Lipid Profiles in HIV‐Infected Patients Receiving Combination Antiretroviral Therapy: Are Different Antiretroviral Drugs Associated with Different Lipid Profiles?

HIV-1, reactive oxygen species, and vascular complications

Over 1 million people in the United States and 33 million individuals worldwide suffer from HIV/AIDS. Since its discovery, HIV/AIDS has been associated with an increased susceptibility to opportunistic infection due to immune dysfunction. Highly active antiretroviral therapies restore immune function and, as a result, people infected with HIV-1 are living longer. This improved survival of HIV-1 patients has revealed a previously unrecognized risk of developing vascular complications, such as atherosclerosis and pulmonary hypertension. The mechanisms underlying these HIV-associated vascular disorders are poorly understood. However, HIV-induced elevations in reactive oxygen species (ROS), including superoxide and hydrogen peroxide, may contribute to vascular disease development and progression by altering cell function and redox-sensitive signaling pathways. In this review, we summarize the clinical and experimental evidence demonstrating HIV- and HIV antiretroviral therapy-induced alterations in reactive oxygen species and how these effects are likely to contribute to vascular dysfunction and disease.

Differences in lipid measurements by antiretroviral regimen exposure in cohorts from Asia and australia

We explored the mean differences in routinely measured lipids (total cholesterol, triglycerides, and high-density lipoprotein cholesterol) according to exposure to different combination antiretroviral regimens in Asian (n = 2051) and Australian (predominantly Caucasian, n = 794) cohorts. The regimen was defined as at least 3 antiretroviral drugs with at least 2 nucleoside-reverse transcriptases (NRTIs) and either of at least one protease inhibitor (PI) or non-nucleoside-reverse transcriptases (NNRTIs). We categorised cART regimens as: NRTIs as tenofovir based or not; NNRTIs as nevirapine or efavirenz (but not both); and PI as atazanavir based or not. We found that the impact of various antiretroviral regimens on lipids in Asian and Australian cohorts was only different by cohort for total cholesterol (P for interaction between regimen and cohort: <0.001) but not in case of other lipids (P for interaction: >0.05). The differences in total cholesterol were however small and unlikely to be of clinical significance. Overall, tenofovir with nevirapine or atazanavir was associated with the most favorable lipids, while the PI regimens without tenofovir and atazanavir were associated with least favorable lipids. We conclude that the impact of various ART regimens on lipids is largely similar in Asian and Australian cohorts and that the newer drugs such as tenofovir and atazanavir are likely to provide similar benefit in terms of lipid profiles in both populations.

The feature of Metabolic Syndrome in HIV naive patients is not the same of those treated: results from a prospective study

Metabolic Syndrome (MS) is a common disorder combining obesity, dyslipidemia, hypertension, and insulin resistance. Its prevalence among HIV-infected people is still debated. Besides, how antiretroviral therapy and HIV infection per se are related to MS is still unclear. All treatment-naïve patients attending scheduled visits at CISAI group hospitals between January and December 2007 were eligible for the study. Patients without MS at enrolment were followed-up for 3 years or until they developed MS, diagnosed according to the National Cholesterol Education Program (NCEP) definition. The main objective was to assess the 3-years incidence of MS. MS was evaluated for 188 subjects. Out of them, 62 (33.0%) had started HAART at enrolment, whereas 67 (35.6%) more started during the observation. 59 (31.4%) were still treatment-naive at the study end. MS was newly diagnosed in 14 patients. The incidence was 2.60 cases/100 person-years (95% CI 1.47-4.51), 2.75 (1.11-5.72) among HAART-naïve patients and 2.65 (1.23-5.03) in subjects on HAART. Blood pressure did not change in the study period, whereas in naive patients the HDL level significantly lowered (median -6.0 vs. 4.0, P<0.0001) compared to HAART-treated patients. Triglicerides increased significantly in HAART subjects (median 12.0 vs. 1.0, P=0.02), as well as blood glucose (median 6.0 vs. 1.0, P=0.01). In our population, the overall MS incidence was low and largely similar in patients who started HAART or remained naive. However, the feature of MS was different in the two groups, suggesting that in untreated and treated patients MS developed through different metabolic pathways.

Optimal antiretroviral therapy for aging

The introduction of highly active antiretroviral therapy (HAART) has irrevocably changed the nature of the HIV epidemic in developed countries. Although the use of HAART does not completely restore health in HIV-infected individuals, it has dramatically reduced morbidity and mortality. Increases in life expectancy resulting from effective long-term treatment mean that the proportion of older people living with HIV has increased substantially in the past 15 years. Increasing age is associated with many complications including cardiovascular disease, neurological complications, kidney and liver dysfunction, and metabolic complications such as dyslipidaemia and diabetes. HIV infection and antiretroviral drugs have also been associated with similar complications to those seen with increasing age. The increase in HIV prevalence in older age groups has not been accompanied by the development of treatment guidelines or recommendations for appropriate antiretroviral therapy or clinical management in these patients.

Antiretroviral therapy-associated dyslipidemia in patients from a reference center in Brazil

The aim of this study was to determine the impact of antiretroviral therapy on the lipid profile of human immunodeficiency virus (HIV) patients before and after the initiation of highly active antiretroviral therapy (HAART). This was a cross-sectional analysis of patients receiving HAART at a reference center in Belo Horizonte, Brazil, on the basis of medical records from 2002 to 2006. Patients were included if they had at least one lipid test or a clinical or laboratory diagnosis of dyslipidemia/lipodystrophy. Among the 692 patients, 620 met the eligibility criteria. The majority were males (66.5%), middle age (average 39 years), had a low educational level (60.4%), and low income (51.0%). HAART duration ranged from 11 days to 4.6 years, with a mean of 28.6 months (SD = ± 470.19 days). The prevalence of dyslipidemia/lipodystrophy nearly tripled (11.3% pre- and 32.4% post-HAART). Dyslipidemia was associated with older age (P = 0.007), nucleoside reverse transcriptase inhibitor (NRTI) + protease inhibitor (PI) regimens (P = 0.04), NRTI + non-NRTI (NNRTI) regimens (P = 0.026), the use of stavudine (d4T) in any regimen (P = 0.002) or in NRTI-based regimens (P = 0.006), and longer exposure to HAART (P < 0.000). In addition, there was no correlation between dyslipidemia and gender (P = 0.084). Only 2.0% of the patients received treatment for dyslipidemia during the trial. These results show a need for continuous monitoring of patients under antiretroviral therapy, particularly those using NRTI-based regimens, especially when combined with d4T and PIs. Secondly, interventions should be developed to correct metabolic changes.

First-line antiretroviral therapy and dyslipidemia in people living with HIV-1 in Cameroon: a cross-sectional study

Background

Data on lipid profile derangements induced by antiretroviral treatment in Africa are scarce. The aim of this study was to determine the prevalence and characteristics of lipid profile derangements associated with first-line highly active antiretroviral therapy (ART) among Cameroonians living with human immunodeficiency virus (HIV) infection.

Methods

This cross-sectional study was conducted between November 2009 and January 2010, and involved 138 HIV patients who had never received ART (ART-naive group) and 138 others treated for at least 12 months with first line triple ART regimens that included nevirapine or efavirenz (ART group). Lipid profile was determined after overnight fast and dyslipidemia diagnosed according to the US National Cholesterol Education Program III criteria. Data comparison used chi-square test, Student t-test and logistic regressions.

