Disorders of lipid metabolism in patients with HIV disease treated with antiretroviral agents: frequency, relationship with administered drugs, and role of hypolipidaemic therapy with bezafibrate

Association of single nucleotide polymorphisms with dyslipidemia in antiretroviral exposed HIV patients in a Ghanaian population: A case-control study

Dyslipidemia is a potential complication of long-term usage of antiretroviral therapy (ART) and also known to be associated with genetic factors. The host genetic variants associated with dyslipidemia in HIV patients on ART in Ghana have not been fully explored. The study constituted a total of 289 HIV-infected patients on stable ART for at least a year. Fasting blood was collected into EDTA tube for lipids measurement. Lipid profiles were used to define dyslipidemia based on the NCEP-ATP III criteria. HIV-infected subjects were categorized into two groups; those with dyslipidemia (cases) (n = 90; 31.1%) and without dyslipidemia (controls)(n = 199; 68.9%). Four candidate single nucleotide polymorphism (SNP) genes (ABCA1-rs2066714, LDLR-rs6511720, APOA5-rs662799 and DSCAML1-rs10892151) were determined. Genotyping was performed on isolated genomic DNA of study participants using PCR followed by a multiplex ligation detection reaction (LDR). The percentage of the population who had the rare homozygote alleles for rs6511720 (T/T), rs2066714 (G/G), rs10892151 (T/T) and rs662799 (G/G) among case subjects were 5.5%, 14.4%, 6.6% and 10.0% whiles 2.0% 9.1%, 6.5% and 4.0% were observed among control subjects. There were statistically significant differences in the genotypic prevalence of APOA5 (p = 0.0357) and LDLR polymorphisms (p = 0.0387) between case and control subjects. Compared to the AA genotype of the APOA5 polymorphisms, individuals with the rare homozygote genotype [aOR = 2.38, 95%CI(1.06-6.54), p = 0.004] were significantly associated with an increased likelihood of developing dyslipidemia after controlling for age, gender, treatment duration, CD4 counts and BMI. Moreover, individuals with the rare homozygous genotype of ABCA1 (G/G) [aOR = 10.7(1.3-88.7), p = 0.0280] and LDLR (rs6511720) G>T [aOR = 61.2(7.6-493.4), p<0.0001) were more likely to have high levels of total cholesterol levels. Our data accentuate the presence of SNPs in four candidate genes and their association with dyslipidemia among HIV patients exposed to ART in the Ghanaian population, especially variants in APOA5-rs662799 and LDLR rs6511720 respectively. These findings provide baseline information that necessitates a pre-symptomatic strategy for monitoring dyslipidemia in ART-treated HIV patients. There is a need for longitudinal studies to validate a comprehensive number of SNPs and their associations with dyslipidemia.

HIV treatment is associated with a two-fold higher probability of raised triglycerides: Pooled Analyses in 21 023 individuals in sub-Saharan Africa

BACKGROUND

Anti-retroviral therapy (ART) regimes for HIV are associated with raised levels of circulating triglycerides (TG) in western populations. However, there are limited data on the impact of ART on cardiometabolic risk in sub-Saharan African (SSA) populations.

METHODS

Pooled analyses of 14 studies comprising 21 023 individuals, on whom relevant cardiometabolic risk factors (including TG), HIV and ART status were assessed between 2003 and 2014, in SSA. The association between ART and raised TG (>2.3 mmol/L) was analysed using regression models.

FINDINGS

Among 10 615 individuals, ART was associated with a two-fold higher probability of raised TG (RR 2.05, 95% CI 1.51-2.77, I2=45.2%). The associations between ART and raised blood pressure, glucose, HbA1c, and other lipids were inconsistent across studies.

INTERPRETATION

Evidence from this study confirms the association of ART with raised TG in SSA populations. Given the possible causal effect of raised TG on cardiovascular disease (CVD), the evidence highlights the need for prospective studies to clarify the impact of long term ART on CVD outcomes in SSA.

A Prospective, Multicentre, Open-Label Single-Arm Exploratory Study to Evaluate Efficacy and Safety of Saroglitazar on Hypertriglyceridemia in HIV Associated Lipodystrophy

OBJECTIVE

This study was designed to explore the efficacy and safety of saroglitazar 4 mg on hypertriglyceridemia in patients with HIV associated lipodystrophy.

METHODS

During this 12-week prospective, multi-centric, open-label, single arm exploratory study, 50 patients were enrolled to receive saroglitazar 4 mg orally once daily in the morning before breakfast. The primary efficacy endpoint was the percent change in triglyceride (TG) levels from baseline to Week 6 and Week 12. The secondary efficacy endpoints were assessment of low-density-lipoprotein (LDL), very-low-density-lipoprotein (VLDL), high-density-lipoprotein (HDL), non-HDL cholesterol, total cholesterol, apo-lipoprotein (Apo) A1, Apo B, and C-peptide and fasting insulin for HOMA beta and HOMA IR. Safety assessment was performed during the study.

RESULTS

Saroglitazar 4 mg significantly decreased the serum TG levels from baseline at Week 6 (percent change: -40.98; 95% CI: -50.82, -31.15) and Week 12 (percent change -45.11; 95% CI: -52.37, -37.86). Reduction in VLDL cholesterol (percent change: -46.33; 95% CI: -52.89, -39.76) and total cholesterol (percent change: 7.37; 95% CI: 1.96, 12.78) was observed at week 12 from baseline. Saroglitazar increased HDL cholesterol (percent change: 34.56, 95% CI: 22.22, 46.90), Apo A1 (percent change: 33.16; 95% CI: 18.69, 47.63) and Apo B (percent change: 10.55, 95% CI: 2.86, 18.25) levels at week 12 from baseline. Saroglitazar treatment led to increase in the C-peptide (percent change: 59.42, 95% CI: 48.78, 70.06), fasting insulin levels (percent change: 47.10; 95% CI: 38.63, 55.57), HOMA of beta cell function for C-peptide (percent change: 71.67; 95% CI: 39.09, 104.26) and HOMA of insulin resistance for C-peptide (percent change: 58.29, 95% CI: 46.74, 69.83) at week 12 from baseline. Saroglitazar treatment was safe and well tolerated in this study.

CONCLUSION

Overall, the observed changes in lipid profile after 12 weeks of saroglitazar treatment were in the direction of improvement in patients with HIV associated lipodystrophy.

TRIAL REGISTRATION

Clinical Trial Registry of India Phase II/CTRI/2010/091/000107.

Echocardiography and carotid intima-media thickness among asymptomatic HIV-infected adolescents in Thailand

OBJECTIVES

To evaluate the carotid intima-media thickness (cIMT) in perinatally HIV-infected adolescents and factors associated with cardiovascular abnormalities.

DESIGNS

A cross-sectional study was conducted in perinatally HIV-infected adolescents who had no known cardiovascular condition and healthy controls.

