus enhancing HIV-1 effects in infected cells. HIV-1 infection-mediated interference of PPARγ-dependent pathways in adipocytes and other cells inside adipose depots such as macrophages is likely to create an altered local environment that, after antiretroviral treatment, leads to lipodystrophy in HIV-1-infected and HAART-treated patients.

Metabolic abnormalities and overweight in HIV/AIDS persons-treated with antiretroviral therapy

OBJECTIVE: To describe the proportion of overweight among patients with human immunodeficiency virus/Acquired Immune Deficiency Syndrome and correlate overweight and highly active antiretroviral therapy with metabolic complications. METHODS: A cross-sectional study was conducted among human immunodeficiency virus/Acquired Immune Deficiency Syndrome outpatients undergoing nutritional therapy from 2000 to 2006 in a University Health Center. The sample consisted of 393 human immunodeficiency virus/Acquired Immune Deficiency Syndrome patients. Nutritional and medical records were used as a source of data on personal, clinical and biochemical information. Data analysis included descriptive statistics and the Chi-square test. RESULTS: Sixty-nine percent of the patients were males aging from 26 to 49 years. Overweight and obesity were identified in 49% of this population. The most important metabolic complications were low levels of high-density lipoprotein (70%) and high levels of triglycerides (48%) and cholesterol (40%). Higher body mass index was associated with higher lipid levels and more evidence of insulin resistance. CONCLUSION: This study demonstrated an important proportion of overweight and obesity among human immunodeficiency virus/Acquired Immune Deficiency Syndrome patients. These results suggest that nutritional interventions and lifestyle modifications may be useful strategies to decrease the cardiovascular risk in this population.

Nutritional status of persons with HIV infection, persons with HIV infection and tuberculosis, and HIV-negative individuals from southern India

We compared the nutritional status of individuals with human immunodeficiency virus (HIV) infection alone, individuals with HIV infection and tuberculosis (after completion of antituberculosis treatment), and HIV-negative individuals and found that malnutrition, anemia, and hypoalbuminemia were most pronounced among HIV-positive patients with tuberculosis. Weight loss was associated with loss of fat in female patients and with loss of body cell mass in male patients.

Randomized controlled trial of nutritional counseling on body composition and dietary intake in severe CKD

BACKGROUND

Progressive loss of kidney function results in an increased risk of malnutrition. Despite this, there is little evidence informing the impact of nutrition intervention on predialysis patients with chronic kidney disease (CKD; stages 4 and 5).

STUDY DESIGN

Randomized controlled trial.

SETTING & PARTICIPANTS

56 outpatients (men, 62%; mean age, 70.7 +/- 14.0 [SD] years) with CKD were randomly allocated to intervention (n = 29) or control (n = 27) by using a concealed computer-generated sequence.

INTERVENTION

The intervention group, provided with individualized dietary counseling with regular follow-up aimed at achieving an intake of 0.8 to 1.0 g/kg of protein and greater than 125 kJ/kg of energy, or control, receiving written material only.

OUTCOMES & MEASURES

Change in body composition (body cell mass, measured by means of total-body potassium, in 40 of 56 participants), nutritional status (Subjective Global Assessment), and energy and protein intake (3-day food record).

RESULTS

During the 12 weeks, the intervention group had 3.5% (95% confidence interval, -2.1 to 9.1) less decrease in body cell mass, 17.7-kJ/kg/d (95% confidence interval, 8.2 to 27.2) greater increase in energy intake, greater improvement in Subjective Global Assessment (P < 0.01), and no significant difference in protein intake compared with the control group (-0.04 g/kg/d; 95% confidence interval, -0.73 to 0.16). The intervention was associated with greater increases in energy and protein intake in women than men (interaction P < 0.001 for both).

LIMITATIONS

Power to detect change in body cell mass, potential bias in ascertainment of Subjective Global Assessment.

CONCLUSIONS

In predialysis patients with CKD, structured nutrition intervention had a greater effect on energy and protein intake in women than men. Additional investigations are warranted to determine the impact on body composition.

Human immunodeficiency virus (HIV)-1 viral protein R suppresses transcriptional activity of peroxisome proliferator-activated receptor {gamma} and inhibits adipocyte differentiation: implications for HIV-associated lipodystrophy

HIV-1-infected patients may develop lipodystrophy and insulin resistance. We investigated the effect of the HIV-1 accessory protein viral protein R (Vpr) on the activity of the peroxisome proliferator-activating receptor-gamma (PPARgamma), a key regulator of adipocyte differentiation and tissue insulin sensitivity. We studied expression of PPARgamma-responsive reporter genes in 3T3-L1 mouse adipocytes. We investigated Vpr interaction with the PPAR/retinoid X receptor (RXR)-binding site of the c-Cbl-associating protein (CAP) gene using the chromatin immunoprecipitation assay as well as the interaction of Vpr and PPARgamma using coimmunoprecipitation. Finally, we studied the ability of exogenous Vpr protein to enter cultured adipocytes and retard differentiation. We found that Vpr suppressed PPARgamma-induced transactivation in both undifferentiated and differentiated 3T3-L1 cells. Transcriptional suppression by Vpr required an intact LXXLL coactivator motif. Vpr suppressed mRNA expression of PPARgamma-responsive genes in undifferentiated 3T3-L1 cells and associated with the PPAR/RXR-binding site located in the promoter region of the CAP gene. Vpr interacted with the ligand-binding domain of PPARgamma in an agonist-dependent fashion in vitro. Vpr delivered either by an expression plasmid or as protein added to media suppressed PPARgamma agonist-induced adipocyte differentiation, assessed as lipid accumulation and mRNA expression of the adipocyte differentiation marker adipocyte P2 in 3T3-L1 cells. In conclusion, circulating Vpr or, alternatively, Vpr produced as a consequence of direct infection of adipocytes could suppress in vivo differentiation of preadipocytes by acting as a corepressor of PPARgamma-mediated gene transcription. Vpr may alter sensitivity to insulin and thereby contribute to the development of lipodystrophy and insulin resistance observed in HIV-1-infected patients.