Results

The prevalence of total cholesterol ≥ 200 mg/dl was 37.6% and 24.6% respectively in ART group and ART-naive groups (p = 0.019). The equivalents for LDL-cholesterol ≥ 130 mg/dl were 46.4% and 21% (p ≤ 0.001). Proportions of patients with total cholesterol/HDL-cholesterol ratio ≥ 5 was 35.5% in ART group and 18.6% in ART-naive group (p ≤ 0.001). The distribution of HDL-cholesterol and triglycerides was similar between the two groups. In multivariable analysis adjusted for age, sex, body mass index, CD4 count and co-infection with tuberculosis, being on ART was significantly and positively associated with raised total cholesterol, LDL-cholesterol and TC/HDL cholesterol. The adjusted odd ratios (95% confidence interval, p-value) ART-treated vs. ART-naïve was 1.82 (1.06-1.12, p = 0.02) for TC ≥ 200 mg/dl; 2.99 (1.74-5.15), p < 0.0001) for LDL-cholesterol ≥ 130 mg/dl and 1.73 (1.04-2.89, p = 0.03) for TC/HDL-cholesterol ≥ 5.

Conclusions

First-line antiretroviral therapy that includes nonnucleoside reverse transcriptase inhibitors is associated with pro-atherogenic adverse lipid profile in people with HIV-1 infection compared to untreated HIV-infected subjects in Yaounde. Lipid profile and other cardiovascular risk factors should be monitored in patients on such therapy so that any untoward effects of treatments can be optimally managed.

Management of dyslipidemia in HIV-infected patients

Antiretroviral therapy has dramatically increased survival for HIV-infected individuals. As this population lives longer, coronary heart disease has become an important comorbid condition. Dyslipidemia in HIV-infected individuals is a complex condition, with multiple contributing factors including the HIV virus itself, individual genetic characteristics and antiretroviral therapy-induced metabolic changes. Effective management of dyslipidemia in this population is essential to reduce cardiovascular risk but presents multiple challenges due to interactions between antiretroviral therapy agents and lipid-lowering medications.

Elevated triglycerides and risk of myocardial infarction in HIV-positive persons

OBJECTIVES

To explore the relationship between elevated triglyceride levels and the risk of myocardial infarction (MI) in HIV-positive persons after adjustment for total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C) and nonlipid risk factors.

BACKGROUND

Although elevated triglyceride levels are commonly noted in HIV-positive individuals, it is unclear whether they represent an independent risk factor for MI.

METHODS

The incidence of MI during follow-up was stratified according to the latest triglyceride level. Multivariable Poisson regression models were used to describe the independent association between the latest triglyceride level and MI risk after adjusting for TC and HDL-C, nonlipids cardiovascular disease (CVD) risk factors, HIV and treatment-related factors.

RESULTS

The 33,308 persons included in the study from 1999 to 2008 experienced 580 MIs over 178,835 person-years. Unadjusted, the risk of MI increased by 67% [relative risk (RR) 1.67, 95% confidence interval 1.54-1.80] per doubling in triglyceride level. After adjustment for the latest TC and HDL-C level, the RR dropped to 1.33 (95% confidence interval 1.21-1.45); this effect was further attenuated by other CVD risk factors and the RR was reduced to 1.17 (95% confidence interval 1.06-1.29). In models that additionally adjusted for HIV and treatment factors, the risk was further diminished, although remained significant (RR 1.11, 95% confidence interval 1.01-1.23).

CONCLUSION

Higher triglyceride levels were marginally independently associated with an increased risk of MI in HIV-positive persons, although the extent of reduction in RR after taking account of latest TC, latest HDL-C and other confounders suggests that any independent effect is small.

Incident hyperglycaemia among older adults with or at-risk for HIV infection

BACKGROUND

HIV infection has been associated with development of prediabetes and diabetes. Optimum screening practices for these disorders in HIV-infected populations remain unclear.

METHODS

We screened 377 adults, with or at-risk for HIV infection, for incident hyperglycaemia (prediabetes or diabetes) using two oral glucose tolerance tests (OGTTs) a median of 18.6 months apart. We determined proportion of incident cases detected by fasting and 120-min plasma glucose levels. Independent predictors of incident hyperglycaemia were identified using logistic regression.

RESULTS

The baseline OGTT was consistent with diabetes in 7% of participants and with prediabetes in 31%. Among 352 normoglycaemic and prediabetic participants at baseline, 19 (5%) developed diabetes on follow-up. Among participants normoglycaemic at baseline, an additional 38 (16%) developed prediabetes. Overall 52% of incident hyperglycaemia cases were detected by fasting plasma glucose alone, 33% by a 120-min glucose level alone and 15% by both. Factors independently associated with incident hyperglycaemia included age ≥50 years and body mass index ≥30 kg/m(2). Neither HIV infection nor highly active antiretroviral therapy (HAART) use were associated with increased risk of diabetes.

CONCLUSIONS

Incident hyperglycaemia is common among older adults with or at-risk for HIV infection. HIV-infected individuals with classic diabetes risk factors should be screened for hyperglycaemia regardless of HAART use. OGTTs might be the preferred screening strategy in HIV-infected individuals at high risk for developing hyperglycaemia.

Lipid metabolism in treated HIV Infection

Patients infected with the human immunodeficiency virus (HIV) are prone to a great number of lipid and lipoprotein disturbances, as a result of both the infection itself and direct effects on lipid metabolism from the drugs used to treat HIV infection. These lipid disorders account for at least part of the increased risk of cardiovascular disease seen in this population. In general, evaluation and interventions for dyslipidemia in HIV-infected individuals should follow guidelines established for the general population. Special consideration, however, must be given to the potential for adverse drug interactions between lipid lowering drugs and the agents used to treat HIV infection. In this review, we summarize what is known about the relative tendency of different antiretroviral drugs to alter lipid levels, and suggest an approach to intervention for dyslipidemia in this population.

The metabolic syndrome in HIV

The metabolic syndrome (MS) is a term used to describe the clustering of risk factors for cardiovascular disease (CVD), including elevated triglyceride (TG), low high density lipoprotein cholesterol (HDL), hypertension, hyperglycemia/ insulin resistance and intra-abdominal obesity. This paper discusses why the prevalence of MS in the setting of HIV has been reported to range from 7-45% and how antiretroviral drugs might contribute to the development of MS. The MS has been reported to be a 'CVD risk enhancer', and much debate is ongoing on the independent risk of CVD associated with the MS. Based on a limited number of studies on MS in HIV with clinical end-points, there is no data to support that the MS is independently associated with an increased risk of CVD.

Lipid and lipoprotein profile in HIV-infected patients treated with lopinavir/ritonavir as a component of the first combination antiretroviral therapy

We characterized lipid and lipoprotein changes associated with a lopinavir/ritonavir-containing regimen. We enrolled previously antiretroviral-naive patients participating in the Swiss HIV Cohort Study. Fasting blood samples (baseline) were retrieved retrospectively from stored frozen plasma and posttreatment (follow-up) samples were collected prospectively at two separate visits. Lipids and lipoproteins were analyzed at a single reference laboratory. Sixty-five patients had two posttreatment lipid profile measurements and nine had only one. Most of the measured lipids and lipoprotein plasma concentrations increased on lopinavir/ritonavir-based treatment. The percentage of patients with hypertriglyceridemia (TG >150 mg/dl) increased from 28/74 (38%) at baseline to 37/65 (57%) at the second follow-up. We did not find any correlation between lopinavir plasma levels and the concentration of triglycerides. There was weak evidence of an increase in small dense LDL-apoB during the first year of treatment but not beyond 1 year (odds ratio 4.5, 90% CI 0.7 to 29 and 0.9, 90% CI 0.5 to 1.5, respectively). However, 69% of our patients still had undetectable small dense LDL-apoB levels while on treatment. LDL-cholesterol increased by a mean of 17 mg/dl (90% CI -3 to 37) during the first year of treatment, but mean values remained below the cut-off for therapeutic intervention. Despite an increase in the majority of measured lipids and lipoproteins particularly in the first year after initiation, we could not detect an obvious increase of cardiovascular risk resulting from the observed lipid changes.

