Zidovudine/lamivudine contributes to insulin resistance within 3 months of starting combination antiretroviral therapy

Adipose Tissue Dysfunction and Energy Balance Paradigms in People Living With HIV

Over the past 4 decades, the clinical care of people living with HIV (PLWH) evolved from treatment of acute opportunistic infections to the management of chronic, noncommunicable comorbidities. Concurrently, our understanding of adipose tissue function matured to acknowledge its important endocrine contributions to energy balance. PLWH experience changes in the mass and composition of adipose tissue depots before and after initiating antiretroviral therapy, including regional loss (lipoatrophy), gain (lipohypertrophy), or mixed lipodystrophy. These conditions may coexist with generalized obesity in PLWH and reflect disturbances of energy balance regulation caused by HIV persistence and antiretroviral therapy drugs. Adipocyte hypertrophy characterizes visceral and subcutaneous adipose tissue depot expansion, as well as ectopic lipid deposition that occurs diffusely in the liver, skeletal muscle, and heart. PLWH with excess visceral adipose tissue exhibit adipokine dysregulation coupled with increased insulin resistance, heightening their risk for cardiovascular disease above that of the HIV-negative population. However, conventional therapies are ineffective for the management of cardiometabolic risk in this patient population. Although the knowledge of complex cardiometabolic comorbidities in PLWH continues to expand, significant knowledge gaps remain. Ongoing studies aimed at understanding interorgan communication and energy balance provide insights into metabolic observations in PLWH and reveal potential therapeutic targets. Our review focuses on current knowledge and recent advances in HIV-associated adipose tissue dysfunction, highlights emerging adipokine paradigms, and describes critical mechanistic and clinical insights.

Antiretrovirals Promote Insulin Resistance in HepG2 Liver Cells through miRNA Regulation and Transcriptional Activation of the NLRP3 Inflammasome

Metabolic syndrome (MetS) is a non-communicable disease characterized by a cluster of metabolic irregularities. Alarmingly, the prevalence of MetS in people living with Human Immunodeficiency Virus (HIV) and antiretroviral (ARV) usage is increasing rapidly. Insulin resistance is a common characteristic of MetS that leads to the development of Type 2 diabetes mellitus (T2DM). The progression of insulin resistance is strongly linked to inflammasome activation. This study aimed to draw links between the combinational use of Tenofovir disoproxil fumarate (TDF), Lamivudine (3TC), and Dolutegravir (DTG), and inflammasome activation and subsequent promotion of insulin resistance following a 120 h treatment period in HepG2 liver in vitro cell model. Furthermore, we assess microRNA (miR-128a) expression as a negative regulator of the IRS1/AKT signaling pathway. The relative expression of phosphorylated IRS1 was determined by Western blot. Transcript levels of NLRP3, IL-1β, JNK, IRS1, AKT, PI3K, and miR-128a were assessed using quantitative PCR (qPCR). Caspase-1 activity was measured using luminometry. Following exposure to ARVs for 120 h, NLRP3 mRNA expression (p = 0.0500) and caspase-1 activity (p < 0.0001) significantly increased. This was followed by a significant elevation in IL-1β in mRNA expression (p = 0.0015). Additionally, JNK expression (p = 0.0093) was upregulated with coinciding increases in p-IRS1 protein expression (p < 0.0001) and decreased IRS1 mRNA expression (p = 0.0004). Consequently, decreased AKT (p = 0.0005) and PI3K expressions (p = 0.0007) were observed. Interestingly miR-128a expression was significantly upregulated. The results indicate that combinational use of ARVs upregulates inflammasome activation and promotes insulin resistance through dysregulation of the IRS1/PI3K/AKT insulin signaling pathway.

Metabolic Consequences of Antiretroviral Therapy

PURPOSE OF REVIEW

This review reports on published studies describing metabolic changes associated with antiretroviral therapy (ART) to treat HIV disease including a historical perspective of earlier ART agents, but with the main focus on newer ART agents currently in use.

RECENT FINDINGS

Studies from different countries around the world have shown that integrase inhibitor (INSTI)-based regimens as well as tenofovir alafenamide (TAF) are associated with weight gain, with women and people of black race at especially high risk. Some studies preliminarily suggest worsened metabolic outcomes associated with this weight gain including adverse effects on glucose homeostasis. Antiretroviral therapy can affect weight, adipose tissue, glucose, and lipids. As obesity is prevalent and increasing among people with HIV, awareness of risk factors for weight gain, including the ART medications associated with greater weight gain, are needed in order to inform prevention efforts. Further research is needed to better understand the long-term health consequences of INSTI- and TAF-associated weight increases.

Relationships Between Adipose Mitochondrial Function, Serum Adiponectin, and Insulin Resistance in Persons With HIV After 96 Weeks of Antiretroviral Therapy

OBJECTIVE

Some antiretroviral therapy (ART) and HIV itself confer metabolic risk, perhaps through altered mitochondrial function and adipokines. In AIDS Clinical Trials Group study A5224s, adipose mitochondrial DNA (mtDNA) levels decreased on ART, and electron transport chain complex I (CI) and complex IV (CIV) activity decreased. Another study found decreased serum adiponectin on ART with mtDNA mutation m.10398A>G. We hypothesized that decreased adipose tissue mitochondrial function would be associated with lower adiponectin and insulin sensitivity on ART, and m.10398G would influence these changes.

DESIGN

Retrospective analysis of an ART-naive substudy population from A5224s.

METHODS

Analyses included adipose mtDNA levels, CI and CIV activity by immunoassay, visceral adipose tissue by computed tomography, and fasting serum glucose at week 0 and week 96 of ART. Fasting insulin and adiponectin were measured from cryopreserved serum using multiplex bead array. Homeostasis model assessment-2 (HOMA2)-IR and HOMA2-%B estimated insulin resistance and β-cell function, respectively. The m.10398A>G mtDNA variant was available from existing genetic data.

RESULTS

Thirty-seven participants had adipose biopsies at week 0 and week 96. Percent decreases in CIV activity and adiponectin were correlated (Spearman rho 0.41; P = 0.01); this association persisted after controlling for age, sex, body mass index, or visceral adipose tissue in single-covariate regression. HOMA2-IR correlated with decreased CIV (-0.44; P = 0.01) and CI (-0.34; P = 0.05) activity. Among 12 non-Hispanic white persons, m.10398G was associated with decreased adiponectin (P = 0.04).

CONCLUSIONS

Decreased adipose mitochondrial activity correlated with changes in adiponectin and glucose homeostasis on ART. Previous findings that a mtDNA mutation modulates adiponectin levels in persons with HIV were replicated.

Changing concepts of HIV infection and renal disease

PURPOSE OF REVIEW

Human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) was identified as the major renal manifestation of HIV infection early in the HIV epidemic. However, HIV infection now is associated with a different spectrum of renal lesions leading to chronic kidney disease. This review examines the changes in kidney injury occurring in the current HIV era and the factors involved in this transformation of disease expression.

RECENT FINDINGS

The incidence of HIVAN and opportunistic infections in HIV-infected individuals has declined in concert with the use of effective combination antiretroviral agents. Chronic kidney disease has become more prevalent as patients infected with HIV are living longer and developing non-HIV-associated diseases such as hypertension and diabetes. Additionally, noncollapsing focal and segmental glomerulosclerosis, co-infection with hepatitis C, HIV-associated immune complex kidney disease, HIV-related accelerated aging, and antiretroviral therapies contribute to progressive loss of renal function.

SUMMARY

HIV infection is now associated with a variety of renal lesions causing chronic kidney disease, not all of which are virally induced. It is important to determine the cause of renal functional decline in an HIV-infected patient, as this will impact patient management and prognosis.

