Longitudinal study of body composition of 101 HIV men with lipodystrophy: dual-energy X-ray criteria for lipodystrophy evolution

Muscle mass, strength, bone mineral density and vascular function in middle-aged people living with HIV vs. age-matched and older controls

Introduction

Combination antiretroviral therapy (cART) substantially extended the life of people living with HIV (PLHIV). However, prolonged HIV infection and cART increase the risk of comorbidities accelerating age-related muscle, bone, and vascular disorders. This cross-sectional study compared muscle mass and strength, bone mineral density (BMD), and vascular function in middle-aged PLHIV treated with cART vs. non-infected age-matched and older controls.

Methods

After careful screening for secondary diseases and medications, body composition, muscular and vascular function were assessed in 12 PLHIV (43.9±8.7 yrs old; HIV-infection for 16.2±8.6 yrs; on cART for 11.6±9.2 yrs), 12 age-matched (CONT, 43.2±8.5 yrs old), and 12 older (OLDER, 74.4±8.3 yrs old) controls through dual x-ray absorptiometry, isokinetic dynamometry, and venous occlusion plethysmography, respectively.

Results

PLHIV and CONT showed similar relative muscle mass (65.3±8.0 vs. 66.9±7.3%, respectively; P= 0.88) and strength (160.7±53.9 vs. 152.0±52.9 N.m⁻¹, respectively; P= 0.90), which were greater than OLDER (80.6±18.8 N.m^−1; P= 0.001). Total BMD was similar in PLHIV (1.04±0.13 g.cm⁻²) and OLDER (1.00±0.15 g.cm⁻², P= 0.86), and both groups presented lower values than CONT (1.20±0.13 g.cm⁻², P< 0.01). No significant difference across groups was detected for macrovascular reactivity (P= 0.32).

Conclusion

Age-related osteopenia might be accelerated in middle-aged PLHIV on prolonged cART, as their BMD approached values found in older adults. On the other hand, muscle mass, isokinetic strength, and vasodilation capacity were similar in PLHIV and age-matched uninfected controls.

Adipose Tissue in HIV Infection

HIV infection and antiretroviral therapy (ART) treatment exert diverse effects on adipocytes and stromal-vascular fraction cells, leading to changes in adipose tissue quantity, distribution, and energy storage. A HIV-associated lipodystrophic condition was recognized early in the epidemic, characterized by clinically apparent changes in subcutaneous, visceral, and dorsocervical adipose depots. Underlying these changes is altered adipose tissue morphology and expression of genes central to adipocyte maturation, regulation, metabolism, and cytokine signaling. HIV viral proteins persist in circulation and locally within adipose tissue despite suppression of plasma viremia on ART, and exposure to these proteins impairs preadipocyte maturation and reduces adipocyte expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) and other genes involved in cell regulation. Several early nucleoside reverse transcriptase inhibitor and protease inhibitor antiretroviral drugs demonstrated substantial adipocyte toxicity, including reduced mitochondrial DNA content and respiratory chain enzymes, reduced PPAR-γ and other regulatory gene expression, and increased proinflammatory cytokine production. Newer-generation agents, such as integrase inhibitors, appear to have fewer adverse effects. HIV infection also alters the balance of CD4+ and CD8+ T cells in adipose tissue, with effects on macrophage activation and local inflammation, while the presence of latently infected CD4+ T cells in adipose tissue may constitute a protected viral reservoir. This review provides a synthesis of the literature on how HIV virus, ART treatment, and host characteristics interact to affect adipose tissue distribution, immunology, and contribution to metabolic health, and adipocyte maturation, cellular regulation, and energy storage. © 2017 American Physiological Society. Compr Physiol 7:1339-1357, 2017.