Week 48 analysis of once-daily vs. twice-daily darunavir/ritonavir in treatment-experienced HIV-1-infected patients

OBJECTIVE

ODIN (Once-daily Darunavir In treatment-experieNced patients) was a phase III, 48-week, open-label study comparing once-daily vs. twice-daily darunavir/ritonavir (DRV/r) in treatment-experienced patients with no DRV resistance-associated mutations (RAMs) at screening.

METHODS

Patients with no DRV RAMs and receiving stable HAART for at least 12 weeks were stratified by HIV-1 RNA (≤ or > 50 000 copies/ml) and randomized to once-daily DRV/r 800/100 mg or twice-daily DRV/r 600/100 mg and an optimized background regimen (≥2 nucleoside reverse transcriptase inhibitors). Primary objective was to demonstrate noninferiority of once-daily vs. twice-daily DRV/r in confirmed virologic response (HIV-1 RNA < 50 copies/ml) at week 48.

RESULTS

Five hundred and ninety patients received once-daily (n = 294) or twice-daily (n = 296) DRV/r. Mean baseline HIV-1 RNA was 4.16 log10 copies/ml; median CD4 cell count was 228 cells/μl; and 53.9% had previously used at least one protease inhibitor. At week 48, 72.1% of once-daily and 70.9% of twice-daily patients achieved HIV-1 RNA less than 50 copies/ml (intent-to-treat/time-to-loss of virologic response). The difference in response between once-daily and twice-daily arms was 1.2% (95% confidence interval -6.1 to 8.5%; P < 0.001), establishing noninferiority of once-daily DRV/r versus twice-daily DRV/r. Median CD4 cell count increase was 100 (once-daily) and 94 cells/μl (twice-daily). Virologic failure rate was low and similar for both arms; only one patient (once-daily arm) developed primary protease inhibitor mutations. Once-daily DRV/r had a lower incidence of grade 2-4 triglyceride increases (5.2 vs. 11.0%, P < 0.05).

CONCLUSION

Once-daily DRV/r 800/100 mg was noninferior in virologic response to twice-daily DRV/r 600/100 mg at 48 weeks in treatment-experienced patients with no DRV RAMs, and with a more favorable lipid profile. These findings support use of once-daily DRV/r in this population.

Prevalence of Lipodystrophy and Dyslipidemia among Patients with HIV Infection on Generic ART in Rural South India

As antiretroviral therapy (ART) becomes more available to the HIV-infected population, it is important to determine the prevalence of its long-term complications. In this cross-sectional study, 145 HIV-positive patients on ART, 146 HIV-positive patients not on ART, and 72 HIV-negative individuals visiting the Namakkal District Head Quarters Hospital, Tamil Nadu, India, were recruited from February 2007 to April 2009. Among the patients on ART, the prevalence of lipodystrophy was 60.7%; 22.7% with lipohypertrophy, 51.1% with lipoatrophy, and 22.7% with mixed pattern. The proportion of patients with dyslipidemia was significantly higher in the treatment group when compared to ART-naive and HIV-negative controls ( P = .00). Total duration of ART was significantly associated with lipodystrophy ( P = .04) and dyslipidemia ( P = .01). Also, by logistic regression, abnormal metabolic levels were a risk factor in lipodystrophy ( P = .02). This study highlights the need for development of inexpensive and accessible treatments for the reduction of lipodystrophy.

Changes in lipid profiles after switching to a protease inhibitor-containing cART--unfavourable effect of fosamprenavir in obese patients

OBJECTIVE

One focus in the medical care of HIV-infected patients today is cardiovascular risk reduction. Metabolic disturbances occur frequently in patients taking protease inhibitors (PI) and are a major risk factor for atherosclerosis. With few published head-to-head studies substance-specific differences concerning metabolic effects are insufficiently defined. Therefore this cohort study directly compared the metabolic profiles of boosted atazanavir (ATV/r), fosamprenavir (FPV/r) and saquinavir (SQV/r).

METHODS

Data from a cohort of 124 HIV patients initiating a boosted regimen with one of the PIs at the University of Munich (LMU) infectious diseases outpatient clinic were retrospectively analyzed. The main outcome measures were median absolute total cholesterol levels and median relative change of total cholesterol levels after six months of PI-therapy. A multivariate linear regression model was built to identify and control for potential confounders of the association between PI-therapy and serum cholesterol level.

RESULTS

84 patients were treated with ATV/r, 23 patients received FPV/r and 17 patients SQV/r. Demographically the cohort constituted a representative sample of HIV-infected patients in Germany. There were no statistically significant differences between the comparison groups at baseline. - After six months of therapy median serum cholesterol in the ATV/r group dropped significantly from 204 mg/dl to 186 mg/dl, while in the FPV/r and SQV/r groups a rise in serum cholesterol levels was observed from 179 mg/dl to 204 mg/dl and from 173 mg/dl to 209 mg/dl respectively. The multivariate linear regression model identified a significant interaction between BMI at baseline and treatment with FPV/r: patients with higher BMI showed more prominent increases in serum cholesterol while taking FPV/r compared to patients with lower BMI.

CONCLUSION

This cohort study demonstrated the most favourable impact on serum cholesterol levels and thus cardiovascular risk for ATV/r compared to FPV/r and SQV/r under real-life conditions. Given the statistical interaction detected between FPV/r and BMI further studies assessing metabolic profiles of different antiretroviral drugs in specific patient populations are urgently needed.

Dyslipidemia among HIV-infected Patients with tuberculosis taking once-daily nonnucleoside reverse-transcriptase inhibitor-based antiretroviral therapy in India

BACKGROUND

Our aim was to study the incidence and pattern of dyslipidemia among human immunodeficiency virus (HIV)-infected patients with tuberculosis (TB) who received once-daily antiretroviral therapy (ART).

METHODS

Antiretroviral-naive HIV-infected patients with TB were recruited to a trial of once-daily nonnucleoside reverse-transcriptase inhibitor (NNRTI)-based ART and treated with rifampicin-based thrice-weekly antituberculosis treatment (ATT); participants were randomized to receive didanosine (250/400 mg) and lamivudine (300 mg) with either efavirenz (600 mg) or nevirapine (400 mg) once-daily after an intensive phase of ATT. Fasting triglyceride (TG) level, total cholesterol (TC) level, low-density cholesterol (LDL-c) level and high-density cholesterol (HDL-c) level were measured at baseline and at 6 and 12 months. Lipid levels at 6 and 12 months were compared with baseline values with use of repeated measures analyses. McNemar test was used to compare the proportion of patients with lipid abnormality at baseline versus at 12 months, and χ² test was used to compare between the 2 groups.