METHODS

Transthoracic echocardiogram and cIMT measurements were taken by pediatric cardiologists. Serum lipid profiles, high-sensitivity C-reactive protein and N-terminal pro-brain natriuretic peptide were measured.

RESULTS

Hundred HIV-infected and 50 healthy adolescents were enrolled. Echocardiograms revealed overall normal systolic function (median left-ventricular ejection fraction 66 vs. 66%; P = 0.825). The mean overall cIMTs of common carotid arteries and internal carotid arteries were not different between the groups (0.373 vs. 0.371; P = 0.744). Among the HIV-infected adolescents, those who had been receiving protease inhibitor-containing regimens had an increased cIMT (0.364 vs. 0.381 mm; P = 0.009). Hypertriglyceridemia was found in 52% of those who had received protease inhibitors for more than 6 months, but only in 21% of those who had never received protease inhibitors (odds ratio 4.0, 95% confidence interval 1.6-9.7, P = 0.002). Current HIV-RNA, CD4, BMI, sex, cholesterol and low-density lipoprotein-cholesterol were not associated with increased cIMT. Serum high-sensitivity C-reactive protein and N-terminal pro-brain natriuretic peptide were not different between the groups and not associated with cardiac abnormalities.

CONCLUSIONS

Perinatally HIV-infected adolescents had comparable myocardial function and similar cIMT measurements to healthy adolescents. However, hypertriglyceridemia and increased cIMT were found in HIV-infected adolescents receiving protease inhibitor-based regimens. Longer-term follow-up is needed to evaluate HIV-associated cardiovascular disease risk in this population.

Reduced serum paraoxonase 1 (PON1) activity in patients with schizophrenia treated with olanzapine but not quetiapine

BACKGROUND

Second generation antipsychotics (SGAs) are currently the most prescribed drugs in the treatment of schizophrenia. Despite their advantages, which include greater improvement in negative symptoms, cognitive function, prevention of deterioration, quality of life, and fewer extrapyramidal symptoms, the concern regarding metabolic abnormalities which might cause cardiovascular diseases during treatment with SGAs have been rising. Paraoxonase 1 (PON1) is an enzyme mostly located on high-density lipoprotein particles, and has been shown to protect or inhibit lipoprotein oxidation. Growing evidence suggests that PON1 plays a key role in the pathophysiology of atherosclerosis.

METHODS

In the present study, we measured serum PON1 activity and serum levels of total cholesterol (TC), triglyceride, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in patients with schizophrenia, who had been treated with either olanzapine or quetiapine, and in healthy controls. Thirty five patients who had been treated with olanzapine, 29 patients who had been treated with quetiapine, and 32 age, sex, and smoking status-matched healthy control (HC) participants were enrolled. Serum PON1 activity and serum levels of TC, triglyceride, HDL-C, and LDL-C were measured.

RESULTS

Serum PON1 activity in the olanzapine group was significantly lower than that of HC and quetiapine groups. Furthermore, serum levels of TC and LDL-C in the olanzapine group were significantly higher than those of quetiapine and HC groups. Interestingly, there was a positive correlation between PON1 activity and HDL-C levels in the olanzapine group.

CONCLUSION

These findings suggest that serum PON1 activity in patients treated with olanzapine was lower than that of HC and quetiapine groups, and that PON1 may play a role in the metabolic side effects associated with olanzapine treatment. A further study to examine the relationship between serum PON1 activity and cardiovascular and metabolic side effects during treatment with SGAs will be of great interest.

Steady-state pharmacokinetic interactions of darunavir/ritonavir with lipid-lowering agent rosuvastatin

HIV-1 protease inhibitors often cause dyslipidemia, necessitating the use of lipid-lowering agents such as rosuvastatin. However, when given concomitantly, these therapeutic agents often exhibit adverse drug interactions. In this study (phase I open-label trial, n = 12 HIV-1 seronegative participants), the authors assessed the drug interactions between darunavir/ritonavir given in combination with rosuvastatin. Participants were randomized to receive rosuvastatin (10 mg/day) or darunavir/ritonavir (600/100 mg twice daily) alone for 7 days in a crossover design followed by combination therapy for 7 days with intervening 7-day washout periods. Intensive blood sampling for pharmacokinetics and fasting lipids was performed on days 7, 21, and 35. The geometric mean AUC(0-24 h) of rosuvastatin increased from 109 to 161 ng·h/mL (P < .005) and C(max) increased 6.7 to 16.3 ng/mL (P < .001) when coadministered with darunavir/ritonavir. In the presence of darunavir/ritonavir and rosuvastatin, total cholesterol and triglyceride levels increased by 10% (P = .007) and 56% (P = .011), whereas the high-density lipoprotein cholesterol levels decreased by 13% (P = .006) relative to rosuvastatin administration alone. There were no significant adverse events attributable to the coadministration of these drugs. Rosuvastatin levels increase in the presence of darunavir/ritonavir coadministration, whereas the lipid-lowering benefits are blunted. The clinical significance of these changes requires further investigation.

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.

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.

Cardiovascular manifestations in human immunodeficiency virus-infected patients

Human immunodeficiency virus (HIV) is now a pandemic. It afflicts multiple organs, including the cardiovascular system. This occurs by direct invasion as well as opportunistic infections complicating acquired immunodeficiency syndrome. The presence of newer highly active antiretroviral therapy has led to longer survival of patients infected with HIV, but the cardiac abnormalities related to HIV have remained less well characterized. It is now evident that cardiac involvement in patients with acquired immunodeficiency syndrome is relatively common. This includes coronary artery disease, dilated cardiomyopathy, pericardial effusion, pulmonary hypertension, and ill effects of highly active antiretroviral therapy in the form of lipodystrophy, lipoatrophy, and dyslipidemia. In fact, HIV can now be viewed as a potential risk factor for coronary artery disease, and the dilemma facing clinicians is how to quantify this risk. Awareness of accelerated coronary artery disease and dilated cardiomyopathy is critical to implement preventive measures early in the course of HIV. However, better guidelines are still needed on the basis of prospective randomized controlled studies involving large populations. In conclusion, this review describes cardiac abnormalities associated with HIV, including possible molecular mechanisms. The co-morbid sequelae, their presentation, and pharmacologic management are also discussed.

