Dose-dependent action of atorvastatin in type IIB hyperlipidemia: preferential and progressive reduction of atherogenic apoB-containing lipoprotein subclasses (VLDL-2, IDL, small dense LDL) and stimulation of cellular cholesterol efflux

Remnant cholesterol traits and risk of stroke: A multivariable Mendelian randomization study

Observational epidemiological studies have reported a relationship between remnant cholesterol and stroke. However, the results are inconclusive, and causality remains unclear due to confounding or reverse causality. Our objective in this study was to investigate the causal relevance of remnant cholesterol and the risk of stroke and its subtypes using the Mendelian randomization (MR) approach. Genome-wide association studies (GWASs) including 115,082 European individuals (UK Biobank) were used to identify instruments for remnant cholesterol, including intermediate-density lipoprotein (IDL) cholesterol and very-low-density lipoprotein (VLDL) cholesterol. Summary-level data for total stroke, intracerebral hemorrhage, subarachnoid hemorrhage, ischemic stroke (IS), and IS subtypes were obtained from GWAS meta-analyses conducted by the MEGASTROKE consortium. Univariable and multivariable MR analyses were performed. The GWAS identified multiple single-nucleotide polymorphisms after clumping for remnant cholesterol (n = 52), IDL cholesterol (n = 62), and VLDL cholesterol (n = 67). Assessed individually using MR, remnant cholesterol (weighted median: odds ratio [OR] 1.32 per 1-SD higher trait; 95% CI: 1.04-1.67; P = 0.024) had effect estimates consistent with a higher risk of LAS-IS, driven by IDL cholesterol (OR 1.32; 95% CI: 1.04-1.68; P = 0.022). In multivariable MR, IDL cholesterol (OR 1.46; 95% CI: 1.10-1.93; P = 0.009) retained a robust effect on LAS-IS after controlling for VLDL cholesterol and high-density lipoprotein cholesterol. The MR analysis did not indicate causal associations between remnant cholesterol and other stroke subtypes. This study suggests that remnant cholesterol is causally associated with the risk of LAS-IS driven by IDL cholesterol.

Hypercholesterolemia-Induced HDL Dysfunction Can Be Reversed: The Impact of Diet and Statin Treatment in a Preclinical Animal Model

High-density lipoproteins (HDL) undergo adverse remodeling and loss of function in the presence of comorbidities. We assessed the potential of lipid-lowering approaches (diet and rosuvastatin) to rescue hypercholesterolemia-induced HDL dysfunction. Hypercholesterolemia was induced in 32 pigs for 10 days. Then, they randomly received one of the 30-day interventions: (I) hypercholesterolemic (HC) diet; (II) HC diet + rosuvastatin; (III) normocholesterolemic (NC) diet; (IV) NC diet + rosuvastatin. We determined cholesterol efflux capacity (CEC), antioxidant potential, HDL particle number, HDL apolipoprotein content, LDL oxidation, and lipid levels. Hypercholesterolemia time-dependently impaired HDL function (−62% CEC, −11% antioxidant index (AOI); p < 0.01), increased HDL particles numbers 2.8-fold (p < 0.0001), reduced HDL-bound APOM (−23%; p < 0.0001), and increased LDL oxidation 1.7-fold (p < 0.0001). These parameters remained unchanged in animals on HC diet alone up to day 40, while AOI deteriorated up to day 25 (−30%). The switch to NC diet reversed HDL dysfunction, restored apolipoprotein M content and particle numbers, and normalized cholesterol levels at day 40. Rosuvastatin improved HDL, AOI, and apolipoprotein M content. Apolipoprotein A-I and apolipoprotein C-III remained unchanged. Lowering LDL-C levels with a low-fat diet rescues HDL CEC and antioxidant potential, while the addition of rosuvastatin enhances HDL antioxidant capacity in a pig model of hypercholesterolemia. Both strategies restore HDL-bound apolipoprotein M content.

Small dense low-density lipoprotein particles: clinically relevant?

PURPOSE OF REVIEW

Levels of small, dense low-density lipoprotein (LDL) (sdLDL) particles determined by several analytic procedures have been associated with risk of atherosclerotic cardiovascular disease (ASCVD). This review focuses on the clinical significance of sdLDL measurement.

RECENT FINDINGS

Results of multiple prospective studies have supported earlier evidence that higher levels of sdLDL are significantly associated with greater ASCVD risk, in many cases independent of other lipid and ASCVD risk factors as well as levels of larger LDL particles. A number of properties of sdLDL vs. larger LDL, including reduced LDL receptor affinity and prolonged plasma residence time as well as greater oxidative susceptibility and affinity for arterial proteoglycans, are consistent with their heightened atherogenic potential. Nevertheless, determination of the extent to which sdLDL can preferentially impact ASCVD risk compared with other apoprotein B-containing lipoproteins has been confounded by their metabolic interrelationships and statistical collinearity, as well as differences in analytic procedures and definitions of sdLDL.

SUMMARY

A growing body of data points to sdLDL concentration as a significant determinant of ASCVD risk. Although future studies should be aimed at determining the clinical benefit of reducing sdLDL levels, there is sufficient evidence to warrant consideration of sdLDL measurement in assessing and managing risk of cardiovascular disease.

VIDEO ABSTRACT

https://www.dropbox.com/s/lioohr2ead7yx2p/zoom_0.mp4?dl=0.

Small dense low-density lipoprotein-lowering agents

Metabolic disorders, including obesity, diabetes, and hyperlipidemia, as well as cardiovascular diseases (CVD), particularly atherosclerosis, are still leading causes of death worldwide. Plasma levels of low-density lipoprotein (LDL) are currently being considered as a critical risk factor for the diseases mentioned above, especially atherosclerosis. Because of the heterogeneous nature of LDL, many studies have already been conducted on its subclasses, especially small dense LDL (sdLDL). According to available evidence, sdLDL levels can be considered as an ideal alternative to LDL levels for monitoring CVD and early diagnosis of atherosclerosis. Recently, several researchers have focused on factors that are able to decrease sdLDL levels and improve health quality. Therefore, the purpose of this study is to describe the production process of sdLDL particles and review the effects of pharmaceutical and dietary agents as well as lifestyle on sdLDL plasma levels. In brief, their mechanisms of action are discussed. Apparently, cholesterol and LDL-lowering compounds are also effective in the reduction of sdLDL levels. In addition, improving lipid profile, especially the reduction of triglyceride levels, appropriate regimen, and lifestyle can decrease sdLDL levels. Therefore, all the aforementioned parameters should be taken into consideration simultaneously in sdLDL levels reducing strategies.

Association of CETP Gene Variants with Atherogenic Dyslipidemia Among Thai Patients Treated with Statin

Objective

Patients treated with statins for dyslipidemia may still have a residual risk of atherosclerotic cardiovascular disease (ASCVD). To determine whether genetic variants in the cholesteryl ester transport protein (CETP), rs3764261 (C>A), rs708272 (G>A), and rs12149545 (G>A) affect ASCVD risk, we studied the association of these variants with dyslipidemia in statin-treated patients.

Patients and Methods

We included 299 adult Thai patients treated with a statin (95 men and 204 women). Genotyping was performed by conducting a TaqMan real-time polymerase chain reaction-based analysis. We used logistic regression models adjusted for potential confounders of age, body mass index, blood pressure, insulin resistance, and statin dosage to analyze the association between CETP variants and atherogenic lipoprotein patterns.

Results

CETP polymorphisms of rs3764261 and rs708272, but not rs12149545, were significantly associated with high-density lipoprotein cholesterol (HDL-C), apoA-I, triglycerides, very low-density lipoprotein (VLDL)-C, and large LDL (LDL1-C) levels as well as mean LDL particle size (all p < 0.020). However, no significant difference was observed in total cholesterol, LDL-C, or apoB levels by CETP variants. Regardless of sex, the combination of rs3764261 (CC genotype) and rs708272 (GG or GA genotypes) showed a stronger association with atherogenic dyslipidemia, including features of decreased HDL-C, elevated triglycerides, and LDL subclass pattern B (odds ratio [OR] = 2.99, 95% confidence interval [CI]: 1.78–5.02) compared with the single variant rs3764261 (OR = 2.11, 95% CI: 1.27–3.50) or rs708272 (OR = 2.12, 95% CI: 1.29–3.49).

Conclusion

The polymorphisms of CETP rs3764261 (CC genotype) and rs708272 (GG and GA genotypes) may have a higher susceptibility to atherogenic dyslipidemia. Testing for CETP rs3764261 and rs708272 may serve as a surrogate marker for lipid management in statin-treated patients, which may help individualize treatment for reducing the residual risk of ASCVD.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY GUIDELINES FOR MANAGEMENT OF DYSLIPIDEMIA AND PREVENTION OF CARDIOVASCULAR DISEASE

OBJECTIVE

The development of these guidelines is mandated by the American Association of Clinical Endocrinologists (AACE) Board of Directors and American College of Endocrinology (ACE) Board of Trustees and adheres with published AACE protocols for the standardized production of clinical practice guidelines (CPGs).

METHODS

Recommendations are based on diligent reviews of the clinical evidence with transparent incorporation of subjective factors, according to established AACE/ACE guidelines for guidelines protocols.