RESULTS

Of 168 patients (79% men; mean age, 36 years; mean weight, 42 kg; median CD4+ cell count, 93 cells/mm³), 104 received efavirenz-based ART, and 64 received nevirapine-based ART. After 6 months, TC levels increased by 49 mg/dL, LDL-c levels by 30 mg/dL, and HDL-c levels increased by 18 mg/dL (P < .001 for all). At baseline and at 12 months, TC was >200 mg/dL for 1% and 26% of patients, respectively; LDL-c level was >130 mg/dL for 3% and 23%, respectively; HDL-c level was <40 mg/dL for 91% and 23%, respectively; and blood glucose level was >110 mg/dL for 14% and 13%, respectively. TC level >200 mg/dL was more common among patients who received efavirenz than among those who received nevirapine (32% vs 16%; P = .04).

CONCLUSIONS

HIV-infected patients with TB who initiate NNRTI-based ART undergo complex changes in lipid profile, highlighting the importance of screening and treating other cardiovascular disease risk factors in this population.

Impact of NRTIs on lipid levels among a large HIV-infected cohort initiating antiretroviral therapy in clinical care

OBJECTIVE

to assess the associations between nucleoside reverse transcriptase inhibitors (NRTIs) and change in lipid levels among a large cohort of HIV-infected patients in routine clinical care initiating their first potent antiretroviral regimen.

DESIGN

longitudinal observational cohort study from the Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) cohort.

METHODS

we used generalized estimating equations to examine the association between NRTIs and lipids accounting for within-patient correlations between repeated measures and key clinical and demographic characteristics including other antiretroviral medications.

RESULTS

among 2267 individuals who started their first antiretroviral regimen, tenofovir with emtricitabine or lamivudine was associated with lower levels for total cholesterol, low-density lipoprotein (LDL), triglycerides, non-high-density lipoprotein (HDL), and HDL, compared with other NRTI pairs in adjusted analyses. LDL levels were highest among patients receiving didanosine/lamivudine. Triglyceride levels were highest in stavudine/lamivudine users. HDL levels were highest among patients receiving didanosine/stavudine. Hepatitis C infection and younger age were also associated with lower lipid levels.

CONCLUSION

we found clinically important heterogeneity within the NRTI class of antiretroviral medications regarding their effect on lipid levels over time. Although the lipid profile of tenofovir with emtricitabine or lamivudine appeared to be less pro-atherogenic in this large longitudinal study of HIV-infected patients in routine clinical care, there was no association with beneficial HDL levels. In general, the change in lipid levels associated with most antiretroviral agents, particularly those NRTI combinations currently in common use, are relatively modest. Additional studies are needed to understand the long-term implications of these findings on cardiovascular disease risk.

Metabolic complications associated with antiretroviral therapy in HIV-infected and HIV-exposed uninfected paediatric patients

IMPORTANCE OF THE FIELD

HIV-infection has become a chronic disease in paediatric patients with the potential for long-term survival and exposure to antiretroviral (ARV) therapies for 2 decades longer than HIV-infected adults. On the other hand, the administration of ARV to HIV-infected pregnant women has greatly increased both treatment of HIV infection and prevention of perinatal HIV transmission. Therefore, researches aiming to evaluate the safety of ARV therapies in HIV-infected children as well as in HIV-uninfected infants born to HIV-infected mothers are emerging as a new challenge and urgent priority.

AREAS COVERED IN THIS REVIEW

The purpose of this review is to describe some of the more concerning metabolic complications associated with ARV in paediatric population: hyperlactataemia (HLA) syndromes, body shape abnormalities, disorders of glucose homeostasis and dyslipidaemia in HIV-infected children and adolescents. Frequency, risk factors, clinical findings, prevention and intervention strategies of the previously described abnormalities are discussed in depth.

WHAT THE READER WILL GAIN

This review covers our current understanding of HLA syndromes in ARV-exposed uninfected infants born to HIV-infected mothers.

TAKE HOME MESSAGE

Prevention of these metabolic complications should assume prominence and future researches should address several of the existing treatment gaps.

Glyceroneogenesis is inhibited through HIV protease inhibitor-induced inflammation in human subcutaneous but not visceral adipose tissue

Glyceroneogenesis, a metabolic pathway that participates during lipolysis in the recycling of free fatty acids to triglycerides into adipocytes, contributes to the lipid-buffering function of adipose tissue. We investigated whether glyceroneogenesis could be affected by human immunodeficiency virus (HIV) protease inhibitors (PIs) responsible or not for dyslipidemia in HIV-infected patients. We treated explants obtained from subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) depots from lean individuals. We observed that the dyslipidemic PIs nelfinavir, lopinavir and ritonavir, but not the lipid-neutral PI atazanavir, increased lipolysis and decreased glyceroneogenesis, leading to an increased release of fatty acids from SAT but not from VAT. At the same time, dyslipidemic PIs decreased the amount of perilipin and increased interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) secretion in SAT but not in VAT. Parthenolide, an inhibitor of the NFκB pathway, counteracted PI-induced increased inflammation and decreased glyceroneogenesis. IL-6 (100 ng) inhibited the activity of phosphoenolpyruvate carboxykinase, the key enzyme of glyceroneogenesis, in SAT but not in VAT. Our data show that dyslipidemic but not lipid-neutral PIs decreased glyceroneogenesis as a consequence of PI-induced increased inflammation in SAT that could have an affect on adipocytes and/or macrophages. These results add a new link between fat inflammation and increased fatty acids release and suggest a greater sensitivity of SAT than VAT to PI-induced inflammation.

Premature onset of cardiovascular disease in HIV-infected individuals: the drugs and the virus

Life expectancy in HIV-infected individuals has been greatly enhanced through immunologic restoration and virologic suppression resulting from antiretroviral therapy. Current clinical HIV care in Western countries focuses on treatment of drug toxicities and prevention of comorbidities. These non-AIDS HIV-related comorbidities, such as cardiovascular disease, occur even in individuals with virologic suppression and manifest at an earlier age than when normally presenting in the general population. While traditional risk factors are present in many HIV-infected individuals who develop cardiovascular disease, the additional roles of HIV-related chronic inflammation and immune activation as well as chronic HIV viremia may be significant. This review provides current evidence for the contributions of the virus, in terms of both chronic viremia and its contribution via chronic low-level inflammation, immune activation, premature immune senescence and dyslipidemia, to the pathogenesis of HIV-related cardiovascular disease, and balances this against the propensity of specific antiretroviral therapies to cause cardiovascular disease, in particular through altered cholesterol metabolism.

Serious fatal and nonfatal non-AIDS-defining illnesses in Europe

BACKGROUND

Little is known about the incidence and risk factors for serious non-AIDS-defining events.

METHODS

The incidence of non-AIDS events (malignancies, end-stage renal disease, liver failure, pancreatitis, cardiovascular disease), and AIDS after January 1, 2001, was calculated; Poisson regression was used to investigate factors associated with non-AIDS and AIDS.

RESULTS

Among 12,844 patients, 1058 were diagnosed with a non-AIDS event [incidence 1.77 per 100 person-years of follow-up; 95% confidence interval (CI): 1.66 to 1.87]; 462 patients (43.7%) died. The incidence of AIDS (1025 diagnoses; 339 deaths, 33.1%) was 1.72 per 100 person-years of follow-up (1.61 to 1.83). After adjustment, older age [incidence rate ratio (IRR): 1.71 per 10 years older, 95% CI: 1.60 to 1.83], diabetes (IRR: 1.49, 95% CI: 1.22 to 1.82) and hypertension (IRR: 1.63, 95% CI: 1.43 to 1.87) were associated with non-AIDS events. Compared with patients without an event, there was a 4-fold increased risk of death after an AIDS event (relative hazard: 4.14; 95% CI 3.47 to 4.94) and almost a 7-fold increased risk of death after a non-AIDS event (relative hazard: 6.72; 95% CI: 5.61 to 8.05).