Influence of Physical Exercise on Advanced Glycation End Products Levels in Patients Living With the Human Immunodeficiency Virus

Introduction: Combined antiretroviral therapy (cART) used to treat acquired immunodeficiency virus (HIV) induces a number of adverse effects, such as insulin resistance and dyslipidemia, which ultimately increases the cardiovascular risk. Advanced glycation end products (AGEs) have been implicated in the etiology of cardiovascular diseases, diabetes and other chronic diseases. It is known that physical exercise improves the lipid profile, insulin resistance and reduces the risk of cardiovascular diseases. However, the impact of physical exercise on AGE levels in HIV-infected patients has not been so far investigated. Therefore, this study compared AGEs levels in people with and without HIV and verified the effect of physical training on serum AGE levels.

Methods: Participants were initially assigned into three groups: healthy control (CTL, n = 35), physically inactive HIV-infected (In-HIV, n = 33) and physically active HIV-infected (Ac-HIV, n = 19). The In-HIV group underwent physical training for 3 months, consisting of 60-min sessions of multimodal supervised exercise (aerobic, resistance and flexibility) with moderate intensity (50–80% heart rate reserve), performed 3 times/week. AGEs were measured in serum by fluorescence spectrometry.

Results: At baseline, serum AGEs fluorescence level was significantly higher in inactive HIV-patients when compared to controls or active HIV-patients (In-HIV: 0.93 ± 0.08 vs. controls: 0.68 ± 0.13 and Ac-HIV: 0.59 ± 0.04 A.U.; P < 0.001). Triglycerides were also higher in In-HIV than CTL (182.8 ± 102 vs. 132.8 ± 52.3 mg/dL; P < 0.05). Waist circumference was lower in Ac-HIV, compared to In-HIV and controls (83.9 ± 10.4 vs. 92.9 ± 13.5 and 98.3 ± 12.4, respectively; P < 0.05). Body mass, fasting blood glucose, LDL, HDL, and total cholesterol were similar between groups. After training, AGE levels decreased (Baseline: 0.93 ± 0.08 vs. 3 months follow-up: 0.59 ± 0.04 AU; P < 0.001), no further difference being detected vs. CTL or Ac-HIV. Conclusion: HIV-infected patients under cART exhibited elevated AGEs levels compared to healthy individuals and physically active patients. Short-term aerobic training of moderate intensity counteracted this condition.

Immune reconstitution in ART treated, but not untreated HIV infection, is associated with abnormal beta cell function

HIV infection has been associated with increased diabetes risk, but prior work has mostly focused on insulin resistance, as opposed to beta cell effects, or included patients on antiretroviral therapies (ART) directly linked to metabolic toxicity. In this analysis, we measured markers of glucose homeostasis and beta cell function, stress, and death in fasting sera from a cross section of HIV+ individuals off ART (n = 43), HIV+ individuals on ART (n = 23), and HIV- controls (n = 39). Markers included glucose, HOMA%S, HOMA%B, proinsulin:C-peptide ratio (PI:C ratio), and circulating preproinsulin (INS) DNA. We performed multiple linear regressions with adjustments for age, sex, race, BMI, and smoking status. Compared to HIV- controls, HIV+ participants off ART exhibited similar beta cell function and insulin sensitivity, without increases in markers of beta cell stress or death. Specifically, in HIV+ participants with CD4 counts <350 cells/μL, PI:C ratios were lower than in HIV- controls (p<0.01), suggesting a reduction in intrinsic beta cell stress among this group. By contrast, HIV+ participants on ART had higher fasting glucose (p<0.0001) and lower HOMA%B (p<0.001) compared to HIV- controls. Among the entire HIV+ population, higher HIV RNA correlated with lower fasting glucose (r = -0.57, p<0.001), higher HOMA%B (r = 0.40, p = 0.001), and lower PI:C ratios (r = -0.42, p<0.001), whereas higher CD4 counts correlated with higher PI:C ratios (r = 0.2, p = 0.00499). Our results suggest that HIV seropositivity in the absence of ART does not worsen beta cell function or glucose homeostasis, but immune reconstitution with ART may be associated with worsened beta cell function.

Zidovudine ameliorates pathology in the mouse model of Duchenne muscular dystrophy via P2RX7 purinoceptor antagonism

Duchenne muscular dystrophy (DMD) is the most common inherited muscle disorder that causes severe disability and death of young men. This disease is characterized by progressive muscle degeneration aggravated by sterile inflammation and is also associated with cognitive impairment and low bone density. Given that no current treatment can improve the long-term outcome, approaches with a strong translational potential are urgently needed. Duchenne muscular dystrophy (DMD) alters P2RX7 signaling in both muscle and inflammatory cells and inhibition of this receptor resulted in a significant attenuation of muscle and non-muscle symptoms in DMD^mdx mouse model. As P2RX7 is an attractive target in a range of human diseases, specific antagonists have been developed. Yet, these will require lengthy safety testing in the pediatric population of Duchenne muscular dystrophy (DMD) patients. In contrast, Nucleoside Reverse Transcriptase Inhibitors (NRTIs) can act as P2RX7 antagonists and are drugs with an established safety record, including in children. We demonstrate here that AZT (Zidovudine) inhibits P2RX7 functions acting via the same allosteric site as other antagonists. Moreover, short-term AZT treatment at the peak of disease in DMD^mdx mice attenuated the phenotype without any detectable side effects. Recovery was evident in the key parameters such as reduced sarcolemma permeability confirmed by lower serum creatine kinase levels and IgG influx into myofibres, decreased inflammatory cell numbers and inflammation markers in leg and heart muscles of treated mice. Moreover, this short-term therapy had some positive impact on muscle strength in vivo and no detrimental effect on mitochondria, which is the main side-effect of Nucleoside Reverse Transcriptase Inhibitors (NRTIs). Given these results, we postulate that AZT could be quickly re-purposed for the treatment of this highly debilitating and lethal disease. This approach is not constrained by causative DMD mutations and may be effective in alleviating both muscle and non-muscle abnormalities.

Diabetes, metabolic syndrome and dyslipidemia in people living with HIV in Africa: re-emerging challenges not to be forgotten

BACKGROUND

The current challenge in managing people living with human immunodeficiency virus (PLWHIV) includes the identification and monitoring for comorbid health risks associated with HIV and its treatment and longer survival. Dyslipidemia, diabetes mellitus and metabolic syndrome are increasingly seen in PLWHIV.

OBJECTIVE

In this narrative review, we aimed to summarize the current knowledge about diabetes, dyslipidemia and metabolic syndrome in PLWHIV in Africa and also to discuss the challenges that patients as well as health authorities in Africa may face.

METHODS

PubMed and Google scholar published-English literatures concerning earlier mentioned entities regardless of time limit were critically reviewed.

RESULTS

The prevalence of metabolic disorders in HIV population in Africa was estimated to range from 2.1% to 26.5% for diabetes and 20.2% to 43.5% for pre-diabetes, 13% to 58% for metabolic syndrome and 13% to 70% for dyslipidemia.

CONCLUSION

The management of metabolic disorders and cardiovascular disease risks related to HIV is complex especially in Africa due to healthcare resources, but our experience suggests that metabolic clinic is beneficial to patients and staff and should be an important part of HIV services especially as the older HIV population is increasing. In this context, cardiovascular risk assessment of HIV-infected patients will become an important component of care in developing countries in Africa and strategies are needed to deal with progressive increase in the epidemic of type 2 diabetes, dyslipidemia and metabolic syndrome.

