Growth hormone secretion among HIV infected patients: effects of gender, race and fat distribution

OBJECTIVE

To determine the effects of gender, race, and fat redistribution on growth hormone (GH) secretory patterns in HIV-infected patients.

DESIGN

We investigated GH responses to growth hormone releasing hormone (GHRH) + arginine stimulation testing in HIV-infected subjects with fat redistribution, comparing HIV-infected males (n = 139) and females (n = 25) to non HIV-infected male (n = 25) and female (n = 26) control subjects similar in age, body mass index and race.

METHODS

A standard GHRH + arginine stimulation test [GHRH 1 microg/kg and arginine 0.5 g/kg (maximum dose 30 g)] was performed, and fat redistribution was assessed by anthropometry.

RESULTS

HIV-infected women had significantly higher peak GH in response to GHRH + arginine (36.4 +/- 7.3 versus 18.9 +/- 2.0 ng/ml; P = 0.003) and GH area under curve (AUC) (2679 +/- 593 versus 1284 +/- 133 (mg-min)/dl, P < 0.001) compared to HIV-infected men. Among men, a cutoff of 7.5 ng/ml for peak GH response on the GHRH + arginine test achieved good specificity and sensitivity and optimally separated the HIV and control groups (e.g., the failure rates were 37% versus 8%; P = 0.004, respectively). Among women, no specific cutoff could be determined to separate the HIV-infected and control subjects. Non-Caucasians demonstrated a higher GH AUC response compared to Caucasians, among the HIV-infected male subjects. In stepwise regression modeling waist-to-hip ratio was most significantly related to peak GH in response to GHRH + arginine in HIV-infected men.

CONCLUSIONS

HIV-infected men with fat redistribution have significantly reduced GH peak responses and increased failure rates to standardized GH stimulation testing in comparison to healthy male control subjects and to HIV-infected women of similar age and body mass index. GH secretion is related to gender and race in HIV-infected patients.

[Antiretroviral treatments-related lipodystrophy syndrome: clinico-pathological findings]

Effective therapies are available that can stop or slow down the progression of HIV infection. Highly active antiretroviral therapy (HAART) is a combination of antiretroviral drugs such as viral protease inhibitors or nucleoside-analogue reverse-transcriptase inhibitors. Among the side effects due to these drugs, lipodystrophy is a pathology characterized by fat wasting in face and limbs, accumulation of visceral fat, breast adiposity, cervical fat-pads, hyperlipidemia (hypertriglyceridemia and hypercholesterolemia), insulin resistance, and lactic acidemia. The main clinical features include peripheral fat loss (presumed lipoatrophy in the face, limbs, and buttocks) and central fat accumulation (within the abdomen, breasts, and over the dorsocervical spine, so-called "buffalo hump"). Histopathological features disclose a peculiar type of involutional lipodystrophy. Skin biopsies generally show thinning of the subcutaneous fat, associated with fibrosis, lipogranuloma and sometimes vessel proliferation. There is still an open debate concerning the precise responsibility of HAART as well as the metabolic pathways and mechanisms that are involved in the onset of lipodystrophy. There is no proven therapy for any component of lipodystrophy syndrome.

Sympathetic nervous system function in HIV-associated adipose redistribution syndrome

It was recently suggested that HIV-associated adipose redistribution syndrome (HARS) results from an autonomic dysbalance. We investigated the local and global sympathetic nervous system function of patients with HIV-1 infection and HARS. Interstitial noradrenaline concentrations in skeletal muscle and subcutaneous adipose tissue were increased in the absence of changes in global sympathetic nerve activity, consistent with locally increased sympathetic activity. This could promote localized lipolysis in subcutaneous adipose tissue and contribute to the development of HARS.

[Effect of anti-retroviral therapy on body composition changes: a literature review]

Protein-energetic malnutrition, characterized by both lean mass and fat depletion, was common in the pre-HAART era, and was associated with shortened survival and diminished quality of life. The pathogenesis of protein-energy malnutrition was multifactorial, and nutritional treatments were largely ineffective in the absence of disease stabilization. The introduction of HAART brought markedly improved outcomes, including a decrease in the incidence of malnutrition. However, other nutritional and metabolic alterations were noticed, and included changes in body shape, both lipoatrophy and lipohypertrophy, as well as changes in metabolism, notably hyperlipidemia and insulin resistance. These conditions, though sometimes occurring together, may occur independently, suggesting a complex, multifactorial cause. Several mechanisms have been hypothesized, including impairment to adipocyte differentiation and adipokine regulation, production of proinflammatory cytokines and mitochondrial toxicity. The role of the single drug class is still unclear, because both PI and NRTI have been associated with the syndrome, and the therapeutic protocols include both groups. Most of the medical therapies proposed for lipodystrophy are ineffective, and even if surgery remains an alternative, it is not associated with long lasting outcomes.

Caring for HIV-positive and aging patients with associated facial lipoatrophy

Facial lipoatrophy is characterized by fat loss and redistribution. It is a natural, biological phenomenon that occurs over time, presenting as mild-to-moderate volume depletion that gives the skin the appearance of sagging. More recently, highly active antiretroviral therapy, introduced for the management of human immunodeficiency virus, has been associated with moderate-to-severe facial lipoatrophy, and is characterized by sunken cheeks, accentuated nasolabial folds, and protruding musculature and bones. Furthermore, the consequences of facial lipoatrophy have been found to substantially impact patient quality of life. Nurses play an integral role in the treatment of facial lipoatrophy by educating the patients on available therapies and assisting them in making informed treatment decisions. It is important that treating nurses conduct a well-organized interview to understand patient treatment goals. This article will discuss several treatment options available to correct facial lipoatrophy-associated volume deficits, including collagen, hyaluronic acid, calcium hydroxylapatite, poly-L-lactic acid, and permanent implants and injectables.

Pronounced lipoatrophy in HIV-infected men receiving HAART for more than 6 years compared with the background population

OBJECTIVES

To establish the prevalence and quantify the severity of body fat redistribution and dyslipidaemia in HIV-infected men after long-term highly active antiretroviral therapy (HAART) compared with the background population.

METHODS

In a cross-sectional study, we included 87 HIV-infected men who had received HAART for at least 6 years and 34 HIV-negative men. Regional body composition was assessed using dual-energy X-ray absorptiometry. Fasting metabolic parameters were obtained. Associations between regional body fat distribution and metabolic parameters were evaluated.

RESULTS

HIV-infected patients and controls did not differ with regard to height and lean body mass. Compared with controls, HIV-infected men had reduced total fat mass (median 12.3 versus 19.2 kg, P<0.001), limb fat mass (4.3 versus 7.9 kg, P<0.001), and trunk fat mass (6.7 versus 10.8 kg, P<0.001) and higher trunk/limb fat ratio (1.7 versus 1.2, P<0.001). Also, patients without clinical lipodystrophy had reduced amounts of limb and trunk fat. In HIV-infected men, triglyceride levels were higher (2.0 versus 1.2 mmol/L, P<0.001), high-density lipoprotein (HDL)-cholesterol levels were lower (1.2 versus 1.3 mmol/L, P<0.05) and insulin levels were higher (40.8 versus 29.9 pmol/L, P<0.01) than in controls. All adverse metabolic parameters correlated with increased trunk/limb fat ratio, and insulin levels correlated positively with trunk fat mass (P<0.01).

CONCLUSION

Peripheral as well as central fat loss is a general characteristic of HIV-infected men after long-term HAART. Although lipoatrophy was the dominant morphological presentation, the adverse metabolic parameters were mainly associated with the increased ratio of trunk/limb fat.

HIV protease inhibitors block adipocyte differentiation independently of lamin A/C

OBJECTIVES

To determine the importance of lamin A/C for fat cell differentiation in vitro and for the anti-adipogenic activity of HIV protease inhibitors such as indinavir.

METHODS

Lipodystrophy-associated and processing-defective mutants of lamin A were stably expressed at high levels in 3T3-L1 pre-adipocytes. Additionally, 3T3-L1 pre-adipocytes with stable reduction of lamin A/C or emerin were derived. The cells were differentiated for 8 days into mature adipocytes in the presence or absence of indinavir or nelfinavir.

RESULTS

3T3-L1 cells stably expressing high levels of lipodystrophy-associated or processing-defective mutants of lamin A differentiated with comparable efficiencies to control cells. Similarly, cells with dramatically reduced lamin A levels differentiated as efficiently as controls. Although indinavir stimulated the accumulation of unprocessed lamin A, cells with dramatically reduced lamin A/C levels and no detectable prelamin A remained responsive to an indinavir-induced inhibition of adipogenesis.