CONCLUSIONS

Non-AIDS events were common in the combination antiretroviral therapy era and associated with considerably mortality. Evidence on the impact of modifying immunodeficiency and lifestyle-related factors on the risk of non-AIDS events in HIV-infected persons is an important but unmet research need.

HIV protease inhibitors and obesity

PURPOSE OF REVIEW

To review the current scientific literature and recent clinical trials on HIV protease inhibitors and their potential role in the pathogenesis of lipodystrophy and metabolic disorders.

RECENT FINDINGS

HIV protease inhibitor treatment may affect the normal stimulatory effect of insulin on glucose and fat storage. Further, chronic inflammation from HIV infection and protease inhibitor treatment trigger cellular homeostatic stress responses with adverse effects on intermediary metabolism. The physiologic outcome is such that total adipocyte storage capacity is decreased, and the remaining adipocytes resist further fat storage. This process leads to a pathologic cycle of lipodystrophy and lipotoxicity, a proatherogenic lipid profile, and a clinical phenotype of increased central body fat distribution similar to the metabolic syndrome.

SUMMARY

Protease inhibitors are a key component of antiretroviral therapy and have dramatically improved the life expectancy of HIV-infected individuals. However, they are also associated with abnormalities in glucose/lipid metabolism and body fat distribution. Further studies are needed to better define the pathogenesis of protease inhibitor-associated metabolic and body fat changes and their potential treatment.

Changes in lipids and lipoprotein particle concentrations after interruption of antiretroviral therapy

BACKGROUND

The effect of interruption of antiretroviral therapy (ART) on lipoprotein particle subclasses has not been studied. We examined short-term changes in lipids and lipoprotein particles among 332 HIV-infected individuals randomized to interrupt or continue ART in the "Strategies for Management of Antiretroviral Therapy" trial.

METHODS

Lipids and lipoprotein particles measured by nuclear magnetic resonance spectroscopy were compared between randomized groups at month 1; associations with inflammatory and coagulation markers (high sensitivity C-reactive protein; interleukin 6; amyloid A; amyloid P; D-dimer; prothrombin fragment 1 + 2) were assessed.

RESULTS

Compared with continuation of ART, treatment interruption resulted in substantial declines in total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, and triglyceride, at month 1 but had little net effect on total/HDL cholesterol ratio [baseline-adjusted mean difference [95% confidence interval (CI)] interruption versus continuation arms: -0.10 (-0.59 to 0.38); P = 0.67]. ART interruption resulted in declines in total, large, and medium very low density lipoprotein (VLDL) particle concentrations (VLDL-p) and total and medium HDL-p. However, there was no change in small HDL-p [baseline-adjusted percentage difference between arms: -4.6% (-13.1%, +5.1% ); P = 0.35], small LDL-p [-5.0% (-16.9%, +8.6%); P = 0.45], or other LDL-p subclasses. Changes in lipid parameters on ART interruption did not differ according to baseline ART class (protease inhibitor versus non-nucleoside reverse transcriptase inhibitor) but were negatively associated both with changes in HIV viral load and with changes in inflammatory and coagulation markers, particularly D-dimer.

CONCLUSIONS

These results suggest that ART interruption does not favorably influence overall lipid profile: there was little net effect on total/HDL cholesterol ratio, and no change in small LDL-p or small HDL-p, the lipoprotein particle subclasses most consistently linked to coronary risk. Short-term declines in lipid parameters after ART interruption were not associated with class of ART and may be linked to increases in viral replication, inflammation and coagulation.

Lipid profiles in HIV-infected adults receiving atazanavir and atazanavir/ritonavir: systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

To compare lipid profiles in HIV-infected adults receiving atazanavir-based regimens.

METHODS

We conducted a systematic review of randomized controlled trials (RCTs) comparing atazanavir or atazanavir/ritonavir with a comparator and evaluated lipids at 48 weeks. We searched MEDLINE, EMBASE, CENTRAL, LILACS, Current Controlled Trials, National Institutes of Health Clinical Trials Registry, trials at AIDSinfo and HIV conference proceedings to May 2009. Standardized mean difference (SMD) between study arms in change from baseline to week 48 in lipid parameters was determined weighted by study size and 95% confidence intervals (CI) were calculated.

RESULTS

Nine eligible RCTs were identified (n = 3346). SMDs (mmol/L) in four RCTs comparing atazanavir/ritonavir with a ritonavir-boosted protease inhibitor were: total cholesterol, -0.62 (95% CI -0.72, -0.51); low-density lipoprotein (LDL) cholesterol, -0.31 (95% CI -0.44, -0.17); high-density lipoprotein (HDL) cholesterol, -0.16 (95% CI -0.27, -0.06); non-HDL cholesterol, -0.58 (95% CI -0.69, -0.48); and triglycerides, -0.46 (95% CI -0.58, -0.34). Atazanavir compared with non-atazanavir (three RCTs) found lower total, LDL and non-HDL cholesterol, and triglycerides [SMD -0.87 mmol/L (95% CI -0.99, -0.76); -0.56 mmol/L (95% CI -0.67, -0.45); -0.88 mmol/L (95% CI -0.99, -0.76); and -0.56 mmol/L (95% CI -0.75, -0.36), respectively], but HDL cholesterol did not differ [-0.16 mmol/L (95% CI -0.49, 0.16)]. In the atazanavir/ritonavir versus atazanavir comparison (two RCTs), total [SMD 0.44 mmol/L (95% CI 0.23, 0.65)] and non-HDL cholesterol [SMD 0.44 mmol/L (95% CI 0.23, 0.65)] were higher, but HDL cholesterol, LDL cholesterol and triglycerides were not different.

CONCLUSIONS

At 48 weeks, plasma lipid concentrations were lower with atazanavir/ritonavir than with other ritonavir-boosted protease inhibitor regimens. Total and non-HDL cholesterol were higher with atazanavir/ritonavir than atazanavir alone.

Hospitalizations in a cohort of HIV patients in Australia, 1999-2007

OBJECTIVES

To describe hospitalization rates, risk factors and associated diagnoses in people with HIV in Australia between 1999 and 2007.

DESIGN

Retrospective cohort study of people with HIV (n = 842) using data linkage between the Australian HIV Observational Database and administrative hospital morbidity data collections.

METHODS

Incidence rate ratios with 95% confidence intervals were estimated using Poisson regression models to assess risk factors for hospitalization. Predictors of length of stay were assessed using generalized mixed models. The association between hospitalization and mortality was assessed using Cox regression.

RESULTS

In 4519 person-years of observation, there were 2667 hospital admissions; incidence rate of 59 per 100 person-years. Hospitalization rates were 50-300% higher in this cohort than comparable age and sex strata in the general population. Older age (incidence rate ratio 1.46, 95% confidence interval 1.28-1.65 per 10-year increase) and prior AIDS (incidence rate ratio 1.71, 95% confidence interval 1.24-2.35) were significantly associated with hospitalization. Other predictors of hospitalization included lower CD4 cell counts, higher HIV RNA, longer duration of HIV infection and experience with more drug classes. Lower CD4 cell counts, older age and hepatitis C virus antibody positivity were independently associated with longer hospital stay. Non-AIDS diseases were the principle reason for admission in the majority of cases. Mortality was associated with more frequent hospitalization during the study period.

CONCLUSION

Hospitalization rates are higher in people with HIV than the general population in Australia and are associated with markers of advanced HIV disease despite the widespread use of combination antiretroviral therapy.