Alterations in lipid transfer to High-Density Lipoprotein (HDL) and activity of paraoxonase-1 in HIV+ patients

HIV+ patients often develop alterations of the plasma lipids that may implicate in development of premature coronary artery disease. High-density lipoprotein (HDL) has an important role in preventing atherogenesis and the aim of this study was to investigate aspects of HDL function in HIV+ patients. HIV+ patients (n = 48) and healthy control subjects (n = 45) of both sexes with similar age were studied. Twenty-five were not being treated with antiretroviral agents, 13 were under reverse transcriptase inhibitor nucleosidic and non-nucleosidic (NRTI+NNRTI) and 10 were under NRTI + protease inhibitors (NRTI+PI) treatment. Paraoxonase 1 (PON1) activity and the transfer of free and esterified cholesterol, tryglicerides and phospholipids from a lipidic nanoemulsion to HDL were analyzed. In comparison with healthy controls, HIV+ patients presented low PON-1 activity and diminished transfer of free cholesterol and tryglicerides. In contrast, phospholipid transfer was increased in those patients, whereas the transfer of cholesteryl esters was unchanged. NRTI+NNRTI increases the transfer of cholesteryl esters and triglycerides but in NRTI+PI there was no difference in respect to non-treated HIV+ patients. HDL from HIV+ patients has smaller antioxidant properties, as shown by lower PON-1 activity, and the transfer of lipids to this lipoprotein fraction is also altered, suggesting that HDL function is defective in those patients.

Regional adipose tissue and lipid and lipoprotein levels in HIV-infected women

BACKGROUND

HIV infection and antiretroviral therapy are associated with dyslipidemia, but the association between regional body fat and lipid levels is not well described.

METHODS

Multivariable linear regression analyzed the association between magnetic resonance imaging-measured regional adipose tissue and fasting lipids in 284 HIV-infected and 129 control women.

RESULTS

Among African Americans, HIV-infected women had higher triglyceride (116 vs. 83 mg/dL; P < 0.001), similar high-density lipoprotein (HDL; 52 vs. 50 mg/dL; P = 0.60), and lower low-density lipoprotein (LDL; 99 vs. 118 mg/dL; P = 0.008) levels than controls. Among whites, HIV-infected women had higher triglyceride (141 vs. 78 mg/dL; P < 0.001), lower HDL (46 vs. 57 mg/dL; P < 0.001), and slightly lower LDL (100 vs. 107 mg/dL; P = 0.059) levels than controls. After adjustment for demographic and lifestyle factors, the highest tertile of visceral adipose tissue (VAT) was associated with higher triglyceride (+85%, 95% confidence interval [CI]: 55 to 121) and lower HDL (-9%, 95% CI: -18 to 0) levels in HIV-infected women; the highest tertile of leg subcutaneous adipose tissue (SAT) was associated with lower triglyceride levels in HIV-infected women (-28%, 95% CI: -41 to -11) and controls (-39%, 95% CI: -5 to -18). After further adjustment for adipose tissue, HIV infection remained associated with higher triglyceride (+40%, 95% CI: 21 to 63) and lower LDL (-17%, 95% CI: -26 to -8) levels, whereas HIV infection remained associated with lower HDL levels (-21%, 95% CI: -29 to -12) in whites but not in African Americans (+8%, 95% CI: -2 to 19).

CONCLUSIONS

HIV-infected white women are more likely to have proatherogenic lipid profiles than HIV-infected African American women. Less leg SAT and more VAT are important factors associated with adverse lipid levels. HIV-infected women may be at particular risk for dyslipidemia because of the risk for HIV-associated lipoatrophy.

HIV infection and the pancreas: risk factors and potential management guidelines

One thousand and eighty-one evaluable HIV-infected patients were assessed for pancreatic abnormalities in a prospective case-control study including the whole follow-up period of each patient (minimum 12 months). The 435 patients (40.2%), who experienced at least one episode of confirmed pancreatic laboratory abnormality had a longer duration of seropositivity, exposure to protease inhibitors, a more frequent immunodeficiency, AIDS, chronic liver and/or biliary disease and hypertriglyceridaemia, while no relation was found with antiretroviral administration, and the duration of type of nucleoside analogues, when compared with the 646 controls. High and prolonged laboratory alterations eventually associated with signs of organ involvement occurred in 166 cases (38.2%), and were related to the administration of didanosine, stavudine, lamivudine, pentamidine, cotrimoxazole or antitubercular/antimycobacterial therapy, cytotoxic chemotherapy, illicit substance or alcohol abuse, opportunistic infections, chronic liver and/or biliary disease, a protease inhibitor-based highly active antiretroviral therapy (HAART) and hypertriglyceridaemia (usually associated with HAART administration). No difference was noticed between the 46 patients with clinical and/or imaging evidence of pancreatic involvement and the 120 asymptomatic subjects. Although recurrences of enzyme alterations involved 69.6% of patients, only in 30.1% of cases did a change of the underlying antiretroviral or antimicrobial therapy become necessary. An acute, uncomplicated pancreatitis occurred in nine of the 46 symptomatic subjects (19.6%). A two to four week gabexate and/or octreotide administration (performed in 79 cases of 166, 47.6%), achieved a significant laboratory, clinical and imaging cure or improvement in 82.3% of cases, with a better success rate of combined (gabexate mesilate plus octreotide) vs. single (gabexate mesilate or ocreotide) therapy. Reduced disease recurrences and a better tolerability of antiretroviral regimens, were also noticed.

Prediction and identification of drug interactions with the human ATP-binding cassette transporter multidrug-resistance associated protein 2 (MRP2; ABCC2)

The chemical space of registered oral drugs was explored for inhibitors of the human multidrug-resistance associated protein 2 (MRP2; ABCC2), using a data set of 191 structurally diverse drugs and drug-like compounds. The data set included a new reference set of 75 compounds, for studies of hepatic drug interactions with transport proteins, CYP enzymes, and compounds associated with liver toxicity. The inhibition of MRP2-mediated transport of estradiol-17beta-D-glucuronide was studied in inverted membrane vesicles from Sf9 cells overexpressing human MRP2. A total of 27 previously unknown MRP2 inhibitors were identified, and the results indicate an overlapping but narrower inhibitor space for MRP2 compared with the two other major ABC efflux transporters P-gp (ABCB1) and BCRP (ABCG2). In addition, 13 compounds were shown to stimulate the transport of estradiol-17beta-D-glucuronide. The experimental results were used to develop a computational model able to discriminate inhibitors from noninhibitors according to their molecular structure, resulting in a predictive power of 86% for the training set and 72% for the test set. The inhibitors were in general larger and more lipophilic and presented a higher aromaticity than the noninhibitors. The developed computational model is applicable in an early stage of the drug discovery process and is proposed as a tool for prediction of MRP2-mediated hepatic drug interactions and toxicity.

