Relationships between HDL subpopulation proteome and HDL function in overweight/obese people with and without coronary heart disease.

BACKGROUND AND AIMS: The structure-function relationships of high-density lipoprotein (HDL) subpopulations are not well understood. Our aim was to examine the interrelationships between HDL particle proteome and HDL functionality in subjects with and without coronary heart disease (CHD). METHODS: We isolated 5 different HDL subpopulations based on charge, size, and apolipoprotein A1 (APOA1) content from the plasma of 33 overweight/obese CHD patients and 33 age-and body mass index (BMI)-matched CHD-free subjects. We measured the relative molar concentration of HDL-associated proteins by liquid chromatography tandem mass spectrometry (LC-MS/MS) and assessed particle functionality. RESULTS: We quantified 110 proteins associated with the 5 APOA1-containing HDL subpopulations. The relative molar concentration of these proteins spanned five orders of magnitude. Only 10 proteins were present in >1% while 73 were present in <0.1% concentration. Only 6 of the 10 most abundant proteins were apolipoproteins. Interestingly, the largest (α-1) and the smallest (preß-1) HDL particles contained the most diverse proteomes. The protein composition of each HDL subpopulation was altered in CHD cases as compared to controls with the most prominent differences in preß-1 and α-1 particles. APOA2 concentration was positively correlated with preß-1 particle functionality (ABCA1-CEC/mg APOA1 in preß-1) (R2 = 0.42, p = 0.005), while APOE concentration was inversely correlated with large-HDL particle functionality (SRBI-CEC/mg APOA1 in α-1+α-2) (R2 = 0.18, p = 0.01). CONCLUSIONS: The protein composition of the different HDL subpopulations was altered differentially in CHD patients. The functionality of the small and large HDL particles correlated with the protein content of APOA2 and APOE, respectively. Our data indicate that distinct particle subspecies and specific particle associated proteins provide new information about the role of HDL in CHD.

Ethyl EPA and ethyl DHA cause similar and differential changes in plasma lipid concentrations and lipid metabolism in subjects with low-grade chronic inflammation.

BACKGROUND: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been shown to similarly lower plasma TG concentrations but differentially regulate plasma LDL-C and HDL-C concentrations. OBJECTIVE: The aim of this study was to evaluate the common and differential effects of these ω-3 fatty acids on plasma lipids and lipoproteins and to assess the metabolic mechanisms of the effects. METHODS: In a randomized, double-blind, crossover study, we assessed the effect of 10-week supplementation with 3 g/d pure EPA and pure DHA (both as ethyl ester, ≥97% purity) on plasma lipid and lipoprotein concentrations and activities of lipoprotein lipase (LPL), cholesteryl ester transfer protein (CETP) and lecithin:cholesterol acyl transferase (LCAT) in 21 older (>50 y) men and postmenopausal women with some characteristics of metabolic syndrome and low-grade chronic inflammation. RESULTS: Both EPA and DHA lowered plasma TG concentrations and increased LDL-C/apoB and HDL-C/apoA-I ratios, but only DHA increased LDL-C concentrations. The reductions in plasma TG were inversely associated with the changes in LPL activity after both EPA and DHA supplementation. EPA lowered CETP, while DHA lowered LCAT activity. EPA and DHA worked differently in men and women, with DHA increasing LPL activity and LDL-C concentrations in women, but not in men. CONCLUSIONS: EPA and DHA exerted similar effects on plasma TG, but differences were observed in LDL-C concentrations and activities of some enzymes involved in lipoprotein metabolism. It was also noted that EPA and DHA worked differently in men and women, supporting sex-specific variations in lipoprotein metabolism.

The role of HDL- and non-HDL-related parameters in cell-cholesterol efflux capacity.

BACKGROUND AND AIMS: The regulation of cell-cholesterol efflux is not completely understood. Our aim was to assess the role of HDL- and non-HDL-related parameters in ATP-binding cassette transporter-A1 (ABCA1) and scavenger receptor class B-type-I (SRBI) cell-cholesterol efflux capacity (CEC) in coronary heart disease (CHD) cases and controls. METHODS: Lipids and apoA-I-containing HDL particles (by 2D gel-electrophoresis and immunodetection) were measured in 534 statin-treated CHD patients and in 1076 age-, gender-, and BMI-matched controls. ABCA1-CEC and SRBI-CEC were measured in apoB-depleted serum of 100 cases and 100 controls. RESULTS: Cases had significantly higher concentrations of preß-1 particles (88%) and ABCA1-CEC (34%) compared to controls. ABCA1-CEC was positively correlated with the concentrations of preß-1 particles, triglycerides, small-dense (sd) LDL-C, and LDL-C in both cases and controls. Moreover, both the concentration and the functionality of preß-1 particles (ABCA1-CEC/mg preß-1) were positively associated with the concentrations of sdLDL-C and triglycerides. Cases had 27% lower levels of large HDL particles but similar SRBI-CEC compared to controls. SRBI-CEC was correlated positively with HDL-C, apoA-I, and large-HDL particle levels. However, the functionality of large-HDL particles (SRBI-CEC/mg large particles) was significantly and positively correlated with the preß-1/α-1 ratio, sdLDL-C, and triglycerides. CONCLUSIONS: CHD patients have significantly higher concentration, but less functional preß-1 particles in term of cholesterol efflux capacity compared to controls. Triglyceride-rich lipoproteins have significant influence on either the concentration or the functionality or both of HDL particles and consequently HDL-CEC.