CONCLUSIONS

The ability of HIV protease inhibitor to stimulate the accumulation of unprocessed lamin A is neither necessary nor sufficient to explain their anti-adipogenic activity. Furthermore, lamin A/C plays a minimal role in the differentiation of 3T3-L1.

Persistence of lipoatrophy after a four-year long interruption of antiretroviral therapy for HIV1 infection: case report

BACKGROUND

HIV-infected patients on long-term highly active antiretroviral therapy often present peculiar patterns of fat redistribution, referred to as lipodystrophy. In spite of recent investigations, it is not known whether and to what extent the main features of lipodystrophy--that is lipoatrophy of peripheral fat at face, limbs and buttocks, as well as fat accumulation at breasts, abdomen and the dorso-cervical region--can be reversible once clinically manifest.

CASE PRESENTATION

A 35 year old Caucasian HIV infected female developed severe diffuse lipodystrophy while on highly active antiretroviral therapy. A remarkable increase of breast size, fat accumulation at waist, and a fat pad on her lumbar spine were paralleled by progressive and disfiguring lipoatrophy of face, limbs and buttocks. The patient decided to interrupt her therapy after 20 months, with a stably suppressed viremia and a CD4 lymphocyte count > 500/microL. She could carry on a safe treatment interruption for longer than 4 years. Most sites of fat accumulation switched to nearly normal appearance, whereas lipoatrophy was substantially unchanged at all affected sites.

CONCLUSION

our observation provides pictorial evidence that lipoatrophy may not be reversible even under ideal circumstances. Therefore, strategies to prevent lipoatrophy should be considered when defining therapeutic regimens for HIV infected patients, especially those at high risk.

Laser scanning as a tool for assessment of HIV-related facial lipoatrophy: evaluation of accuracy and reproducibility

BACKGROUND

Facial lipoatrophy (LA) is a common complication of highly active antiretroviral therapy (HAART). Research into causes and treatment of facial LA is hindered by the lack of an objective measurement tool.

OBJECTIVE

To evaluate the accuracy and reproducibility of three-dimensional laser scanning (LS) for estimating cheek volume changes.

METHODS

Paired laser scans were performed and the images superimposed using commercial software. The volume difference between images was computed within a circle of radius 25 mm placed in a standardized position over the cheek area. Accuracy was tested by scanning before and after known volumes of plasticine (0.5--5 mL) were applied to the cheek area of a mannequin to simulate volume change. Reproducibility was tested by repeated scanning of the mannequin with and without 2 mL of plasticine, and repeated scanning of 10 healthy subjects over the course of 1 week.

RESULTS

The mean difference between actual and estimated volume change was small across the range of volumes tested [mean difference 0.08 mL; 95% confidence interval (CI)-0.36 to 0.20 mL). The coefficient of variation for repeated measurements of 2-mL volume change was 5.8%. The intraclass correlation coefficient for scan-to-scan variability was 0.812 (95% CI 0.515--0.947) and for day-to-day variability it was 0.764 (95% CI 0.332--0.935). Conclusions LS is an accurate and reproducible method for estimating cheek volume changes. It may be useful as an objective tool for assessment of facial LA in clinical research studies.

Evaluation of ultrasound for assessing facial lipoatrophy in a randomized, placebo-controlled trial

We investigated the utility of ultrasonography for assessing facial lipoatrophy changes in HIV-infected adults receiving antiretroviral therapy who participated in a 48-week, randomized, placebo-controlled trial of rosiglitazone. Ultrasound was performed at weeks 0, 24 and 48 to determine the subcutaneous fat thickness over the malar bone. Changes in facial fat assessed by ultrasonography did not correlate significantly with more established objective measures of lipoatrophy severity. The measurement of malar fat using ultrasonography is not recommended.

Short communication: HIV infection, antiretrovirals, and apoptosis: studies on skeletal muscle

Increased apoptosis in CD4+ T lymphocytes plays an important role in the pathogenesis of HIV infection and it has also invoked some HIV-related as well as antiretroviral-related adverse events. We assessed whether increased apoptosis is also present in the skeletal muscle of HIV-infected patients. We included 36 consecutive individuals, 18 without (group A) and 18 with HIV infection. The latter group consisted of five asymptomatic antiretroviral-naive HIV-infected individuals (group B), six asymptomatic HIV-infected individuals on highly active antiretroviral therapy (HAART, group C), and seven HIV-infected individuals on HAART with lipodystrophy (group D). Immunohistochemical reaction using deoxyribonucleotidyltransferase-mediated- dUTP-biotin nick-end labeling (TUNEL) was performed on skeletal muscle samples. None of the uninfected patients (group A) showed data of increased apoptosis, while 16 out of 18 infected patients did (p < 0.001). All subgroups of infected subjects (groups B-D) showed a significant increase of apoptosis in TUNEL with respect to uninfected individuals, but the comparison between the different subgroups of infected patients did not reveal significant differences. We conclude that skeletal muscle of HIV-infected patients exhibits increased apoptosis compared with that of uninfected patients, but the role of HAART in inducing apoptosis remains to be established.

HIV antiretroviral treatment alters adipokine expression and insulin sensitivity of adipose tissue in vitro and in vivo

HIV-1-infected patients on antiretroviral therapy frequently develop a lipodystrophy syndrome, characterized by peripheral lipoatrophy and visceral fat redistribution associated with metabolic alterations including dyslipidemia and insulin resistance. Its pathophysiology remains unclear but the antiretroviral treatment, associating protease inhibitors (PIs) and nucleoside analogue inhibitors of the viral reverse transcriptase (NRTIs), plays a major role. Some antiretroviral molecules inhibit differentiation and induce insulin resistance and apoptosis in adipose cells both in vitro and in vivo. In vitro, PIs and NRTIs increase the expression and secretion of pro-inflammatory cytokines such as TNF alpha, IL-6 and L-1beta, which are involved in altered adipocyte functions and decrease that of adiponectin, a positive modulator of insulin sensitivity. Similar alterations are observed in fat and serum from HIV-1-infected lipodystrophic patients under antiviral treatment associating PIs and NRTIs. Altered adipokine secretion could result from patients' exposure to PIs and NRTIs and lead to altered adipocyte differentiation, insulin resistance and apoptosis, ultimately resulting in lipoatrophy. These disorders probably result in a decreased secretion of adiponectin and an increased release of free fatty acids by insulin-resistant adipose tissue. Therefore, they could be involved in whole body insulin resistance and metabolic alterations in lipodystrophic HIV-1-infected patients.

Increased adipocyte apoptosis in lipoatrophy improves within 48 weeks of switching patient therapy from Stavudine to abacavir or zidovudine

OBJECTIVES

Lipoatrophy is an important manifestation of the lipodystrophy syndrome and is particularly associated with stavudine exposure. Increased apoptosis has been suggested as a possible mechanism of lipoatrophy. We assessed the degree and reversibility of adipocyte apoptosis in patients with lipoatrophy before and 48 weeks after substituting abacavir or zidovudine for stavudine.

METHODS

Apoptotic adipocytes were identified using terminal transferase dUTP nick end labeling and quantified using video image analysis.

RESULTS

Fat biopsy specimens were obtained from patients before (n = 15) and 48 weeks after (n = 10) switching from stavudine and from 20 HIV-uninfected controls. More apoptotic cells were seen in fat samples from patients with lipoatrophy treated with stavudine than in specimens from controls (P < 0.0001). Forty-eight weeks after switching from stavudine to abacavir or zidovudine, there was a reduction in apoptotic cells per unit area (P = 0.01) and as a proportion of all adipocytes present (P = 0.02) in patient biopsy specimens. Levels of adipocyte apoptosis in the 48-week biopsy specimens were no longer significantly different from those seen in control biopsy specimens (P > 0.1).

CONCLUSIONS

Increased apoptosis is present in fat samples from patients with lipoatrophy treated with stavudine. This improves toward normal within 48 weeks of switching from stavudine to abacavir or zidovudine, suggesting a causative role for stavudine in this process.

Chronic loss of subcutaneous adipose tissue in HIV-associated lipodystrophy may not be associated with accelerated apoptosis

HIV-associated lipodystrophy (HIV-LD) is characterized by a loss of adipose tissue from the subcutaneous compartment. Previously reported data suggested that this loss of adipose tissue was the result of an increased rate of apoptosis in subcutaneous adipose tissue (SAT). The present study examined the rate of apoptosis in SAT with a sensitive ligase-mediated polymerase chain reaction technique to amplify DNA ladders. Individuals with HIV-LD were compared with HIV-infected subjects without LD and subjects without HIV disease. Although apoptosis was observed in subjects with HIV-LD, there was no difference in the incidence of individuals with apoptosis among those with HIV-LD (10 of 22 subjects), those with HIV but no LD (13 of 25 subjects), and those without HIV disease (13 of 27 subjects). These data suggest that HIV-related chronic loss of SAT may not always be associated with increased frequency of adipocyte apoptosis.