Characterization of a novel human immunodeficiency virus type 1 protease inhibitor, A-790742

A-790742 is a potent human immunodeficiency virus type 1 (HIV-1) protease inhibitor, with 50% effective concentrations ranging from 2 to 7 nM against wild-type HIV-1. The activity of this compound is lowered by approximately sevenfold in the presence of 50% human serum. A-790742 maintained potent antiviral activity against lopinavir-resistant variants generated in vitro as well as against a panel of molecular clones containing proteases derived from HIV-1 patient isolates with multiple protease mutations. During in vitro selection, A-790742 selected two primary mutations (V82L and I84V) along with L23I, L33F, K45I, A71V/A, and V77I in the pNL4-3 background and two other mutations (A71V and V82G) accompanied by M46I and L63P in the HIV-1 RF background. HIV-1 pNL4-3 clones with a single V82L or I84V mutation were phenotypically resistant to A-790742 and ritonavir. Taking these results together, A-790742 displays a favorable anti-HIV-1 profile against both the wild type and a large number of mutants resistant to other protease inhibitors. The selection of the uncommon V82L and V82G mutations in protease by A-790742 suggests the potential for an advantageous resistance profile with this protease inhibitor.

The role of C-reactive protein as a marker for cardiovascular risk associated with antiretroviral therapy in HIV-infected patients

C-reactive protein (CRP) has been associated with prognosis of HIV-infection, but its relationship with cardiovascular disease remains unknown. We aimed to evaluate whether CRP may be a marker of cardiovascular risk in HIV-infected patients, and to determine the influence of antiretroviral therapy (ART) on CRP levels. We conducted a cross-sectional study on 245 consecutive HIV-infected patients during a 2-month period. An extensive workup for cardiovascular risk was performed, including determination of CRP levels measured by an ultrasensitive immunoturbidimetric assay (detection limit, 0.003 mg/dl). Ninety-nine (40.4%) patients had serum CRP concentrations above 0.3 mg/dl, considered to represent individuals at high risk for developing cardiovascular complications. In univariate analysis, CRP levels correlated positively with total cholesterol (p=0.01), LDL cholesterol (p=0.001), triglycerides (p=0.04) and Framingham risk score (p=0.006), and negatively with HDL cholesterol (p=0.004). Concentrations of CRP were higher in males (p=0.05) and smokers (p=0.002). No correlation was found between CRP levels and HIV-viral load or CD4 cell counts. In multivariate analysis, independent factors associated with the highest quartile of serum CRP concentrations (0.49 mg/dl) were LDL-cholesterol (p<0.001), HDL-cholesterol (p=0.001), cigarette smoking (p=0.019) and current ART (p=0.021). Our results show that C-reactive protein is associated with traditional cardiovascular risk factors, and may then be a marker for cardiovascular risk linked to HIV infection and ART.

Use of metabolic drugs and fish oil in HIV-positive patients with metabolic complications and associations with dyslipidaemia and treatment targets

BACKGROUND

Highly active antiretroviral therapy (HAART) with protease inhibitors (PI) is successful in suppressing viral replication, but may lead to a range of metabolic abnormalities associated with cardiovascular disease (CVD).

OBJECTIVES

The first objective of the study was to compare baseline demographic and clinical characteristics between PI users and non-PI users referred to a specialized metabolic clinic during 1999-2003. The second objective was to assess the associations of prescription drugs and fish oil with dyslipidaemia and to determine whether or not patients achieved treatment targets during 6 months of treatment.

METHODS

A retrospective analysis was performed using two sets of charts based on standardized forms with entries for personal data, drug treatment and clinical history. Anonymous linkage with the British Columbia HIV/AIDS Drug Treatment Program and the hospital laboratory was performed to gather information about HAART prescriptions and blood work.

RESULTS

In total, 237 patients were included in the study. There were few differences in any demographic or clinical factors between PI users and non-PI users. Compared with controls not taking lipid-lowering drugs or fish oil (n=48), statins appeared to be the only agent that was significantly associated with a reduced total cholesterol concentration (-15.6%; P=0.009). Fibrate treatment was associated with the largest reduction of triglyceride concentration (-37.4%; P=0.012), closely followed by fish oil (n=18;-32%; P=0.027). Six-month treatment success rates ranged between 17 and 43% of patients for total cholesterol (<5.2 mmol/L) and between 15 and 44% of patients for triglycerides (<2.3 mmol/L).

CONCLUSIONS

Despite the apparent lowering of blood lipids with drug and fish oil treatments, a majority of patients in these treatment groups (56.5-83.3%) still had elevated concentrations after 6 months.

Morphological and molecular course of mitochondrial pathology in cultured human cells exposed long-term to Zidovudine

Long-term use of antiretroviral nucleoside reverse transcriptase inhibitors (NRTIs) as therapy for human immunodeficiency virus-1 (HIV-1) infection is limited by mitochondrial toxicity. Here we document mitochondrial pathology during the long-term culture of human HeLa cells in the presence or absence of the NRTI Zidovudine(R) (AZT, 800 muM) for up to 77-passages (p), with samples taken at early (p5-p11), middle (p36 and p37), and late (p70-p77) passages. Samples were analyzed for changes in mitochondrial morphology, mitochondrial (mt)DNA quantity, nuclear and mitochondrial gene expression, and mitochondrial membrane potential. Mitochondria showed abnormal proliferation at p5 and abnormal morphology >/=p36. mtDNA quantity was increased at p5 and p11, and 65% depleted at p71. Hierarchical clustering of nuclear gene expression, examined at p37 by the NCI cDNA microarray in AZT-exposed cells, showed down-regulation of 13 out of 16 lipid-metabolizing genes, and up-regulation of most oxidative phosphorylation (OXPHOS) genes. OXPHOS genes encoded by mtDNA, examined at p5, p36, and p75 using the Mitochondrial Gene Mini Array, revealed up-regulation of genes coding for polypeptides of NADH dehydrogenase, ATP synthase, and cytochrome c oxidase. Mitochondrial membrane potential, monitored by JC1 staining, was elevated at p10 and p32, and essentially completely absent at p71. The data show that during chronic exposure of HeLa cells to AZT, a compensatory response was induced at the earlier passages (p5-p37), and by p71 there was widespread mitochondrial morphological damage, severe mtDNA depletion, and a substantial loss of mitochondrial membrane potential.

Strategies for management and treatment of dyslipidemia in HIV/AIDS

With the improved survival of HIV-infected patients, there are increased concerns about the long-term effects of treatment, including protease inhibitor (PI)-related dyslipidemia. Some 50-70% of patients receiving combination antiretroviral therapy (ART) involving PIs develop lipid abnormalities consisting of elevated levels of total cholesterol, low-density lipoprotein cholesterol and triglycerides that are well-known risk factors for cardiovascular disease. Treatment of HIV dyslipidemia should include lifestyle modifications such as a low-fat diet, increased exercise, reduced alcohol consumption and smoking cessation. In many patients, however, these changes alone will not correct lipid levels. In some patients, changing the PI component of ART to another PI or non-PI and/or lipid-lowering drugs has proven successful. Each approach is associated with advantages and limitations and the need to maintain viral suppression must be balanced with the need to treat abnormal lipid levels.