RESULTS

The Executive Summary of this document contains 87 recommendations of which 45 are Grade A (51.7%), 18 are Grade B (20.7%), 15 are Grade C (17.2%), and 9 (10.3%) are Grade D. These detailed, evidence-based recommendations allow for nuance-based clinical decision-making that addresses multiple aspects of real-world medical care. The evidence base presented in the subsequent Appendix provides relevant supporting information for Executive Summary Recommendations. This update contains 695 citations of which 203 (29.2 %) are EL 1 (strong), 137 (19.7%) are EL 2 (intermediate), 119 (17.1%) are EL 3 (weak), and 236 (34.0%) are EL 4 (no clinical evidence).

CONCLUSION

This CPG is a practical tool that endocrinologists, other health care professionals, health-related organizations, and regulatory bodies can use to reduce the risks and consequences of dyslipidemia. It provides guidance on screening, risk assessment, and treatment recommendations for a range of individuals with various lipid disorders. The recommendations emphasize the importance of treating low-density lipoprotein cholesterol (LDL-C) in some individuals to lower goals than previously endorsed and support the measurement of coronary artery calcium scores and inflammatory markers to help stratify risk. Special consideration is given to individuals with diabetes, familial hypercholesterolemia, women, and youth with dyslipidemia. Both clinical and cost-effectiveness data are provided to support treatment decisions.

ABBREVIATIONS

4S = Scandinavian Simvastatin Survival Study A1C = glycated hemoglobin AACE = American Association of Clinical Endocrinologists AAP = American Academy of Pediatrics ACC = American College of Cardiology ACE = American College of Endocrinology ACS = acute coronary syndrome ADMIT = Arterial Disease Multiple Intervention Trial ADVENT = Assessment of Diabetes Control and Evaluation of the Efficacy of Niaspan Trial AFCAPS/TexCAPS = Air Force/Texas Coronary Atherosclerosis Prevention Study AHA = American Heart Association AHRQ = Agency for Healthcare Research and Quality AIM-HIGH = Atherothrombosis Intervention in Metabolic Syndrome With Low HDL/High Triglycerides trial ASCVD = atherosclerotic cardiovascular disease ATP = Adult Treatment Panel apo = apolipoprotein BEL = best evidence level BIP = Bezafibrate Infarction Prevention trial BMI = body mass index CABG = coronary artery bypass graft CAC = coronary artery calcification CARDS = Collaborative Atorvastatin Diabetes Study CDP = Coronary Drug Project trial CI = confidence interval CIMT = carotid intimal media thickness CKD = chronic kidney disease CPG(s) = clinical practice guideline(s) CRP = C-reactive protein CTT = Cholesterol Treatment Trialists CV = cerebrovascular CVA = cerebrovascular accident EL = evidence level FH = familial hypercholesterolemia FIELD = Secondary Endpoints from the Fenofibrate Intervention and Event Lowering in Diabetes trial FOURIER = Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects With Elevated Risk trial HATS = HDL-Atherosclerosis Treatment Study HDL-C = high-density lipoprotein cholesterol HeFH = heterozygous familial hypercholesterolemia HHS = Helsinki Heart Study HIV = human immunodeficiency virus HoFH = homozygous familial hypercholesterolemia HPS = Heart Protection Study HPS2-THRIVE = Treatment of HDL to Reduce the Incidence of Vascular Events trial HR = hazard ratio HRT = hormone replacement therapy hsCRP = high-sensitivity CRP IMPROVE-IT = Improved Reduction of Outcomes: Vytorin Efficacy International Trial IRAS = Insulin Resistance Atherosclerosis Study JUPITER = Justification for the Use of Statins in Primary Prevention: An Intervention Trial Evaluating Rosuvastatin LDL-C = low-density lipoprotein cholesterol Lp-PLA2 = lipoprotein-associated phospholipase A2 MACE = major cardiovascular events MESA = Multi-Ethnic Study of Atherosclerosis MetS = metabolic syndrome MI = myocardial infarction MRFIT = Multiple Risk Factor Intervention Trial NCEP = National Cholesterol Education Program NHLBI = National Heart, Lung, and Blood Institute PCOS = polycystic ovary syndrome PCSK9 = proprotein convertase subtilisin/kexin type 9 Post CABG = Post Coronary Artery Bypass Graft trial PROSPER = Prospective Study of Pravastatin in the Elderly at Risk trial QALY = quality-adjusted life-year ROC = receiver-operator characteristic SOC = standard of care SHARP = Study of Heart and Renal Protection T1DM = type 1 diabetes mellitus T2DM = type 2 diabetes mellitus TG = triglycerides TNT = Treating to New Targets trial VA-HIT = Veterans Affairs High-Density Lipoprotein Cholesterol Intervention Trial VLDL-C = very low-density lipoprotein cholesterol WHI = Women's Health Initiative.

Glycosylation of human plasma lipoproteins reveals a high level of diversity, which directly impacts their functional properties

AIMS

Human plasma lipoproteins are known to contain various glycan structures whose composition and functional importance are starting to be recognized. We assessed N-glycosylation of human plasma HDL and LDL and the role of their glycomes in cellular cholesterol metabolism.

METHODS

N-glycomic profiles of native and neuraminidase-treated HDL and LDL were obtained using HILIC-UHPLC-FLD. Relative abundance of the individual chromatographic peaks was quantitatively expressed as a percentage of total integrated area and N-glycan structures present in each peak were elucidated by MALDI-TOF MS. The capacity of HDL to mediate cellular efflux of cholesterol and the capacity of LDL to induce cellular accumulation of cholesteryl esters were evaluated in THP-1 cells.

RESULTS

HILIC-UHPLC-FLD analysis of HDL and LDL N-glycans released by PNGase F resulted in 22 and 18 distinct chromatographic peaks, respectively. The majority of N-glycans present in HDL (~70%) and LDL (~60%) were sialylated with one or two sialic acid residues. The most abundant N-glycan structure in both HDL and LDL was a complex type biantennary N-glycan with one sialic acid (A2G2S1). Relative abundances of several N-glycan structures were dramatically altered by the neuraminidase treatment, which selectively removed sialic acid residues. Native HDL displayed significantly greater efficacy in removing cellular cholesterol from THP-1 cells as compared to desialylated HDL (p < 0.05). Cellular accumulation of cholesteryl esters in THP-1 cells was significantly higher after incubations with desialylated LDL particles as compared to native LDL (p < 0.05).

CONCLUSIONS

N-glycome of human plasma lipoproteins reveals a high level of diversity, which directly impacts functional properties of the lipoproteins.

Effects of Increasing Exercise Intensity and Dose on Multiple Measures of HDL (High-Density Lipoprotein) Function

OBJECTIVE

Measures of HDL (high-density lipoprotein) function are associated with cardiovascular disease. However, the effects of regular exercise on these measures is largely unknown. Thus, we examined the effects of different doses of exercise on 3 measures of HDL function in 2 randomized clinical exercise trials.

APPROACH AND RESULTS

Radiolabeled and boron dipyrromethene difluoride-labeled cholesterol efflux capacity and HDL-apoA-I (apolipoprotein A-I) exchange were assessed before and after 6 months of exercise training in 2 cohorts: STRRIDE-PD (Studies of Targeted Risk Reduction Interventions through Defined Exercise, in individuals with Pre-Diabetes; n=106) and E-MECHANIC (Examination of Mechanisms of exercise-induced weight compensation; n=90). STRRIDE-PD participants completed 1 of 4 exercise interventions differing in amount and intensity. E-MECHANIC participants were randomized into 1 of 2 exercise groups (8 or 20 kcal/kg per week) or a control group. HDL-C significantly increased in the high-amount/vigorous-intensity group (3±5 mg/dL; P=0.02) of STRRIDE-PD, whereas no changes in HDL-C were observed in E-MECHANIC. In STRRIDE-PD, global radiolabeled efflux capacity significantly increased 6.2% (SEM, 0.06) in the high-amount/vigorous-intensity group compared with all other STRRIDE-PD groups (range, -2.4 to -8.4%; SEM, 0.06). In E-MECHANIC, non-ABCA1 (ATP-binding cassette transporter A1) radiolabeled efflux significantly increased 5.7% (95% CI, 1.2-10.2%) in the 20 kcal/kg per week group compared with the control group, with no change in the 8 kcal/kg per week group (2.6%; 95% CI, -1.4 to 6.7%). This association was attenuated when adjusting for change in HDL-C. Exercise training did not affect BODIPY-labeled cholesterol efflux capacity or HDL-apoA-I exchange in either study.

CONCLUSIONS

Regular prolonged vigorous exercise improves some but not all measures of HDL function. Future studies are warranted to investigate whether the effects of exercise on cardiovascular disease are mediated in part by improving HDL function.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifiers: NCT00962962 and NCT01264406.

Structure-function relationships in reconstituted HDL: Focus on antioxidative activity and cholesterol efflux capacity

AIMS

High-density lipoprotein (HDL) contains multiple components that endow it with biological activities. Apolipoprotein A-I (apoA-I) and surface phospholipids contribute to these activities; however, structure-function relationships in HDL particles remain incompletely characterised.