Body Composition and Metabolic Changes in Antiretroviral-Naive Patients Randomized to Didanosine and Stavudine vs. Abacavir and Lamivudine

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

Buffalo Hump Seen in HIV-Associated Lipodystrophy is Associated With Hyperinsulinemia But Not Dyslipidemia

Accumulation of dorsocervical fat, or a "buffalo hump" (BH), is commonly reported in adults with HIV-associated lipodystrophy (HIVLD). The pathogenesis underlying this aspect of a syndrome characterized by loss of subcutaneous fat from other body sites is poorly understood. We aimed to identify risk factors for a BH in HIV-infected adults in cross-sectional analyses of 2 HIV-infected ambulatory populations. The first group (Australian Lipodystrophy Prevalence Survey [APS]) consisted of 1348 Australian HIV-infected adults (95% male) irrespective of changes in body composition. The second group (Lipodystrophy Case Definition [LDCD] study) comprised 417 subjects (83% male) with at least 1 reported moderate or severe feature of HIVLD. A BH was reported in 24 (2%) APS subjects and 79 (19%) LDCD study subjects. A BH was not an isolated finding. Patients with a BH had a high prevalence of other features of HIVLD, similar to lipodystrophic patients without a BH, such as facial lipoatrophy reported in 100% and 61% BH-positive subjects from the APS and LDCD study, respectively. In both groups, those with a BH had higher fasting insulin (P<or=0.007), a higher body mass index (P<or=0.003), a higher waist/hip ratio (P<or=0.001), higher limb fat (P<or=0.003), and higher systolic blood pressure (P<0.05). On multivariate analysis, higher serum insulin, systolic blood pressure, age, and duration of exposure to ritonavir were independently associated with a BH in the APS group. In the LDCD group, higher insulin, diastolic blood pressure, and duration of exposure to zidovudine were independently associated with a BH. There was no association between a BH and hyperlipidemia. These data show that a BH is associated with other physical features of the lipodystrophy phenotype and suggest that hyperinsulinemia, a feature common to HIVLD, obesity, and hypercortisolism, is an important component of this phenotype, thus warranting closer monitoring of BH-positive patients for glucose intolerance and diabetes.

Loss of Subcutaneous Adipose Tissue in HIV-Associated Lipodystrophy Is Not Due to Accelerated Apoptosis

HIV-associated lipodystrophy is characterized by a loss of adipose tissue from the subcutaneous compartment. Previously reported data suggested that this loss of adipose tissue was the result of an increased rate of apoptosis in subcutaneous adipose tissue. The present study examined the rate of apoptosis in subcutaneous adipose tissue with a sensitive ligase-mediated polymerase chain reaction technique to amplify DNA ladders. Individuals with HIV lipodystrophy were compared with HIV-infected subjects without lipodystrophy and subjects without HIV disease. Although apoptosis was observed in subjects with HIV lipodystrophy, there was no difference in the frequency of individuals with apoptosis among those with HIV lipodystrophy (10/22), those with HIV but no lipodystrophy (13/25), and subjects without HIV disease (13/27).

Defective glucose and lipid metabolism in human immunodeficiency virus-infected patients with lipodystrophy involve liver, muscle tissue and pancreatic beta-cells

OBJECTIVES

Lipodystrophy and insulin resistance are prevalent among human immunodeficiency virus (HIV)-infected patients on combined antiretroviral therapy (HAART). Aiming to provide a detailed description of the metabolic adverse effects of HIV-lipodystrophy, we investigated several aspects of glucose metabolism, lipid metabolism and beta-cell function in lipodystrophic HIV-infected patients.

METHODS

[3-3H]glucose was applied during euglycaemic hyperinsulinaemic clamps in association with indirect calorimetry in 43 normoglycaemic HIV-infected patients (18 lipodystrophic patients on HAART (LIPO), 18 patients without lipodystrophy on HAART (NONLIPO) and seven patients who were naive to antiretroviral therapy (NAIVE) respectively). beta-cell function was evaluated by an intravenous glucose tolerance test.

RESULTS

Compared with NONLIPO and NAIVE separately, LIPO displayed markedly reduced ratio of limb to trunk fat (RLF; > 34%, P < 0.001), hepatic insulin sensitivity (> 40%, P < 0.03), incremental glucose disposal (>50%, P < 0.001) and incremental exogenous glucose storage (>50%, P < 0.05). Furthermore, LIPO displayed reduced incremental glucose oxidation (P < 0.01), increased clamp free fatty acids (P < 0.05) and attenuated insulin-mediated suppression of lipid oxidation (P < 0.05) compared with NONLIPO. In combined study groups, RLF correlated with hepatic insulin sensitivity (r = 0.69), incremental glucose disposal (r = 0.71) and incremental exogenous glucose storage (r = 0.40), all P < 0.01. Disposition index (i.e. first-phase insulin response to intravenous glucose multiplied by incremental glucose disposal) was reduced by 46% (P = 0.05) in LIPO compared with the combined groups of NONLIPO and NAIVE, indicating an impaired adaptation of beta-cell function to insulin resistance in LIPO.

CONCLUSION

Our data suggest that normoglycaemic lipodystrophic HIV-infected patients display impaired glucose and lipid metabolism in multiple pathways involving liver, muscle tissue and beta-cell function.

Facial fat volume in HIV-infected patients with lipoatrophy

BACKGROUND

The volume and anatomical distribution of facial fat depletion in HIV related lipoatrophy have not been properly quantified. We aimed to determine the extent and distribution of facial fat loss in HIV-infected patients with lipoatrophy and whether this differs from wasting.

DESIGN

We studied HIV-infected patients with clinically defined moderate to severe lipoatrophy without wasting (n = 15), clinically defined wasting (> 10% weight loss and recent opportunistic infection) with no previous reported lipodystrophy (n = 15), and controls without lipodystrophy or wasting (n = 15). Facial MRI scans were performed, and areas of fat were manually traced bilaterally in all individual image slices and summed to calculate volume in anatomically defined regions of interest.

RESULTS

Patients with lipoatrophy had lower fat volumes in the temporal region (8.9 +/- 9.4 vs 20.5 +/- 7.2 ml; P < 0.001), cheek region (25.6 +/- 24.9 vs 55.5 +/- 15.0 ml; P < 0.001), periorbital region (1.9 +/- 1.0 vs 2.7 +/- 1.0 ml; P = 0.09) and buccal fat pad (13.4 +/- 9.4 vs 21.8 +/- 9.8 ml; P = 0.030) compared with controls. Patients with wasting had temporal, cheek, periorbital and buccal fat pad volumes (10.4 +/- 6.7 ml, 34.0 +/- 14.8 ml, 1.4 +/- 1.1 ml and 13.1 +/- 4.6 ml respectively) that were lower than controls (all P < 0.01) but similar to lipoatrophy patients (all P > 0.5).

CONCLUSIONS

Facial fat depletion in lipoatrophy is substantial (approximately 50% volume loss) and involves superficial and deep fat (buccal fat pad). The distribution and volume of fat change is similar to that seen in wasting. Given the extent of the changes, complete surgical correction is unlikely to be possible and hence emphasis should be placed on prevention of lipoatrophy [corrected]

Body fat changes among antiretroviral-naive patients on PI- and NNRTI-based HAART in the Swiss HIV cohort study

BACKGROUND

Body fat changes are common in patients with HIV. For patients on protease inhibitor (PI)-based highly active antiretroviral therapy (HAART), these changes have been associated with increasing exposure to therapy in general and to stavudine in particular. Our objective is to show whether such associations are more or less likely for patients on non-nucleoside reverse transcriptase inhibitor (NNRTI)-based HAART.

METHODS

We included all antiretroviral-naive patients in the Swiss HIV Cohort Study starting HAART after April 2000 who had had body weight, CD4 cell count and plasma HIV RNA measured between 6 months before and 3 months after starting HAART, and at least one assessment of body fat changes after starting HAART. At visits scheduled every 6 months, fat loss or fat gain is reported by agreement between patient and physician. We estimate the association between reported body fat changes and both time on therapy and time on stavudine, using conditional logistical regression.