Relationship Between Adiposity Indices, Lipodystrophy, and Sarcopenia in HIV-Positive Individuals With and Without Lipodystrophy

Metabolism disorders, as well as body shape abnormalities, have been associated with the introduction of antiretroviral therapy. The objective of this study was to compare the diagnostic ability of adiposity indices and to discuss criteria for the classification of lipodystrophy and sarcopenia (SP) in HIV-positive individuals. Anthropometric measurements were determined in 268 individuals of both genders, also submitted to the dual-energy X-ray absorptiometry exam. The adiposity indices calculated were body mass index, body mass index adjusted for fat mass (BMIfat), body adiposity index, body adiposity Index for the Fels Longitudinal Study sample, and The Clínica Universidad de Navarra body adiposity estimator. The presence of lipodystrophy was evaluated using the fat mass ratio (FMR). SP was classified using the appendicular lean mass/height² ratio. The subjects were divided into 3 groups: HIV⁺LIPO⁺ (n = 41), HIV⁺LIPO^- (n = 65), and control (C, HIV-negative individuals; n = 162). Among the adiposity indices assessed, BMIfat showed the strongest correlation with total body fat (in percent) for men (r = 0.87, p < 0.001) and women (r = 0.92, p < 0.001). The frequency of SP was 44.8% and 41.7% in HIV⁺LIPO⁺, 27.8% and 20.7% in HIV⁺LIPO^- and 63.3% and 45.45% in C, for men and women, respectively. The cutoff point suggested for the diagnosis of lipodystrophy according to the FMR was 1.14. The adiposity indices, particularly the BMIfat, have strong correlation with body fat determined by dual-energy X-ray absorptiometry in HIV-positive patients. The implementation of FMR is recommended for more standardized estimates of the frequency of lipodystrophy.

Switching from zidovudine/lamivudine to tenofovir/emtricitabine improves fat distribution as measured by fat mass ratio

OBJECTIVES

Fat mass ratio (FMR) has been suggested as an objective indicator of abnormal body fat distribution in HIV infection. Although it could provide more comprehensive information on body fat changes than limb fat mass, FMR has scarcely been used in clinical trials examining body fat distribution in HIV-infected patients.

METHODS

A subanalysis of a controlled, randomized clinical trial in virologically suppressed HIV-1-infected men switching from zidovudine (ZDV)/lamivudine (3TC) to emtricitabine (FTC)/tenofovir (TDF) versus continuing on ZDV/3TC was carried out. FMR was assessed by dual X-ray absorptiometry (DEXA) for a period of 72 weeks. Lipoatrophy was defined as FMR ≥ 1.5. Multivariate linear regression models for the change in FMR from baseline were fitted.

RESULTS

Sixty-five men were randomized and treated (28 in the FTC/TDF arm and 37 in the ZDV/3TC arm), and 57 completed the study (25 and 32 in each arm, respectively). In the FTC/TDF arm, adjusted mean FMR decreased by 0.52 at week 72 (P = 0.014), and in the ZDV/3TC arm it increased by 0.13 (P = 0.491; P between arms = 0.023). Among subjects with lipoatrophy (baseline FMR ≥ 1.5), adjusted FMR decreased by 0.76 (P = 0.003) in the FTC/TDF arm and increased by 0.21 (P = 0.411; P between arms = 0.009) in the ZDV/3TC arm. Baseline FMR and treatment group were significant predictors (P < 0.05) of post-baseline changes in FMR.

CONCLUSIONS

Switching from ZDV/3TC to FTC/TDF led to an improvement in FMR, compared with progressive worsening of FMR in subjects receiving ZDV/3TC, showing that fat mass not only increased but was also distributed in a healthier way after the switch.

Multiple frequency bioimpedance is an adequate tool to assess total and regional fat mass in HIV-positive patients but not to diagnose HIV-associated lipoatrophy: a pilot study

Introduction

HIV-associated lipodystrophy syndrome causes systemic metabolic alterations and psychological distress that worsen the quality of life of these patients. An early detection should be considered to efficiently treat it. Objective criteria or reference indices are needed for an early diagnosis. Bioelectrical Impedance Analysis (BIA) is an operator-independent, repeatable and non-invasive method of body composition evaluation that is less expensive than dual-energy X-ray absorptiometry (DXA) and/or CT scans. The aims of this pilot study were to validate the data obtained by BIA to measure fat mass in HIV-positive patients with/without lipoatrophy and to determine if BIA correctly diagnoses lipoatrophy in HIV-positive patients.