METHODS

Reconstituted HDLs (rHDLs) were prepared from apoA-I and soy phosphatidylcholine (PC) at molar ratios of 1:50, 1:100 and 1:150. Oxidative status of apoA-I was varied using controlled oxidation of Met112 residue. HDL-mediated inactivation of PC hydroperoxides (PCOOH) derived from mildly pre-oxidized low-density lipoprotein (LDL) was evaluated by HPLC with chemiluminescent detection in HDL+LDL mixtures and re-isolated LDL. Cellular cholesterol efflux was characterised in RAW264.7 macrophages.

RESULTS

rHDL inactivated LDL-derived PCOOH in a dose- and time-dependent manner. The capacity of rHDL to both inactivate PCOOH and efflux cholesterol via ATP-binding cassette transporter A1 (ABCA1) increased with increasing apoA-I/PC ratio proportionally to the apoA-I content in rHDL. Controlled oxidation of apoA-I Met112 gradually decreased PCOOH-inactivating capacity of rHDL but increased ABCA1-mediated cellular cholesterol efflux.

CONCLUSIONS

Increasing apoA-I content in rHDL enhanced its antioxidative activity towards oxidized LDL and cholesterol efflux capacity via ABCA1, whereas oxidation of apoA-I Met112 decreased the antioxidative activity but increased the cholesterol efflux. These findings provide important considerations in the design of future HDL therapeutics. Non-standard abbreviations and acronyms: AAPH, 2,2'-azobis(-amidinopropane) dihydrochloride; ABCA1, ATP-binding cassette transporter A1; apoA-I, apolipoprotein A-I; BHT, butylated hydroxytoluene; CV, cardiovascular; EDTA, ethylenediaminetetraacetic acid; HDL-C, high-density lipoprotein cholesterol; LOOH, lipid hydroperoxides; Met(O), methionine sulfoxide; Met112, methionine 112 residue; Met86, methionine 86 residue; oxLDL, oxidized low-density lipoprotein; PBS, phosphate-buffered saline; PC, phosphatidylcholine; PL, phospholipid; PCOOH, phosphatidylcholine hydroperoxide; PLOOH, phospholipid hydroperoxide.

High-Density Lipoprotein Subfractions and Cholesterol Efflux Capacity Are Not Affected by Supervised Exercise but Are Associated with Baseline Interleukin-6 in Patients with Peripheral Artery Disease

OBJECTIVE

To quantify the association between high-density lipoprotein (HDL) subfractions, efflux capacity, and inflammatory markers at baseline and the effect of supervised exercise on these HDL parameters in patients with peripheral artery disease (PAD).

METHODS

The study to improve leg circulation (SILC) was a randomized trial of supervised treadmill exercise, leg resistance training, or control in individuals with PAD. In a post hoc cross-sectional analysis, we quantified the associations between baseline HDL subfraction concentrations (HDL2 and HDL3), HDL-C efflux capacity, and inflammatory markers [C-reactive protein (CRP) and interleukin-6 (IL-6)]. We then examined the effect of supervised exercise on changes in these lipoprotein parameters and inflammatory markers in 88 patients from SILC.

RESULTS

Baseline HDL-C efflux capacity was associated with baseline concentrations of HDL2 (β = 0.008, p = 0.0106), HDL3 (β = 0.013, p < 0.0001), and IL-6 (β = -0.019, p = 0.03). Baseline HDL3 concentration was inversely associated with IL-6 concentration (β = -0.99, p = 0.008). Compared to control, changes in HDL2, HDL3, normalized HDL-C efflux capacity, CRP, or IL-6 were not significantly different at 6 months following the structured exercise intervention.

CONCLUSION

HDL efflux and HDL3 were inversely associated with IL-6 in PAD patients. Structured exercise was not associated with changes in HDL subfractions, HDL-C efflux capacity, CRP, and IL-6 in PAD patients. Our preliminary findings support the theory that inflammation may adversely affect HDL structure and function; however, further studies are needed to evaluate these findings.

Meta-analysis of genome-wide association studies of HDL cholesterol response to statins

BACKGROUND

In addition to lowering low density lipoprotein cholesterol (LDL-C), statin therapy also raises high density lipoprotein cholesterol (HDL-C) levels. Inter-individual variation in HDL-C response to statins may be partially explained by genetic variation.

METHODS AND RESULTS

We performed a meta-analysis of genome-wide association studies (GWAS) to identify variants with an effect on statin-induced high density lipoprotein cholesterol (HDL-C) changes. The 123 most promising signals with p<1×10-4 from the 16 769 statin-treated participants in the first analysis stage were followed up in an independent group of 10 951 statin-treated individuals, providing a total sample size of 27 720 individuals. The only associations of genome-wide significance (p<5×10-8) were between minor alleles at the CETP locus and greater HDL-C response to statin treatment.

CONCLUSIONS

Based on results from this study that included a relatively large sample size, we suggest that CETP may be the only detectable locus with common genetic variants that influence HDL-C response to statins substantially in individuals of European descent. Although CETP is known to be associated with HDL-C, we provide evidence that this pharmacogenetic effect is independent of its association with baseline HDL-C levels.

Poor glycemic control in type 2 diabetes enhances functional and compositional alterations of small, dense HDL3c

High-density lipoprotein (HDL) possesses multiple biological activities; small, dense HDL3c particles displaying distinct lipidomic composition exert potent antiatherogenic activities which can be compromised in dyslipidemic, hyperglycemic insulin-resistant states. However, it remains indeterminate (i) whether such functional HDL deficiency is related to altered HDL composition, and (ii) whether it originates from atherogenic dyslipidemia, dysglycemia, or both. In the present work we analyzed compositional characteristics of HDL subpopulations and functional activity of small, dense HDL3c particles in treatment-naïve patients with well-controlled (n=10) and poorly-controlled (n=8) type 2 diabetes (T2D) and in normolipidemic age- and sex-matched controls (n=11). Our data reveal that patients with both well- and poorly-controlled T2D displayed dyslipidemia and low-grade inflammation associated with altered HDL composition. Such compositional alterations in small, dense HDL subfractions were specifically correlated with plasma HbA1c levels. Further analysis using a lipidomic approach revealed that small, dense HDL3c particles from T2D patients with poor glycemic control displayed additional modifications of their chemical composition. In parallel, antioxidative activity of HDL3c towards oxidation of low-density lipoprotein was diminished. These findings indicate that defective functionality of small, dense HDL particles in patients with T2D is not only affected by the presence of atherogenic dyslipidemia, but also by the level of glycemic control, reflecting compositional alterations of HDL.

Modulating cholesterol efflux capacity to improve cardiovascular disease

PURPOSE OF REVIEW

Low HDL-cholesterol (HDL-C) levels are predictive of incident atherosclerotic cardiovascular disease events. However, the use of medication to raise HDL-C levels has not consistently shown clinical benefit. As a result, studies have shifted toward HDL function, specifically cholesterol efflux, which has been inversely associated with prevalent subclinical atherosclerosis as well as subsequent atherosclerotic cardiovascular disease events. The purpose of this review is to summarize the effects of current medications and interventions on cholesterol efflux capacity.

RECENT FINDINGS

Medications for cardiovascular health, including statins, fibrates, niacin, and novel therapeutics, are reviewed for their effect on cholesterol efflux. Differences in population studied and assay used are addressed appropriately. Lifestyle interventions, including diet and exercise, are also included in the review.

SUMMARY

The modification of cholesterol efflux capacity (CEC) by current medications and interventions has been investigated in both large randomized control trials and smaller observational cohorts. This review serves to compile the results of these studies and evaluate CEC modulation by commonly used medications. Altering CEC could be a novel therapeutic approach to improving cardiovascular risk profiles.

Dysfunctional high-density lipoproteins in coronary heart disease: implications for diagnostics and therapy

Low plasma levels of high-density lipoprotein (HDL) cholesterol are associated with increased risks of coronary heart disease. HDL mediates cholesterol efflux from macrophages for reverse transport to the liver and elicits many anti-inflammatory and anti-oxidative activities which are potentially anti-atherogenic. Nevertheless, HDL has not been successfully targeted by drugs for prevention or treatment of cardiovascular diseases. One potential reason is the targeting of HDL cholesterol which does not capture the structural and functional complexity of HDL particles. Hundreds of lipid species and dozens of proteins as well as several microRNAs have been identified in HDL. This physiological heterogeneity is further increased in pathologic conditions due to additional quantitative and qualitative molecular changes of HDL components which have been associated with both loss of physiological function and gain of pathologic dysfunction. This structural and functional complexity of HDL has prevented clear assignments of molecules to the functions of normal HDL and dysfunctions of pathologic HDL. Systematic analyses of structure-function relationships of HDL-associated molecules and their modifications are needed to test the different components and functions of HDL for their relative contribution in the pathogenesis of atherosclerosis. The derived biomarkers and targets may eventually help to exploit HDL for treatment and diagnostics of cardiovascular diseases.

Impaired Cholesterol Efflux Capacity of High-Density Lipoprotein Isolated From Interstitial Fluid in Type 2 Diabetes Mellitus-Brief Report

Supplemental Digital Content is available in the text.