RESULTS

Body fat changes were reported for 85 (9%) out of 925 patients at their first assessment; a further 165 had only one assessment. Of the remaining 675 patients, body fat changes were reported for 156 patients at a rate of 13.2 changes per 100 patient-years. Body fat changes are more likely with increasing age [odds ratio (OR) 1.18 (1.00-1.38) per 10 years], with increasing BMI [OR 1.06 (1.01-1.11)] and in those with a lower baseline CD4 cell count [OR 0.91 (0.83-1.01) per 100 cells/microl]. There is only weak evidence that body fat changes are more likely with increasing time on HAART [OR 1.16 (0.93-1.46)]. After adjusting for time on HAART, fat loss is more likely with increasing stavudine use [OR 1.70 (1.34-2.15)]. There is no evidence of an association between reported fat changes and time on NNRTI therapy relative to PI therapy in those patients who used either one therapy or the other [OR 0.98 (0.56-1.63)].

CONCLUSION

Fat loss is more likely to be reported with increasing exposure to stavudine. We find no evidence of major differences between PI and NNRTI therapy in the risk of reported body fat changes.

Single-Slice Computed Tomography and Anthropometric Skinfold Analysis for Evaluation of Facial Lipoatrophy in HIV-Infected Patients

We assessed the value of computed tomography (CT) and anthropometric skinfold analysis for evaluating subcutaneous facial fat in human immunodeficiency virus-infected patients. Patients with facial lipoatrophy had smaller areas of facial adipose tissue, lower ratios of adipose tissue area to total tissue area of the face, and lower malar skinfold values, compared with patients without facial wasting. CT may be a useful technique to diagnose and monitor facial lipoatrophy.

Comparison of dual-energy X-ray absorptiometry machines for measuring fat distribution changes of HIV-associated lipodystrophy

BACKGROUND

Dual-energy X-ray absorptiometry (DXA) is regarded as a useful objective method for diagnosis of HIV-associated lipodystrophy (LD).

OBJECTIVE

To determine whether the use of different DXA machines may affect the diagnosis of LD.

METHODS

Body composition in 24 HIV-infected patients, 12 of whom had clinically diagnosed LD, was measured on two DXA machines (Lunar and Hologic).

RESULTS

Hologic gave significantly higher values than Lunar DXA for total body fat percent (22.9 vs 20.5%, P<0.001), arm fat percent (27.9 vs 14.5%, P<0.001) and leg fat percent (23.4 vs 17.5%, P<0.001), and significantly lower values than Lunar for trunk fat percent (22.3 vs 24.7%, P<0.001) and trunk-to-limb fat percent ratio (0.89 vs 1.62, P<0.001). When measured by Lunar, patients with LD had significantly lower leg fat percent (13.5 vs 21.6%, P=0.04) and higher trunk-to-limb fat percent ratio (1.85 vs 1.38; P=0.012) than those without LD. When measured by Hologic, patients with LD had values of leg fat percent (20.1 vs 26.8%, P=0.11) and trunk-to-limb fat percent ratio (0.95 vs 0.85, P=0.43) that did not differ significantly from those without LD. There was a significant difference in the contribution to a composite LD score between Lunar and Hologic measurements.

CONCLUSION

DXA machines from different manufacturers give major differences in measurements of body fat content and distribution, and this may affect the ability to distinguish patients with LD from those without LD. Further standardization of DXA technology is needed before widespread application in the clinical diagnosis of LD.

Altered fat differentiation and adipocytokine expression are inter-related and linked to morphological changes and insulin resistance in HIV-1-infected lipodystrophic patients

OBJECTIVE

To achieve a better understand of the pathophysiology of HIV-related lipoatrophy, we compared the mRNA expression of adipocytokines in fat samples from patients and healthy HIV-seronegative controls together with fat morphology and we studied the relationship between changes in fat morphology, adipocytokine expression, markers of adipose tissue differentiation and whole body insulin sensitivity.

DESIGN

Cross-sectional analytical study.

SUBJECTS AND METHODS

The mRNA expression of adipocytokines and transcriptional factors in fat samples from 26 patients with peripheral lipoatrophy (all under anti-retroviral therapy associating protease inhibitor and nucleoside-analogue reverse transcriptase inhibitors) and from 16 non-HIV-infected controls was measured by real time quantitative RT-PCR. Fat morphology was assessed histologically on a subgroup of 10 patients and six controls: collagen fibres by Sirius Red staining, apoptosis by the TUNEL technique, vessels by smooth muscle alpha-actin staining and macrophages by CD68 staining. Insulin resistance was assessed by using the homeostasis model assessment.

RESULTS

The patients' fat showed higher values of apoptosis (P=0.005), fibrosis (P<0.05), vessel density (P=0.001) and macrophage infiltration (P<0.05) than the controls' fat, together with lower adiponectin and leptin mRNA levels and higher interleukin (IL)-6 and tumour necrosis factor (TNF)alpha mRNA levels. TNFa and IL-6 expression correlated positively with the level of apoptosis (P=0.05 and P<0.05, respectively) and negatively with CCAAT-enhancer binding protein (C/EBP)alpha (P<0.001 and P<0.05, respectively). Apoptosis correlated negatively with the expression level of sterol-regulatory-element-binding-protein-1c (SREBP1c) (P=0.01) and C/EBPalpha (P=0.01) whilst the vessel density correlated negatively with SREBP1c (P<0.005), C/EBPalpha (P=0.001) and beta (P=0.001). Adiponectin and leptin expression correlated positively with each other, and also with adipogenic marker expression and overall insulin sensitivity. These relationships were also present when the patient group was studied separately. Finally, fat morphological abnormalities correlated positively with whole body insulin resistance.

CONCLUSIONS

Adipose tissue from patients with HIV-1-related lipoatrophy shows increased apoptosis, together with decreased adipocyte differentiation. Increased TNFalpha and IL-6 expression could be a major phenomenon linking these alterations. Decreased adiponectin and leptin expression, which may result from decreased adipocyte differentiation, could be involved in the observed whole body insulin resistance.

Antiretroviral therapy, fat redistribution and hyperlipidaemia in HIV-infected children in Europe

OBJECTIVES

To estimate prevalence of body fat redistribution and dyslipidaemia in HIV-infected children and to assess associated risk factors, ultimately to inform the definition of lipodystrophy in children.

DESIGN

Cross-sectional observational study.

METHODS

During a 2-3 month period, 477 HIV-infected children aged >or= 3 years (median 9.78; range, 3-18) in 30 paediatric HIV clinics were assessed at their first visit. Sociodemographic, clinical and immunological data were recorded and the presence or absence of clinical signs of fat redistribution (peripheral lipoatrophy and central lipohypertrophy) determined according to an agreed protocol. Laboratory indicators of lipid/glucose metabolism were recorded for all children in 18 centres.

RESULTS

Prevalence was 26.0% [95% confidence interval (CI), 22.1-30.2] for any fat redistribution, 8.81% (95% CI, 6.42-11.7) for central lipohypertrophy, 7.55% (95% CI, 5.34-10.3) for peripheral lipoatrophy and 9.64% (95% CI, 7.15-12.7) for the combined subtype (more than one sign of each). Independent predictors of fat redistribution included Centers for Disease Control and Prevention class C disease, female gender, ever used versus never use of protease inhibitors and of stavudine. Increasing time since initiation of antiretroviral therapy was associated with increased severity of fat redistribution. In the metabolic assessment subgroup, 27% (95% CI, 21.6-32.7) of children had hypercholesterolaemia and 21% (95% CI, 16.4-26.6) hypertriglyceridaemia; however, significantly more children had fat redistribution in this subgroup than overall (31%).

CONCLUSIONS

Approximately a quarter of children and adolescents could be taken to have signs of lipodystrophy, with clinical presentation and risk factors similar to those described in adults.

New insights into inhibitors of adipogenesis

PURPOSE OF REVIEW

Adipose tissue is a dynamic organ that changes mass throughout life in response to the metabolic needs of the animal. In the past three decades, significant advances have been made in delineating key extracellular and intracellular stimulators of fat cell formation or adipogenesis. In this review, the author focuses on new findings of specific inhibitors of adipogenesis. Understanding the balance between positive and negative regulators of adipogenesis has important health-related implications for anti-obesity medical therapy and lipodystrophy.

RECENT FINDINGS

Adipogenesis is a highly regulated process requiring coordinated expression and activation of two main groups of adipogenic transcription factors, CCAAT/enhancer binding proteins and peroxisome proliferators activated receptor gamma. In response to hormonal and nutrient stimuli, the increased expression and activation of these transcription factors induce the expression of adipocyte-specific genes. More recently, several groups have identified extracellular inhibitors of adipocyte formation, including cytokines, lipid molecules, genistein, and protease inhibitors. Intracellular signaling molecules, which negatively regulate adipogenesis, include Pref-1, Foxo1, Foxa2, SMAD-3, WNT-10b, GATA-2 and GATA-3.

