The effect of individual antiretroviral drugs on body composition in HIV-infected persons initiating highly active antiretroviral therapy. J Acquir Immune Defic Syndr. 2009;51:298-304. [PMID: 19412117 DOI: 10.1097/qai.0b013e3181aa1308]

Serum Interleukin-6 and Weight Loss in Antiretroviral-naïve and Antiretroviral-treated Patients with HIV/AIDS: Relationships and Predictors

BACKGROUND

Cachexia is usually associated with elevated serum interleukin-6 (IL.6) as it stimulates the breakdown of muscle proteins and promotes wasting.

OBJECTIVE

A case-control study to evaluate the relationship between weight loss, facial fat loss, and IL-6 in antiretroviral-naïve and treated participants living with HIV/AIDS.

METHODS

IL-6 was assayed by High performance liquid chromatography (HPLC) in 97 in consecutive newly diagnosed antiretroviral-naive (ART-naïve) people living with HIV/AIDS (age ≥18 years); and 118 consecutive, age-matched participants currently on Highly Active Antiretroviral Therapy (HAART), using age as a criterion. In the treated group, 78 (66.7%) subjects were on zidovudine, lamivudine with nevirapine (Z+L+N); 27(23.1%) on tenofovir, lamivudine with emtricitabine (T+L+E); 5(4.3%) on zidovudine, lamivudine with emtricitabine (Z+L+E); 4(3.4%) on zidovudine, lamivudine with tenofovir (Z+L+T); 2(1.7%) on lamivudine, tenofovir with nevirapine (L+T+N); 1(0.9%) on tenofovir, zidovudine, emtricitabine (Z+T+E).

RESULTS

A total of 215 participants: 97 ART-naive and 118 HAART-treated, age-matched subjects (40.3±9.6 versus 42.7±10.20years, p=0.08). The mean IL-6 was significantly higher in naïve than treated (0.69±0.04 versus 0.66±0.04 pg/ml, p =0.002). In all, 73 subjects experienced weight loss, 56(76.7%) naive, 17(23.3%) treated, p <0.0001, with significantly higher IL-6 in those with weight loss (0.69±0.05 versus 0.67±0.05pg/ml, p= 0.047). Fifty-eight (27.0%) subjects experienced facial fat loss, 49 (84.5%) naïve, and 9 (15.5%) treated, p <0.0001, with significantly higher IL-6 in those with facial fat loss (0.7 ± 0.05 versus 0.67±0.05pg/ml, p= 0.0001). Negative correlation exists between IL-6 and CD4+ count (r=-0.141, p=0.041). In logistic regression, independent predictors of weight loss include: IL-6 (Adjusted Odds Ratio, aOR 1.3, 95%CI 0·1-2·6, p=0.047); HIV duration (aOR 11.6, p <0.0001); AIDS-defining illness (aOR 3.5, p <0.0001); CD4+ count (aOR 3.2, p=0.004); HAART status (aOR 2.7, p<0.0001).

CONCLUSION

HIV infection is associated with elevation of serum interleukin-6, which likely contributes to weight and facial fat loss among the treatment-naïve participants; while HAART is associated with suppressed IL-6 levels, thereby ameliorating weight and facial fat loss. Inverse relationship exists between serum IL-6 and CD4+ count; serum IL-6 could differentiate between mild- to moderate and severe immunosuppressive states.

People living with HIV have low trabecular bone mineral density, high bone marrow adiposity, and poor trabecular bone microarchitecture at the proximal femur

People living with HIV (PLWH) have increased risk of osteoporosis and fractures. We assessed the proximal femur of PLWH and age-matched seronegative controls using quantitative computed tomography and magnetic resonance imaging. Results suggest that the trabecular compartment is compromised at fracture-prone regions in the proximal femur of PLWH.

INTRODUCTION

People living with HIV (PLWH) have increased risk of osteoporosis and fractures. However, studies assessing the main determinants of bone strength in the proximal femur exclude this vulnerable population. We assessed the proximal femur of 40 PLWH and 26 age-matched seronegative controls using quantitative computed tomography and magnetic resonance imaging.