Objective—

Patients with type 2 diabetes mellitus (T2D) have an increased risk of cardiovascular disease, the mechanism of which is incompletely understood. Their high-density lipoprotein (HDL) particles in plasma have been reported to have impaired cholesterol efflux capacity. However, the efflux capacity of HDL from interstitial fluid (IF), the starting point for reverse cholesterol transport, has not been studied. We here investigated the cholesterol efflux capacity of HDL from IF and plasma from T2D patients and healthy controls.

Approach and Results—

HDL was isolated from IF and peripheral plasma from 35 T2D patients and 35 age- and sex-matched healthy controls. Cholesterol efflux to HDL was determined in vitro, normalized for HDL cholesterol, using cholesterol-loaded macrophages. Efflux capacity of plasma HDL was 10% lower in T2D patients than in healthy controls, in line with previous observations. This difference was much more pronounced for HDL from IF, where efflux capacity was reduced by 28% in T2D. Somewhat surprisingly, the efflux capacity of HDL from IF was lower than that of plasma HDL, by 15% and 32% in controls and T2D patients, respectively.

Conclusion—

These data demonstrate that (1) HDL from IF has a lower cholesterol efflux capacity than plasma HDL and (2) the efflux capacity of HDL from IF is severely impaired in T2D when compared with controls. Because IF comprises the compartment where reverse cholesterol transport is initiated, the marked reduction in cholesterol efflux capacity of IF-HDL from T2D patients may play an important role for their increased risk to develop atherosclerosis.

D25V apolipoprotein C-III variant causes dominant hereditary systemic amyloidosis and confers cardiovascular protective lipoprotein profile

Apolipoprotein C-III deficiency provides cardiovascular protection, but apolipoprotein C-III is not known to be associated with human amyloidosis. Here we report a form of amyloidosis characterized by renal insufficiency caused by a new apolipoprotein C-III variant, D25V. Despite their uremic state, the D25V-carriers exhibit low triglyceride (TG) and apolipoprotein C-III levels, and low very-low-density lipoprotein (VLDL)/high high-density lipoprotein (HDL) profile. Amyloid fibrils comprise the D25V-variant only, showing that wild-type apolipoprotein C-III does not contribute to amyloid deposition in vivo. The mutation profoundly impacts helical structure stability of D25V-variant, which is remarkably fibrillogenic under physiological conditions in vitro producing typical amyloid fibrils in its lipid-free form. D25V apolipoprotein C-III is a new human amyloidogenic protein and the first conferring cardioprotection even in the unfavourable context of renal failure, extending the evidence for an important cardiovascular protective role of apolipoprotein C-III deficiency. Thus, fibrate therapy, which reduces hepatic APOC3 transcription, may delay amyloid deposition in affected patients.

Structural Insights into High Density Lipoprotein: Old Models and New Facts

The physiological link between circulating high density lipoprotein (HDL) levels and cardiovascular disease is well-documented, albeit its intricacies are not well-understood. An improved appreciation of HDL function and overall role in vascular health and disease requires at its foundation a better understanding of the lipoprotein's molecular structure, its formation, and its process of maturation through interactions with various plasma enzymes and cell receptors that intervene along the pathway of reverse cholesterol transport. This review focuses on summarizing recent developments in the field of lipid free apoA-I and HDL structure, with emphasis on new insights revealed by newly published nascent and spherical HDL models constructed by combining low resolution structures obtained from small angle neutron scattering (SANS) with contrast variation and geometrical constraints derived from hydrogen-deuterium exchange (HDX), crosslinking mass spectrometry, electron microscopy, Förster resonance energy transfer, and electron spin resonance. Recently published low resolution structures of nascent and spherical HDL obtained from SANS with contrast variation and isotopic labeling of apolipoprotein A-I (apoA-I) will be critically reviewed and discussed in terms of how they accommodate existing biophysical structural data from alternative approaches. The new low resolution structures revealed and also provided some answers to long standing questions concerning lipid organization and particle maturation of lipoproteins. The review will discuss the merits of newly proposed SANS based all atom models for nascent and spherical HDL, and compare them with accepted models. Finally, naturally occurring and bioengineered mutations in apoA-I, and their impact on HDL phenotype, are reviewed and discuss together with new therapeutics employed for restoring HDL function.

Dysfunctional HDL and atherosclerotic cardiovascular disease

High-density lipoproteins (HDLs) protect against atherosclerosis by removing excess cholesterol from macrophages through the ATP-binding cassette transporter A1 (ABCA1) and ATP-binding cassette transporter G1 (ABCG1) pathways involved in reverse cholesterol transport. Factors that impair the availability of functional apolipoproteins or the activities of ABCA1 and ABCG1 could, therefore, strongly influence atherogenesis. HDL also inhibits lipid oxidation, restores endothelial function, exerts anti-inflammatory and antiapoptotic actions, and exerts anti-inflammatory actions in animal models. Such properties could contribute considerably to the capacity of HDL to inhibit atherosclerosis. Systemic and vascular inflammation has been proposed to convert HDL to a dysfunctional form that has impaired antiatherogenic effects. A loss of anti-inflammatory and antioxidative proteins, perhaps in combination with a gain of proinflammatory proteins, might be another important component in rendering HDL dysfunctional. The proinflammatory enzyme myeloperoxidase induces both oxidative modification and nitrosylation of specific residues on plasma and arterial apolipoprotein A-I to render HDL dysfunctional, which results in impaired ABCA1 macrophage transport, the activation of inflammatory pathways, and an increased risk of coronary artery disease. Understanding the features of dysfunctional HDL or apolipoprotein A-I in clinical practice might lead to new diagnostic and therapeutic approaches to atherosclerosis.

Lack of Atorvastatin Protective Effect Against Atrial Fibrillation in CETP TaqIB2B2 Genotype

There has been some evidence for a role of statins in reducing the risk of atrial fibrillation, but the response to statin treatment varies considerably due to environmental and genetic factors. One of these is related to CETP expression. So we assessed whether CETP TaqIB polymorphism influences atrial fibrillation occurrence after treatment with statins. 200 unrelated dyslipidemic Caucasian patients (146 men and 54 women; mean age 75±8) from Salento (Southern Italy), assigned to atorvastatin treatment, and 158 normolipidemic subjects (119 men and 39 women; mean age 75±11), selected from the same ward, were enrolled. All patients were followed at six-month intervals. CETP TaqIB polymorphism was genotyped by RFLP-PCR. During a mean follow-up time of 71±6 months, 64 patients (32%) of the group treated with atorvastatin and 70 subjects (44%) of the group without atorvastatin experienced at least one episode of AF, with a statistically significant difference (p = 0,0208) between the two groups. No significant differences were observed between the two groups with regard to demographic and echocardiographic data, to clinical history and pharmacological treatment. While in patients not assuming atorvastatin there was no significant difference (p = 1) between TaqIB genotype and atrial fibrillation occurence, in subjects treated with atorvastatin B2B2 genotype was more frequent in patients with atrial fibrillation (p = 0,0001). According to these data the subjects with the B2B2 genotype seem to be more susceptible to atrial fibrillation development (RR 2,74; IC 95% 1,92-3,90; p<0.025). Our data seem to provide a further evidence for the hypothesis that statins may have adverse effect in subjects with genetically low CETP levels. Because statins reduce CETP activity up to 30%, we hypothesize that such CETP activity reduction by statins, in patients with low CETP levels induced by polymorphism, may counteract the beneficial effect of statins on atrial fibrillation.

Lipid-lowering efficacy of atorvastatin

BACKGROUND

This represents the first update of this review, which was published in 2012. Atorvastatin is one of the most widely prescribed drugs and the most widely prescribed statin in the world. It is therefore important to know the dose-related magnitude of effect of atorvastatin on blood lipids.

OBJECTIVES

Primary objective To quantify the effects of various doses of atorvastatin on serum total cholesterol, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol and triglycerides in individuals with and without evidence of cardiovascular disease. The primary focus of this review was determination of the mean per cent change from baseline of LDL-cholesterol. Secondary objectives • To quantify the variability of effects of various doses of atorvastatin.• To quantify withdrawals due to adverse effects (WDAEs) in placebo-controlled randomised controlled trials (RCTs).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 11, 2013), MEDLINE (1966 to December Week 2 2013), EMBASE (1980 to December Week 2 2013), Web of Science (1899 to December Week 2 2013) and BIOSIS Previews (1969 to December Week 2 2013). We applied no language restrictions.

SELECTION CRITERIA

Randomised controlled and uncontrolled before-and-after trials evaluating the dose response of different fixed doses of atorvastatin on blood lipids over a duration of three to 12 weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility criteria for studies to be included and extracted data. We collected information on withdrawals due to adverse effects from placebo-controlled trials.