Is there sufficient evidence for a causal association between antiretroviral therapy and diabetes in HIV-infected patients? A meta-analysis

The association of antiretroviral therapy (ART) with diabetes is inconsistent and varies widely across primary epidemiological studies. A comprehensive and more precise estimate of this association is fundamental to establishing a plausible causal link between ART and diabetes. We identified epidemiological studies that compared mean fasting plasma glucose (FPG) concentrations and proportions of diabetes and metabolic syndrome between HIV-infected patients naïve and exposed to ART. Mean difference in FPG concentrations and odds ratios of diabetes and metabolic syndrome were pooled using random-effects meta-analyses. Data on 20 178 participants from 41 observational studies were included in the meta-analyses. Mean FPG concentrations (Pooled mean difference: 4.66 mg/dL; 95% confidence interval [CI], 2.52 to 6.80; 24 studies) and the odds of diabetes (Pooled odds ratios: 3.85; 95% CI, 2.93 to 5.07; 10 studies) and metabolic syndrome (Pooled odds ratios: 1.45; 95% CI, 1.03 to 2.03; 18 studies) were significantly higher among ART-exposed patients, compared to their naïve counterparts. ART was also associated with significant increases in FPG levels in studies with mean ART duration ≥18 months (Pooled mean difference: 4.97 mg/dL; 95% CI, 3.10 to 6.84; 14 studies), but not in studies with mean ART duration <18 months (Pooled mean difference: 4.40 mg/dL, 95% CI, -0.59 to 9.38; 7 studies). ART may potentially be the single most consistent determinant of diabetes in people living with HIV worldwide. However, given the preponderance of cross-sectional studies in the meta-analysis, the association between ART and diabetes cannot be interpreted as cause and effect.

Adipose tissue: between the extremes

Adipose tissue represents a critical component in healthy energy homeostasis. It fulfills important roles in whole-body lipid handling, serves as the body's major energy storage compartment and insulation barrier, and secretes numerous endocrine mediators such as adipokines or lipokines. As a consequence, dysfunction of these processes in adipose tissue compartments is tightly linked to severe metabolic disorders, including obesity, metabolic syndrome, lipodystrophy, and cachexia. While numerous studies have addressed causes and consequences of obesity-related adipose tissue hypertrophy and hyperplasia for health, critical pathways and mechanisms in (involuntary) adipose tissue loss as well as its systemic metabolic consequences are far less understood. In this review, we discuss the current understanding of conditions of adipose tissue wasting and review microenvironmental determinants of adipocyte (dys)function in related pathophysiologies.

Reversible diabetes mellitus induced by use of, and improved after discontinuation of, the antiretroviral medication zidovudine: a case report

BACKGROUND

With the advent of effective antiretroviral therapy, the care of patients with human immunodeficiency virus infection became more like that of other chronic diseases. Diabetes mellitus can also occur as one of the chronic illnesses affecting patients with human immunodeficiency virus infection. We report a case of newly developed diabetes mellitus in a patient with human immunodeficiency virus infection, most likely caused by the nucleoside analogue zidovudine, and its improvement after discontinuation of zidovudine.

CASE PRESENTATION

A Chinese man in his 30s visited our outpatient clinic for routine follow-up of human immunodeficiency virus infection. Blood tests showed hyperglycemia with a glucose level of 31.8 mmol/L and hemoglobin A1c of 8.5%. He was diagnosed with diabetes mellitus and treated with oral diabetic medications. The use of zidovudine was suspected as the cause of his diabetes, and it was replaced by other antiretroviral medication. His hyperglycemia improved, and he now no longer requires diabetic medications.

CONCLUSIONS

Diabetes mellitus can develop with the use of antiretroviral medications, but its occurrence associated with use of zidovudine is quite rare. Healthcare personnel should be aware of this rare, yet important, side effect.

Skin advanced glycation end products in HIV infection are increased and predictive of development of cardiovascular events

OBJECTIVE

HIV-1 infection is associated with an increased cardiovascular disease (CVD) risk. Advanced glycation end products are formed as stable markers of glycaemic and oxidative stress. Skin autofluorescence (SAF) as marker of accumulated advanced glycation end products is increased and predictive of CVD events in diabetes mellitus, chronic kidney disease (CKD), and preexisting CVD. We determined SAF levels in HIV-1 infected patients, testing the hypothesis that SAF predicts CVD events in HIV infection.

DESIGN

Single-centre prospective cohort study.

METHODS

In 2010-2011, SAF was measured in 91 patients. Development of CVD events was monitored during a median follow-up of 4.8 years. SAF values of the patients were expressed as a ratio (rSAF) to expected SAF levels in age-matched healthy volunteers.

RESULTS

Seventy-nine men and 12 women were included, mean age 47 years; 81 patients were on combination antiretroviral therapy. With a mean rSAF of 1.155, SAF levels in patients were 15.5% higher than predicted for their age (95% confidence interval, 10.0-20.0; P < 0.001). In multivariate regression analysis, rSAF was associated with nadir CD4 cell count less than 200 cells/μl (β -0.274; P = 0.01), smoking (β 0.240; P = 0.03), and men who have sex with men (MSM) (β 0.202; P = 0.07). CVD events occurred in six patients (7%). In Cox regression analysis including age, SAF, smoking, diabetes, hypertension and CKD, SAF (P = 0.01), and (Wet Medisch-wetenschappelijk Onderzoek met mensen; WMO) CKD (P = 0.03) remained as independent predictors of CVD events.

CONCLUSION

SAF is increased in HIV-infected patients, and related with smoking, low nadir CD4 cell count, and MSM. Larger studies are needed to confirm whether SAF is an independent predictor of CVD events.

Incidence of diabetes mellitus and factors associated with its development in HIV-positive patients over the age of 50

OBJECTIVE

We sought to determine the incidence and factors associated with development of diabetes mellitus (DM) in older HIV-infected individuals.

RESEARCH DESIGN AND METHODS

We analyzed data from people living with HIV (PLWH) ≥50 years of age enrolled in a large urban HIV outpatient clinic in Vancouver, British Columbia. Patients were categorized as having DM if they had random blood sugar ≥11.1 mmol/L, fasting blood sugar ≥7 mmol/L, HbA1C ≥6.5%, antidiabetic medication use during the follow-up period, or medical chart review confirming diagnosis of DM. We estimated the probability of developing DM, adjusting for demographic and clinical factors, using a logistic regression model.

RESULTS

Among 1065 PLWH followed for a median of 13 years (25th and 75th percentile (Q1-Q3): 9-18), the incidence of DM was 1.61/100 person-years follow-up. In the analysis of factors associated with new-onset DM (n=703), 88% were male, 38% had a history of injection drug use, 43% were hepatitis C coinfected, and median body mass index was 24 kg/m² (Q1-Q3: 21-27). Median age at antiretroviral therapy (ART) initiation was 48 years (Q1-Q3: 43-53) and at DM diagnosis was 55 years (Q1-Q3: 50-61). Patients who started ART in 1997-1999 and had a longer exposure to older ART were at the highest risk of developing DM.

CONCLUSIONS

Among PLWH aged ≥50 years, the incidence of DM was 1.39 times higher than men in the general Canadian population of similar age. ART initiated in the early years of the epidemic and exposure to older ART appeared to be the main drivers of the development of DM.

Improved adipose tissue function with initiation of protease inhibitor-only ART

OBJECTIVES

Use of ART containing HIV PIs has previously been associated with toxicity in subcutaneous adipose tissue (SAT), potentially contributing to the development of lipodystrophy and insulin resistance. However, the effect of PIs on SAT function in ART-naive patients independent of other ART classes is unknown. This study aimed to elucidate the effect of initiating PI-only ART on SAT function in ART-naive subjects.

METHODS

In the HIVNAT-019 study, 48 HIV-infected, ART-naive Thai adults commencing PI-only ART comprising lopinavir/ritonavir/saquinavir for 24 weeks underwent assessments of fasting metabolic parameters and body composition. In a molecular substudy, 20 subjects underwent SAT biopsies at weeks 0, 2 and 24 for transcriptional, protein, mitochondrial DNA (mtDNA) and histological analyses. ClinicalTrials.gov registration number: NCT00400738.

