Differentiating hyperlipidaemia associated with antiretroviral therapy

Metabolic Disorders in HIV-Infected Adolescents Receiving Protease Inhibitors

Protease inhibitor (PI) may cause abnormal glucose metabolism, abnormal lipid metabolism, and metabolic syndrome in HIV-infected adults but less well studied in Asian adolescents. This cross-sectional study evaluated anthropometric factors, oral glucose tolerance test, and lipid profiles of perinatally HIV-infected Thai adolescents who had received PI-based antiretroviral therapy for at least 6 months. Eighty adolescents were enrolled [median (IQR) age 16.7 (14.6–18.0) years, 42 males]. Metabolic syndrome, prediabetes, and type 2 diabetes mellitus (T2DM) were found in 8 (10%), 17 (22.1%), and 3 (3.8%) adolescents, respectively. Dyslipidemia was found in 56 (70%) adolescents, with hypertriglyceridemia being the most common type. In multivariate analysis, presence of lipohypertrophy (OR: 25.7, 95% CI: 3.2–202.8; p = 0.002) and longer duration of PI use (OR: 1.04, 95% CI: 1.00–1.08; p = 0.023) were associated with metabolic syndrome. Obesity (OR: 7.71, 95% CI: 1.36–43.7; p = 0.021), presence of lipohypertrophy (OR: 62.9, 95% CI: 4.97–795.6; p = 0.001), and exposure to stavudine for ≥6 months (OR: 8.18, 95% CI: 1.37–48.7; p = 0.021) were associated with prediabetes/T2DM, while exposure to tenofovir for ≥6 months reduced the risk (OR: 0.17, 95% CI: 0.04–0.78; p = 0.022). Metabolic disorders were commonly found in adolescents receiving PI. Careful monitoring and early intervention to modify cardiovascular risk should be systematically implemented in this population particularly those with exposure to stavudine.

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.

The relationships of ABCB1 3435C>T and CYP2B6 516G>T with high-density lipoprotein cholesterol in HIV-infected patients receiving Efavirenz

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are associated with a favorable increase in high-density lipoprotein cholesterol (HDL-c) level. Isolated studies have found a direct correlation between efavirenz (EFV) exposure and HDL-c level changes. Here we explore the impact that drug disposition variants associated with EFV exposure have on changes in HDL-c level. Seventy-six patients on first-line EFV-based regimens were genotyped for CYP2B6 516G>T and ABCB1 3435C>T. There was a 37% increase (+0.32 mmol/l, P < 0.001) in mean HDL-c level over 48 weeks, and this was univariately associated with gender (male +0.26 mmol/l, female +0.55 mmol/l; P = 0.03), ABCB1 3435C>T (CC +0.26 mmol/l, CT +0.16 mmol/l, TT +0.54 mmol/l; P(ANOVA) = 0.003) and CYP2B6 516 G>T (GG +0.27 mmol/l, GT +0.29 mmol/l, TT +0.72 mmol/l; P(ANOVA) = 0.08). There was a significant association between the cumulative number of predictive genotypes (CYP2B6 516TT or ABCB1 3435TT) and mean HDL-c level change: (group 0 +0.20 mmol/l, group 1 +0.47 mmol/l, group 2 +1.00 mmol/l; P(ANOVA) < 0.0001). These findings need to be validated in independent cohorts.

Safety and Efficacy of Extended-Release Niacin for the Treatment of Dyslipidaemia in Patients with HIV Infection: Aids Clinical Trials Group Study A5148

Background

Dyslipidaemia is very common in patients with HIV infection, but current therapies are often suboptimal. Since niacin may cause insulin resistance and hepatotoxicity, it has generally been avoided in this setting.

Methods

Non-diabetic male subjects ( n=33) who had well-controlled HIV infection on antiretroviral therapy, fasting triglycerides ≥2.26 mmol/l and non-high density lipoprotein cholesterol (non-HDL-C) ≥4.66 mmol/l received escalating doses of extended-release niacin (ERN) up to 2,000 mg nightly for up to 44 weeks.