Methods

Thirty-nine participants were included in this preliminary study. Fourteen were HIV-negative (eight men) whereas 25 were HIV-positive patients (17 men). Eleven of the HIV-positive patients were classified as lipoatrophic according to subjective evaluation by the physicians. Total and regional body composition was measured in basal conditions by DXA and by BIA. To obtain abdominal CT scan fat values, transverse slices with 6-mm thickness were acquired at the L4-L5 intervertebral space.

Results

BIA measurements of total and regional body fat were significantly correlated with those obtained by DXA (p < 0.05 to <0.01) in HIV-positive patients. However, agreement between methods was poor as not very high ICC (intraclass correlation coefficient) values were observed. BIA and DXA showed higher ICC values in lipoatrophic patients. The visceral index obtained by BIA was correlated with total and visceral fat in L4 measured by CT scan (r = 0.607 and r = 0.617, respectively, p < 0.01) in HIV-positive patients. The Fat Mass Ratio (FMR) calculated by BIA did not correlate or agree with DXA values.

Conclusions

Multi-frequency BIA could be an effective method to evaluate the evolution of total and regional fat composition in HIV-positive patients with/without lipoatrophy. The correlations between BIA and DXA improved in lipoatrophic patients and in men, suggesting that its efficacy depends on fat mass, gender and probably other factors. The visceral index obtained by BIA seems to be a reliable indicator of abdominal obesity. However, BIA did not fulfil the need for easy quantitative diagnostic tools for lipoatrophy, and it did not provide sufficient diagnostic cut-off values for this syndrome.

Small-dense LDL cholesterol/large-buoyant LDL cholesterol ratio as an excellent marker for indicating lipodystrophy in HIV-infected patients

OBJECTIVES

To examine whether the lipid parameters are predicting factors for human immunodeficiency virus (HIV)-associated lipodystrophy.

METHODS

Whole-body fat compositions of HIV-positive patients receiving stavudine-containing antiretroviral regimens (n = 79) were determined. Lipodystrophy was defined as a ratio of trunk fat mass/lower limb fat mass greater than 2.28. Blood samples were analyzed for total cholesterol (TC), triglycerides, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), small-dense LDL-C (sdLDL-C), apoAI, apoB, lipoprotein(a), and CD4 cell counts. Large-buoyant LDL-C (lbLDL-C) was calculated (LDL-C minus sdLDL-C).

RESULTS

Twenty-six patients were classified as having lipodystrophy. The mean values of triglycerides, HDL-C, sdLDL-C, apoB, TC/HDL-C, apolipoprotein (apo) B/apoAI, and sdLDL-C/lbLDL-C showed significant differences between patients with and without lipodystrophy (P < .02). Using logistic regression analysis, sdLDL-C/lbLDL-C was identified as a significant predictor of lipodystrophy (P < .001). At a ratio of 0.554, the odds ratio was 17.8 with a likelihood ratio of 5.5.

CONCLUSIONS

The sdLDL-C/lbLDL-C ratio is an excellent marker for indicating lipodystrophy in HIV-infected patients.

Body composition study by dual-energy x-ray absorptiometry in familial partial lipodystrophy: finding new tools for an objective evaluation

BACKGROUND

Familial partial lipodystrophies (FPLD) are clinically heterogeneous disorders characterized by selective loss of adipose tissue, insulin resistance and metabolic complications. Until genetic studies become available for clinical practice, clinical suspicion and pattern of fat loss are the only parameters leading clinicians to consider the diagnosis. The objective of this study was to compare body composition by dual energy X-ray absorptiometry (DXA) in patients with FPLD and control subjects, aiming to find objective variables for evaluation of FPLD.

METHODS

Eighteen female patients with partial lipodystrophy phenotype and 16 healthy controls, matched for body mass index, sex and age were studied. All participants had body fat distribution evaluated by DXA measures. Fasting blood samples were obtained for evaluation of plasma leptin, lipid profile and inflammatory markers. Genetic studies were carried out on the 18 patients selected that were included for statistical analysis. Thirteen women confirmed diagnosis of Dunnigan-type FPLD (FPLD2).