SUMMARY

The prevalence of obesity is increasing in the United States and in other westernized societies. Understanding the mechanisms of excessive energy storage in adipose tissue is necessary to develop a comprehensive strategy to prevent and treat obesity. One potential, but unrealized, approach to obesity treatment is to target excessive adipose tissue enlargement. A number of promising extra- and intracellular inhibitors of fat cell formation have been identified, but the modulation of adipose tissue mass may have both advantageous and deleterious health effects.

The role of nucleoside reverse transcriptase inhibitors in the fat redistribution syndrome

Fat redistribution associated with the use of antiretroviral therapy, which has been broadly termed 'lipodystrophy', incorporates distinct body composition changes including lipoatrophy (subcutaneous fat loss) as well as fat accumulation. This review examines the role of nucleoside reverse transcriptase inhibitor (NRTI) therapy in the overall context of lipodystrophy, providing converging evidence from observational cohort studies, clinical trials and pathological studies that lipoatrophy is strongly and specifically associated with the use of certain NRTI drugs (stavudine more than zidovudine), and that host factors also have a modulating effect on risk of NRTI-associated lipoatrophy. Implications for clinical assessment and management are also considered, within a broader contest that incorporates treatment efficacy as well as toxicity.

Reversibility of lipoatrophy in HIV-infected patients 2 years after switching from a thymidine analogue to abacavir: the MITOX Extension Study

OBJECTIVE

To determine if long-term improvement in HIV lipoatrophy can be attained by substitution of thymidine analogues zidovudine (ZDV) or stavudine (d4T) with abacavir (ABC).

DESIGN

Long-term follow-up (104 weeks) of a randomized, open-label study.

SETTING

Seventeen ambulatory HIV clinics in Australia and London.

SUBJECTS

Patients with HIV lipodystrophy were randomized to switch from a thymidine analogue to ABC, while continuing all other antiretroviral therapy (ABC arm) (n = 42) or continue current therapy (ZDV/d4T arm) (n = 43).

INTERVENTION

At week 24, all control patients could switch to ABC. Of the original 111 patients randomized, 85 had long-term follow-up data, with 77 having imaging data available at 104 weeks.

MAIN OUTCOME MEASURE

The primary endpoint was time-weighted change in limb fat mass, measured by dual-energy X-ray absorptiometry (DEXA).

RESULTS

At week 104, the mean increase in limb fat for the ABC and ZDV/d4T group was 1.26 +/- 2.02 kg and 0.49 +/- 1.38 kg, respectively. The time-weighted change for limb fat was significantly different between the two arms (0.43 kg; P = 0.008). On-treatment analysis demonstrated a trend for increased limb fat in patients in the ABC arm. Visceral fat accumulation, buffalo hump, self-assessed lipodystrophy or the lipodystrophy case definition score (LCDS) did not improve.

CONCLUSIONS

In patients with moderate-to-severe lipodystrophy, significant improvements in subcutaneous fat continued over 104 weeks after switching from a thymidine analogue to ABC. Nevertheless, the lipodystrophy syndrome was still evident, indicating additional strategies need evaluating.

Adipocytes targets and actors in the pathogenesis of HIV-associated lipodystrophy and metabolic alterations

The recent clinical use of potent HIV-1 drugs, including nucleoside reverse transcriptase inhibitors (NRTIs) and non-peptidic viral protease inhibitors (PIs), and their combinations, termed highly active antiretroviral therapy (HAART), has dramatically reduced the infection-related mortality of AIDS patients, but it is associated with severe metabolic adverse events such as lipodystrophy syndrome, dyslipidaemia, insulin resistance and diabetes mellitus. The aetiology of this syndrome and metabolic alterations appear to be multifactorial, including HIV drug inhibitory effects on adipocyte differentiation, alteration of mitochondrial functions in adipocytes and altered leptin, adiponectin and cytokine expression in adipose tissue of patients. Adipose tissue may thus be a central regulator in disorganized lipid metabolism and insulin resistance associated with antiretroviral therapy, and we propose in this review to explore how adipose tissue may be a target, but also an actor, in the aetiopathogenesis of the lipodystrophy syndrome.

Increased systemic and adipose tissue cytokines in patients with HIV-associated lipodystrophy

The lipodystrophy syndrome (adipose tissue redistribution and metabolic abnormalities) observed with highly active antiretroviral therapy (HAART) during human immunodeficiency virus (HIV) infection may be related to increased proinflammatory cytokine activity. We measured acute cytokine (TNF-alpha, IL-6, leptin), glycerol, and lactate secretion from abdominal subcutaneous adipose tissue (SAT), and systemic cytokine levels, in HIV-infected subjects with and without lipodystrophy (HIVL+ and HIVL-, respectively) and healthy non-HIV controls. Lipodystrophy was confirmed and characterized as adipose tissue redistribution in HIVL+ compared with HIVL- and controls, by dual-energy X-ray absorptiometry and by whole body MRI. TNF-alpha secretion from abdominal SAT and circulating levels of IL-6, soluble TNF receptors I and II, and insulin were elevated in HIVL+ relative to HIVL- and/or controls, particularly in HIVL+ undergoing HAART. In the HIV-infected group as a whole, IL-6 secretion from abdominal SAT and serum IL-6 were positively associated with visceral fat and were negatively associated with the relative amount of lower limb adipose tissue (P < 0.01). Decreased leptin and increased lactate secretion from abdominal SAT were specifically associated with HAART. In conclusion, increased cytokine secretion from adipose tissue and increased systemic proinflammatory cytokine activity may play a significant role in the adipose tissue remodeling and/or the metabolic abnormalities associated with the HIV-lipodystrophy syndrome in patients undergoing HAART.

Psoas muscle attenuation measurement with computed tomography indicates intramuscular fat accumulation in patients with the HIV-lipodystrophy syndrome

The human immunodeficiency virus (HIV)-lipodystrophy syndrome is characterized by abnormalities of lipid metabolism, glucose homeostasis, and fat distribution. Overaccumulation of intramuscular lipid may contribute to insulin resistance in this population. We examined 63 men: HIV positive with lipodystrophy (n = 22), HIV positive without lipodystrophy (n = 20), and age- and body mass index-matched HIV-negative controls (n = 21). Single-slice computed tomography was used to determine psoas muscle attenuation and visceral fat area. Plasma free fatty acids (FFA), lipid profile, and markers of glucose homeostasis were measured. Muscle attenuation was significantly decreased in subjects with lipodystrophy [median (interquartile range), 55.0 (51.0-58.3)] compared with subjects without lipodystrophy [57.0 (55.0-59.0); P = 0.05] and HIV-negative controls [59.5 (57.3-64.8); P < 0.01]. Among HIV-infected subjects, muscle attenuation correlated significantly with FFA (r = -0.38; P = 0.02), visceral fat (r = -0.49; P = 0.002), glucose (r = -0.38; P = 0.02) and insulin (r = -0.60; P = 0.0001) response to a 75-g oral glucose tolerance test. In forward stepwise regression analysis with psoas attenuation as the dependent variable, visceral fat (P = 0.02) and FFA (P < 0.05), but neither body mass index, subcutaneous fat, nor antiretroviral use, were strong independent predictors of muscle attenuation (r2 = 0.39 for model). Muscle attenuation (P = 0.02) and visceral fat (P = 0.02), but not BMI, subcutaneous fat, FFA, or antiretroviral use, were strong independent predictors of insulin response (area under the curve) to glucose challenge (r2 = 0.47 for model). These data demonstrate that decreased psoas muscle attenuation due to intramuscular fat accumulation may contribute significantly to hyperinsulinemia and insulin resistance in HIV-lipodystrophy patients. Further studies are needed to assess the mechanisms and consequences of intramuscular lipid accumulation in HIV-infected patients.

Mitochondrial DNA depletion and respiratory chain enzyme deficiencies are present in peripheral blood mononuclear cells of HIV-infected patients with HAART-related lipodystrophy

The main objective of the present study was to ascertain if mitochondrial DNA (mtDNA) depletion as reported in HIV-infected patients with highly active antiretroviral therapy (HAART)-related lipodystrophy (LD) implies any degree of mitochondrial respiratory chain (MRC) dysfunction. For this purpose, we evaluated HIV patients on different HAART schedules with LD (group A; n=12) and on HAART but without LD (group B; n=12), and untreated HIV-infected patients as controls (group C; n=24). mtDNA content was determined on peripheral blood mononuclear cells (PBMCs) with a real-time PCR method. Complex II, III and IV activities of the MRC were simultaneously measured spectrophotometrically, as were spontaneous and stimulated oxygen consumption by PBMCs. Compared to controls (group C, 100%), patients with LD (group A) showed a decreased mtDNA content (54%, P<0.001), which was associated with a decline in complex III (62%, P<0.05) and IV activity (69%, P<0.05) (both complexes partially encoded by mtDNA), but not in complex II activity (exclusively encoded by nuclear DNA). Patients in group B showed a similar pattern of mitochondrial dysfunction but to a lesser extent and without statistical significance. Respiratory activities in both treated groups (A and B) did not differ in comparison with controls. We conclude that mtDNA depletion occurring during HAART is associated with deficiencies in MRC complexes partially encoded by mtDNA, which are detectable by PBMCs. Presented in 'Late Breakers and Hot Topics' session at 6th International Congress on Drug Therapy in HIV Infection, Glasgow, UK, 17-21 November 2002.