METHODS

We examined cortical volumetric bone mineral density (Ct.vBMD), trabecular vBMD (Tb.vBMD), cortical thickness (Ct.Th), bone marrow adiposity (BMA), and trabecular number, separation, and bone volume fraction. Parametric comparisons between the two groups were made for the femoral head, femoral neck, trochanter, and total hip using linear regression adjusting for several covariates, including metrics of body composition. In addition, we investigated the associations of BMA with Tb.vBMD and trabecular microarchitecture with Spearman's rank partial correlations.

RESULTS

PLWH had lower Tb.vBMD and deteriorated trabecular microarchitecture in the femoral neck, trochanter and total hip, and elevated BMA in the femoral head, femoral neck, and total hip. Ct.vBMD and Ct.Th were not significantly different between the two groups. BMA was significantly associated with lower Tb.vBMD and deteriorated trabecular microarchitecture in both groups albeit at different femoral regions.

CONCLUSIONS

Our findings suggest that the trabecular, and not the cortical, compartment is compromised in the proximal femur of PLWH. The observed impairments in fracture-prone regions in PLWH indicate lower femoral strength and suggest higher fracture risk. The inverse associations of BMA with trabecular bone density and microarchitecture quality agree with findings at other anatomic sites and in other populations, suggesting that excess BMA possibly due to a switch from the osteoblast to the adipocyte lineage may be implicated in the pathogenesis of bone fragility at the femur in PLWH.

Severe insulin resistance syndromes

Severe insulin resistance syndromes are a heterogeneous group of rare disorders characterized by profound insulin resistance, substantial metabolic abnormalities, and a variety of clinical manifestations and complications. The etiology of these syndromes may be hereditary or acquired, due to defects in insulin potency and action, cellular responsiveness to insulin, and/or aberrations in adipose tissue function or development. Over the past decades, advances in medical technology, particularly in genomic technologies and genetic analyses, have provided insights into the underlying pathophysiological pathways and facilitated the more precise identification of several of these conditions. However, the exact cellular and molecular mechanisms of insulin resistance have not yet been fully elucidated for all syndromes. Moreover, in clinical practice, many of the syndromes are often misdiagnosed or underdiagnosed. The majority of these disorders associate with an increased risk of severe complications and mortality; thus, early identification and personalized clinical management are of the essence. This Review aims to categorize severe insulin resistance syndromes by disease process, including insulin receptor defects, signaling defects, and lipodystrophies. We also highlight several complex syndromes and emphasize the need to identify patients, investigate underlying disease mechanisms, and develop specific treatment regimens.

Adipocytokine dysregulation, abnormal glucose metabolism, and lipodystrophy in HIV-infected adolescents receiving protease inhibitors

BACKGROUND

Lipodystrophy is common in HIV-infected patients receiving protease inhibitors (PIs), stavudine, and zidovudine. Adipocytokines may be altered in lipodystrophy. We evaluated risk factors, adipocytokine levels, insulin resistance, and lipid profiles in HIV-infected adolescents with different lipodystrophy types.

METHODS

A cross-sectional study was conducted in 80 perinatally HIV-infected adolescents receiving PI-based highly active antiretroviral therapy for ≥ 6 months. Patients underwent oral glucose tolerance tests and measurements of high-molecular-weight (HMW) adiponectin, leptin, resistin, insulin, and lipids. They were classified into 3 groups based on the clinical findings: no lipodystrophy, isolated lipoatrophy, and any lipohypertrophy (isolated lipohypertrophy or combined type).