RESULTS

Over 24 weeks, limb fat increased (+416.4 g, P = 0.023), coinciding with larger adipocytes as indicated by decreased adipocyte density in biopsies (-32.3 cells/mm², P = 0.047) and increased mRNA expression of adipogenesis regulator PPARG at week 2 (+58.1%, P = 0.003). Increases in mtDNA over 24 weeks (+600 copies/cell, P = 0.041), decreased NRF1 mRNA expression at week 2 (-33.7%, P < 0.001) and increased COX2/COX4 protein ratio at week 24 (+288%, P = 0.038) indicated improved mitochondrial function. Despite decreased AKT2 mRNA at week 2 (-28.6%, P = 0.002) and increased PTPN1 mRNA at week 24 (+50.3%, P = 0.016) suggesting insulin resistance, clinical insulin sensitivity [by homeostasis model assessment (HOMA-IR)] was unchanged.

CONCLUSIONS

Initiation of PI-only ART showed little evidence of SAT toxicity, the changes observed being consistent with a return to health rather than contributing to lipodystrophy.

Naringin improves zidovudine- and stavudine-induced skeletal muscle complications in rats

Chronic use of nucleoside reverse transcriptase inhibitors (NRTIs) in managing human immunodeficiency virus (HIV) infection has been associated with several complications. Available management options for these complications have yielded controversial results, thus the need to urgently find newer alternatives. Naringin, a plant-derived flavonoid, has been shown to possess antioxidant and antiapoptotic properties which can be exploited in managing NRTI-induced complications. This study therefore investigated the effects of naringin on some NRTI-induced complications. Forty-nine rats (200-250 g) were divided into seven groups and were orally treated with stavudine (d4T)-only, d4T + naringin, d4T + vitamin E, zidovudine (AZT)-only, AZT + naringin, AZT + vitamin E, and distilled water, respectively. Drugs were administered once daily for 56 days, and oral glucose tolerance tests conducted on day 54 of the experiments and rats were thereafter sacrificed on day 56 by halothane overdose. Plasma samples and the left gastrocnemius muscles were stored at -80°C for further analysis. There was significant glucose intolerance, insulin resistance, oxidative stress, and apoptosis in the skeletal muscles of AZT- or d4T-only-treated rats. Naringin, however, significantly reduced fasting blood glucose and fasting plasma insulin concentrations, mitigated glucose intolerance, and insulin resistance in addition to reducing malondialdehyde and carbonyl protein concentrations when coadministered with either NRTIs. Furthermore, naringin improved antioxidant enzyme activities, reduced skeletal muscle BCL-2-associated X protein expression, and improved B-cell lymphoma-2 protein expression compared to AZT- or d4T-only-treated rats. Naringin ameliorated AZT- and d4T-induced complications and therefore should be further investigated as a possible nutritional supplement in managing HIV infection.

Effects of once-daily darunavir/ritonavir versus atazanavir/ritonavir on insulin sensitivity in HIV-infected persons over 48 weeks: results of an exploratory substudy of METABOLIK, a phase 4, randomized trial

Background: The phase 4, METABOLIK trial demonstrated that changes in metabolic parameters with darunavir with low-dose ritonavir (DRV/r) were comparable to those observed with atazanavir with low-dose ritonavir (ATV/r). A comprehensive assessment of the effects of these agents on insulin sensitivity will provide additional, relevant clinical information.

Methods: In this substudy of METABOLIK, HIV-1–infected, antiretroviral agent–naïve male subjects aged ≥18 years with a viral load of >1,000 copies/mL were randomized to receive DRV/r 800/100 mg once daily (qd) or ATV/r 300/100 mg qd, both with a fixed dose of tenofovir disoproxil fumarate/emtricitabine 300/200 mg qd. The effects of DRV/r versus ATV/r on insulin sensitivity over 48 weeks were compared using the euglycemic hyperinsulinemic clamp, the preferred method to assess insulin sensitivity; primary end point was the effect on insulin sensitivity during the first 12 weeks.

Results: Twenty-seven subjects completed the study. In the DRV/r arm (n = 14), median glucose disposal from baseline through weeks 12 and 48 was 9.3, 11.4, and 9.9 mg/kg*min, respectively; in the ATV/r arm (n = 13), these values were 8.9, 8.6, and 9.1 mg/kg*min, respectively. Median insulin sensitivity in the DRV/r arm at baseline, week 12, and week 48 was 24.0, 25.0, and 21.5 mg/kg*min per μIU/mL × 100, respectively; these values in the ATV/r arm were 20.7, 22.0, and 22.0 mg/kg*min per μIU/mL × 100, respectively. Most subjects had ≥1 adverse event, including three serious adverse events (n = 2 [DRV/r], n = 1 [ATV/r]).

Conclusions: DRV/r and ATV/r displayed similar modest effects on insulin sensitivity using a euglycemic hyperinsulinemic clamp.

Risk Factors for Incident Diabetes in a Cohort Taking First-Line Nonnucleoside Reverse Transcriptase Inhibitor-Based Antiretroviral Therapy

Efavirenz is the preferred nonnucleoside reverse transcriptase inhibitor (NNRTI) in first-line antiretroviral therapy (ART) regimens in low- and middle-income countries, where the prevalence of diabetes is increasing. Randomized control trials have shown mild increases in plasma glucose in participants in the efavirenz arms, but no association has been reported with overt diabetes. We explored the association between efavirenz exposure and incident diabetes in a large Southern African cohort commencing NNRTI-based first-line ART. Our cohort included HIV-infected adults starting NNRTI-based ART in a private sector HIV disease management program from January 2002 to December 2011. Incident diabetes was identified by the initiation of diabetes treatment. Patients with prevalent diabetes were excluded. We included 56,298 patients with 113,297 patient-years of follow-up (PYFU) on first-line ART. The crude incidence of diabetes was 13.24 per 1000 PYFU. Treatment with efavirenz rather than nevirapine was associated with increased risk of developing diabetes (hazard ratio 1.27 (95% confidence interval (CI): 1.10-1.46)) in a multivariate analysis adjusting for age, sex, body mass index, baseline CD4 count, viral load, NRTI backbone, and exposure to other diabetogenic medicines. Zidovudine and stavudine exposure were also associated with an increased risk of developing diabetes. We found that treatment with efavirenz, as well as stavudine and zidovudine, increased the risk of incident diabetes. Interventions to detect and prevent diabetes should be implemented in ART programs, and use of antiretrovirals with lower risk of metabolic complications should be encouraged.

Impact of antiretroviral therapy on serum lipoprotein levels and dyslipidemias: a systematic review and meta-analysis

BACKGROUND

Antiretroviral drugs increase biosynthesis and reduce hepatic clearance of serum cholesterol. It is thus important to evaluate the impact of antiretroviral treatment on serum lipoprotein levels and the risk of dyslipidemia.

METHODS

We searched EMBASE and PubMed for articles comparing lipid profiles between HIV-infected adult patients naïve and exposed to antiretroviral therapy (ART). Eligible studies were pooled by performing random-effects meta-analyses of mean serum lipoprotein levels and prevalence estimates of dyslipidemias.

RESULTS

51 observational studies comprising 37,110 patients were included in the meta-analyses. ART-exposed patients had significantly higher concentrations of total cholesterol (45 studies, mean difference [MD]=29.4mg/dL, 95% confidence interval [CI] 26.5 to 32.4, I(2)=82.2%), low density lipoprotein-cholesterol (37 studies, MD=14.9mg/dL, 95% CI 11.2 to 18.5, I(2)=86.1%), and triglycerides (43 studies, MD=46.8mg/dL, 95% CI 37.8 to 55.8, I(2)=97.1%), compared with ART-naïve patients. The risks of hypercholesterolemia (25 studies, pooled odds ratio [OR] 3.8, 95% CI 3.1 to 4.7, I(2)=60.0%) and hypertriglyceridemia (21 studies, OR 2.2, 95% CI 1.7 to 2.9, I(2)=81.7%) were also significantly higher among ART-exposed patients, compared with ART-naïve patients.

CONCLUSION

Antiretroviral therapy is significantly associated with increase in serum lipid levels and increased risk of dyslipidemia. Whether or not these associations are causal should be investigated by future studies.

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.