MAIN RESULTS

In this update, we found an additional 42 trials and added them to the original 254 studies. The update consists of 296 trials that evaluated dose-related efficacy of atorvastatin in 38,817 participants. Included are 242 before-and-after trials and 54 placebo-controlled RCTs. Log dose-response data from both trial designs revealed linear dose-related effects on blood total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides. The Summary of findings table 1 documents the effect of atorvastatin on LDL-cholesterol over the dose range of 10 to 80 mg/d, which is the range for which this systematic review acquired the greatest quantity of data. Over this range, blood LDL-cholesterol is decreased by 37.1% to 51.7% (Summary of findings table 1). The slope of dose-related effects on cholesterol and LDL-cholesterol was similar for atorvastatin and rosuvastatin, but rosuvastatin is about three-fold more potent. Subgroup analyses suggested that the atorvastatin effect was greater in females than in males and was greater in non-familial than in familial hypercholesterolaemia. Risk of bias for the outcome of withdrawals due to adverse effects (WDAEs) was high, but the mostly unclear risk of bias was judged unlikely to affect lipid measurements. Withdrawals due to adverse effects were not statistically significantly different between atorvastatin and placebo groups in these short-term trials (risk ratio 0.98, 95% confidence interval 0.68 to 1.40).

AUTHORS' CONCLUSIONS

This update resulted in no change to the main conclusions of the review but significantly increases the strength of the evidence. Studies show that atorvastatin decreases blood total cholesterol and LDL-cholesterol in a linear dose-related manner over the commonly prescribed dose range. New findings include that atorvastatin is more than three-fold less potent than rosuvastatin, and that the cholesterol-lowering effects of atorvastatin are greater in females than in males and greater in non-familial than in familial hypercholesterolaemia. This review update does not provide a good estimate of the incidence of harms associated with atorvastatin because included trials were of short duration and adverse effects were not reported in 37% of placebo-controlled trials.

Effects of established hypolipidemic drugs on HDL concentration, subclass distribution, and function

The knowledge of an inverse relationship between plasma high-density lipoprotein cholesterol (HDL-C) concentrations and rates of cardiovascular disease has led to the concept that increasing plasma HDL-C levels would be protective against cardiovascular events. Therapeutic interventions presently available to correct the plasma lipid profile have not been designed to specifically act on HDL, but have modest to moderate effects on plasma HDL-C concentrations. Statins, the first-line lipid-lowering drug therapy in primary and secondary cardiovascular prevention, have quite modest effects on plasma HDL-C concentrations (2-10%). Fibrates, primarily used to reduce plasma triglyceride levels, also moderately increase HDL-C levels (5-15%). Niacin is the most potent available drug in increasing HDL-C levels (up to 30%), but its use is limited by side effects, especially flushing.The present chapter reviews the effects of established hypolipidemic drugs (statins, fibrates, and niacin) on plasma HDL-C levels and HDL subclass distribution, and on HDL functions, including cholesterol efflux capacity, endothelial protection, and antioxidant properties.

Impact of lipid disorders on mortality among Saudi patients with heart failure

Background

Dyslipidemia, a known cardiovascular risk factor, is extremely common among Saudis, both adults and children. The impact, however, of dyslipidemia and several other lipid disorders in patients with congestive heart failure in this particular population has not been documented. This study aims to fill the gap.

Methods

This retrospective, single center study was conducted at King Abdulaziz Medical City, Riyadh, Saudi Arabia. Of the 500 cases seen during the period between 2002 and 2008, 392 were included in the study. Charts were reviewed and information on medical history, medications, and lipid status were documented.

Results

Low HDL-cholesterol level was the most common lipid disorder with 82.9%, followed by hypertriglyceridemia (35.2%), atherogenic dyslipidemia (27.8%), and hypercholesterolemia (9.2%). Diabetes mellitus was the single most significant predictor of mortality (p = 0.001). Among the lipid disorders, only low levels of HDL-cholesterol contributed to significant mortality risk [OR 1.29 (Confidence Interval 1.04–1.59) (p-value < 0.01)] adjusted for age, gender and statin use.

Conclusion

The results of this study suggest that emphasis should be on the elevation of HDL-cholesterol levels among subjects with congestive heart failure, without compromising any ongoing management of LDL-lowering drugs. Management should not be limited to conventional statin use and should promote other treatments to elevate HDL-cholesterol levels.

Beginning to understand high-density lipoproteins

This article reconciles the classic view of high-density lipoproteins (HDL) associated with low risk for cardiovascular disease (CVD) with recent data (genetics studies and randomized clinical trials) casting doubt over the widely accepted beneficial role of HDL regarding CVD risk. Although HDL cholesterol has been used as a surrogate measure to investigate HDL function, the cholesterol content in HDL particles is not an indicator of the atheroprotective properties of HDL. Thus, more precise measures of HDL metabolism are needed to reflect and account for the beneficial effects of HDL particles. Current and emerging therapies targeting HDL are discussed.

Defective functionality of HDL particles in familial apoA-I deficiency: relevance of alterations in HDL lipidome and proteome

To evaluate functional and compositional properties of HDL in subjects from a kindred of genetic apoA-I deficiency, two homozygotes and six heterozygotes, with a nonsense mutation at APOA1 codon -2, Q[-2]X, were recruited together with age- and sex-matched healthy controls (n = 11). Homozygotes displayed undetectable plasma levels of apoA-I and reduced levels of HDL-cholesterol (HDL-C) and apoC-III (5.4% and 42.6% of controls, respectively). Heterozygotes displayed low HDL-C (21 ± 9 mg/dl), low apoA-I (79 ± 24 mg/dl), normal LDL-cholesterol (132 ± 25 mg/dl), and elevated TG (130 ± 45 mg/dl) levels. Cholesterol efflux capacity of ultracentrifugally isolated HDL subpopulations was reduced (up to -25%, P < 0.01, on a glycerophospholipid [GP] basis) in heterozygotes versus controls. Small, dense HDL3 and total HDL from heterozygotes exhibited diminished antioxidative activity (up to -48%, P < 0.001 on a total mass basis) versus controls. HDL subpopulations from both homozygotes and heterozygotes displayed altered chemical composition, with depletion in apoA-I, GP, and cholesteryl ester; enrichment in apoA-II, free cholesterol, and TG; and altered phosphosphingolipidome. The defective atheroprotective activities of HDL were correlated with altered lipid and apo composition. These data reveal that atheroprotective activities of HDL particles are impaired in homozygous and heterozygous apoA-I deficiency and are intimately related to marked alterations in protein and lipid composition.

Altered lipidome and antioxidative activity of small, dense HDL in normolipidemic rheumatoid arthritis: relevance of inflammation

OBJECTIVE

High-density lipoprotein (HDL) particles exert potent antiatherogenic activities, including antioxidative actions, which are relevant to attenuation of atherosclerosis progression. Such activities are enriched in small, dense HDL and can be compromised under conditions of chronic inflammation like rheumatoid arthritis (RA). However, structure-function relationships of HDL largely remain indeterminate.

METHODS

The relationships between HDL structure and function were evaluated in normolipidemic patients with active RA (DAS28 > 3.2; n = 12) and in normolipidemic age-matched controls (n = 10). Small, dense HDL3b and 3c particles were isolated from plasma or serum by density gradient ultracentrifugation and their physicochemical characteristics, lipidome (by LC/MS/MS) and antioxidative function (as protection of normolipidemic LDL from free radical-induced oxidation) were evaluated.

RESULTS

As expected, active RA patients featured significantly elevated plasma levels of high-sensitivity C-reactive protein (hsCRP; p < 0.001) and serum amyloid A (SAA; p < 0.01) relative to controls. Antioxidative activity and weight % chemical composition of small, dense HDL did not differ between RA patients and controls (p > 0.05), whereas HDL phosphosphingolipidome was significantly altered in RA. Subgroup analyses revealed that RA patients featuring high levels of inflammation (hsCRP>10 mg/l) possessed small, dense HDL with reduced antioxidative activities (p < 0.01). Furthermore, antioxidative activity of HDL was inversely correlated with plasma hsCRP (p < 0.01).

CONCLUSIONS

These data revealed that (i) despite normolipidemic state, the lipidome of small, dense HDL was altered in RA and (ii) high levels of inflammation can be responsible for the functional deficiency of small, dense HDL in RA.

The composition and metabolism of large and small LDL

PURPOSE OF REVIEW

Decreased size and increased density of LDL have been associated with increased coronary heart disease (CHD) risk. Elevated plasma concentrations of small dense LDL (sdLDL) correlate with high plasma triglycerides and low HDL cholesterol levels. This review highlights recent findings about the metabolism and composition of LDL subfractions.

RECENT FINDINGS

The development of an automated assay has recently made possible the assessment of the CHD risk associated with sdLDL in large clinical trials and has demonstrated convincingly that sdLDL cholesterol levels are a more significant independent determinant of CHD risk than total LDL cholesterol. Metabolic studies have revealed that sdLDL particles originate through the delipidation of larger atherogenic VLDL and large LDL and from direct de novo production by the liver. Proteins associated with LDL, in addition to apolipoprotein (apo) B, include the C apolipoproteins, apoA-I, apoA-IV, apoD, apoE, apoF, apoH, apoJ, apoL-1, apoM, α-1 antitrypsin, migration inhibitory factor-related protein 8, lysosome C, prenylcysteine oxidase 1, paraoxonase 1, transthyretin, serum amyloid A4, and fibrinogen α chain. The role of the increasing number of LDL-associated proteins remains unclear; however, the data do indicate that LDL particles not only transport lipids but also carry proteins involved in inflammation and thrombosis. The sdLDL proteome in diabetic individuals differs significantly from that of larger LDL, being enriched in apoC-III.