Results

Fourteen subjects (42%) had pre-diabetes at entry. Twenty-three subjects (70%) received the maximum dose, eight (24%) received 1,500 mg. Niacin was well-tolerated. Only four subjects (12%) discontinued study treatment. There were small increases in fasting glycaemia and insulin resistance estimated by the homeostasis model assessment, but insulin resistance measures from the 2-h oral glucose tolerance test only transiently worsened. No subject developed persistent fasting hyperglycaemia; one had persistently elevated 2-h glucose >11.1 mmol/l. There were no significant changes in serum transaminases or uric acid. At week 48, the median change in fasting lipid levels in mmol/l (interquartile range) were: total cholesterol -0.21 (-1.35, -0.05), HDL-C +0.013 (-0.03,+0.28), non-HDL-C -0.49 (-1.37, +0.08) and triglycerides -1.73 (-3.68, -0.72). Favourable changes in large HDL and large very low density lipoprotein particle concentration were observed by nuclear magnetic resonance spectroscopy.

Conclusions

ERN in doses up to 2,000 mg daily was safe, well-tolerated and efficacious in HIV-infected subjects with atherogenic dyslipidaemia. Increases in glycaemia and insulin resistance tended to be transient.

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.

Antiretroviral therapy in HIV-positive men is associated with increased apolipoprotein CIII in triglyceride-rich lipoproteins

OBJECTIVES

Dyslipidaemia has become a common problem in HIV disease, especially in patients on current antiretroviral therapy. However, the pathogenic mechanisms involved are not well understood or documented using conventional lipid measurements.

METHODS

Using a cross-sectional design, the prevalence of abnormal standard lipid measurements and novel biomarkers for abnormal lipid metabolism was determined in 271 HIV-positive men from two HIV clinics in Atlanta, GA, USA.

RESULTS

A total of 147 men were treated with protease inhibitors (PIs) for >3 months (54%), 84 were treated with nonnucleoside reverse transcriptase inhibitors (NNRTIs) for >3 months (31%) and 40 had not received antiretroviral therapy in the past 3 months (15%). Patients being treated with a PI had higher total cholesterol and triglyceride (TG) levels than patients on no therapy (P<0.05 for each). Patients in the NNRTI group had higher TG, lower high-density lipoprotein (HDL) levels, and higher low-density lipoprotein (LDL) levels than patients on no therapy (P<0.05 for each). Patients treated with either PIs or NNRTIs were more likely to have higher apolipoprotein CIII (apoCIII) levels (P<0.05 for each) than patients on no therapy. Elevated TG was associated with disproportionably elevated apoCIII levels in both treatment groups.

CONCLUSIONS

In this cross-sectional study of HIV-infected men, either PI or NNRTI therapy elevated levels of TG and apoCIII. Higher concentrations of apoCIII in apoB-containing lipoproteins [very low-density lipoproteins (VLDLs), intermediate density lipoprotein (IDL) and LDLs] have been predictive of an increased incidence of coronary events in clinical trials and more rapid progression of coronary lesions measured by angiography. These findings, on a background of an older population with additional risk factors of smoking and diabetes, portend future atherosclerotic events in these patients.

The Nurse Practitioner’s Role in Managing Dyslipidemia and Other Cardiovascular Risk Factors in HIV-Infected Patients: Impact of Antiretroviral Therapy

The beneficial effects of antiretroviral therapy (ART) for the treatment of HIV disease have been accompanied by metabolic changes associated with an increased risk of cardiovascular disease. These changes, which include dyslipidemia, change in body fat distribution, and insulin resistance, resemble the symptoms of metabolic syndrome. Protease inhibitors, nucleoside analogue reverse transcriptase inhibitors, and nonnucleoside reverse transcriptase inhibitors have all been associated with dyslipidemia to varying degrees. In addition, patients on ART show an increased risk of myocardial infarction and other cardiovascular events. According to the recommendations of the National Cholesterol Education Program and the Adult AIDS Clinical Trial Group, health care providers should assess cardiovascular risk before starting ART and then continue to monitor lipid levels. Treatment of ART-associated dyslipidemia should follow the following sequence: therapeutic lifestyle changes, lipid-lowering drug therapy, and finally, modifying ART if necessary. By providing education, support, and follow-up care, nurse practitioners can help to implement these steps.