RESULTS

Of the 80 patients (median age, 16.7 years), 18 (22.5%) had isolated lipoatrophy, while 8 (10%) had any lipohypertrophy (four with isolated lipohypertrophy, and four with the combined type). In a multivariate analysis, longer exposure to stavudine (OR: 1.03; 95% CI, 1.01-1.06; p = 0.005) and indinavir (OR: 1.03; 95% CI, 1.01-1.06; p = 0.012) were associated with lipoatrophy, while longer exposure to didanosine (OR: 1.04; 95% CI, 1.01-1.08; p = 0.017) and indinavir (OR: 1.10; 95% CI, 1.00-1.21; p = 0.045) were associated with any lipohypertrophy. Leptin levels were highest in the any-lipohypertrophy group and lowest in the isolated-lipoatrophy group (p = 0.013). HMW adiponectin levels were significantly lowest in the any-lipohypertrophy group and highest in the no-lipodystrophy group (p = 0.001). There were no significant differences in the levels of resistin among the three groups (p = 0.234). The prevalence of insulin resistance (p = 0.002) and prediabetes/diabetes (p < 0.001) were significantly highest in the any-lipohypertrophy group. Patients with lipoatrophy and those without lipodystrophy had comparable degrees of insulin resistance (p = 0.292). In multiple linear regression analysis, adjusted for age, sex, and waist-height ratio, HMW adiponectin levels were associated with Matsuda index (β = 0.5; p = 0.003) and quantitative insulin sensitivity check index (QUICKI) (β = 40.1; p = 0.010) and almost significantly associated with homeostatic model assessment of insulin resistance (HOMA-IR) (p = 0.054). Leptin and resistin levels were not associated with HOMA-IR, Matsuda index, or QUICKI (all p > 0.05).

CONCLUSIONS

Abnormal glucose metabolism and dysregulation of adipocytokines were common in the HIV-infected adolescents with lipohypertrophy and the combined type. Preventive screening for cardiovascular diseases caused by metabolic alterations should be routinely performed.

Fat Mass Ratio in Brazilian HIV-infected Patients Under Antiretroviral Therapy and Its Relationship With Anthropometric Measurents

INTRODUCTION

Human immunodeficiency virus-related lipodystrophy is characterized by a variety of phenotypes and metabolic changes; however, consensus has not yet been reached on its diagnostic criteria. Different cutoff values for fat mass ratio have been proposed for this specific population as an objective diagnostic criterion for lipodystrophy. This study aimed to establish sex-specific reference values for fat mass ratio and to correlate them with anthropometric measurements for the diagnosis of human immunodeficiency virus-related lipodystrophy.

METHODOLOGY

A cross-sectional study was performed on 189 human immunodeficiency virus-infected patients under antiretroviral therapy. Anthropometric measurements were evaluated, and body composition was determined using dual-energy X-ray absorptiometry. Fat mass ratio was calculated as the ratio of the percentage of the trunk fat mass and the percentage of the lower limb fat mass.

RESULTS

One hundred and thirty-two patients (69%) presented lipodystrophy by objective criteria. In men, the cutoff for the fat mass ratio was 1.55 (area under the receiver operating characteristic curve: 0.73 [95% confidence interval: 0.62-0.83], p = 0.000008), with a sensitivity of 62.5%, a specificity of 70.5%, a positive predictive value of 77.8%, and a negative predictive value of 53.4%. In women, the cutoff for the fat mass ratio was 0.959 (area under the receiver operating characteristic curve: 0.70 [95% confidence interval: 0.56-0.85], p = 0.03), with a sensitivity of 83.60%, a specificity of 61.5%, a positive predictive value of 90.2%, and a negative predictive value of 47.1%. Fat mass ratio was positively correlated with waist circumference (men: r = 0.246, p = 0.019; women: r = 0.302, p = 0.014) and neck circumference (men: r = 0.304, p = 0.004; women: r = 0.366, p = 0.003) in both sexes; and body mass index (r = 0.288, p = 0.006) and waist-hip ratio (r = 0.288, p = 0.006) in men.

CONCLUSION

The fat mass ratio evaluated using dual-energy X-ray absorptiometry with the sex-specific cutoffs is an objective tool to define human immunodeficiency virus-related lipodystrophy.

Impact of antiretroviral therapy on lipid metabolism of human immunodeficiency virus-infected patients: Old and new drugs

For human immunodeficiency virus (HIV)-infected patients, the 1990s were marked by the introduction of highly active antiretroviral therapy (HAART) representing a new perspective of life for these patients. The use of HAART was shown to effectively suppress the replication of HIV-1 and dramatically reduce mortality and morbidity, which led to a better and longer quality of life for HIV-1-infected patients. Apart from the substantial benefits that result from the use of various HAART regimens, laboratory and clinical experience has shown that HAART can induce severe and considerable adverse effects related to metabolic complications of lipid metabolism, characterized by signs of lipodystrophy, insulin resistance, central adiposity, dyslipidemia, increased risk of cardiovascular disease and even an increased risk of atherosclerosis. New drugs are being studied, new therapeutic strategies are being implemented, and the use of statins, fibrates, and inhibitors of intestinal cholesterol absorption have been effective alternatives. Changes in diet and lifestyle have also shown satisfactory results.