SUMMARY

Progress in our understanding of the composition and metabolism of LDL subfractions strengthens the association between sdLDL and CHD risk.

Red yeast rice and coenzyme Q10 as safe alternatives to surmount atorvastatin-induced myopathy in hyperlipidemic rats

Statins are the first line treatment for the management of hyperlipidemia. However, the primary adverse effect limiting their use is myopathy. This study examines the efficacy and safety of red yeast rice (RYR), a source of natural statins, as compared with atorvastatin, which is the most widely used synthetic statin. Statin interference with the endogenous synthesis of coenzyme Q10 (CoQ10) prompted the hypothesis that its deficiency may be implicated in the pathogenesis of statin-associated myopathy. Hence, the effects of combination of CoQ10 with either statin have been evaluated. Rats were rendered hyperlipidemic through feeding them a high-fat diet for 90 days, during the last 30 days of the diet they were treated daily with either atorvastatin, RYR, CoQ10, or combined regimens. Lipid profile, liver function tests, and creatine kinase were monitored after 15 and 30 days of drug treatments. Heart contents of CoQ9 and CoQ10 were assessed and histopathological examination of the liver and aortic wall was performed. RYR and CoQ10 had the advantage over atorvastatin in that they lower cholesterol without elevating creatine kinase, a hallmark of myopathy. RYR maintained normal levels of heart ubiquinones, which are essential components for energy production in muscles. In conclusion, RYR and CoQ10 may offer alternatives to overcome atorvastatin-associated myopathy.

Simvastatin and bezafibrate increase cholesterol efflux in men with type 2 diabetes

BACKGROUND

The importance of functional properties of high-density lipoproteins (HDL) for atheroprotection is increasingly recognized. We determined the impact of lipid-lowering therapy on 3 key HDL functionalities in Type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

A placebo-controlled, randomized cross-over study (three 8-week treatment periods with simvastatin (40 mg daily), bezafibrate (400 mg daily), alone and in combination) was carried out in 14 men with T2DM. Cholesterol efflux was determined using human THP-1 monocyte-derived macrophages, HDL antioxidative capacity was measured as inhibition of low-density lipoprotein oxidation in vitro, and HDL anti-inflammatory capacity was assessed as suppression of thrombin-induced monocyte chemotactic protein 1 expression in human umbilical vein endothelial cells. Pre-β-HDL was assayed using crossed immunoelectrophoresis.

RESULTS

While cholesterol efflux increased in response to simvastatin, bezafibrate and combination treatment (+12 to +23%; anova, P = 0.001), HDL antioxidative capacity (P = 0.23) and HDL anti-inflammatory capacity (P = 0.15) did not change significantly. Averaged changes in cellular cholesterol efflux during active treatment were correlated positively with changes in HDL cholesterol, apoA-I and pre-β-HDL (P < 0.05 to P < 0.001). There were no inter-relationships between changes in the three HDL functionalities during treatment (P > 0.10). Changes in HDL antioxidative capacity and anti-inflammatory capacity were also unrelated to changes in HDL cholesterol and apoA-I, while changes in HDL antioxidative capacity were related inversely to pre-β-HDL (P < 0.05).

CONCLUSION

Simvastatin and bezafibrate increase cholesterol efflux, parallel to HDL cholesterol and apoA-I responses. The antioxidative and anti-inflammatory properties of HDL are not to an important extent affected by these therapeutic interventions.

Cholesteryl ester transfer protein polymorphisms, statin use, and their impact on cholesterol levels and cardiovascular events

The association of nonfunctional variants of the cholesteryl ester transfer protein (CETP) with efficacy of statins has been a subject of debate. We evaluated whether three functional CETP variants influence statin efficacy. The effect of CETP genotype on achieved levels of high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), and total cholesterol during statin treatment was estimated by meta-analysis of the linear regression outcomes of three studies (11,021 individuals). The effect of these single-nucleotide polymorphisms (SNPs) on statin response in protecting against myocardial infarction (MI) was estimated by meta-analysis of statin × SNP interaction terms from logistic regression in five studies (16,570 individuals). The enhancer SNP rs3764261 significantly increased HDLc by 0.02 mmol/l per T allele (P = 6 × 10(-5)) and reduced protection against MI by statins (interaction odds ratio (OR) = 1.19 per T allele; P = 0.04). Focusing on functional CETP variants, we showed that in carriers of the rs3764261 T variant, HDLc increased more during statin treatment, and protection against MI by statins appeared to be reduced as compared with those in noncarriers.

Review of the cost effectiveness of pharmacogenetic-guided treatment of hypercholesterolaemia

Hypercholesterolaemia is a highly prevalent condition that has major health and cost implications for society. Pharmacotherapy is an important and effective treatment modality for hypercholesterolaemia, with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors ('statins') the most commonly used class of drugs. Over the past decade, there has been intensive research to identify pharmacogenetic markers to guide treatment of hypercholesterolaemia. This study aimed to review the evidence of incremental cost, effect and cost effectiveness of pharmacogenetic-guided treatment of hypercholesterolaemia. Three cost-effectiveness analyses (CEAs) were identified that studied the value of screening for genotypes of angiotensin I converting enzyme (ACE), cholesteryl ester transfer protein (CETP), and kinesin family member 6 (KIF6) prior to initiating statin therapy. For all three CEAs, a major limitation identified was the reproducibility of the evidence supporting the clinical effect of screening for the pharmacogenetic marker. Associated issues included the uncertain value of pharmacogenetic markers over or in addition to existing approaches for monitoring lipid levels, and the lack of evidence to assess the effectiveness of alternative therapeutic options for individuals identified as poor responders to statin therapy. Finally, the economic context of the market for diagnostic tests (is it competitive or is there market power?) and the practicality of large-scale screening programmes to inform prescribing in a complex and varied market may limit the generalizability of the results of the specific CEAs to policy outcomes. The genotype of solute carrier organic anion transporter family member 1B1 (SLCO1B1) has recently been associated with increased risk of muscle toxicity with statin therapy and the review identified that exploration of cost effectiveness of this pharmacogenetic marker is likely warranted.

Lipid lowering efficacy of atorvastatin

BACKGROUND

Atorvastatin is one of the most widely prescribed drugs and the most widely prescribed statin in the world. It is therefore important to know the dose-related magnitude of effect of atorvastatin on blood lipids.

OBJECTIVES

To quantify the dose-related effects of atorvastatin on blood lipids and withdrawals due to adverse effects (WDAE).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library Issue 4, 2011, MEDLINE (1966 to November 2011), EMBASE (1980 to November 2011), ISI Web of Science (1899 to November 2011) and BIOSIS Previews (1969 to November 2011). No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled and uncontrolled before-and-after trials evaluating the dose response of different fixed doses of atorvastatin on blood lipids over a duration of 3 to 12 weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. WDAE information was collected from the placebo-controlled trials.

MAIN RESULTS

Two hundred fifty-four trials evaluated the dose-related efficacy of atorvastatin in 33,505 participants. Log dose-response data revealed linear dose-related effects on blood total cholesterol, low-density lipoprotein (LDL)-cholesterol and triglycerides. Combining all the trials using the generic inverse variance fixed-effect model for doses of 10 to 80 mg/day resulted in decreases of 36% to 53% for LDL-cholesterol. There was no significant dose-related effects of atorvastatin on blood high-density lipoprotein (HDL)-cholesterol. WDAE were not statistically different between atorvastatin and placebo for these short-term trials (risk ratio 0.99; 95% confidence interval 0.68 to 1.45).

AUTHORS' CONCLUSIONS

Blood total cholesterol, LDL-cholesterol and triglyceride lowering effect of atorvastatin was dependent on dose. Log dose-response data was linear over the commonly prescribed dose range. Manufacturer-recommended atorvastatin doses of 10 to 80 mg/day resulted in 36% to 53% decreases of LDL-cholesterol. The review did not provide a good estimate of the incidence of harms associated with atorvastatin because of the short duration of the trials and the lack of reporting of adverse effects in 37% of the placebo-controlled trials.

Reverse cholesterol transport in familial hypercholesterolemia

PURPOSE OF REVIEW

Familial hypercholesterolemia is characterized by a major elevation in circulating LDL-cholesterol levels, cholesterol deposition within the arterial wall and an increased risk of premature coronary artery disease. The reverse cholesterol transport (RCT) is now considered as a key process that protects against development of atherosclerosis. The major antiatherogenic action of HDL particles is intimately linked to their determinant role in RCT pathway. However, the steady-sate of HDL-cholesterol levels does not represent the optimal marker to evaluate the efficiency of the RCT in all circumstances.

RECENT FINDINGS

By using ex-vivo systems for the evaluation of the efficacy of RCT a strong inverse relationship between HDL efflux capacity from macrophages and atherosclerosis progression has been demonstrated. Low HDL-C phenotype observed in familial hypercholesterolemia patients is associated with defective capacities of HDL particles to mediate major steps of the centripetal movement of cholesterol from peripheral cells to feces. However, current available treatment used to reduce LDL-C to therapeutic goals does not correct altered functions of HDL particles in humans.