A randomized controlled trial of single-class maintenance therapy with abacavir/lamivudine/zidovudine after standard triple antiretroviral induction therapy: final 96-week results from the FREE study

OBJECTIVES

The aim of the study was to test the antiviral efficacy of a triple nucleoside reverse transcriptase inhibitor (NRTI) regimen, with potential beneficial metabolic effects, as maintenance therapy after induction with dual NRTIs and a boosted protease inhibitor (PI).

METHODS

An open-label, noninferiority study was carried out. Antiretroviral therapy (ART)-naïve patients with CD4 count ≤ 350 cells/μL and HIV-1 RNA >30000 copies/mL (n=207) were treated with zidovudine/lamivudine and lopinavir/ritonavir. After achieving HIV-1 RNA <50 copies/mL on two consecutive occasions between weeks 12 and 24 after baseline, 120 patients (baseline: median HIV-1 RNA 5.19 log10 copies/mL; median CD4 count 180 cells/μL) were randomized to receive abacavir/lamivudine/zidovudine (ABC/3TC/ZDV) (n=61) or to continue the PI-based ART (n=59).

RESULTS

For the proportions of patients (intention-to-treat; missing=failure) with HIV-1 RNA <400 copies/mL (PI group, 66%; ABC/3TC/ZDV group, 71%) and <50 copies/mL (PI group, 63%; ABC/3TC/ZDV group, 62%) at 96 weeks, switching to ABC/3TC/ZDV was noninferior compared with continuing the PI regimen; the difference in failure rate (ABC/3TC/ZDV minus PI) was -4.4 percentage points [95% confidence interval (CI) -21.0 to +12.3 percentage points] and +0.4 percentage points (95% CI -16.9 to +17.7 percentage points), respectively. In the per protocol analysis, the difference in virological failure for HIV-1 RNA >400 copies/mL (0 of 39 patients in the PI group and two of 45 patients in the NRTI group) and for HIV-1 RNA >50 copies/mL (two of 39 and three of 45 patients, respectively) was +4.4 percentage points (95% CI -2.1 to +11.0 percentage points) and +1.5 percentage points (95% CI -8.6 to +11.7 percentage points), respectively, also showing noninferiority. Serum lipids significantly improved in the NRTI group, but not in the PI arm.

CONCLUSIONS

A single-class NRTI regimen after successful induction with standard ART had similar antiviral efficacy compared to continuation of a PI-based regimen at 96 weeks after baseline, with improved serum lipids.

Prevalence of insulin resistance and risk of diabetes mellitus in HIV-infected patients receiving current antiretroviral drugs

OBJECTIVE

HIV-infected patients had a higher prevalence of insulin resistance (IR) and risk of diabetes mellitus (DM) than that observed in healthy controls, but there are no data about the current prevalence considering the changes in HIV presentation and the use of newer antiretroviral drugs.

DESIGN

Longitudinal study which involved 265 HIV patients without DM, receiving first (n=71) and advanced lines of antiretroviral therapy (n=194).

METHODS

Prevalence of IR according to clinical and anthropometric variables, including dual X-ray absorptiometry (DXA) scan evaluation. IR was defined as homeostasis model assessment of IR≥3.8. Incident DM was assessed during the follow-up.

RESULTS

First-line patients had a short time of HIV infection, less hepatitis C virus coinfection, and received mainly an efavirenz-based regimen. Overall, the prevalence of IR was 21% (55 patients, 6% in first-line, 27% in pretreated). In a logistic regression analysis, significant associations were found between the waist/hip circumference ratio (RR 10; 95% CI 1.66-16; P<0.01, per unit), and central fat in percentage (RR 1.08; 95% CI 1.01-1.17; P=0.04, per unit) as evaluated by DXA, and IR. During 770.8 patient-years, DM was diagnosed in 8% (22 patients), mostly in pretreated patients (10 vs 4%; P=0.1). Thus, the overall rate of incident DM was 2.85 per 100 person-years, mostly in previous IR (10.39 vs 0.82/100 person-years; P=0.01).

CONCLUSIONS

A lower prevalence of IR is observed in the current HIV-infected patients with fewer risk factors and receiving newer antiretroviral drugs. IR continues to identify patients at high risk for developing DM in the short term.

A systematic review of a single-class maintenance strategy with nucleoside/nucleotide reverse transcriptase inhibitors in HIV/AIDS

BACKGROUND

Single-drug class regimens with nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) are generally not recommended as initial therapy because they are inferior compared with therapy with two NRTIs plus efavirenz. However, triple-NRTI combinations can be useful in specific circumstances such as in tuberculosis coinfection, pregnancy or dyslipidaemia. Here, we review the potential of such combinations to maintain viral suppression after induction of suppression by standard combination antiretroviral therapy (cART) and to evaluate the trade-off of NRTI-only regimens for metabolic control.

METHODS

We conducted a systematic search of the literature in two databases from 1 January 1998 up to 1 March 2013: Medline, through the search engine PubMed, and Embase.

RESULTS

A total of 11 randomized controlled trials (RCTs) with 2,105 patients and 3 observational studies with 2,639 patients were included. Studies including patients with mono- or dual-NRTI treatment before start of effective cART showed a tendency to higher failure rate because of resistance based on archived viral mutations. In studies with ART-naive subjects before start of cART, triple-NRTI combination showed virological activity comparable to two NRTIs plus a protease inhibitor or a non-nucleoside reverse transcriptase inhibitor in all RCTs, but not in one cohort study. Switching improved serum lipids significantly.

CONCLUSIONS

Of the studied triple-NRTI combinations only abacavir/lamivudine/zidovudine was sufficiently potent. Triple-NRTI maintenance after successful induction with two-class cART appeared successful in treatment-naive subjects and remains a useful option in specific circumstances, especially when other drugs are not available or drug interactions are an issue.

Metabolic syndrome in HIV-infected individuals: underlying mechanisms and epidemiological aspects

The success of highly active antiretroviral therapy (HAART) has determined a dramatic decline in AIDS- and immunodeficiency-related causes of death in the HIV-infected population. As life-expectancy increases, such individuals have become gradually exposed not only to the effects of aging itself, but also to the influence of environmental risk factors, which are known to act in the general population. These features can lead to obesity, diabetes mellitus and ultimately cardiovascular diseases (CVD). Metabolic complications and abnormal fat distribution were frequently observed after a few years of antiretroviral therapy and, as the array of antiretroviral drugs became broader, long term metabolic alterations are becoming far more common worldwide. Nevertheless, the risk of not being on HAART is overwhelmingly greater than the metabolic adverse events in terms of morbidity and mortality events. HIV/HAART-induced metabolic unbalances overlap in some extent the components of Metabolic Syndrome (MetS) and its high rates in the HIV population place infected individuals in an elevated CVD risk category. MetS can explain at least in part the emergence of CVD as the major morbidity and mortality conditions in the HIV population. In this review we convey information on the underlying aspects of MetS during HIV infection, highlighting some physiopathological and epidemiological features of this comorbidity along with the role played by HIV itself and the synergy action of some antiretroviral drugs. Considerations on MetS management in the HIV population are also depicted.

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).

HIV and the heart: the impact of antiretroviral therapy: a global perspective

From a global perspective, cardiovascular disease (CVD) in human immunodeficiency virus (HIV) may result from cardiac involvement upon presentation of opportunistic infections in the presence of advanced immunosuppression, be a consequence of HIV-induced immune activation or derive from antiretroviral therapy-associated dyslipidaemia and insulin resistance. Indeed, in developed countries with unlimited access to antiretroviral therapy CVD has become one of the major causes of death in HIV. Therefore, cardiovascular risk reduction and lifestyle modifications are essential and careful selection of the antiretroviral drugs according to underlying cardiovascular risk factors of great importance. In developing countries with delayed roll-out of antiretroviral therapy pericardial disease (often related to TB), HIV-associated cardiomyopathy, and HIV-associated pulmonary hypertension are the most common cardiac manifestations in HIV. In Africa, the epicentre of the HIV epidemic, dynamic socio-economic and lifestyle factors characteristic of epidemiological transition appear to have positioned the urban African community at the cross-roads between historically prevalent and 'new' forms of CVD, such as coronary artery disease. In this context, cardiovascular risk assessment of HIV-infected patients will become a critical element of care in developing countries similar to the developed world, and access to antiretroviral therapy with little or no impact on lipid and glucose metabolism of importance to reduce CVD in HIV.