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.

High frequency of Fredrickson's phenotypes IV and IIb in Brazilians infected by human immunodeficiency virus

Background

Human immunodeficiency virus (HIV) infection is very prevalent in Brazil. HIV therapy has been recently associated with coronary heart disease (CHD). Dyslipidemia is a major risk factor for CHD that is frequently described in HIV positive patients, but very few studies have been conducted in Brazilian patients evaluating their lipid profiles.

Methods

In the present work, we evaluated the frequency and severity of dyslipidemia in 257 Brazilian HIV positive patients. Two hundred and thirty-eight (93%) were submitted to antiretroviral therapy (224 treated with protease inhibitors plus nucleoside reverse transcriptase inhibitors, 14 treated only with the latter, 12 naive and 7 had no records of treatment).

The average time on drug treatment with antiretroviral therapy was 20 months. None of the patients was under lipid lowering drugs. Cholesterol, triglyceride, phospholipid and free fatty acids were determined by enzymatic colorimetric methods. Lipoprotein profile was estimated by the Friedewald formula and Fredrickson's phenotyping was obtained by serum electrophoresis on agarose. Apolipoprotein B and AI and lipoprotein "a" were measured by nephelometry.

Results

The Fredrickson phenotypes were: type IIb (51%), IV (41%), IIa (7%). In addition one patient was type III and another type V. Thirty-three percent of all HIV+ patients presented serum cholesterol levels ≥ 200 mg/dL, 61% LDL-cholesterol ≥ 100 mg/dL, 65% HDL-cholesterol below 40 mg/dL, 46% triglycerides ≥ 150 mg/dL and 10% have all these parameters above the limits. Eighty-six percent of patients had cholesterol/HDL-cholesterol ratio ≥ 3.5, 22% increased lipoprotein "a", 79% increased free fatty acids and 9% increased phospholipids. The treatment with protease inhibitors plus nucleoside reverse transcriptase inhibitors increased the levels of cholesterol and triglycerides in these patients when compared with naïve patients. The HDL-cholesterol (p = 0.01) and apolipoprotein A1 (p = 0.02) levels were inversely correlated with the time of protease inhibitor therapy while total cholesterol levels had a trend to correlate with antiretroviral therapy (p = 0.09).

Conclusion

The highly varied and prevalent types of dyslipidemia found in Brazilian HIV positive patients on antiretroviral therapies indicate the urgent need for their early diagnosis, the identification of the risk factors for CHD and, when needed, the prompt intervention on their lifestyle and/or with drug treatment.

Safety of lopinavir/ritonavir for the treatment of HIV-infection

Kaletra, a fixed-dose co-formulation of lopinavir/ritonavir, was the first boosted protease inhibitor developed for the treatment of HIV-infection. In September 2000, the US FDA granted Kaletra fast-track approval as data showed a higher efficacy in the treatment of HIV-infection than standard protease inhibitors of that time. Although potency was of major concern in the early years of highly active antiretroviral therapy (HAART), presently, with the perspective of HIV-infection becoming a chronic but well controllable disease, other issues begin to draw increased attention in the long-term management of HIV-infected patients. Among general health issues such as cardiovascular disease, metabolic disorders or hepatitis co-infection, the long-term toxicity and safety of HAART is an important concern when choosing antiretroviral drugs for each individual patient. In this review, the authors report on the safety of lopinavir/ritonavir in the treatment of HIV-infected patients, and focus on special patient groups and relevant safety issues.