SUMMARY

In the context of familial hypercholesterolemia, a growing body of evidence suggests that impaired efficacy of the RCT pathway contributes significantly to the progression of atherosclerosis.

Dyslipidemia and pediatric obesity

Cardiovascular disease is the leading cause of death in the United States despite a reduction in mortality over the past 4 decades. Much of this success is attributed to public health efforts and more aggressive treatment of clinical disease. The rising rates of obesity and diabetes, especially among adolescents and young adults, raise concern for increases in mortality. National vital statistics have shown a leveling of cardiovascular disease death rates in the fifth decade of life. Public health efforts have begun to address childhood obesity. This article reviews the dyslipidemia associated with obesity in childhood and outlines a proposed approach to management.

Relationships between cholesterol efflux and high-density lipoprotein particles in patients with type 2 diabetes mellitus

BACKGROUND

High-density lipoprotein (HDL) encompasses a heterogeneous population of lipoproteins with differences in functionality. The impact of HDL heterogeneity on its ability to support HDL-mediated cholesterol efflux has not been previously studied in patients with type 2 diabetes mellitus (T2DM).

OBJECTIVES

To examine the relationships between various HDL subtypes and cholesterol efflux from macrophages in patients with T2DM.

METHODS

Lipoprotein molecular profiles of 44 patients were studied by NMR spectroscopy. Cholesterol efflux was expressed as percentage efflux of radioactivity from lipid-laden THP-1 macrophages preincubated with (3)H-cholesterol and then incubated with serum depleted of apolipoprotein B to provide an HDL-enriched acceptor medium.

RESULTS

There was a predominance of small HDL particles (59%) and small putatively atherogenic low-density lipoprotein particles (56%). Neither HDL-C nor ApoA-I concentrations showed statistically significant correlations with percentage cholesterol efflux, but a significant positive relationship was found with the total HDL particle concentration (r = 0.41, P = .005) contributed to largely by medium HDL particles (r = 0.41, P = .006). The correlation between medium-sized HDL particle concentration remained significantly associated with cholesterol efflux when assessed with the use of a linear regression model that included all the HDL lipoprotein subclass concentrations as well as apolipoprotein A-I. Importantly, no statistically significant association was observed between the number of small HDL particles and cholesterol efflux. Hemoglobin A1c showed a significant inverse correlation with cholesterol efflux (r = -0.31, P = .04).

CONCLUSION

In patients with moderately controlled type 2 diabetes mellitus, cholesterol efflux from macrophages incubated with apolipoprotein B-depleted plasmas correlated significantly and positively with the concentration of total and medium-sized HDL and not with that of the smallest particles.

Spectrophotometric determination of atorvastatin and amlodipine by H-point standard addition method with simultaneous addition of both analytes in nonaqueous solution

H-point standard addition method(HPSAM) with simultaneous addition of both analytes in nonaqueous solution was applied for determination of Atorvastatin (AT) and Amlodipine (AML). The results showed that simultaneous determination could be performed with the ratio 0.16 to 4.3 of AT–AML. The corresponding values of LOD were obtained for AT and AML 1.2 × 10–6 and 9 × 10–7 mol l–1, respectively, and the corresponding values of LOQ were obtained for AT and AML 4 × 10–6 and 3 × 10–6 mol l–1, respectively. Underworking conditions, the proposed method was successfully applied for simultaneous determination of AT and AML in several synthetic mixtures and Amostatine tablets.

Pharmacokinetics and bioequivalence evaluation of two different atorvastatin calcium 10-mg tablets: A single-dose, randomized-sequence, open-label, two-period crossover study in healthy fasted Chinese adult males

BACKGROUND

Atorvastatin calcium is a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor indicated for the prevention of cardiovascular disease and for the treatment of dyslipidemia. Information on the pharmacokinetics of atorvastatin in a Chinese population is lacking, and regulatory requirements necessitate a bioequivalence study for the marketing of a generic product in China.

OBJECTIVE

The aim of the present study was to assess the pharmacokinetics and bioequivalence of a test and branded reference formulation of atorvastatin calcium 10-mg tablets in healthy fasted Chinese male volunteers.

METHODS

This was a single-dose, randomized-sequence, open-label, 2-period crossover study with a 2-week washout period between doses. Healthy Chinese males were randomly assigned to receive 20 mg of either the test or reference formulation, and 13 blood samples were obtained over a 48-hour interval. Plasma concentrations of parent atorvastatin and ortho-hydroxy-atorvastatin (primary active metabolite) were simultaneously determined using a validated liquid chromatography-isotopic dilution mass spectrometry method. Pharmacokinetic parameters, including C(max), T(max), t((1/2)), AUC(0-t), and AUC(0-infinity)), were calculated. The 2 formulations were to be considered bioequivalent if 90% CIs for the log transformed ratios of AUC and C(max) of atorvastatin were within the predetermined bioequivalence range (0.80-1.25 for AUC and 0.70-1.43 for C(max)) as established by the State Food and Drug Administration of China. Tolerability was evaluated throughout the study by vital signs monitoring, physical examinations, 12-lead ECGs, and subject interviews on adverse events (AEs).

RESULTS

A total of 66 subjects were assessed for inclusion; 20 were excluded prior to study initiation. Of the 46 healthy subjects (mean [SD] age, 24.1 [2.5] years; height, 170.8 [5.1] cm; weight, 64.6 [6.4] kg; body mass index (BMI), 22.1 [1.7] kg/m(2)) who completed the study, 45 subjects (mean [SD] age, 24.1 [2.5] years; height, 171.1 [4.9] cm; weight, 64.8 [6.3] kg; BMI, 22.1 [1.7] kg/m(2)) were included in the pharmacokinetic and bioequivalence analyses; 1 subject was excluded from these analyses because he mistakenly received the same formulation in both periods. No period or sequence effect was observed. The mean values of C(max), AUC(0-t), and AUC(0-infinity)) for the test and reference formulations of atorvastatin (8.78 and 10.76 ng/mL, 38.22 and 40.02 ng/mL/h, 42.73 and 44.51 ng/mL/h, respectively) and ortho-hydroxy-atorvastatin (5.78 and 5.77 ng/mL, 47.32 and 48.47 ng/mL/h, 52.36 and 53.14 ng/mL/h) were not significantly different. The 90% CIs for natural log-transformed ratios of C(max), AUC(0-t), and AUC(0-infinity)) of both atorvastatin (0.73-0.91, 0.92-1.02, and 0.91-1.01, respectively) and ortho-hydroxy-atorvastatin (0.83-1.05, 0.92-1.02, and 0.93-1.02) were within the bioequivalence acceptance limits. Three subjects (6.5%) reported a total of 4 mild AEs (1 abdominal discomfort and 3 venipuncture syncope), which were not considered to be associated with administration of the study drug.

CONCLUSIONS

This single-dose (20 mg) study found that the test and reference formulations of atorvastatin calcium 10-mg tablet met the regulatory definition for assuming bioequivalence in these healthy fasted Chinese male volunteers. Both formulations were generally well tolerated in the population studied. Chinese National Registry Code: 2007L02512.

Functional food ingredients as adjunctive therapies to pharmacotherapy for treating disorders of metabolic syndrome

Abstract Information regarding the use of functional foods and nutraceuticals (FFN) in combating disease is rarely communicated to health care practitioners as medicinal strategies for patients. Metabolic syndrome (MetS) is an ideal paradigm for demonstrating the therapeutic properties of FFN. Encompassing multiple etiologies, including atherogenic dyslipidemia, insulin resistance, and hypertension, MetS affects over a third of American adults. However, as disease-related risk factors accumulate over time, guidelines for treating disorders of MetS progressively de-emphasize the use of FFN. Using marine omega-3 fatty acids, plant sterols, fiber, and tomato extract as examples, the purpose of this review is to endorse FFN as long-term adjunctive therapies to pharmaceutical treatment for disorders and risk factors for MetS. An additional goal is to compare physiological and molecular targets of FFN against corresponding prescription medications. Results reveal that FFN are viable treatment strategies for disorders of MetS, complementing pharmacological interventions by targeting and improving the biological processes that foster the development of disease. Thus, efficacious FFN therapies should be emphasized throughout all stages of treatment as adjuncts to pharmacotherapy for disorders of MetS. Accordingly, new developments in FFN research must be implemented into clinical guidelines with the prospect of improving disease prognoses as accessories to prescription medications.

Distinct HDL subclasses present similar intrinsic susceptibility to oxidation by HOCl

The heme protein myeloperoxidase (MPO) functions as a catalyst for lipoprotein oxidation. Hypochlorous acid (HOCl), a potent two-electron oxidant formed by the MPO-H(2)O(2)-chloride system of activated phagocytes, modifies antiatherogenic high-density lipoprotein (HDL). The structural heterogeneity and oxidative susceptibility of HDL particle subfractions were probed with HOCl. All distinct five HDL subfraction were modified by HOCl as demonstrated by the consumption of tryptophan residues and free amino groups, cross-linking of apolipoprotein AI, formation of HOCl-modified epitopes, increased electrophoretic mobility and altered content of unsaturated fatty acids in HDL subclasses. Small, dense HDL3 were less susceptible to oxidative modification than large, light HDL2 on a total mass basis at a fixed HOCl:HDL mass ratio of 1:32, but in contrast not on a particle number basis at a fixed HOCl:HDL molar ratio of 97:1. We conclude that structural and physicochemical differences between HDL subclasses do not influence their intrinsic susceptibility to oxidative attack by HOCl.