RESULTS

DXA revealed a marked decrease in truncal fat and 3 folds decrease in limbs fat percentage in FPLD2 patients (p <0.001). Comparative analysis showed that ratio between trunk and lower limbs fat mass, characterized as Fat Mass Ratio (FMR), had a greater value in FLPD2 group (1.86 ± 0.43 vs controls 0.93 ± 0.10; p <0.001) and a improved accuracy for evaluating FPLD2 with a cut-off point of 1.2. Furthermore, affected women showed hypoleptinemia (FLPD2 4.9 ± 2.0 vs controls 18.2 ± 6.8; p <0.001), insulin resistance and a more aggressive lipid profile.

CONCLUSION

In this study, assessment of body fat distribution by DXA permitted an objective characterization of FLPD2. A consistent pattern with marked fat reduction of lower body was observed in affected patients. To our knowledge this is the first time that cut-off values of objective variables were proposed for evaluation of FPLD2.

The frequency of low muscle mass and its overlap with low bone mineral density and lipodystrophy in individuals with HIV--a pilot study using DXA total body composition analysis

As a result of the advances in antiretroviral therapy, the life span of human immunodeficiency virus (HIV)-infected patients has increased dramatically. Attendant to these effects are signs of premature aging with notable changes in the musculoskeletal system. Although changes in bone and fat distribution have been studied extensively, far less is known about changes in muscle. This study examined the extent of low muscle mass (LMM) and its relationship with low bone mineral density (BMD) and lipodystrophy (LD) in HIV-positive males. As such, HIV-positive males on therapy or treatment naive underwent dual-energy X-ray absorptiometry total body composition measurements. Appendicular lean mass/(height)2 and lowest 20% of residuals from regression analysis were used to define LMM. BMD criteria defined osteopenia/osteoporosis, and the percent central fat/percent lower extremity ratio defined LD. Several potential risk factors were assessed through chart review. Sixty-six males (57 with treatment and 9 treatment naive) volunteered. Treated individuals were older than naive (44 vs 34 yr) and had HIV longer (108 vs 14 mo). When definitions for sarcopenia (SP) in elderly individuals were applied, the prevalence of LMM was 21.9% and 18.8% depending on the definition used. Low BMD was present in 68.2% of participants. LD with a cutoff of 1.5 and 1.961 was present in 54.7% and 42.2% of participants, respectively. LMM and LD were negatively associated. In conclusion, this study shows that LMM is common in males with HIV and that SP affecting muscle function could be present in a substantial number of individuals. Future research needs to examine what impact decreased muscle mass and function has on morbidity, physical function, and quality of life in individuals with HIV.

Changes in body composition and mitochondrial DNA in HIV-1-infected patients switching to fixed-dose abacavir/lamivudine or tenofovir/emtricitabine: a substudy of the BICOMBO trial

BACKGROUND

Fat distribution, bone mineral density (BMD) and mitochondrial DNA (mtDNA) may improve, in the long-term, after switching from nucleoside reverse transcriptase inhibitors (NRTIs) to fixed-dose abacavir (ABC)/lamivudine (3TC) or tenofovir (TDF)/emtricitabine (FTC).

METHODS

This was a prospective, randomized, open-label, multicentre substudy of the BICOMBO trial in which virologically suppressed patients had their NRTIs switched to ABC/3TC or TDF/FTC. Whole-body dual-energy X-ray absorptiometry (DXA) was used to measure limb, trunk and total body fat and total BMD. Lumbar and hip DXA scans were used to measure lumbar and hip BMD. Fat mass ratio (FMR; % trunk fat/% leg fat by whole-body DXA) was used to assess fat distribution. mtDNA was measured in peripheral blood mononuclear cells (PBMCs). Parameters of interest were measured at baseline, 48 and 96 weeks, and were compared between treatment groups.

RESULTS

Of 56 patients included, 45 (20 ABC/3TC and 25 TDF/FTC) completed the substudy. After 96 weeks, ABC/3TC (+756 g, +12.1%) and TDF/FTC (+337 g, +7.6%) led to non-significantly different increases in limb fat (P=0.60). By contrast, trunk fat showed a significant increase (P=0.04) with ABC/3TC (+1,184 g, +10.6%) relative to TDF/FTC (-370 g, -4.2%). Median (IQR) FMR remained unchanged with ABC/3TC (-0.01 [-0.16-0.06]; P=0.23), but it decreased significantly with TDF/FTC (-0.13 [-0.30-0.00]; P=0.007). Total BMD and mtDNA significantly increased after 96 weeks, without differences between groups.