Alteraciones lipídicas y riesgo cardiovascular asociado a la terapia antirretroviral

Dyslipidemia is common in HIV-infected patients receiving antiretroviral therapy (ART) and it is often associated with the use of specific antiretroviral drugs. The phenotypic profile can include elevated triglycerides or cholesterol alone, or mixed patterns with varying changes in LDL and HDL lipoproteins, which imply different levels of cardiovascular risk. Growing evidence indicates that ART-associated hyperlipidemia accelerates the development of atherosclerosis and coronary heart disease in HIV-infected patients. In recent years, a number of retrospective database reviews and prospective cohort studies have reported a higher incidence of coronary events in patients receiving ART, which seems to be closely related with the presence of dyslipidemia and the duration of exposure to ART. Although the clinical benefit of treating ART-related dyslipidemia remains unproven, most experts recommend a policy of cardiovascular disease prevention and management similar to that used in non-HIV-infected individuals. In addition, the use of antiretrovirals associated with a more favorable lipid profile is considered. Clinical experience with lipid-lowering therapy in HIV-infected patients is still limited, but there is increasing data confirming its efficacy and safety in this setting. Drug interactions should be taken into account when statins are used in patients receiving protease inhibitors.

Identification of potential pharmacological and toxicological targets differentiating structural analogs by a combination of transcriptional profiling and promoter analysis in LS-180 and Caco-2 adenocarcinoma cell lines

Detecting and understanding the potential for off-target pharmacological effects is critical in the optimization of lead compounds in drug discovery programs. Compound-mediated activation of the pregnane X receptor (PXR; NR1I2), a key regulator for drug metabolism genes, is often monitored to avoid potential drug-drug interactions. Two structural analogs, MRL-1 and MRL-2, were determined to be equivalent PXR activators in trans-activation assays. To differentiate these two PXR activators, their transcriptional effects were examined in PXR-sufficient (LS180) and PXR-deficient (Caco-2) adenocarcinoma cell lines. Both compounds regulated drug-management genes (e.g. CYP3A4, CYP2B6, UGT1A1 and ABCB1) in LS180 cells, but not in PXR-deficient Caco-2 cells. The potency of MRL-1 and MRL-2 on PXR activation was again equivalent as revealed by a set of 113 genes that were regulated by four prototypical PXR agonists (rifampicin, ritonavir, troglitazone and dexamethasone) in the LS180 cells. The specificity of the PXR signature genes was supported by the enrichment of putative PXR binding sites uncovered by sequence-based promoter analyses. Interestingly, an additional off-target activity of MRL-2 was suggested where sterol response element binding protein binding sites were found enriched in a subset of PXR signature genes. These genes, involved in cholesterol and fatty acid synthesis, were significantly regulated by ritonavir, chlorpromazine and MRL-2, which were linked to the manifestation of phospholipidosis. The present study demonstrates the utility of our approach in the differentiation and selection of lead compounds for drug development.

The effect of low-dose ritonavir monotherapy on fasting serum lipid concentrations

OBJECTIVES

Ritonavir (RTV) at doses of 400 mg twice a day (bid) or higher adversely affects serum lipids. However, the effect of RTV 100 mg bid on serum lipids is unknown. We conducted a study to evaluate the effect of RTV 100 mg bid on fasting serum lipid profiles in HIV-negative healthy volunteers.

METHODS

Ritonavir 100 mg bid was administered for 14 days to 20 healthy HIV-seronegative adults with normal serum lipids. After a 7-day washout, lopinavir/ritonavir (LPV/RTV) 400/100 mg bid was administered for 14 days. Fasting serum lipid parameters were measured twice at baseline, after 14 days of RTV, and after 14 days of LPV/RTV, and comparisons were made at each time-point for levels of total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, the total/HDL cholesterol ratio and triglycerides.

RESULTS

After 14 days of RTV 100 mg bid, total cholesterol level increased by 10.2% (P<0.001), LDL cholesterol level increased by 16.2% (P<0.001), triglyceride levels increased by 26.5% (P<0.001), HDL cholesterol level decreased by 5.4% (P<0.01) and the total/HDL cholesterol ratio increased by 17.3% (P<0.001). The addition of LPV 400 mg bid to RTV 100 mg bid resulted in no significant further changes in LDL cholesterol or triglyceride level or total/HDL cholesterol ratio, but there were significant increases in both total cholesterol (8.0% increase; P=0.007) and HDL cholesterol levels (6.7% increase; P=0.008).

CONCLUSIONS

Ritonavir dosed at 100 mg bid significantly increased the concentration of total cholesterol, LDL cholesterol, total/HDL cholesterol ratio and triglycerides and reduced HDL cholesterol concentration. The addition of LPV 400 mg bid to RTV 100 mg bid further increased both total and HDL cholesterol levels without affecting the total/HDL ratio.

Hypertriglyceridemia and hypercholesterolemia in human immunodeficiency virus-1-infected children treated with protease inhibitors

BACKGROUND

Adverse effects associated with highly active antiretroviral therapy (HAART), particularly protease inhibitors (PIs), have been identified in adult and pediatric patients. In this study, we monitored, for cholesterol and triglyceride levels, a cohort of HIV-1-infected children receiving a HAART regimen.

METHODS

HIV-infected patients <17 years old belonging to a cohort that has been followed since 1997 were enrolled in the study. Patients were receiving either a three- or four-drug antiretroviral regimen that included two nucleoside reverse transcriptase inhibitors (lamivudine and zidovudine) combined with one or two PIs (ritonavir and/or saquinavir). Cholesterol and triglyceride levels were measured on fasting serum samples drawn at the time of enrollment and every 3 months thereafter. Clinical evaluation was performed on a monthly basis.

RESULTS

Twenty four patients were included. Median age at HIV infection diagnosis was 15 months. Twenty one patients received a four-drug antiretroviral regimen, while three patients received ritonavir plus zidovudine and lamivudine. Median follow-up was 27 months; 62.5% of patients had hypercholesterolemia and 79.2% had hypertriglyceridemia, most typically after 15 months of treatment. None of the patients had physical changes in body fat distribution suggesting lipodystrophy.

CONCLUSIONS

Hyperlipidemia is a frequent complication in HIV-1-infected children undergoing antiretroviral treatment that includes PIs. Additional studies with larger cohorts and a longer follow-up are needed to propose a rationale and alternatives for patients who develop dyslipidemia while receiving PIs.

Recomendaciones de GEAM/SPNS sobre el tratamiento de las alteraciones metabólicas y morfológicas en el paciente con infección por VIH

OBJECTIVE

To provide an update of the metabolic and morphologic alterations in patients infected with HIV with an in-depth analysis of their clinical management and treatment.

METHODS

These recommendations were agreed by consensus by a committee of experts in metabolic alterations and HIV patient care, under the auspices of the Secretariat for the National AIDS Plan. To do this, the latest clinical, epidemiological and physiopathological advances described in studies published in the scientific literature and/or presented in congresses were reviewed.