Randomized trial of a computerized coronary heart disease risk assessment tool in HIV-infected patients receiving combination antiretroviral therapy

BACKGROUND

Exposure to combination antiretroviral therapy (cART) can lead to important metabolic changes and increased risk of coronary heart disease (CHD). Computerized clinical decision support systems have been advocated to improve the management of patients at risk for CHD but it is unclear whether such systems reduce patients' risk for CHD.

METHODS

We conducted a cluster trial within the Swiss HIV Cohort Study (SHCS) of HIV-infected patients, aged 18 years or older, not pregnant and receiving cART for >3 months. We randomized 165 physicians to either guidelines for CHD risk factor management alone or guidelines plus CHD risk profiles. Risk profiles included the Framingham risk score, CHD drug prescriptions and CHD events based on biannual assessments, and were continuously updated by the SHCS data centre and integrated into patient charts by study nurses. Outcome measures were total cholesterol, systolic and diastolic blood pressure and Framingham risk score.

RESULTS

A total of 3,266 patients (80% of those eligible) had a final assessment of the primary outcome at least 12 months after the start of the trial. Mean (95% confidence interval) patient differences where physicians received CHD risk profiles and guidelines, rather than guidelines alone, were total cholesterol -0.02 mmol/l (-0.09-0.06), systolic blood pressure -0.4 mmHg (-1.6-0.8), diastolic blood pressure -0.4 mmHg (-1.5-0.7) and Framingham 10-year risk score -0.2% (-0.5-0.1).

CONCLUSIONS

Systemic computerized routine provision of CHD risk profiles in addition to guidelines does not significantly improve risk factors for CHD in patients on cART.

Dyslipidemia in HIV-infected individuals: from pharmacogenetics to pharmacogenomics

HIV-infected individuals may have accelerated atherogenesis and an increased risk for premature coronary artery disease. Dyslipidemia represents a key pro-atherogenic mechanism. In HIV-infected patients, dyslipidemia is typically attributed to the adverse effects of antiretroviral therapy. Nine recent genome-wide association studies have afforded a comprehensive, unbiased inventory of common SNPs at 36 genetic loci that are reproducibly associated with dyslipidemia in the general population. Genome-wide association study-validated SNPs have now been demonstrated to contribute to dyslipidemia in the setting of HIV infection and antiretroviral therapy. In a Swiss HIV-infected study population, a similar proportion of serum lipid variability was explained by antiretroviral therapy and by genetic background. In the individual patient, both antiretroviral therapy and the cumulative effect of SNPs contribute to the risk of high low-density lipoprotein cholesterol, low high-density lipoprotein cholesterol and hypertriglyceridemia. Genetic variants presumably contribute to additional major metabolic complications in HIV-infected individuals, including diabetes mellitus and coronary artery disease. In an effort to explain an increasing proportion of the heritability of complex metabolic traits, ongoing large-scale gene resequencing studies are focusing on the effects of rare SNPs and structural genetic variants.

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.

High prevalence of the metabolic syndrome in HIV-infected patients: impact of different definitions of the metabolic syndrome

INTRODUCTION

This study describes the characteristics of the metabolic syndrome in HIV-positive patients in the Data Collection on Adverse Events of Anti-HIV Drugs study and discusses the impact of different methodological approaches on estimates of the prevalence of metabolic syndrome over time.

METHODS

We described the prevalence of the metabolic syndrome in patients under follow-up at the end of six calendar periods from 2000 to 2007. The definition that was used for the metabolic syndrome was modified to take account of the use of lipid-lowering and antihypertensive medication, measurement variability and missing values, and assessed the impact of these modifications on the estimated prevalence.

RESULTS

For all definitions considered, there was an increasing prevalence of the metabolic syndrome over time, although the prevalence estimates themselves varied widely. Using our primary definition, we found an increase in prevalence from 19.4% in 2000/2001 to 41.6% in 2006/2007. Modification of the definition to incorporate antihypertensive and lipid-lowering medication had relatively little impact on the prevalence estimates, as did modification to allow for missing data. In contrast, modification to allow the metabolic syndrome to be reversible and to allow for measurement variability lowered prevalence estimates substantially.

DISCUSSION

The prevalence of the metabolic syndrome in cohort studies is largely based on the use of nonstandardized measurements as they are captured in daily clinical care. As a result, bias is easily introduced, particularly when measurements are both highly variable and may be missing. We suggest that the prevalence of the metabolic syndrome in cohort studies should be based on two consecutive measurements of the laboratory components in the syndrome definition.

Human immunodeficiency virus and highly active antiretroviral therapy-associated metabolic disorders and risk factors for cardiovascular disease

The successful introduction of highly active antiretroviral therapy (HAART), a combination of potent antiretroviral agents, including protease inhibitors, nucleoside reverse transcriptase inhibitors, and nonnucleoside reverse transcriptase inhibitors, has impacted positively on morbidity and mortality among human immunodeficiency virus (HIV)-positive patients. Over time, HAART has been associated with a number of metabolic and anthropometric abnormalities, including dyslipidemia and insulin resistance as well as subcutaneous fat loss and abdominal obesity, potentially contributing to cardiovascular risk. Recent studies have more firmly established that both HIV infection and HAART might increase the risk of clinical cardiovascular events. Furthermore, whereas HIV/HAART is associated with multiple aspects of endocrine dysfunction, there has been less focus on bone disease, although some studies indicate a higher prevalence of osteoporosis among HIV-positive subjects compared to HIV-negative controls. The relationship between bone and fat metabolism under HIV-positive conditions deserves further attention, and available data suggest the possibility of an intriguing connection. In the future, an increasing population of aging HIV-positive patients with a spectrum of antiretroviral therapies and accumulation of endocrine abnormalities and conventional cardiovascular risk factors will present preventive and therapeutic challenges to our health-care system.

Antiretroviral therapy as a cardiovascular disease risk factor: fact or fiction? A review of clinical and surrogate outcome studies

PURPOSE OF REVIEW

The aim of this paper is to assess the contribution of antiretroviral therapy to cardiovascular disease, by evaluating relevant clinical and surrogate outcome studies.

RECENT FINDINGS

A large proportion of patients receiving antiretroviral therapy develop insulin resistance and dyslipidemia, particularly if exposed to protease inhibitors. Recent findings from clinical outcome studies suggest that protease inhibitor-based therapy is associated with an increased risk of cardiovascular disease, with a consistent estimated increased risk of 1.16 to 1.17 for each additional year of protease inhibitor exposure. Antiretroviral therapy discontinuation, however, has also been linked with increased risk of cardiovascular disease. There are some data from clinical and surrogate outcome studies, that interventions addressing conventional risk factors and switching antiretroviral therapy may reduce cardiovascular disease risk.

SUMMARY

Combination antiretroviral therapy in general, and protease inhibitor-based antiretroviral therapy in particular, is associated with an increased risk of cardiovascular disease. This risk is likely mediated, in part, by changes in blood lipids. The absolute risk of cardiovascular disease for the individual patient depends on his or hers composite risk profile. It is becoming increasingly important to carry out an adequate cardiovascular disease risk assessment in each patient, in order to identify patients in need of specific interventions.

Cardiovascular complications of HIV: an overview of risk and a novel approach to prevention - the HIV polypill study

PURPOSE OF REVIEW

To review the risk of cardiovascular complications in HIV-infected patients receiving combination antiretroviral treatment.