Increased mitochondrial DNA content in peripheral blood lymphocytes from HIV-infected patients with lipodystrophy

We have evaluated mitochondrial (mt) DNA content in CD4 and CD8 peripheral blood lymphocytes (PBLs) from HIV-infected patients taking highly active antiretroviral therapy (HAART) who display different types of adipose tissue alterations. A cross-sectional study was performed in a total of 23 patients with lipodystrophy (LD): nine patients with fat accumulation, six patients with fat loss, eight patients with combined form, who were compared to 11 individuals infected by HIV without LD (HIV-positive) and 10 seronegative controls (CTRL). PBLs were obtained by standard methods, that is, gradient density centrifugation on Ficoll, and CD4 or CD8 cells were positively isolated by magnetic sorting to eliminate the contamination of platelets. mtDNA content was then measured by an original assay based upon real-time PCR. mtDNA content was significantly increased in CD4 T cells from patients with LD, while no differences were present between CD4 and CD8 cells from HIV-positive and CTRL individuals. Nor were any differences found when comparing LD or HIV-positive patients treated with stavudine or zidovudine, or taking D-drugs or non D-drugs. Patients with fat accumulation had significantly higher mtDNA content compared to HIV-positive and CTRL, this phenomenon regarding both CD4 and CD8 PBLs. Considering all HIV-positive patients (including LD), mtDNA content showed a significant, positive correlation with cholesterolaemia but not with triglyceridaemia and glycaemia. Relatively high mtDNA content in LD patients, as well as the correlation between mtDNA content and cholesterol in all HIV-positive subjects, suggest the involvement of mitochondria in such a pathology. However, further studies are needed to confirm these initial observations and ascertain whether the quantification of mtDNA in PBL is a useful and reliable marker to investigate and monitor HAART-related changes in fat distribution.

Correlates of risk of adipose tissue alterations and their modifications over time in HIV-1-infected women treated with antiretroviral therapy

OBJECTIVE

To assess the correlates of risk of the different types of lipodystrophy and their modifications over time in a cohort of HIV-positive women receiving antiretroviral therapy (ART).

METHODS

A consecutive series of HIV-infected women receiving ART was prospectively enrolled between 1 and 31 March 1998, and followed up for 2 years. Adipose tissue alterations (ATAs) and their variations over time were assessed by means of clinical observation and anthropometric measurements, and logistic regression analysis was used to describe the associated risk factors identified by univariate and multivariate analyses.

RESULTS

One-hundred-and-seventeen of the 212 women (55.2%) developed ATAs during the 24 months of follow-up. Central adiposity was observed in 95 patients and peripheral lipoatrophy in 91, with 21 patients (9.9%) showing pure lipoatrophy, 26 (12.3%) pure fat accumulation and 70 (33%) combined forms. Only six of the 223 regional adipose tissue alterations identified in 74 patients during the first 12 months of the study had disappeared by month 24. Of the 43 patients who developed breast enlargement during the first 12 months, 11 (25.6%) showed a decrease in breast size during the second year of follow-up that was unrelated to changes in therapy or therapeutic success. The development of ATAs during the first 12 months of follow-up independently correlated with protease inhibitor (PI) use (OR 2.81, P=0.002) but, by the end of the second year of follow-up, the only factor significantly related to the development of ATAs was the overall duration of ART (OR 1.85, P=0.041). The use of PI significantly increased the risk of developing central adiposity during the first 12 months of the study (OR 2.27, P=0.002), whereas the only variable significantly influencing the risk at month 24 was HIV-infection due to intravenous drug use, which proved to be protective (OR 0.53, P=0.043). During the first 12 months of follow-up, the development of peripheral lipoatrophy was significantly associated with stavudine (OR 2.19, P=0.037) and PI use at enrolment (OR 2.27, P=0.023). At the end of the study, the variables associated with peripheral lipoatrophy were stavudine use at enrolment (OR 2.82, P=0.002), ART exposure for >1000 days at enrolment (OR 2.32, P=0.007), a CD4 cell count of >200/microl at enrolment (OR 2.89, P=0.002) and an age of >28 years (OR 1.91, P=0.036). The only factor significantly associated with an increased risk of breast enlargement during the first 12 months of follow-up was PI use (adjusted OR 2.51; 95% CI: 1.16-5.46, P=0.02); however, at month 24, none of the tested variables was associated with a significantly increased risk of this ATA.

CONCLUSIONS

ATAs (particularly central adiposity) are frequent in women treated with ART, and the different forms have different correlates of risk. Once they have become clinically evident, they generally tend to remain or worsen, and improve in only a small minority of cases. The considerable variations in adipomasty over time are apparently unrelated to changes in ART.

Fat distribution is altered in HIV-infected men without clinical evidence of the HIV lipodystrophy syndrome

OBJECTIVE

To determine if fat distribution is altered in HIV-infected men without clinical evidence of lipodystrophy.

METHODS

In a cross-sectional design, 14 protease inhibitor (PI)-treated men with lipodystrophy and 12 PI-treated and five PI-naive men without clinical evidence of lipodystrophy underwent body composition and fat distribution analysis by dual-energy X-ray absorptiometry and computed tomography. Their fat distribution was compared to 43 uninfected male controls matched for age and BMI.

RESULTS

The percent of body fat in the trunk of men with HIV lipodystrophy was significantly greater compared to both HIV-infected and healthy controls. The percentage of body fat in the extremities was significantly lower in men with HIV lipodystrophy compared to both HIV-infected and healthy controls. HIV-infected men without clinical evidence of lipodystrophy also had a significantly greater percentage of total body fat in the trunk and a significantly lower percent of body fat in the extremities compared to healthy controls. Among the HIV-infected men, age was an independent predictor of truncal and extremity adiposity.

CONCLUSION

This study suggests that a continuum of change is present in the adipose organ of HIV-infected men on antiretroviral therapy. Physical examination alone can miss significant changes in body fat distribution in HIV-infected patients.

HIV lipodystrophy: prevalence, severity and correlates of risk in Australia

OBJECTIVE

To establish the prevalence, severity and factors associated with the HIV lipodystrophy syndrome.

METHODS

Cross-sectional study of lipodystrophy conducted in high HIV caseload primary care sites and HIV outpatient clinics. A subset of patients was examined using dual energy X-ray absorptiometry (DEXA) and single cut abdominal computerized tomography (CT) at the L4 vertebral level to quantify regional and total body fat. Factors associated with lipodystrophy, lipoatrophy and lipohypertrophy were assessed using multiple logistic regression based on assignment of cases and non-cases.

RESULTS

One thousand, three hundred and forty-eight patients (95% male) were surveyed, 20% had AIDS, the mean CD4 lymphocyte count was 486 cells/microL, and 55% had <500 HIV-1 RNA copies/mL. Most participants (87%) had previously received or were currently receiving combination antiretroviral therapy, 73% with at least one protease inhibitor (PI) and 14% a non-PI-containing regimen. Lipodystrophy prevalence was 53% and of these, 55% reported both peripheral lipoatrophy and central lipohypertrophy, 31% experienced peripheral lipoatrophy only and 14% had central lipohypertrophy only. The prevalence of any body habitus change was 62% in PI-experienced patients, 33% in PI-naive patients and 21% in antiretroviral-naive patients. Lipodystrophy severity was less in antiretroviral-naive patients and most severe in PI-experienced patients. Increasing severity of lipodystrophy was both positively and significantly correlated with elevated liver enzymes, decreased testosterone levels, decreased skin-fold thickness, lower levels of total and peripheral fat (DEXA) and higher levels of visceral fat (CT). Lipodystrophy was also significantly associated with increasing age, symptomatic HIV disease, effective viral suppression, and increasing duration of therapy with both nucleoside reverse transcriptase inhibitors and PIs.