RESULTS

The most frequent metabolic alterations in HIV patients and in antiretroviral treatment (ART) are dyslipidemia with an atherogenic profile and alterations in carbohydrate metabolism/insulin resistance. A high prevalence of cardiovascular risk factors, especially smoking, has been described. The same criteria for their management as those used in the general population have been employed, with specific nuances. Diet and exercise should be the first therapeutic recommendation. In patients with dyslipidemia who require drug treatment, statins and/or fibrates are indicated. Glitazones have demonstrated efficacy in the treatment of insulin resistance. The approach to anomalous fat distribution continues to be controversial. The main approaches at present are a switch of ART, reparative surgery, psychological support and lifestyle changes. Lactic acidosis is an infrequent but highly serious complication, and the first step is withdrawal of ART. In bone metabolism alterations, prevention and early detection are essential, especially in children and perimenopausal women. Sexual dysfunction is a frequent problem in both men and women; because the causes are highly varied, treatment should be individualized.

CONCLUSIONS

The prevalence of metabolic and morphologic alterations has increased since the introduction of highly active antiretroviral treatment (HAART). Knowledge of the various aspects involved in their diagnosis and treatment is essential for the appropriate care of patients with HIV infection.

Tolerability and safety of HIV protease inhibitors in adults

Antiretroviral drugs are associated with both short-term and long-term adverse events. Like other HIV drugs, protease inhibitors (PIs) may affect metabolic processes influencing body shape and body tissue composition, appearance, bone integrity, and cardiovascular status. However, numerous confounding variables including age, cigarette smoking, body mass index (BMI), duration of HIV infection, degree of immunodeficiency, concomitant antiretroviral agents, extent of previous treatment, and duration of treatment all blur the relationship between PI use and adverse events. Recent data suggest that the early PIs appear to have greater effects on such surrogate markers of disease risk as insulin resistance and cholesterol and triglyceride levels than the recently developed PIs. These data also suggest that evaluation of PIs as a class should be reconsidered and that it is probably not appropriate to extrapolate safety data obtained from individuals treated with first-generation agents in the era of potent combination antiretroviral therapy to those treated with recently developed PIs. Because PIs remain a critical component of successful antiretroviral therapy, evaluation of potential long-term complications with prolonged PI use is essential, as is delineation of the significant differences in safety profiles among individual PIs.

Lipids, metabolic syndrome, and risk factors for future cardiovascular disease among HIV-infected patients

The availability of potent combination antiretroviral therapy has changed the long-term prognosis for people living with HIV/AIDS. There is increasing concern, however, about the effect of HIV therapy on lipid disorders and subsequent development of coronary artery disease. Virtually all classes of antiretroviral drugs have been associated with some aspect of atherogenic changes in the lipid profiles. This article reviews the current literature on HIV-associated dyslipidemias and the metabolic syndrome, their potential effect on future coronary heart disease, and reviews strategies for management.

The effects of antipsychotic therapy on serum lipids: a comprehensive review

OBJECTIVES

The purpose of this paper is to review the literature since 1970 documenting the effects of antipsychotic agents on serum lipids, including a discussion of possible mechanisms for the observed phenomena, the clinical significance and recommendations for monitoring hyperlipidemia during antipsychotic therapy.

RESULTS

High-potency conventional antipsychotics (e.g., haloperidol) and the atypical antipsychotics, ziprasidone, risperidone and aripiprazole, appear to be associated with lower risk of hyperlipidemia. Low-potency conventional antipsychotics (e.g., chlorpormazine, thioridazine) and the atypical antipsychotics, quetiapine, olanzapine and clozapine, are associated with higher risk of hyperlipidemia. Possible hypotheses for lipid dysregulation include weight gain, dietary changes and the development of glucose intolerance.

CONCLUSIONS

Given the multiple cardiovascular risk factors seen in patients with schizophrenia, great care must be exercised in the choice of antipsychotic therapy to minimize the medical burden of additional risk imposed by hyperlipidemia. It is recommended that a lipid panel be obtained at baseline in all patients with schizophrenia, annually thereafter for patients on agents associated with lower risk of hyperlipidemia and quarterly in patients on agents associated with higher risk for hyperlipidemia. All patients with persistent dyslipidemia should be referred for lipid-lowering therapy or switched to a less lipid-offending antipsychotic agent.

Management of Dyslipidaemia in HIV-Infected Patients Receiving Antiretroviral Therapy

Dyslipidaemia associated with the treatment of HIV infection, particularly with the use of protease inhibitors (PIs), can raise cholesterol and triglyceride (TG) levels to the thresholds indicated for intervention. Recent evidence from epidemiological studies has shown that there are correlations between antiretroviral drug use and increased risks for, and incidences of, cardiovascular disease, including myocardial infarction and coronary heart disease. The primary goals of dyslipidaemia therapy for HIV patients are reductions of both low-density lipoprotein cholesterol (LDL-C) and markedly elevated TG levels. Dietary strategies and exercise programs may be tried, although these have shown inconsistent results. The two options for drug therapy are switching anti-retroviral agents and using lipid-lowering drugs. Each approach is associated with advantages and limitations, and the need to maintain viral suppression must be balanced with the need to treat abnormal lipid levels. Most drug switches replace the PI component with drugs from another antiretroviral class. Selection of drug therapy for lipid lowering depends on the type of dyslipidaemia predominating and the potential for drug interactions. The use of the statins pravastatin and atorvastatin is recommended for the treatment of patients with elevated LDL-C levels and gemfibrozil or fenofibrate for patients with elevated TG concentrations. Development of new PIs with more favourable effects on the lipid profile should be of benefit.

Efavirenz Versus Nevirapine in Current Clinical Practice: A Prospective, Open-Label Observational Study