Quality of life of people living with HIV and AIDS and antiretroviral therapy

The development of antiretroviral drugs has significantly changed the perception of HIV/AIDS from a very fatal to a chronic and potentially manageable disease, and the availability and administration of antiretroviral therapy (ART) has significantly reduced mortality and morbidity associated with HIV and AIDS. There is a relationship between ART and quality of life of people living with HIV and AIDS, and several studies have reported a strong positive association between ART and improved quality of life in different domains among people living with HIV and AIDS in both developed and developing countries. However, a few studies have reported on the negative effects of ART, which directly or indirectly relate to the quality of life and longevity of HIV-infected persons. In this review, the effects and benefits of ART on people living with HIV and AIDS based on studies done in developed and developing countries is examined.

Lipodystrophy in HIV patients: its challenges and management approaches

HIV-associated lipodystrophy is a term used to describe a constellation of body composition (lipoatrophy and lipohypertrophy) and metabolic (dyslipidemia and insulin resistance) alterations that accompany highly active antiretroviral therapy. These changes, which resemble metabolic syndrome, have been associated with a variety of adverse outcomes including accelerated cardiovascular disease. The body composition and metabolic changes appear to cluster in HIV infection, although they are distinct alterations and do not necessarily coexist. Epidemiological studies have demonstrated multiple pathogenic influences associated with host, disease, and treatment-related factors. The adverse treatment effects were more prominent in early regimens; continued drug development has led to the application of metabolically safer regimens with equal or greater potency than the regimens being replaced. Disease-related factors include HIV infection as well as inflammation, immune activation, and immune depletion. The body composition changes promote anxiety and depression in patients and may affect treatment adherence. Treatment of dyslipidemia and alterations in glucose metabolism is the same as in non-HIV-infected individuals. Lipoatrophy is managed by strategic choice of antivirals or by antiviral switching, and in some cases by plastic/reconstructive surgery. Lipohypertrophy has been managed mainly by lifestyle modification, ie, a hypocaloric diet and increased exercise. A growth hormone releasing factor, which reduces central fat, has recently become available for clinical use.

Peripheral and central fat changes in subjects randomized to abacavir-lamivudine or tenofovir-emtricitabine with atazanavir-ritonavir or efavirenz: ACTG Study A5224s

BACKGROUND

We compare the effect of 4 different antiretroviral regimens on limb and visceral fat.

METHODS

A5224s was a substudy of A5202, a trial of human immunodeficiency virus type 1 (HIV-1)-infected, treatment-naive subjects randomized to blinded abacavir-lamivudine (ABC-3TC) or tenofovir DF-emtricitabine (TDF-FTC) with open-label efavirenz (EFV) or atazanavir-ritonavir (ATV-r). The primary endpoint was the presence of lipoatrophy (≥ 10% loss of limb fat) at week 96 by intent-to-treat (ITT) analysis. Secondary endpoints included changes in limb and visceral fat. Statistical tests included linear regression, binomial, two-sample t test, and Fisher's exact test.

RESULTS

A5224s enrolled 269 subjects; 85% were male, and 47% were white non-Hispanic. The subjects had a median baseline HIV-1 RNA level of 4.6 log(10) copies/mL, a median age of 38 years, a median CD4+ cell count of 233 cells/μL, median limb fat of 7.4 kg, median visceral adipose tissue (VAT) of 84.1 cm(2), and VAT: total adipose tissue (TAT) ratio of 0.31. At week 96, estimated prevalence of lipoatrophy (upper 95% confidence interval [CI]) was 18% (25%) for ABC-3TC and 15% (22%) for TDF-FTC (P = .70); this was not significantly less than the hypothesized 15% for both (P ≥ .55 for both). The secondary as-treated (AT) analysis showed similar results. At week 96, the estimated mean percentage change from baseline in VAT was higher for the ATV-r group than for the EFV group (26.6% vs 12.4%; P = .090 in ITT analysis and 30.0% vs 14.5%; P = .10 in AT analysis); however, the percentage change in VAT:TAT was similar by ITT and AT analysis (P ≥ .60 for both). Results were similar for absolute changes in VAT and VAT:TAT.

CONCLUSIONS

ABC-3TC- and TDF-FTC-based regimens increased limb and visceral fat at week 96, with a similar prevalence of lipoatrophy. Compared to the EFV group, subjects assigned to ATV-r had a trend towards higher mean percentage increase in VAT.

CLINICAL TRIALS REGISTRATION

NCT00118898.

Management of the metabolic effects of HIV and HIV drugs

Morphologic and metabolic abnormalities, including subcutaneous adipose tissue wasting, central adipose tissue accumulation, dyslipidemia and disorders of glucose metabolism are common among HIV-infected patients receiving highly active antiretroviral therapy (HAART) and contribute to the risk of cardiovascular disease in this population. The pathogenesis of these disorders is due to complicated interactions between effects of chronic HIV infection, HAART medications and patient factors, including genetic susceptibility. HAART has transformed HIV into a chronic condition for many patients and as a result the majority of HIV-infected patients in many areas of the developed world will soon be aged ≥50 years. Given that metabolic and cardiovascular diseases increase with aging, knowledge of the optimal management of these conditions is essential for practitioners caring for HIV-infected patients, including endocrine subspecialists. This Review highlights the clinical management of these disorders, focusing on the latest evidence regarding the efficacy of treatment strategies, newly available medications and potential interactions between HAART medications and medications used to treat metabolic disorders.

Molecular mechanisms for insulin resistance in treated HIV-infection

Identification and characterization of the molecular mechanisms contributing to the high incidence of insulin resistance in HIV infected patients treated with combined antiretroviral therapy remains a critically important goal in the quest to improve the safety of antiretroviral treatment regimens. The use of in vitro model systems together with the investigation of drug-mediated effects on glucose homeostasis in animals and healthy human volunteers has provided important insight into the contribution of individual drugs to insulin resistance and affected cellular pathways. HIV protease inhibitor mediated blockade of glucose transport and nucleoside reverse transcriptase inhibitor mediated mitochondrial toxicity have been well characterized. Together with growing understanding of mediators of insulin resistance in non-HIV metabolic syndrome, additional cellular effects including the induction of endoplasmic reticulum and oxidative stress, altered adipocytokine secretion, and lipotoxicity have been integrated into this developing picture. Further elucidation of these mechanisms provides potential for the continued development of safer antiviral drugs and targeted treatment of insulin resistance in affected patients.

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.

Association between systemic inflammation and incident diabetes in HIV-infected patients after initiation of antiretroviral therapy

OBJECTIVE

To determine whether systemic inflammation after initiation of HIV-antiretroviral therapy (ART) is associated with the development of diabetes.

RESEARCH DESIGN AND METHODS

We conducted a nested case-control study, comparing 55 previously ART-naive individuals who developed diabetes 48 weeks after ART initiation (case subjects) with 55 individuals who did not develop diabetes during a comparable follow-up (control subjects), matched on baseline BMI and race/ethnicity. Stored plasma samples at treatment initiation (week 0) and 1 year later (week 48) were assayed for levels of high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and the soluble receptors of tumor necrosis factor-α (sTNFR1 and sTNFR2).

RESULTS

Case subjects were older than control subjects (median age 41 vs. 37 years, P = 0.001), but the groups were otherwise comparable. Median levels for all markers, except hs-CRP, decreased from week 0 to week 48. Subjects with higher levels of hs-CRP, sTNFR1, and sTNFR2 at 48 weeks had an increased odds of subsequent diabetes, after adjustment for baseline marker level, age, BMI at week 48, CD4 count at week 48 (< vs. >200 cells/mm(3)), and indinavir use (all P(trend) ≤ 0.05). After further adjustment for week 48 glucose, effects were attenuated and only sTNFR1 remained significant (odds ratio, highest quartile vs. lowest 23.2 [95% CI 1.28-423], P = 0.03).