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.

Abnormal adipose tissue distribution with unfavorable metabolic profile in five children following hematopoietic stem cell transplantation: a new etiology for acquired partial lipodystrophy

We report five consecutive patients who underwent hematopoietic stem cell transplantation (HSCT) to treat leukemia or neuroblastoma early in their lives and later manifested abnormal patterns of adipose tissue distribution. Lipoatrophy was remarkable in the gluteal regions and extremities, whereas subcutaneous fat was preserved in the cheeks, neck, and abdomen. In addition, visceral fat deposition, fatty changes in the liver, and metabolic derangements such as insulin resistance and hypertriglyceridemia were evident. These features resemble Dunnigan-type familial partial lipodystrophy, which is a rare condition caused by LMNA gene mutation. These patients shared a common medical history involving HSCT, including conditioning with total body irradiation (TBI). They also received intensive chemotherapy because of multiple metastases (n = 3), relapse (n = 3), and repetitive HSCT (n = 3). We propose HSCT as a new etiology for acquired partial lipodystrophy and recommend that patients who undergo HSCT with TBI and intensive chemotherapy early in their lives must receive careful observation for the possible development of lipodystrophy and metabolic complications.

Abnormal adipose tissue distribution with unfavorable metabolic profile in five children following hematopoietic stem cell transplantation: a new etiology for acquired partial lipodystrophy

We report five consecutive patients who underwent hematopoietic stem cell transplantation (HSCT) to treat leukemia or neuroblastoma early in their lives and later manifested abnormal patterns of adipose tissue distribution. Lipoatrophy was remarkable in the gluteal regions and extremities, whereas subcutaneous fat was preserved in the cheeks, neck, and abdomen. In addition, visceral fat deposition, fatty changes in the liver, and metabolic derangements such as insulin resistance and hypertriglyceridemia were evident. These features resemble Dunnigan-type familial partial lipodystrophy, which is a rare condition caused by LMNA gene mutation. These patients shared a common medical history involving HSCT, including conditioning with total body irradiation (TBI). They also received intensive chemotherapy because of multiple metastases (n = 3), relapse (n = 3), and repetitive HSCT (n = 3). We propose HSCT as a new etiology for acquired partial lipodystrophy and recommend that patients who undergo HSCT with TBI and intensive chemotherapy early in their lives must receive careful observation for the possible development of lipodystrophy and metabolic complications.

Exploring the pathophysiology behind the more common genetic and acquired lipodystrophies

Lipodystrophies are an immense group of genetic or acquired metabolic disorders that are characterized by varying degrees of body fat loss and in some instances localized accumulation of subcutaneous fat. Lipodystrophies are often tightly linked with profound metabolic complications; this strong bond emphasizes and reinforces the significance of adipose tissue as a dynamic endocrine organ. The extent of fat loss determines the severity of associated metabolic complications such as diabetes mellitus, hypertriglyceridemia and hepatic steatosis. The lipodystrophies can be divided into generalized, partial or local, depending on the degree and locality of the observable fat loss; moreover, the generalized and partial divisions can be partitioned further into inherited or acquired forms. The major genetic factors in the generalized forms of the lipodystrophies, particularly Congenital generalized lipodystrophy (CGL)-Berardinelli-Seip syndrome, are the AGPAT2, BSCL2, caveolin 1 (CAV1) and polymerase-I-and-transcriptrelease factor (PTRF) genes. In the acquired forms, genes such as LMNA, PPARG, CIDEC (cell-death-inducing DNA fragmentation factor a-like effector c) and PLIN1 are heavily involved in familial partial lipodystrophy (FPLD) type 2 (also known as the Dunnigan-Variety) and WRN along with RECQL5 in Werner Syndrome (WS). Autoimmune causes are particularly noted in acquired partial lipodystrophy (APL)-Barraquer-Simons syndrome and in AGL-Lawrence syndrome; panniculitis has been shown to have a substantial role in the former as well as in other forms of localized lipodystrophies. Patients with human immunodeficiency virus (HIV) exposed to protease inhibitors, nucleoside reverse transcriptase inhibitors (NRTIs) (for example, zidovudine and stavudine) or non-nucleoside reverse transcriptase inhibitors (NNRTIs) (for example, efavirenz) while undergoing Highly Active Antiretroviral Therapy (HAART) have led to the current most-prevalent form of the lipodystrophies: lipodystrophy in HIV-infected patients (LD-HIV) and HAART-associated lipodystrophy syndrome (HALS).