RECENT FINDINGS

Recent data suggest that patients with chronic HIV infection will require continuous lifelong combination antiretroviral treatment, which may increase the risk of cardiovascular disease in all populations by substantial amounts. Simple, safe and effective interventions to reduce cardiovascular complications in HIV-infected patients will be required. Studies in the general population suggest that the primary prevention of cardiovascular disease with a pill combining blood-pressure-lowering, cholesterol-lowering and antiplatelet treatments (a polypill) might decrease cardiovascular events. An HIV polypill study with 8000 HIV-infected patients with a moderate risk of cardiovascular disease randomized to either a polypill of low-dose pravastatin, aspirin, hydrochlorothiazide and lisinopril or to placebo is described. The primary clinical endpoint would be a composite of cardiovascular mortality, non-fatal myocardial infarction and stroke. A vanguard study of 400 patients could assess changes in cholesterol, blood pressure and other risk factors. The clinical endpoint study described would have 80% power to detect a 23% reduction in the rate of cardiovascular events in the polypill arm.

SUMMARY

A study of a polypill like that proposed for the general population will provide crucial information on the risks and benefits of primary cardiovascular prevention in HIV-infected patients.

Lipoprotein Particle Profiles by Nuclear Magnetic Resonance Spectroscopy in Medically-Underserved HIV-Infected Persons

BACKGROUND: HIV infection is associated with dyslipidemia and increased risk for cardiovascular events. Few studies have described lipid status in medically-underserved, HIV-infected ethnic minorities, a group that is characterized by health disparities. OBJECTIVE: The objective was to characterize the lipid profile of a medically-underserved, largely ethnic minority sample of HIV-infected persons using standard lipid panels and nuclear magnetic resonance (NMR) -derived lipoprotein particle profiles. METHODS: Participants were recruited from a randomized controlled trial of a dietary supplement to manage HIV-related dyslipidemia (N=132). At the initial screening visit, sociodemographic, clinical, and behavioral data were collected, and fasting peripheral venous blood specimens were obtained and lipid status was analyzed using the standard lipid panel and the NMR-derived lipoprotein particle profile. RESULTS: Using NMR-derived LDL particle cutoffs, a higher percentage of participants was outside the target range (50%) than when standard LDL cholesterol NCEP cutoffs were used (24%). Antiretroviral therapy, especially protease inhibitor-containing regimens, was associated with higher LDL particle concentration. CONCLUSION: Substantial numbers of medically-underserved, asymptomatic HIV-infected minorities may be at increased risk for CHD based on NMR-derived lipoprotein values.

AIDS-related and non-AIDS-related mortality in the Asia-Pacific region in the era of combination antiretroviral treatment

OBJECTIVE

Although studies have shown reductions in mortality from AIDS after the introduction of combination antiretroviral treatment (cART), little is known about cause-specific mortality in low-income settings in the cART era. We explored predictors of AIDS and non-AIDS mortality and compared cause-specific mortality across high-income and low-income settings in the Asia-Pacific region.

METHODS

We followed patients in the Asia Pacific HIV Observational Database from the date they started cART (or cohort enrolment if cART initiation was identified retrospectively), until the date of death or last follow-up visit. Competing risks methods were used to estimate the cumulative incidence, and to investigate predictors, of AIDS and non-AIDS mortality.

RESULTS

Of 4252 patients, 215 died; 89 from AIDS, 97 from non-AIDS causes and 29 from unknown causes. Age more than 50 years [hazard ratio 4.29; 95% confidence interval (CI) 2.10-8.79] and CD4 cell counts less than or equal to 100 cells/microl (hazard ratio 8.59; 95% CI 5.66-13.03) were associated with an increased risk of non-AIDS mortality. Risk factors for AIDS mortality included CD4 cell counts less than or equal to 100 cells/microl (hazard ratio 34.97; 95% CI 18.01-67.90) and HIV RNA 10 001 or more (hazard ratio 4.21; 95% CI 2.07-8.55). There was some indication of a lower risk of non-AIDS mortality in Asian high-income, and possibly low-income, countries compared to Australia.

CONCLUSION

Immune deficiency is associated with an increased risk of AIDS and non-AIDS mortality. Older age predicts non-AIDS mortality in the cART era. Less conclusive was the association between country-income level and cause-specific mortality because of the relatively high proportion of unknown causes of death in low-income settings.

Contribution of genome-wide significant single-nucleotide polymorphisms and antiretroviral therapy to dyslipidemia in HIV-infected individuals: a longitudinal study

BACKGROUND

HIV-infected individuals have an increased risk of myocardial infarction. Antiretroviral therapy (ART) is regarded as a major determinant of dyslipidemia in HIV-infected individuals. Previous genetic studies have been limited by the validity of the single-nucleotide polymorphisms (SNPs) interrogated and by cross-sectional design. Recent genome-wide association studies have reliably associated common SNPs to dyslipidemia in the general population.

METHODS AND RESULTS

We validated the contribution of 42 SNPs (33 identified in genome-wide association studies and 9 previously reported SNPs not included in genome-wide association study chips) and of longitudinally measured key nongenetic variables (ART, underlying conditions, sex, age, ethnicity, and HIV disease parameters) to dyslipidemia in 745 HIV-infected study participants (n=34 565 lipid measurements; median follow-up, 7.6 years). The relative impact of SNPs and ART to lipid variation in the study population and their cumulative influence on sustained dyslipidemia at the level of the individual were calculated. SNPs were associated with lipid changes consistent with genome-wide association study estimates. SNPs explained up to 7.6% (non-high-density lipoprotein cholesterol), 6.2% (high-density lipoprotein cholesterol), and 6.8% (triglycerides) of lipid variation; ART explained 3.9% (non-high-density lipoprotein cholesterol), 1.5% (high-density lipoprotein cholesterol), and 6.2% (triglycerides). An individual with the most dyslipidemic antiretroviral and genetic background had an approximately 3- to 5-fold increased risk of sustained dyslipidemia compared with an individual with the least dyslipidemic therapy and genetic background.

CONCLUSIONS

In the HIV-infected population treated with ART, the weight of the contribution of common SNPs and ART to dyslipidemia was similar. When selecting an ART regimen, genetic information should be considered in addition to the dyslipidemic effects of ART agents.

The implications of pharmacogenomics in the treatment of HIV-1-infected patients of African descent

One of the great advances in the treatment of HIV-1 infection was the development of the highly active antiretroviral therapy (HAART). Although this treatment strategy is highly effective in many individuals, interpatient variability of drug response and high incidences of short- and long-term toxicities remain significant problems associated with this treatment. Logically, pharmacogenetic differences among HIV-1-infected individuals are thought to represent important factors contributing to antiretroviral drug response. Studies have identified polymorphisms in drug-metabolizing enzymes, drug transporters, and most recently the human leukocyte antigen locus that appears to have significant effects on the clinical outcomes of antiretroviral therapy. Furthermore, some studies have shown that many of these crucial polymorphisms are more likely or less likely in certain populations. This review investigates the potential role of pharmacogenomics in the management of HIV-1 infection in people of African descent.

Is estimated cardiovascular risk higher in HIV-infected patients than in the general population?