An open-label, observational, prospective 18-month survey was conducted to compare the efficacy and tolerability of the 2 available nonnucleoside reverse transcriptase inhibitors (NNRTIs) in all possible indications of current clinical practice. A broad range of clinical and laboratory variables accounting for drug efficacy and tolerability (with special emphasis on metabolic and hepatic toxicity) were measured in 287 evaluable patients treated with efavirenz, compared with 258 subjects taking nevirapine for 18 months. A separate efficacy analysis was performed in 154 antiretroviral-naive subjects, 298 patients experienced with 2-7 prior anti-HIV lines who abandoned protease inhibitors (PIs), and 103 subjects entering a salvage regimen containing at least 4 drugs, including PIs. Antiretroviral-naive patients experienced greater efavirenz activity at 3-12 months (maximum HIV RNA drop =-2.4 log(10) copies/mL), associated with a significantly higher rate of complete viral suppression, while immunologic results proved significant only after 6-9 months. When assessing experienced patients and those on rescue regimens, a similar and progressively blunted laboratory response was achieved, on the ground of a worse baseline virologic and immunologic profile, and duration of prior anti-HIV therapy. Both first-month (4.2 and 4.3% for efavirenz and nevirapine, respectively) and overall discontinuation rates (11.5 and 12%, respectively) proved similar, but a profound difference emerged as to the different spectrum of untoward events: central nervous system (CNS) disturbances, persisting metabolic abnormalities, and possibly gynecomastia and laboratory pancreatic abnormalities for efavirenz vs. immediate allergy and increased hepatotoxicity (regardless of chronic infection with hepatitis B or C virus and methadone use) for nevirapine. A limited virologic and immunologic advantage of efavirenz was observed in the first 12-month assessment of antiretroviral-naive patients, whereas all other examined situations did not disclose relevant efficacy differences between efavirenz and nevirapine throughout the 18-month comparison. Although the short- and long-term toxicity and withdrawal rates of the 2 drugs were comparable, the different pathways prompting allergic, metabolic, liver, and CNS disturbances observed with NNRTIs deserve careful investigation, to prevent toxicity of these relevant antiretroviral compounds.

Ritonavir exhibits anti-atherogenic properties on vascular smooth muscle cells

OBJECTIVES

HIV protease inhibitors (PI) such as ritonavir have dramatically decreased HIV-related morbidity and mortality. However they exhibit significant side-effects such as hyperlipidemia, hyperglycemia with or without lipodystrophy, which may increase patients' risk for atherosclerosis. Direct effects of PI on the vascular wall have not been investigated. Platelet-derived growth factor (PDGF) is a major contributor to atherogenesis.

DESIGN

In the present study the effects of ritonavir on PDGF-BB-induced responses of vascular smooth muscle cells (VSMCs) were evaluated.

METHODS

PDGF-induced proliferation of VSMCs was measured by BrdU-incorporation, and chemotaxis was assessed by utilizing modified Boyden chambers. Cytotoxicity and apoptosis were quantified using LDH-release- and apoptosis-kits. Immunoprecipitation and Western blot analyses were performed to evaluate betaPDGF receptor (betaPDGFR) expression and phosphorylation, and to monitor intracellular signaling.

RESULTS

Pretreatment of VSMCs with ritonavir resulted in a significant concentration-dependent inhibition of PDGF-BB-induced cellular responses. At a therapeutic concentration (10 microg/ml), ritonavir significantly reduced PDGF-induced DNA synthesis and chemotaxis by 46.8 +/- 5.5% and 37.2 +/- 3.3%, respectively (P < 0.05 each). In addition it significantly inhibited PDGF-dependent downstream signaling, such as Erk activation. These inhibitory effects were not due to cytotoxicity or apoptosis. Instead, ritonavir inhibited the ligand-induced tyrosine phosphorylation of the betaPDGFR, whereas it did not alter betaPDGFR expression.

CONCLUSIONS

Ritonavir has direct effects on VSMCs at clinically relevant concentrations in vitro, as it inhibits betaPDGFR activation and PDGF-dependent proliferation and migration of VSMCs. Although ritonavir may increase the risk of vascular disease by its metabolic side effects, it may exhibit anti-atherogenic properties on the cellular level.

Indinavir alters sterol and fatty acid homeostatic mechanisms in primary rat hepatocytes by increasing levels of activated sterol regulatory element-binding proteins and decreasing cholesterol 7α-hydroxylase mRNA levels

Human immunodeficiency virus protease inhibitors induce hyperlipidemia in many patients treated with these drugs. We examined the effects of indinavir on cholesterol and bile acid homeostatic mechanisms in a primary rat hepatocyte (PRH) culture model. In PRH, indinavir up-regulated (2.5-fold) 3-hydroxy-3-methylglutaryl-Coenzyme A reductase mRNA levels 24hr after drug addition. In these same experiments, cholesterol 7alpha-hydroxylase (CYP7A1) mRNA levels, the rate-limiting enzyme in bile acid biosynthesis, was decreased up to 10-fold. Fatty acid synthase mRNA levels were up-regulated more than 3-fold under these conditions. Indinavir did not alter CYP7A1 transcriptional activity, but decreased CYP7A1 mRNA half-life in PRH from 1.5hr to less than 0.5hr. Sterol regulatory element-binding protein-1 (SREBP-1) mature form was increased approximately 6-fold by this drug. Indinavir-induced mRNA changes and SREBP-1 mature protein levels were significantly abated by the addition of cholesterol, solubilized in beta-cyclodextrin, to culture medium. Indinavir markedly decreased endogenous cholesterol esterification and increased cholesterol in intracellular membranes in primary hepatocytes. Indinavir gavaged into intact mice also markedly increased SREBP-1 and SREBP-2 (mature forms) in hepatic nuclei. CYP7A1 mRNA was also decreased approximately 52% in indinavir-treated animals. We propose that indinavir disrupts cellular cholesterol homeostasis by increasing SREBP's and decreasing CYP7A1 mRNA.

HIV infection and advanced age emerging epidemiological, clinical, and management issues

While the mean age of HIV/AIDS patients at first diagnosis is progressively rising, no updated epidemiological estimates, controlled clinical data, and randomized therapeutic trials, are available regarding clinical and laboratory response to antiretroviral therapy, safety of anti-HIV compounds and their associations, potential drug-drug interactions, short- and long-term toxicity, consequences on underlying disorders, or interactions with concomitant pharmacological regimens, in the elderly. The life expectancy of HIV-infected persons treated with highly active antiretroviral therapy (HAART) now approximates that of general population matched for age, while also AIDS definition itself has lost most of its epidemiological and clinical significance, thanks to the immunoreconstitution resulting from the large-scale use of potent HAART regimens. The increased survival of HIV-infected patients, the late recognition of other subjects with missed or delayed diagnosis are responsible for a further expected rise of mean age of HIV-infected individuals, so that the patient population aged 60-70 years or more is expected to increase in coming years. Unfortunately, the majority of therapeutic trials involving antiretroviral therapy, as well as antimicrobial chemoprophylaxis for AIDS-related opportunistic complications, have advanced age and/or concurrent end-organ disorders among main exclusion criteria, or the design of these studies does not allow to extrapolate data regarding older patients, compared with younger ones. The very limited data presently available seem to demonstrate that HAART has a virological efficacy in the elderly comparable with that of younger adults, but immunological recovery is often slower and blunted, although several studies clearly demonstrated that thymic function is preserved until late adult age. When facing an HIV-infected patient with advanced age, health care givers have to pay careful attention to eventual end-organ disorders, all possible pharmacological interactions, overlapping toxicity due to concurrent drug administration. All these issues may significantly interfere with HAART activity, patient's adherence to prescribed medications, and frequency and severity of untoward effects. The guidelines of antiretroviral therapy and those of treatment and prophylaxis of AIDS-related diseases deserve appropriate updates, paralleling the increasing mean age of HIV-infected population. Moreover, epidemiological figures need an increased focus on older age, while clinical trials specifically targeting on the elderly population are mandatory to have reliable data on all aspects of HAART administration in advanced age.