Adipokines in the HIV/HAART-associated lipodystrophy syndrome

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

Weight and lean body mass change with antiretroviral initiation and impact on bone mineral density

OBJECTIVE

To compare the effect that initiating different antiretroviral therapy (ART) regimens has on weight, BMI, and lean body mass (LBM) and explore how changes in body composition are associated with bone mineral density (BMD).

METHODS

A5224s was a sub-study of A5202, a prospective trial of 1857 ART-naive participants randomized to blinded abacavir-lamivudine (ABC/3TC) or tenofovir DF-emtricitabine (TDF/FTC) with open-label efavirenz (EFV) or atazanavir-ritonavir (ATV/r). All participants underwent dual-energy absorptiometry (DXA) and abdominal computed tomography for body composition. Analyses used two-sample t-tests and linear regression.

RESULTS

A5224s included 269 participants: 85% men, 47% white non-Hispanic, median age 38 years, HIV-1 RNA 4.6 log10 copies/ml, and CD4 cell count 233 cells/μl. Overall, significant gains occurred in weight, BMI, and LBM at 96 weeks post-randomization (all P<0.001). Assignment to ATV/r (vs. EFV) resulted in significantly greater weight (mean difference 3.35 kg) and BMI gain (0.88 kg/m; both P=0.02), but not LBM (0.67 kg; P=0.15), whereas ABC/3TC and TDF/FTC were not significantly different (P≥0.10). In multivariable analysis, only lower baseline CD4 cell count and higher HIV-1 RNA were associated with greater increase in weight, BMI, or LBM. In multivariable analyses, increased LBM was associated with an increased hip BMD.

CONCLUSION

ABC/3TC vs. TDF/FTC did not differ in change in weight, BMI, or LBM; ATV/r vs. EFV resulted in greater weight and BMI gain but not LBM. A positive association between increased LBM and increased hip BMD should be further investigated through prospective interventional studies to verify the impact of increased LBM on hip BMD.

Insulin resistance, lipodystrophy and cardiometabolic syndrome in HIV/AIDS

HIV associated insulin resistance, lipodistrophy and cardiometabolic syndrome have been extensively studied and continue to be the scope of much research. There is compelling evidence that both the HIV itself and the therapeutical regimes are major contributors to all of these associated comorbidities. HIV has increasingly been recognized as a disease of accelerated aging, manifested by increased progression of vascular disease and cellular markers of aging. The antiretroviral medication can increase insulin resistance and cause lipotoxocity and HIV-associated lipodystrophy leading to cardiovascular pathology. In this article we review the pathogenesis, management, and prevention of the long-term complications of HIV and its therapies, including cardiovascular disease, lipodystrophy, and insulin resistance along with the growing focus on biomarkers to predict development of end-organ disease. Through a focused literature search we review the established evidence, the developing research about the treatment strategies in treated HIV infection as well as identify potential areas for future research.

Accelerated Aging in HIV Patients

Life expectancy has been increasing in the last few decades in the Western world and is accompanied by higher occurrence of age-related diseases like metabolic, cardiovascular, and renal diseases and also with a decline in immune functions. In HIV-infected people, due to the use of combination antiretroviral therapy (cART), life expectancy has increased. As a result, non-AIDS conditions which are age-associated have become more prevalent and appear earlier, resulting in accelerated aging in HIV patients. These non-AIDS conditions in HIV patients are associated with CD4+ T cell counts: lower counts are associated with higher rates of liver, cardiovascular, renal, and neurocognitive disorders. The effect of viral load and cART on the earlier occurrence of age-associated diseases is less significant than the CD4 count effect. Thus, the loss of immune functions in HIV-infected patients may enhance aging.