CONCLUSIONS

Inflammatory markers 48 weeks after ART initiation were associated with increased risk of diabetes. These findings suggest that systemic inflammation may contribute to diabetes pathogenesis among HIV-infected patients.

The effect of tenofovir disoproxil fumarate on whole-body insulin sensitivity, lipids and adipokines in healthy volunteers

BACKGROUND

Certain antiretrovirals are known to affect lipid and glucose homeostasis. The aim of this study was to assess the effect on insulin sensitivity (determined by peripheral glucose uptake using a hyperinsulinaemic euglycaemic clamp) of tenofovir disoproxil fumarate (TDF) administration compared with placebo for 2 weeks in HIV-1-seronegative healthy male volunteers. Changes in lipids, adiponectin, leptin, plasminogen activator inhibitor 1 (PAI-1) and the adhesion molecules E-selectin and P-selectin were also assessed.

METHODS

This was a single-centre, randomized, double-blinded, placebo-controlled study that used a two-sequence, two-period cross-over design. A total of 19 HIV-negative males were recruited to the study and randomized 1:1 to receive either 2 weeks of TDF (300 mg once daily) followed by 2 weeks of placebo or placebo initially followed by tenofovir. Clamps were performed at baseline, after 2 weeks and after 4 weeks.

RESULTS

All three clamps were completed by 16 participants. During the euglycaemic clamp, there were no significant changes in insulin sensitivity after 2 weeks of TDF administration compared with placebo or baseline. There was a significant reduction in the mean total cholesterol (9.4%) and low-density lipoprotein (LDL; 8.1%) cholesterol following 2 weeks of TDF compared with placebo. Levels of adiponectin, leptin, PAI-1, P-selectin and E-selectin were not significantly altered.

CONCLUSIONS

TDF use for 2 weeks does not affect insulin sensitivity, as assessed by the hyperinsulinaemic euglycaemic clamp in HIV-negative male volunteers. TDF use resulted in modest, but statistically significant, reductions in total and LDL cholesterol.

[AIDS Study Group/Spanish AIDS Plan consensus document on antiretroviral therapy in adults with human immunodeficiency virus infection (updated January 2010)]

OBJECTIVE

This consensus document is an update of antiretroviral therapy recommendations for adult patients with human immunodeficiency virus infection.

METHODS

To formulate these recommendations a panel made up of members of the Grupo de Estudio de Sida (Gesida, AIDS Study Group) and the Plan Nacional sobre el Sida (PNS, Spanish AIDS Plan) reviewed the advances in the current understanding of the pathophysiology of human immunodeficiency virus (HIV) infection, the efficacy and safety of clinical trials, and cohort and pharmacokinetic studies published in biomedical journals or presented at scientific meetings. Three levels of evidence were defined according to the data source: randomized studies (level A), cohort or case-control studies (level B), and expert opinion (level C). The decision to recommend, consider or not to recommend ART was established in each situation.

RESULTS

Currently, the treatment of choice for chronic HIV infection is the combination of three drugs of two different classes, including 2 nucleosides or nucleotide analogs (NRTI) plus 1 non-nucleoside (NNRTI) or 1 boosted protease inhibitor (PI/r), but other combinations are possible. Initiation of ART is recommended in patients with symptomatic HIV infection. In asymptomatic patients, initiation of ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts below 350 cells/microl; 2) When CD4 counts are between 350 and 500 cells/microl, therapy should be started in case of cirrhosis, chronic hepatitis C, high cardiovascular risk, HIV nephropathy, HIV viral load above 100,000 copies/ml, proportion of CD4 cells under 14%, and in people aged over 55; 3) Therapy should be deferred when CD4 are above 500 cells/microl, but could be considered if any of previous considerations concurs. Treatment should be initiated in case of hepatitis B requiring treatment and should be considered for reduce sexual transmission. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures but undetectable viral loads maybe possible with the new drugs even in highly drug experienced patients. Genotype studies are useful in these situations. Drug toxicity of ART therapy is losing importance as benefits exceed adverse effects. Criteria for antiretroviral treatment in acute infection, pregnancy and post-exposure prophylaxis are mentioned as well as the management of HIV co-infection with hepatitis B or C.

CONCLUSIONS

CD4 cells counts, viral load and patient co-morbidities are the most important reference factors to consider when initiating ART in asymptomatic patients. The large number of available drugs, the increased sensitivity of tests to monitor viral load, and the ability to determine viral resistance is leading to a more individualized therapy approach in order to achieve undetectable viral load under any circumstances.

The association of mitochondrial content with prevalent and incident type 2 diabetes

CONTEXT

It has been shown that mitochondrial DNA (mtDNA) content is associated with type 2 diabetes (T2D) and related traits. However, empirical data, often based on small samples, did not confirm this observation in all studies. Therefore, the role of mtDNA content in T2D remains elusive.

OBJECTIVE

In this study, we assessed the heritability of mtDNA content in buccal cells and analyzed the association of mtDNA content in blood with prevalent and incident T2D.

DESIGN AND SETTING

mtDNA content from cells from buccal and blood samples was assessed using a real-time PCR-based assay. Heritability of mtDNA content was estimated in 391 twins from the Netherlands Twin Register. The association with prevalent T2D was tested in a case control study from The Netherlands (n = 329). Incident T2D was analyzed using prospective samples from Finland (n = 444) and The Netherlands (n = 238).

MAIN OUTCOME MEASURES

We measured the heritability of mtDNA content and the association of mtDNA content in blood with prevalent and incident T2D.

RESULTS

A heritability of mtDNA content of 35% (19-48%) was estimated in the twin families. We did not observe evidence of an association between mtDNA content and prevalent or incident T2D and related traits. Furthermore, we observed a decline in mtDNA content with increasing age that was male specific (P = 0.001).

CONCLUSION

In this study, we show that mtDNA content has a heritability of 35% in Dutch twins. There is no association between mtDNA content in blood and prevalent or incident T2D and related traits in our study samples.

Antiretroviral therapy with heart

Antiretroviral therapy (ART) has resulted in a substantial improvement in the morbidity and mortality associated with human immunodeficiency virus (HIV) infection. As this population ages, cardiovascular disease is becoming an increasingly important health burden. It is clear that many factors are involved in the development of this problem, with traditional risk factors (smoking, dyslipidemia, diabetes, family history, hypertension) the main contributors. ART and HIV infection itself can modify the risk of cardiovascular disease. Not only does this increased risk seem to be mediated through effects on traditional cardiovascular risk factors, namely dyslipidemia and insulin resistance, but there is also some evidence that HIV and ART may be associated with accelerated atherosclerosis and endothelial dysfunction. Current data are conflicting and further investigation into this area is needed. Drugs from both nucleoside reverse transcriptase inhibitor and protease inhibitor classes have been demonstrated to increase cardiovascular risk; however these effects are variable not only between classes but also between drugs in the same class. As newer therapies become available (in existing and new drug classes), the cardiovascular impact of these will need careful evaluation. Currently published guidelines suggest regular monitoring of cardiovascular risks (both before and after commencing ART) and pre-emptive treatment. Existing risk assessment tools have not been fully validated in an HIV setting and need to be used with caution. Lifestyle modification, in the first instance, and pharmacological intervention to reduce traditional risk factors are important management strategies. Initiating, or switching to, ART with a lower potential for metabolic derangement should also be considered.

HIV protease inhibitors and insulin resistance: lessons from in-vitro, rodent and healthy human volunteer models

PURPOSE OF REVIEW

Although the use of HIV protease inhibitors is linked to the development of insulin resistance and other metabolic changes that greatly increase the risk for cardiovascular disease, the molecular mechanisms responsible remain incompletely understood. This review summarizes recent advances that have been made in understanding the relative contributions of individual protease inhibitors to both acute and chronic insulin resistance together with newly identified cellular mediators.