CONCLUSIONS

Switching from NRTIs to either ABC/3TC or TDF/FTC led to similar increases in limb fat, BMD and PBMC mtDNA after 96 weeks.

Impact of switching from lopinavir/ritonavir to atazanavir/ritonavir on body fat redistribution in virologically suppressed HIV-infected adults

Changes in body fat distribution in virologically suppressed HIV-infected patients switching from lopinavir/ritonavir (LPV/r) to atazanavir/ritonavir (ATV/r) were assessed. A prospective comparative study was conducted of 37 patients receiving LPV/r regimens switching to ATV/r with 46 patients continuing with LPV/r. Body composition was assessed with whole-body dual-energy x-ray absorptiometry (DXA). Abdominal CT scans were also performed in a subset of patients. Groups were comparable in baseline demographic, clinical, and anthropometric characteristics. After 12 months, peripheral fat did not change significantly, but an increase in trunk fat was observed only in the ATV/r group (0.87 kg, p = 0.021). The percentage of patients with an increase ≥20% in total fat was 37.8% and 15.2% in the ATV/r and LPV/r groups, respectively (p = 0.018). In the ATV/r group, the increase in trunk fat (9.4%) was significantly higher than in peripheral fat (3.7%) (p = 0.007), leading to a significant increase in fat mass ratio (3.76%, p = 0.028), whereas no significant differences were found among LPV/r patients. CT scans showed that abdominal fat increase corresponded to both visceral (28%, p = 0.008) and subcutaneous fat (42%, p = 0.008). These data suggest that switching from LPV/r to ATV/r is associated with increased trunk fat, both subcutaneous and visceral.

Age-related skeletal muscle decline is similar in HIV-infected and uninfected individuals

BACKGROUND

Skeletal muscle (SM) mass decreases with advanced age and with disease in HIV infection. It is unknown whether age-related muscle loss is accelerated in the current era of antiretroviral therapy and which factors might contribute to muscle loss among HIV-infected adults. We hypothesized that muscle mass would be lower and decline faster in HIV-infected adults than in similar-aged controls.

METHODS

Whole-body (1)H-magnetic resonance imaging was used to quantify regional and total SM in 399 HIV-infected and 204 control men and women at baseline and 5 years later. Multivariable regression identified associated factors.

RESULTS

At baseline and Year 5, total SM was lower in HIV-infected than control men. HIV-infected women were similar to control women at both time points. After adjusting for demographics, lifestyle factors, and total adipose tissue, HIV infection was associated with lower Year 5 SM in men and higher SM in women compared with controls. Average overall 5-year change in total SM was small and age related, but rate of change was similar in HIV-infected and control men and women. CD4 count and efavirenz use in HIV-infected participants were associated with increasing SM, whereas age and stavudine use were associated with decreasing SM.

CONCLUSIONS

Muscle mass was lower in HIV-infected men compared with controls, whereas HIV-infected women had slightly higher SM than control women after multivariable adjustment. We found evidence against substantially faster SM decline in HIV infected versus similar-aged controls. SM gain was associated with increasing CD4 count, whereas stavudine use may contribute to SM loss.

New and emerging agents in the management of lipodystrophy in HIV-infected patients

Lipodystrophy remains a major long-term complication in human immunodeficiency virus-infected patients under antiretroviral (ARV) therapy. Patients may present with lipoatrophy or lipohypertrophy or both. The choice of treatments to improve fat redistribution depends on the form of lipodystrophy and its duration. Measures known to improve lipoatrophy are switches in ARV therapy (stavudine or zidovudine to abacavir or tenofovir) and filling interventions. Pioglitazone may be added to these measures, although any benefits appear small. Uridine and leptin were found to be disappointing so far. Regarding lipohypertrophy, diet and exercise, recombinant human growth hormone, and metformin may reduce visceral fat, but may worsen subcutaneous lipoatrophy. Surgical therapy may be required. Attractive pharmacologic treatments include growth hormone-releasing factor and leptin. Adiponectin and adiponectin receptors are promising therapeutic targets to explore.