Body composition and metabolic changes in HIV-infected patients

As antiretroviral therapy has decreased human immunodeficiency virus (HIV)-associated mortality, cardiometabolic abnormalities have become increasingly apparent in HIV-infected individuals. Many patients treated for HIV infection exhibit body composition changes, including peripheral fat atrophy and visceral lipohypertrophy. In addition, HIV-infected individuals demonstrate a higher prevalence of dyslipidemia, insulin resistance and diabetes, and cardiovascular risk, compared with the general population. Although antiretroviral therapy appears to contribute to some of the cardiometabolic abnormalities in HIV infection, HIV itself, immunologic factors, and lifestyle factors are also important mediators of cardiovascular risk. Treatment strategies for body composition changes and cardiometabolic abnormalities in HIV infection include lifestyle modification, lipid-lowering agents, insulin sensitizers, and treatments to reverse endocrine abnormalities in HIV, including growth hormone-releasing hormone. None of these strategies has comprehensively addressed the abnormalities experienced by this population, however, and further research is needed into combined strategies to improve body composition and ameliorate cardiovascular risk.

Leptin in relation to the lipodystrophy-associated metabolic syndrome

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

Body fat abnormality in HIV-infected children and adolescents living in Europe: prevalence and risk factors

OBJECTIVES

To estimate the prevalence of and identify risk factors for lipodystrophy syndrome (LS) and body fat abnormality in a population of HIV-infected children and adolescents.

DESIGN

Cross-sectional observational study.

METHODS

HIV-infected subjects aged 2-18 years were recruited from 15 HIV centers in Belgium, Italy, and Poland between January 2007 and December 2008. Standardized assessments by the patient's long-term clinician were performed to establish the presence of abnormality. Risk factors were explored in logistic regression models for fat abnormality outcomes and LS (abnormality plus dyslipidemia).

RESULTS

Among 426 subjects (70% white), median age was 12.2 years (interquartile range: 9.0-15.0 years) and median duration of antiretroviral therapy was 5.2 years (interquartile range: 2.2-8.8 years). Prevalence was 57% (n = 235) for LS and 42% (n = 176) for fat abnormality; 90 subjects with abnormality were affected in ≥3 locations. Lipoatrophy occurred in 28% (n = 117) of subjects and lipohypertrophy in 27% (n = 115), most commonly in the face and trunk, respectively. In multivariable analysis, white ethnicity, body mass index, ritonavir/lopinavir, and nonnucleoside reverse transcriptase inhibitors were each associated with an increased risk of LS (P < 0.05). White ethnicity, history of Centers for Disease Control and Prevention-defined disease, and stavudine were associated with risk of lipoatrophy (P < 0.05). Increased risk of lipohypertrophy was associated with body mass index and prior HIV disease.

CONCLUSIONS

Fat abnormality was prevalent in close to half of children and adolescents, who had accumulated long treatment durations. Risk of fat abnormality was associated with specific drugs, including stavudine and ritonavir, and other variables. Our results underline the importance of continued surveillance of children treated with antiretroviral therapy.

Lipodystrophy: pathophysiology and advances in treatment

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

An update on the use of Atripla in the treatment of HIV in the United States

Atripla^® (Gilead Sciences Inc, Foster City, CA, USA and Bristol-Myers Squibb, New York City, NY, USA) is a coformulated single pill composed of efavirenz, emtricitabine, and tenofovir disoproxil, intended as a once-daily potent combination antiretroviral therapeutic agent. Its efficacy is equivalent to the 3 component drugs taken in a combination as single medications. The coformulated antiretroviral regimen can be quite effective in patients whose human immunodeficiency virus is sensitive to all 3 components of Atripla. However, women at risk of pregnancy, already pregnant, or nursing mothers should not take Atripla, due to the teratogenic potential of the efavirenz moiety. Adverse effects are similar to those seen with the constituent medications, including potential central nervous system effects and renal toxicity. Since its US Food and Drug administration approval, prescriptions for Atripla have increased steadily.