Cardiovascular disease (CVD) is an increasing concern for human immunodeficiency virus (HIV)-infected patients, and risk assessment is recommended in routine HIV care. The absolute cardiovascular risk in an individual is determined by several factors, and various algorithms may be applied. To date, few comparisons of HIV patients with persons of the same age from the general population have been conducted. We hypothesized that the calculated risk of CVD may be increased in HIV patients. The probability for acute coronary events within 10 y (Framingham Risk Score) and the probability for fatal cardiovascular disease (SCORE algorithm) were assessed in 403 consecutive HIV-positive subjects free from overt cardiovascular disease, as well as in 96 age- and gender-matched control subjects drawn from the general population living in the same geographical area. The average 10-y risk for acute coronary events (Framingham Risk Score) was 7.0%+/-5% in HIV subjects and 6.3%+/-5% in the control group (p =0.32). The 10-y estimated risk for cardiovascular mortality (SCORE algorithm) was 1.23%+/-2.3% and 0.83%+/-0.9%, respectively (p =0.01). The main contributor to the increased CVD risk was the high proportion of smokers, but not an increase in cholesterol level. In conclusion, a limited increase in estimated risk of CVD was found in HIV-infected patients compared to the general population. In HIV-infected individuals other factors of less value in the general population and not included in any cardiovascular algorithm might be important. In our patients intervention to modify traditional risk factors should be addressed primarily towards modifying smoking habits.

Serum lipid profiles among patients initiating ritonavir-boosted atazanavir versus efavirenz-based regimens

BACKGROUND

Antiretrovirals used to treat HIV-infected patients have the potential to adversely affect serum lipid profiles and increase the risk of cardiovascular disease which is an emerging concern among HIV-infected patients. Since boosted atazanavir and efavirenz are both considered preferred antiretrovirals a head to head comparison of their effects on serum lipids is needed.

AIM

The primary objective of the study was to compare the effects of atazanavir (boosted and unboosted) and efavirenz based regimens on serum lipid profiles.

STUDY DESIGN

Prospective cohort study nested within three ongoing cohorts of HIV-infected individuals.

STUDY POPULATION AND METHODS

Participants initiating either atazanavir or efavirenz based regimens with documented pre- and post-initiation lipid values. Multivariate linear regression was conducted to estimate adjusted mean differences between treatment groups for high density lipoprotein cholesterol (HDL-c), non-HDL-c, and log total cholesterol (TC) to HDL-c ratio outcomes; log-linear regression models were used to estimate differences in prevalence of low HDL-c and desirable TC.

RESULTS

The final study population was comprised of 380 efavirenz and 281 atazanavir initiators. Both atazanavir and efavirenz users had increases in serum HDL-c and decreases in TC/HDL ratio. In comparison to individuals initiating efavirenz, boosted atazanavir users on average had lower HDL-c (-4.12 mg/dl, p < 0.001) and non HDL-c (-5.75 mg/dl, p < 0.01), but similar declines in TC/HDL ratio.

CONCLUSION

Both efavirenz and atazanavir-based regimens (boosted and unboosted) resulted in similar beneficial declines in the TC/HDL ratio.

Metabolic outcomes in a randomized trial of nucleoside, nonnucleoside and protease inhibitor-sparing regimens for initial HIV treatment

BACKGROUND

The metabolic effects of initial therapy for HIV-1 infection are important determinants of regimen selection.

METHODS

Open-label study in 753 subjects randomized equally to efavirenz or lopinavir/ritonavir(r) plus two nucleoside reverse-transcriptase inhibitor (NRTI) vs. the NRTI-sparing regimen of lopinavir/r plus efavirenz. Zidovudine, stavudine, or tenofovir with lamivudine was selected prior to randomization. Metabolic outcomes through 96 weeks were lipoatrophy, defined as at least 20% loss in extremity fat, and fasting serum lipids.

RESULTS

Lipoatrophy by dual-energy X-ray absorptiometry at week 96 occurred in 32% [95% confidence interval (CI) 25-39%] of subjects in the efavirenz plus two NRTIs arm, 17% (95% CI 12-24) in the lopinavir/r plus two NRTIs arm, and 9% (95% CI 5-14) in the NRTI-sparing arm (P < or = 0.023 for all comparisons). Varying the definition of lipoatrophy (> or =10 to > or =40% fat loss) and correction for baseline risk factors did not affect the significant difference in lipoatrophy between the NRTI-containing regimens. Lipoatrophy was most frequent with stavudine-containing regimens and least frequent with tenofovir-containing regimens (P < 0.001), which were not significantly different from the NRTI-sparing regimen. Total cholesterol increases at week 96 were greatest in the NRTI-sparing arm (median +57 mg/dl) compared with the other two arms (+32-33 mg/dl; P < 0.001). Use of lipid-lowering agents was more common (25 vs. 11-13%) in the NRTI-sparing arm.

CONCLUSION

Lipoatrophy was more frequent with efavirenz than lopinavir/r when combined with stavudine or zidovudine, and less frequent when either drug was combined with tenofovir. Lipoatrophy was least frequent with the NRTI-sparing regimen, but this benefit was offset by greater cholesterol elevations and the need for lipid-lowering agents.

Fatty liver and hyperlipidemia in a cohort of HIV-positive Africans on highly active antiretroviral therapy

AIM

To determine the prevalence of fatty liver and to assess its association with hyperlipidemia and other metabolic risk factors in HIV/AIDS patients on long-term antiretroviral therapy.

METHODS

A prospective cross-sectional study of 113 adults attending an urban outpatient HIV clinic in Lagos, Nigeria. Demographic characteristics were obtained using interviewer administered questionnaires, and serum levels of fasting glucose, total cholesterol, high-density lipoprotein (HDL-C) and low-density lipoprotein cholesterol (LDL-C), and alanine transaminase were determined. Ultrasound scan imaging was used to identify hepatic steatosis.

RESULTS

One hundred thirteen subjects, mean age (SD), 38.7 (9.9) years on highly active antiretroviral therapy (HAART) therapy for 6 to 42 months were evaluated. Sixty-six (58.4%) were female and 47 (41.6) were male. Fifteen (13.3%) had hepatic steatosis. Total cholesterol > 200 mg/dL, LDL-C > 130 mg/dL, and fasting serum triglycerides > 150 mg/dL were seen in 28%, 24% and 35%, respectively. The presence of fatty liver was significantly associated with hepatomegaly (p = .03) and elevated LDL-C (p = .01).

CONCLUSION

The prevalence of hepatic steatosis is lower than reported in Caucasian populations, but strongly associated with hepatomegaly and hyperlipidemia in subjects on long-term HAART. Early recognition of fatty liver and regular screening for lipid are warranted in Africans receiving long-term HAART.

Heart Disease in Patients with HIV/AIDS-An Emerging Clinical Problem

HIV/AIDS (Human immunodeficiency virus/ Acquired immuno deficiency syndrome) is a growing global problem, in terms of its incidence and mortality. Patients with HIV/AIDS are living much longer with HAART (Highly active antiretroviral therapy) therapy so much so that HIV/AIDS has now become a part of the chronic disease burden, like hypertension and diabetes. Patients with HIV/AIDS and symptoms suggestive of cardiac disease represent a diagnostic and therapeutic challenge in clinical practice; Cardiologists are more frequently encountering this problem. An algorithmic, anatomic approach to diagnosis, localizing disease to the endocardium, myocardium and pericardium can be useful. An intimate knowledge of opportunistic infections affecting the heart, effects of HAART therapy and therapy for opportunistic infections on the heart is needed to be able to formulate a differential diagnosis. Effects of HAART therapy, especially protease inhibitors on lipid and glucose metabolism, and their influence on progression to premature vascular disease require consideration. Treatment of cardiac disease, in HIV/AIDS patients can vary from non-HIV patients, based on drug interactions, differences in responsiveness, and other factors; and this area requires further research.