HIV disease and advanced age: an increasing therapeutic challenge

The mean age of patients at both first HIV detection and AIDS diagnosis is progressively rising over time. However, reliable epidemiological estimates, clinical data or controlled therapeutic and outcome figures are lacking for elderly patients, especially with regard to laboratory and clinical response to antiretroviral therapy, treatment tolerability, drug-drug interactions, short- and long-term toxicity, and interactions with underlying illnesses and concurrent pharmacological treatment. In fact, the large majority of randomised, controlled trials evaluating and comparing new antiretroviral drugs or anti-HIV therapeutic strategies, as well as antimicrobial treatment or chemoprophylaxis of HIV-related complications, either excluded patients with advanced age and/or concurrent disorders or did not offer substudies or detailed data analysis focusing on older patients compared with younger ones. The life expectancy of HIV-infected persons receiving highly active antiretroviral therapy (HAART) is now extended (approaching that of the general population), so that the definition of AIDS has lost its epidemiological and clinical significance thanks to the immune reconstitution resulting from potent antiretroviral therapy. However, an ever-increasing number of individuals aged > or =50 years with HIV infection is expected in the coming years, as a result of both increased survival of patients with treated disease and delayed recognition of individuals with occult HIV disease. The limited data available about combined antiretroviral therapy in the elderly seem to show an overlapping virological success rate but a slower and blunted immune recovery compared with younger patients. Thymic output, however, seems somewhat preserved even in adulthood and may contribute to the reconstitution of most of the quantitative and functional T cell abnormalities caused by HIV disease. More attention must be paid to underlying end-organ disorders, as well as expected pharmacological interactions and combined drug toxicity that may interfere with HAART efficacy and patients' compliance with recommended regimens and could lead to increased adverse effects. The available guidelines for antiretroviral treatment and therapy and prophylaxis of AIDS-related illnesses should be regularly updated and should include problems related to HIV disease in an aging population. Specific trials or substudies focusing on older people are warranted to obtain controlled data on all issues of antiretroviral therapy in the elderly, including time and mode of initiation, and modification and salvage HAART regimens. Antiretroviral drug dosage adjustment to take into account underlying pathological conditions or other pharmacological treatments is another emerging issue.

Evaluation and management of dyslipidemia in patients with HIV infection

OBJECTIVE

Persons with HIV infection develop metabolic abnormalities related to their antiretroviral therapy and HIV infection itself. The objective of this study was to summarize the emerging evidence for the incidence, etiology, health risks, and treatment of dyslipidemias in HIV disease.

DESIGN

Systematic review of original research with quantitative synthesis.

MAIN RESULTS

Dyslipidemia is common in persons with HIV infection on highly active antiretroviral therapy (HAART), but methodologic differences between studies preclude precise estimates of prevalence and incidence. The typical pattern includes elevated total cholesterol, low-density lipoprotein cholesterol, and triglycerides, which may be markedly elevated. The dyslipidemia may be associated with lipodystrophy, insulin resistance, and, rarely, frank diabetes mellitus. Exposure to protease inhibitors (PIs) is associated with this entire range of metabolic abnormalities. PI-naïve patients on nucleoside reverse transcriptase inhibitors (NRTIs) may develop lipodystrophy, insulin resistance, hypercholesterolemia, and possibly modest elevations in triglycerides but not severe hypertriglyceridemia, which appears to be linked to PIs alone. Most studies have not found an association between CD4 lymphocyte count or HIV viral load and lipid abnormalities. The pathogenesis is incompletely understood and appears to be multifactorial. There are insufficient data to definitively support an increased coronary heart disease risk in patients with HIV-related dyslipidemia. However, some of the same metabolic abnormalities remain firmly established risk factors in other populations. Patients on HAART with severe hypertriglyceridemia may develop pancreatitis or other manifestations of the chylomicronemia syndrome. Some of the metabolic derangements (particularly hypertriglyceridemia) may improve upon replacing a PI with a non-nucleoside reverse transcriptase inhibitor. The limited experience suggests that fibrates, pravastatin, and atorvastatin can safely treat lipid abnormalities in HIV-infected patients.

CONCLUSIONS

Patients with HIV infection on HAART should be screened for lipid disorders, given their incidence, potential for morbidity, and possible long-term cardiovascular risk. Treatment decisions are complex and must include assessments of cardiac risk, HIV infection status, reversibility of the dyslipidemia, and the effectiveness and toxicities of lipid-lowering medications. The multiple potential drug interactions with antiretroviral or other HIV-related medications should be considered in lipid-lowering drug selection and monitoring.

Atazanavir: a novel HIV-1 protease inhibitor

The introduction of HIV-1 protease inhibitors in 1995 ushered in the era of highly active antiretroviral therapy. For the first time, inhibition of two key enzymes responsible for HIV replication, reverse transcriptase and protease, was possible. The combination of two nucleoside reverse transcriptase inhibitors with a single protease inhibitor proved highly effective at reducing viral burden. In resource-rich countries where such combination therapy is readily available, dramatic reductions in HIV-related morbidity and mortality have been seen. However, long-term use of highly active antiretroviral therapy has led to several issues, including development of drug resistance and metabolic complications. Atazanavir (formerly BMS-232632), a novel azapeptide protease inhibitor, is a potent protease inhibitor that is not associated with significant dyslipidaemia as seen with other protease inhibitors. In this review, the current standard approach to the treatment of HIV in the US will be discussed as background to understand the potential utility of this new antiretroviral agent.

Human immunodeficiency virus genotype and hypertriglyceridemia

Many HIV patients develop a progressive syndrome of abnormal body fat distribution accompanied by hypertriglyceridemia. Antiretroviral agents are thought to be etiologic in the syndrome, often termed "highly active antiretroviral therapy (HAART)-associated lipodystrophy." In the course of clinical HIV genotype testing, we observed that our HIV patients with hypertriglyceridemia had viral genotypes that were more highly mutated than those of our therapy-matched control patients. Hypertriglyceridemia was statistically associated with predicted resistance for three nucleoside reverse transcriptase inhibitors: zidovudine, abacavir, and stavudine. Statistical analysis of 51 patients in retrospect revealed a strong association of mutations at reverse transcriptase codons M41 and T215 with hypertriglyceridemia (chi-square (chi(2)) = 8.375, P=.0038; and chi(2)=7.445, P=.0064, respectively). This was in contrast to silent mutations, which occurred at equivalent rates in retroviral genotypes of patients with and without hypertriglyceridemia. The findings imply that the HIV genotype itself may be a significant etiologic factor in antiretroviral-associated lipodystrophy.