Targets of statin therapy: LDL cholesterol, non-HDL cholesterol, and apolipoprotein B in type 2 diabetes in the Collaborative Atorvastatin Diabetes Study (CARDS)

BACKGROUND

LDL can vary considerably in its cholesterol content; thus, lowering LDL cholesterol (LDLC) as a goal of statin treatment implies the existence of considerable variation in the extent to which statin treatment removes circulating LDL particles. This consideration is particularly applicable in diabetes mellitus, in which LDL is frequently depleted of cholesterol.

METHODS

Type 2 diabetes patients randomly allocated to 10 mg/day atorvastatin (n = 1154) or to placebo (n = 1196) for 1 year were studied to compare spontaneous and statin-induced apolipoprotein B (apo B) concentrations (a measure of LDL particle concentration) at LDLC and non-HDL cholesterol (non-HDLC) concentrations proposed as statin targets in type 2 diabetes.

RESULTS

Patients treated with atorvastatin produced lower serum apo B concentrations at any given LDLC concentration than patients on placebo. An LDLC concentration of 1.8 mmol/L (70 mg/dL) during atorvastatin treatment was equivalent to a non-HDLC concentration of 2.59 mmol/L (100 mg/dL) or an apo B concentration of 0.8 g/L. At the more conservative LDLC targets of 2.59 mmol/L (100 mg/dL) and 3.37 mmol/L (130 mg/dL) for non-HDLC, however, the apo B concentration exceeded the 0.9-g/L value anticipated in the recent Consensus Statement from the American Diabetes Association and the American College of Cardiology.

CONCLUSIONS

The apo B concentration provides a more consistent goal for statin treatment than the LDLC or non-HDLC concentration.

Effects of statin on small dense low-density lipoprotein cholesterol and remnant-like particle cholesterol in heterozygous familial hypercholesterolemia

AIM

The effects of statin on small dense low-density lipoprotein cholesterol (sd-LDL-C) and remnant-like particle cholesterol (RLP-C) levels in heterozygous familial hypercholesterolemia (FH) have not been examined. This study aimed to clarify the effects of statin on sd-LDL-C and RLP-C levels in heterozygous FH.

METHODS

Seventeen patients with heterozygous FH were randomly assigned to 2 mg/day pitavastatin or 10 mg/day atorvastatin. At baseline and 12 weeks after treatment with statin, we measured sd-LDL-C and RLP-C levels.

RESULTS

Sd-LDL-C levels significantly decreased from 43 +/- 24 to 16 +/- 10 mg/dL (-63%, p=0.001) in the pitavastatin group, and from 44 +/- 17 to 19 +/- 10 mg/dL (-55%, p<0.001) in the atorvastatin group. RLP-C levels decreased from 8.4 +/- 2.8 to 6.6 +/- 2.7 mg/dL (-16%, p=0.156) in the pitava-statin group, and from 9.8 +/- 4.7 to 5.9 +/- 5.4 mg/dL (-45%, p=0.044) in the atorvastatin group. There were no significant differences in percent changes of sd-LDL-C (p=0.370) and RLP-C levels (p=0.097) between the two groups.

CONCLUSIONS

Sd-LDL-C measured by the heparin-magnesium precipitation method and RLP-C levels in heterozygous FH were decreased by 12 weeks of statin therapy. Statin might have additional anti-atherogenic effects by reducing not only LDL-C but also sd-LDL-C and RLP-C.

Atherogenic lipoprotein particle size and concentrations and the effect of pravastatin in children with familial hypercholesterolemia

OBJECTIVE

To determine lipoprotein particle concentrations and size in children with familial hypercholesterolemia (FH) and investigate the effect of pravastatin therapy on these measures.

STUDY DESIGN

Lipoprotein particle concentrations and sizes were examined by nuclear magnetic resonance (NMR) spectroscopy in 144 children with FH and 45 unaffected siblings. The effect of pravastatin therapy (20 to 40 mg) on lipoprotein particle concentration and size were compared with placebo after 1 year of treatment, using analysis of covariance.

RESULTS

Compared with the unaffected siblings, the children with FH had significantly higher concentrations of very-low-density lipoprotein (VLDL) particles (115.6 nmol/L vs 51.2 nmol/L; P < .001) and low-density lipoprotein (LDL) particles (1726.8 nmol/L vs 955.3 nmol/L; P < .001), and lower concentrations of high-density lipoprotein (HDL) particles (23.2 micromol/L vs 26.9 micromol/L; P < .001). Compared with placebo, pravastatin therapy decreased the concentration of VLDL particles by 35.9 nmol/L (P < .001), of total LDL particles by 342.7 nmol/L (P < .001), of large LDL particles by 189.5 nmol/L (P < .001), and of small LDL particles by 156.2 nmol/L (P = .152), but increased the concentration of total HDL particles by 2.2 micromol/L (P < .001), of large HDL particles by 1.0 micromol/L (P = .006), and of medium HDL particles by 1.1 micromol/L (P = .003). VLDL particle size increased by 1.0 nm (P = .032).

CONCLUSIONS

Compared with their healthy siblings, children with FH have an atherogenic lipoprotein profile based on their lipoprotein distribution and lipoprotein particle diameter. Pravastatin therapy can improve, but not fully restore, these lipoprotein abnormalities toward normal levels in these children.

Metabolic syndrome features small, apolipoprotein A-I-poor, triglyceride-rich HDL3 particles with defective anti-apoptotic activity

The metabolic syndrome (MetS) phenotype is typically characterized by visceral obesity, insulin resistance, atherogenic dyslipidemia involving hypertriglyceridemia and subnormal levels of high density lipoprotein-cholesterol (HDL-C), oxidative stress and elevated cardiovascular risk. The potent antioxidative activity of small HDL3 is defective in MetS [Hansel B, et al. J Clin Endocrinol Metab 2004;89:4963-71]. We evaluated the functional capacity of small HDL3 particles from MetS subjects to protect endothelial cells from apoptosis induced by mildly oxidized low-density lipoprotein (oxLDL). MetS subjects presented an insulin-resistant obese phenotype, with hypertriglyceridemia, elevated apolipoprotein B and insulin levels, but subnormal HDL-C concentrations and chronic low grade inflammation (threefold elevation of C-reactive protein). When human microvascular endothelial cells (HMEC-1) were incubated with oxLDL (200 microg apolipoprotein B/ml) in the presence or absence of control HDL subfractions (25 microg protein/ml), small, dense HDL3b and 3c significantly inhibited cellular annexin V binding and intracellular generation of reactive oxygen species. The potent anti-apoptotic activity of small HDL3c particles was reduced (-35%; p<0.05) in MetS subjects (n=16) relative to normolipidemic controls (n=7). The attenuated anti-apoptotic activity of HDL3c correlated with abdominal obesity, atherogenic dyslipidemia and systemic oxidative stress (p<0.05), and was intimately associated with altered physicochemical properties of apolipoprotein A-I (apoA-I)-poor HDL3c, involving core cholesteryl ester depletion and triglyceride enrichment. We conclude that in MetS, apoA-I-poor, small, dense HDL3c exert defective protection of endothelial cells from oxLDL-induced apoptosis, potentially reflecting functional anomalies intimately associated with abnormal neutral lipid core content.

Comparison of a dietary portfolio diet of cholesterol-lowering foods and a statin on LDL particle size phenotype in hypercholesterolaemic participants

The effect of dietv. statins on LDL particle size as a risk factor for CVD has not been examined. We compared, in the same subjects, the impact of a dietary portfolio of cholesterol-lowering foods and a statin on LDL size electrophoretic characteristics. Thirty-four hyperlipidaemic subjects completed three 1-month treatments as outpatients in random order: a very-low saturated fat diet (control); the same diet with 20 mg lovastatin; a dietary portfolio high in plant sterols (1 g/4200 kJ), soya proteins (21·4 g/4200 kJ), soluble fibres (9·8 g/4200 kJ) and almonds (14 g/4200 kJ). LDL electrophoretic characteristics were measured by non-denaturing polyacrylamide gradient gel electrophoresis of fasting plasma at 0, 2 and 4 weeks of each treatment. The reductions in plasma LDL-cholesterol levels with the dietary portfolio and with statins were comparable and were largely attributable to reductions in the estimated concentration of cholesterol within the smallest subclass of LDL (portfolio − 0·69 (se0·10) mmol/l, statin − 0·99 (se0·10) mmol/l). These were significantly greater (P < 0·01) than changes observed after the control diet ( − 0·17 (se0·08) mmol/l). Finally, baseline C-reactive protein levels were a significant predictor of the LDL size responsiveness to the dietary portfolio but not to the other treatments. The dietary portfolio, like the statin treatment, had only minor effects on several features of the LDL size phenotype, but the pronounced reduction in cholesterol levels within the small LDL fraction may provide additional cardiovascular benefit over the traditional low-fat diet of National Cholesterol Education Program Step II.