RECENT FINDINGS

Individual protease inhibitors, alone and in combination, have differing propensities to induce insulin resistance, reflecting relative differences in both affinities for identified molecular targets and pharmacokinetic profiles. Several of the most recent protease inhibitors approved for clinical use or in development appear to be less likely to induce insulin resistance. In addition to direct effects on glucose transporter-4 activity, induction of oxidative stress, proteosome inhibition, alteration of adipokine levels, and changes in suppressors of cytokine signaling-1 have been implicated.

SUMMARY

A better understanding of the propensity of individual HIV protease inhibitors to produce insulin resistance will allow the tailoring of individual treatment plans based upon overall risk for diabetes. The elucidation of the molecular mechanisms for alterations in glucose homeostasis will facilitate the development of newer generations of HIV protease inhibitors that maintain their clinical efficacy without contributing to the development of diabetes mellitus and other proatherogenic effects.

Lipoatrophy of the Footpad in HIV-Treated Patients Is Associated With Increased PAI-1

Purpose: To describe lipoatrophy of the plantar pedis fat pads in human immunodeficiency virus (HIV) patients with or without long-term antiretroviral therapy (ART); to compare the characteristics of ART patients with and without plantar pedis lipoatrophy; and to examine the effects of HIV and metabolic/cardiovascular risk parameters and treatment history on plantar pedis lipoatrophy. Design: Participants included 134 patients who started protease inhibitors in antiretroviral therapy (ART) in 1996 and 49 treatment-naive patients, recruited in 2004. Participants were examined and graded for lipoatrophy of five body compartments including the plantar fat pads. Baseline HIV- and ART-related factors were documented together with follow-up metabolic/ cardiovascular risk parameters. Results: Plantar pedis lipoatrophy occurred more often among ART patients (60%) than among treatment-naive patients (12%; p < .001). ART patients with plantar lipoatrophy were older, had higher plasminogen activator inhibitor 1 (PAI-1) values, a higher prevalence of lipoatrophy in other body compartments, and longer stavudine and didanosine treatment history as compared to patients without plantar lipoatrophy. Multiple logistic regression modeling revealed that among the metabolic/cardiovascular parameters, increased PAI-1 was strongly and positively associated with plantar lipoatrophy. Among the treatment history parameters, didanosine was the strongest independent predictor for plantar lipoatrophy. Increased PAI-1 was not associated to lipoatrophy in any other location. Conclusions: Plantar lipoatrophy is common among patients on long-term ART and, though often overlooked, may cause significant discomfort. The association to PAI-1, a well-known marker of increased cardiovascular risk, is intriguing and places further focus on the need for an active approach to evaluating and lowering cardiovascular risk factors in long-term HIV treatment.

A rosiglitazone-induced increase in adiponectin does not improve glucose metabolism in HIV-infected patients with overt lipoatrophy

HIV-infected patients on antiretroviral therapy frequently develop changes in body fat distribution and disturbances in glucose metabolism, associated with reduced adiponectin levels. Because adiponectin, principally the high-molecular-weight (HMW) form, has insulin-sensitizing properties, we investigated the effects of an increase in adiponectin on glucose metabolism in HIV-lipodystrophy. In this randomized, double-blind, placebo-controlled trial, we included HIV-1-infected patients with severe lipoatrophy, with an undetectable viral load and who had received neither protease inhibitors nor stavudine for ≥6 mo. Patients were randomized to rosiglitazone [8 mg daily (n = 8)] to increase adiponectin levels or placebo (n = 5) for 16 wk. Peripheral glucose disposal, glucose production, and lipolysis were measured after an overnight fast and during a hyperinsulinemic-euglycemic clamp using stable isotopes. Body composition was assessed by computed tomography and dual-energy X-ray absorptiometry. Although body fat distribution was unaffected, rosiglitazone increased total plasma adiponectin levels by 107% (P < 0.02) and the ratio of HMW to total adiponectin by 73% (P < 0.001). In the placebo group, neither total adiponectin levels (P = 0.62) nor the ratio of HMW to total adiponectin changed (P = 0.94). The marked increase in adiponectin induced by rosiglitazone was not associated with significant changes in basal endogenous glucose production (P = 0.90), basal lipolysis (P = 0.90), insulin-mediated suppression of glucose production (P = 0.17) and lipolysis (P = 0.54) nor with changes in peripheral glucose disposal (P = 0.13). Acknowledging the limited statistical power of our small study, these findings, if confirmed by larger studies, could question the importance of adiponectin in regulating glucose metabolism in HIV-lipodystrophy.

A review of co-morbidity between infectious and chronic disease in Sub Saharan Africa: TB and diabetes mellitus, HIV and metabolic syndrome, and the impact of globalization

Background

Africa is facing a rapidly growing chronic non-communicable disease burden whilst at the same time experiencing continual high rates of infectious disease. It is well known that some infections increase the risk of certain chronic diseases and the converse. With an increasing dual burden of disease in Sub Saharan Africa the associations between diseases and our understanding of them will become of increased public health importance.

Aims

In this review we explore the relationships reported between tuberculosis and diabetes mellitus, human immunodeficiency virus, its treatment and metabolic risk. We aimed to address the important issues surrounding these associations within a Sub Saharan African setting and to describe the impact of globalization upon them.

Findings

Diabetes has been associated with a 3-fold incident risk of tuberculosis and it is hypothesised that tuberculosis may also increase the risk of developing diabetes. During co-morbid presentation of tuberculosis and diabetes both tuberculosis and diabetes outcomes are reported to worsen. Antiretroviral therapy for HIV has been associated with an increased risk of developing metabolic syndrome and HIV has been linked with an increased risk of developing both diabetes and cardiovascular disease. Globalization is clearly related to an increased risk of diabetes and cardiovascular disease. It may be exerting other negative and positive impacts upon infectious and chronic non-communicable disease associations but at present reporting upon these is sparse.

Conclusion

The impact of these co-morbidities in Sub Saharan Africa is likely to be large. An increasing prevalence of diabetes may hinder efforts at tuberculosis control, increasing the number of susceptible individuals in populations where tuberculosis is endemic, and making successful treatment harder. Roll out of anti-retroviral treatment coverage within Sub Saharan Africa is an essential response to the HIV epidemic however it is likely to lead to a growing number of individuals suffering adverse metabolic consequences. One of the impacts of globalization is to create environments that increase both diabetes and cardiovascular risk but further work is needed to elucidate other potential impacts. Research is also needed to develop effective approaches to reducing the frequency and health impact of the co-morbidities described here.

Cardiovascular disease and HIV infection: host, virus, or drugs?

PURPOSE OF REVIEW

With effective antiretroviral therapy, cardiovascular disease has gained importance as a cause of morbidity and mortality in HIV-infected persons. We review the risk of cardiovascular disease in HIV-infected persons compared with that in uninfected persons and discuss the relative contributions of host, HIV, and antiretroviral therapy in the light of current knowledge.

RECENT FINDINGS

The incidence of cardiovascular disease in HIV-infected patients receiving antiretroviral therapy is low. However, the risk of cardiovascular disease increased compared with that in uninfected persons. This fact is substantially due to a higher prevalence of underlying traditional cardiovascular risk factors that are mostly host dependent. HIV may additionally contribute both directly through immune activation and inflammation, and indirectly through immunodeficiency. In a more modest way than that of HIV infection, the type of antiretroviral therapy may also contribute through its impact on metabolic and body fat parameters, and possibly through other factors that are currently unclear.

SUMMARY

Prevention of cardiovascular disease in HIV-infected patients should be standard of care. Traditional risk factors should be investigated and aggressively treated when possible. Antiretroviral therapy should be initiated earlier in patients with high cardiovascular risk. From a purely cardiovascular perspective, the benefits of antiretroviral therapy clearly outweigh any potential risk.