CONCLUSIONS

The prevalence and severity of lipodystrophy reflects both length and type of treatment with antiretroviral therapy and is associated with decreased testosterone, increases in liver enzymes and greater suppression of HIV RNA. The reports of lipodystrophy in a small percentage of antiretroviral-naive patients suggests that factors other than antiretroviral therapy may be involved in the aetiology of this syndrome or that some conditions, such as wasting or age-associated obesity, may mimic lipoatrophy and lipohypertrophy, respectively.

Mitochondrial DNA depletion and morphologic changes in adipocytes associated with nucleoside reverse transcriptase inhibitor therapy

BACKGROUND

Nucleoside analogue reverse transcriptase inhibitor (NRTI) therapy provides sufficient conditions for progressive subcutaneous fat wasting in HIV-infected patients. As NRTI-induced host toxicity is proposed to involve cellular mitochondrial DNA (mtDNA) depletion, determinants of cellular mtDNA copy number and mitochondrial mass in adipocyte samples from NRTI-treated HIV-infected patients and antiretroviral-naive controls were investigated. Adipose tissue morphology was also assessed.

METHODS

Subcutaneous fat samples were obtained from NRTI-treated, HIV-infected patients (n = 21), antiretroviral therapy-naive HIV-infected controls (n = 11), and HIV-seronegative controls (n = 6). Non-adipocytes were removed by collagenase digestion. Adipocyte mtDNA copies/cell was measured using a real time PCR-based assay, and adipocyte mitochondrial protein content was also measured. Light and electron microscopy were performed on tissue samples.

FINDINGS

Adipocyte mtDNA copies/cell values were similar (P = 0.56) in HIV seronegative and HIV-infected control groups. NRTI treatment was associated with reduced adipocyte mtDNA copies/cell, representing mean mtDNA depletion in NRTI-treated individuals of 77.7% compared with the mean value for the HIV-infected control group (P < 0001). Additionally, significant differences were found in adipocyte mtDNA copies/cell between patients receiving stavudine (n = 12, mean mtDNA depletion 87.1%) and zidovudine (n = 9, mean mtDNA depletion 52.1%) (P < 0.001). Adipocyte mitochondrial mass was increased in the stavudine group only (mean increase 289%, P < 0.01).

INTERPRETATION

NRTI therapy is associated with mtDNA depletion and mitochondrial proliferation in adipocytes, consistent with the hypothesis that NRTI-induced mtDNA depletion contributes to the pathogenesis of subcutaneous fat wasting. Morphologic assessment also supports a role for NRTI therapy in inducing adipocyte metabolic dysfunction and cell death.

The cellular structure and lipid/protein composition of adipose tissue surrounding chronically stimulated lymph nodes in rats

To test the hypothesis that chronic immune stimulation of a peripheral lymph node induces the formation of additional mature adipocytes in adjacent adipose tissue, one popliteal lymph node of large male rats was stimulated by local injection of 10 microg or 20 microg lipopolysaccharide three times a week for 6 weeks. Adipocyte volumes in sites defined by their anatomical relations to the stimulated and homologous unstimulated popliteal lymph nodes were measured, plus adipocyte complement of the popliteal depot, and the lipid and protein content of adipocytes and adipose stroma. The higher dose of lipopolysaccharide doubled the mass of the locally stimulated lymph node and the surrounding adipose tissue enlarged by the appearance of additional mature adipocytes. Similar but smaller changes were observed in the popliteal adipose depot of the unstimulated leg and in a nodeless depot. The lipid content of the adipocytes decreased and that of the stroma increased dose-dependently in all samples measured but the changes were consistently greater in the depot surrounding the stimulated lymph node. The protein content of both adipocytes and stroma increased in samples surrounding the stimulated node. We conclude that chronic immune stimulation of lymphoid tissues induces the formation of more adipocytes in the adjacent adipose tissue. These findings suggest a mechanism for the selective hypertrophy of lymphoid-containing adipose depots in the HIV-associated adipose redistribution syndrome.

Urinary 8-hydroxy-2'-deoxyguanosine, a metabolite of oxidized DNA, is not elevated in HIV patients on combination antiretroviral therapy

Mitochondrial toxicity of nucleoside analogues has been proposed to be the etiology of a range of side-effects from antiretroviral therapy of HIV infection. In this study, urinary 8-hydroxy-2'-deoxyguanosine (8OH2'dG), a metabolite of oxidized DNA, was measured to determine if antiretroviral therapy leads to oxidative damage to DNA. A cross-sectional study was carried out measuring urinary 8OH2'dG in three groups of HIV-infected patients: (1) antiretroviral medication naïve, (2) patients on antiretroviral medications without lipodystrophy and (3) patients on antiretroviral medications with lipodystrophy. Twenty-five patients were enrolled in each group. The mean spot urinary 8OH2'dG measurements per mg creatinine for the three groups were: antiretroviral naïve 4.27 +/- 0.61 (ng 8OH2'dG/mg creatinine +/- SEM), on antiretroviral medications without lipodystrophy 2.88 +/- 0.26, and on antiretroviral medications with lipodystrophy 3.27 +/- 0.30. The differences between the means of the three groups is not statistically significant (p = 0.055), and these results are not significantly different from reported values for healthy controls [A carbon column-based liquid chromatography electrochemical approach to routine 8-hydroxy-2-deoxyguanosine measurements in urine and other biologic matrices: a one-year evaluation of methods. Free Radical Biology and Medicine 27 (1999) 647-666].

Preferential loss of omental-mesenteric fat during growth hormone therapy of HIV-associated lipodystrophy

Lipodystrophy with increased intra-abdominal fat in human immunodeficiency virus (HIV) infection is common in the era of highly active antiretroviral therapy. It contributes to the metabolic derangements, as it does in non-HIV-related conditions. Growth hormone administration reduces intra-abdominal fat content. This study compared the relative changes in omental-mesenteric (OMAT) and retroperitoneal adipose tissues (RPAT) during therapy with recombinant human growth hormone (rhGH) in HIV-associated lipodystrophy. Of 30 subjects who began rhGH therapy (6 mg/day), 25 completed 12 wk and 19 completed 24 wk. Fourteen subjects were followed for an additional 12 wk. Volumes of OMAT and RPAT were calculated from total body MRI scans and compared by paired t-tests. Both OMAT and RPAT significantly decreased after 12 and 24 wk of rhGH treatment (P < 0.001), but the reduction was more pronounced in OMAT than in RPAT (P < 0.001). Both OMAT and RPAT increased significantly (P < 0.001) after therapy was discontinued, but OMAT increased significantly more than did RPAT (122 vs. 37%, P < 0.001). There is preferential loss and regain of OMAT, compared with RPAT, in subjects with HIV-associated lipodystrophy undergoing growth hormone treatment.

Hypoadiponectinemia is associated with insulin resistance, hypertriglyceridemia, and fat redistribution in human immunodeficiency virus-infected patients treated with highly active antiretroviral therapy

A lipodystrophic syndrome and metabolic abnormalities have been observed in HIV-infected patients treated with highly active antiretroviral therapy (HAART). A murine model of lipodystrophy is associated with decreased levels of adiponectin, an adipocyte-secreted protein, the administration of which improves the metabolic syndrome in these mice. To investigate the association of adiponectin with metabolic changes in human lipodystrophy, we conducted a cross-sectional study of 112 HIV-infected patients treated with HAART. Mean adiponectin levels were higher in patients with no fat redistribution (FR) vs. FR (4.8 +/- 5.0 vs. 2.2 +/- 2.7 microg/ml, P < 0.01), but no significant differences in adiponectin levels were observed between FR subgroups. The difference in adiponectin levels between subjects with and without FR remained significant after adjusting for age, gender, leptin, HIV medication use, and CD4 count using logistic regression (odds ratio, 0.54, P = 0.008). Adiponectin was significantly correlated with triglycerides (r = -0.40), abdominal visceral fat (r = -0.35), extremity fat (r = 0.37), insulin resistance (HOMA-IR) (r = -0.28), nucleoside reverse transcriptase inhibitor (NRTI) use (r = -0.32), and high-density lipoprotein (HDL) (r = 0.41) using bivariate analysis (all P < 0.01). The association with HDL weakened but remained significant on multivariate analysis (standard beta = 0.29, P = 0.01). However, the association of adiponectin with HOMA-IR became nonsignificant after adjusting for NRTI use (standard beta = -0.15, P = 0.12), suggesting that changes in adiponectin levels may underlie the effect of NRTI use on insulin resistance. The associations of adiponectin with triglycerides and HOMA-IR were also slightly weakened after adjusting for visceral and extremity fat, indicating that adiponectin may, in part, mediate the effect of FR on triglycerides and insulin resistance. This study indicates that adiponectin is inversely correlated with abdominal visceral fat mass, serum triglycerides, and insulin resistance and is directly correlated with HDL and extremity fat in a sample of HIV-infected patients treated with HAART. The results also indicate that NRTI use may worsen insulin resistance by decreasing adiponectin levels. Thus, adiponectin replacement may be a potential treatment option to ameliorate the metabolic changes observed in this patient population.