Traitement antirétroviral et risque cardio-vasculaire

Current antiretroviral therapy protocols enable long-term survival of HIV-infected patients, decreasing the risk of infectious complications. Three classes of anti-HIV treatments are available. With longer survival, unusual cardiovascular complications related to iatrogenic biological anomalies (dyslipidemia and impaired glucose tolerance) have appeared among this young population which is exposed to usual risk factors of atherosclerosis. Antiretroviral therapies are suspected to cause these complications, inducing maturity-onset diabetes in 4 to 20% of patients, impaired glucose tolerance in 15 to 60%, hypertriglyceridemia in 15 to 74% depending on the survey, and hypercholesterolemia in 20 to 60%, especially in case of associated lipodystrophia. A lipid battery including total cholesterol, HDL, and triglycerides, and 12-h fasting blood glucose should be obtained before initiating antiretroviral therapy. Any anomalous finding should be followed carefully with regular surveillance every 3 to 6 months and search for other causes of secondary dyslipidemia. In the event of casual and persisting elevation of LDL-cholesterol levels, a statin treatment can be introduced. For secondary prevention, irrespective of the context, recommendations currently merge with the consensus applying to the general population. These patients require careful surveillance of cardiovascular risk factors and a specific care in addition to treatment of their immunodeficiency.

Risk of Metabolic Abnormalities in Patients Infected with HIV Receiving Antiretroviral Therapy that Contains Lopinavir‐Ritonavir

The evolution of fasting glucose, triglyceride, and total and high-density lipoprotein (HDL) cholesterol level and the factors associated with development of clinically significant abnormalities in these metabolic parameters at 6 months were assessed in 353 consecutive human immunodeficiency virus (HIV)-infected patients who were receiving antiretroviral therapy containing lopinavir-ritonavir. Although glucose and HDL cholesterol levels did not change, triglyceride and total cholesterol levels significantly increased (P<.0001 for each), as did the proportion of patients with a triglyceride level of >400 mg/dL and a total cholesterol level of >240 mg/dL (P=.002). A baseline triglyceride level of >400 mg/dL and a baseline total cholesterol level of >240 mg/dL were identified as independent factors predicting clinically significant hypertriglyceridemia and hypercholesterolemia, respectively, at 6 months. These findings may have clinical implications when the therapeutic option of lopinavir-ritonavir is considered.

Riesgo vascular en pacientes con infección crónica por el VIH-1: controversias con implicaciones terapéuticas, clínicas y pronósticas

Atherosclerosis increases cardiovascular risk and the possibility of developing acute myocardial infarction (AMI) or stroke. Patients infected with human immunodeficiency virus (HIV) often present morphological and metabolic alterations (hypercholesterolemia, hypertriglyceridemia, insulin resistance, diabetes) that can increase vascular risk. The frequent coexistence of classic risk factors (atherogenic diet, smoking, physical inactivity, cocaine abuse), the progressive increase in mean age of HIV-1 infected patients, and the polymedication they receive make it difficult to estimate the direct effect that new therapies may have on cardiovascular risk. Retrospective clinical studies with diverse designs in large cohorts offer contradictory results for cardiovascular risk in the HIV-infected population. Longer observational periods are needed and the effect of other classic risk factors needs to be controlled, in order to establish the possible detrimental effect the new therapies may have on cardiovascular risk in this population.

[Adverse effects of antiretroviral therapy. Aspects of pathogenesis]

Highly active antiretroviral therapy has resulted in remarkable reduction of morbidity and mortality of HIV infection. With increasing duration of therapy metabolic alterations such as hyperlipidemia, diabetes mellitus type 2 and lipodystrophy are encountered which considerably reduced quality of life for the patients. These adverse events are most likely due to protease inhibitors and nucleoside analogues with synergistic effects. The pathogenesis is related to metabolic alterations of the adipocytes with cellular insulin resistance and enhanced apoptosis of these cells caused by adipocytic cytokines such as adiponectin, leptin, TNF-alpha and interleukin 2. Switch of therapy regimens with elimination of the most suspicious substances and certain protease inhibitors can lead to improvement of deranged metabolism. Also symptomatic therapy is possible to cope with hyperlipidemia and diabetes, although no effective treatment is available to reverse already existing lipodystrophy. Our knowledge about the pathogenesis of these alterations might lead to new concepts and causal therapy in the future.