First-line therapy and mitochondrial damage: different nucleosides, different findings

BACKGROUND

Antiretroviral therapy has been associated with the development of morphologic body-shape changes and metabolic abnormalities, including dislipemia, insulin resistance, and hyperlactatemia. Mitochondrial damage secondary to the use of nucleoside analogue reverse transcriptase inhibitors (NRTIs) has been related to some of these complications, although the role of different NRTIs in their development is not well established.

OBJECTIVES

To assess the incidence of hyperlactatemia and lipodystrophy body-shape changes in drug-naïve HIV-infected patients who began highly active antiretroviral therapy (HAART) based on a backbone of two different NRTI combinations.

METHOD

Prospective, longitudinal, observational study of all consecutive drug-naïve HIV-infected individuals who started HAART with zidovudine (AZT) plus lamivudine (3TC) or didanosine (ddI) plus stavudine (d4T) between June 2000 and June 2001 at one single institution. Serum lactate levels and lipodystrophy body-shape changes were monitored periodically during 12 months.

RESULTS

At 1 year, mean lactate values remained <2 mmol/L in all 26 patients who received AZT+3TC, but they significantly increased (mean, 2.6 mmol/L) in 50 patients treated with ddI+d4T. The percentage of patients with hyperlactatemia (lactate >or=2 mmol/L) steadily increased in those on ddI+d4T (from 30% at 3 months to 71% at 12 months), whereas it remained below 10% in patients treated with AZT+3TC. Two patients on ddI+d4T developed lactic acidosis. Mean serum lactate dehydrogenase (LDH), gamma-glutamyltransferase (GGT), and amylase significantly increased in patients treated with ddI+d4T, whereas they remained unaltered in patients under AZT+3TC. Significant correlations were found between lactate and LDH, alkaline phosphatase (AP), and GGT. In the multivariate analysis, treatment with ddI+d4T, LDH, and AP was significantly associated with lactate levels. At 12 months, subcutaneous lipoatrophy was significantly more frequent in patients treated with ddI+d4T than in those on AZT+3TC (35% vs. 8%; p =.01).

CONCLUSION

In drug-naïve HIV-infected patients who start antiretroviral therapy, ddI+d4T-based combinations produce a greater increase in serum lactate and lipoatrophy than therapies based on AZT+3TC within the first year of therapy. An increase in LDH, amylase, GGT, and AP levels may signal an increase in lactate, which may be harmful.

Paracrine relationships between adipose and lymphoid tissues: implications for the mechanism of HIV-associated adipose redistribution syndrome

The adipocytes anatomically associated with lymph nodes and omental milky spots have site-specific properties that equip them to interact locally with lymphoid cells. Paracine provisioning of peripheral immune responses improves their efficiency and emancipates activated lymphocytes from competition with other tissues for blood-borne nutrients. Prolonged disruption to such paracine interactions might contribute to the HIV-associated adipose redistribution syndrome, causing selective hypertrophy of the mesentery, omentum and other lymphoid tissue-containing adipose depots, while nodeless depots atrophy.

Agreement analysis of variables involved in lipodystrophy syndrome definition in HIV-infected patients

BACKGROUND

Lipodystrophy studies in HIV-infected patients have usually defined abnormalities in body fat by clinical evaluation and patient questionnaires. Despite the risk for bias with these subjective approaches, agreement analysis among the large number of variables employed was seldom performed.

OBJECTIVE

To analyze consistency between the usual approaches for definition of abnormalities in body fat distribution.

DESIGN

We evaluated agreement between the clinical and questionnaire findings for abnormalities in body fat in an HIV patient population under antiretroviral treatment followed in our institution, using different criteria for definitions of body fat abnormalities within the same data set.

METHODS

Kappa analysis for consistency and receiver-operator characteristic (ROC) curve analysis were performed.

RESULTS

Low levels of agreement between clinical and patient perspectives were observed. Only one combination of criteria showed adequate agreement results. The waist/hip ratio showed low levels of agreement with all other variables, and no clear discriminative point was observed by ROC curve analysis. The ratio between the trunk fat content and the leg fat content assessed by dual energy x-ray absorptiometry (DEXA) scan demonstrated better agreement and more clear discriminative values for both male and female patients.

CONCLUSION

Agreement analyses may help in the selection of the subjective variable methodology and in the inclusion of consistent and nonredundant objective measurements for diagnosis of abnormalities in body fat.

High-density lipoprotein cholesterol is low in HIV-infected patients with lipodystrophic fat expansions: implications for pathogenesis of fat redistribution

OBJECTIVE

To demonstrate relationships between plasma high-density lipoprotein (HDL) cholesterol and fat expansions in the fat redistribution syndrome.

DESIGN

Patients who had significant buffalo humps or intra-abdominal fat (IAF) expansions were identified and their HDL levels were measured. Control patients were all those undergoing a single trial of antiretroviral treatment. Some patients answered a self-administered questionnaire concerning self-perceived fat expansions, and their responses were related to their HDL levels. In other patients, relationships were studied between IAF measured by cross-section computerized tomography scans and HDL levels. Finally, patients who had IAF > 70 cm(2), were administered niacin, 3000 mg/day for > or = 6 months, in order to test whether raising HDL induced a decrease in IAF.

RESULTS

Twenty-three patients with buffalo humps had mean HDL of 30.4 mg/dl; 47 HIV-positive controls had mean HDL of 41.9 mg/dl (P = 0.001). In 27 patients, IAF area and HDL were negatively correlated (r, 0.40; P = 0.04). Among these 27, the 17 patients with IAF area > 100 cm(2) had mean HDL of 35.3 mg/dl; the 10 patients with IAF area < 100 cm(2) had mean HDL of 51 mg/dl (P < 0.05). The 24 patients who indicated in a questionnaire that they had self-perceived IAF expansion had a median HDL of 36.0 mg/dl; the 20 who indicated that they did not have IAF expansion had a median HDL of 44.5mg/dl (P = 0.06). IAF decreased by 26.9% in 13 (81%) of the 16 patients who took niacin for 1 year; and the decrease in IAF was associated with a significant (P = 0.002) increase in HDL.

Lipodystrophy syndrome in human immunodeficiency virus-infected children

BACKGROUND

Lipodystrophy syndrome in HIV-infected adults is characterized by a variety of physical and/or metabolic abnormalities, including fat redistribution, hyperlipidemia (hypercholesterolemia and/or hypertriglyceridemia) and peripheral insulin resistance. Many studies suggest that antiretroviral therapy is the underlying cause of the condition. Few data exist for HIV-infected children.

METHODS

This is a cross-sectional study evaluating HIV-infected children age 2 to 16 years. Fat redistribution was identified by physical examination and parental questionnaire. Fasting blood analysis included cholesterol, triglycerides, high density lipoprotein, low density lipoprotein, glucose, insulin and C-peptide.

RESULTS

Forty HIV-infected children were recruited. Seven children (18%) exhibited physical signs of fat redistribution. Twenty-seven (68%), 11 (28%) and 3 (8%) children exhibited evidence for hypercholesterolemia, hypertriglyceridemia and insulin resistance, respectively. Eleven children (28%) had no physical signs or laboratory evidence of lipodystrophy. Statistical analysis did not reveal any significant association between the presence of lipodystrophic features and patient age, HIV-1 viral load, exposure to specific antiretroviral medications or duration of protease inhibitor or nucleoside reverse transcriptase inhibitor therapy. Drug dosing was significantly associated with the development of lipodystrophy features. Children receiving pediatric dosing regimens vs. adult dosing regimens were less likely to develop lipodystrophy (P = 0.003).

CONCLUSIONS

Features associated with lipodystrophy syndrome arise in some HIV-infected children. Subjects receiving pediatric dosing regimens were less likely than those receiving adult regimens to develop lipodystrophy.

HIV-associated lipodystrophy: description, pathogenesis, and molecular pathways

HIV-infected individuals taking antiretroviral medications may experience changes in body shape and metabolism, commonly known as HIV-associated lipodystrophy (HIVLD). In vitro and in vivo research have revealed numerous effects of both protease inhibitors and nucleoside reverse transcriptase inhibitors on the function of various organs--most importantly adipose tissue, liver, and muscle. The metabolic abnormalities could result in an increased risk of cardiovascular disease in this vulnerable and relatively young population. Treatment strategies, normally successful in the general population, have generally been less effective in this group of people, in which the detrimental effects of the antiretroviral medications are ongoing.