Deuterium-depleted water stimulates GLUT4 translocation in the presence of insulin, which leads to decreased blood glucose concentration.

Deuterium (D) is a stable isotope of hydrogen (H) with a mass number of 2. It is present in natural waters in the form of HDO, at a concentration of 16.8 mmol/L, equivalent to 150 ppm. In a phase II clinical study, deuterium depletion reduced fasting glucose concentration and insulin resistance. In this study, we tested the effect of subnormal D-concentration on glucose metabolism in a streptozotocin (STZ)-induced diabetic rat model. Animals were randomly distributed into nine groups to test the effect of D2O (in a range of 25-150 ppm) on glucose metabolism in diabetic animals with or without insulin treatment. Serum glucose, fructose amine-, HbA1c, insulin and urine glucose levels were monitored, respectively. After the 8-week treatment, membrane-associated GLUT4 fractions from the soleus muscle were estimated by Western blot technique. Our results indicate that, in the presence of insulin, deuterium depletion markedly reduced serum levels of glucose, -fructose amine, and -HbA1c, in a dose-dependent manner. The optimal concentration of deuterium was between 125 and 140 ppm. After a 4-week period of deuterium depletion, the highest membrane-associated GLUT4 content was detected at 125 ppm. These data suggest that deuterium depletion dose-dependently enhances the effect of insulin on GLUT4 translocation and potentiates glucose uptake in diabetic rats, which explains the lower serum glucose, -fructose amine, and -HbA1c concentrations. Based on our experimental data, deuterium-depleted water could be used to treat patients with metabolic syndrome (MS) by increasing insulin sensitivity. These experiments indicate that naturally occurring deuterium has an impact on metabolic regulations.

Composition-function analysis of HDL subpopulations: influence of lipid composition on particle functionality.

The composition-function relationship of HDL particles and its effects on the mechanisms driving coronary heart disease (CHD) is poorly understood. We tested the hypothesis that the functionality of HDL particles is significantly influenced by their lipid composition. Using a novel 3D-separation method, we isolated five different-sized HDL subpopulations from CHD patients who had low preß-1 functionality (low-F) (ABCA1-dependent cholesterol-efflux normalized for preß-1 concentration) and controls who had either low-F or high preß-1 functionality (high-F). Molecular numbers of apoA-I, apoA-II, and eight major lipid classes were determined in each subpopulation by LC-MS. The average number of lipid molecules decreased from 422 in the large spherical α-1 particles to 57 in the small discoid preß-1 particles. With decreasing particle size, the relative concentration of free cholesterol (FC) decreased in α-mobility but not in preß-1 particles. Preß-1 particles contained more lipids than predicted; 30% of which were neutral lipids (cholesteryl ester and triglyceride), indicating that these particles were mainly remodeled from larger particles not newly synthesized. There were significant correlations between HDL-particle functionality and the concentrations of several lipids. Unexpectedly, the phospholipid:FC ratio was significantly correlated with large-HDL-particle functionality but not with preß-1 functionality. There was significant positive correlation between particle functionality and total lipids in high-F controls, indicating that the lipid-binding capacity of apoA-I plays a major role in the cholesterol efflux capacity of HDL particles. Functionality and lipid composition of HDL particles are significantly correlated and probably both are influenced by the lipid-binding capacity of apoA-I.

Characterization of an integrated, endogenous mouse mammary tumor virus-like (MMTV) betaretrovirus genome in a black Syrian hamster (Mesocricetus auratus).

Retroviruses (family Retroviridae) are important agents of humans and animals. This study reports the detection and complete genome characterization of a novel endogenous retrovirus from the black Syrian hamster (Mesocricetus auratus) with a squamous cell skin tumor. The proviral genome, tentatively named black Syrian hamster retrovirus (BSHRV/2013/HUN, MK304634), was 8784 nucleotide in length with typical full-length betaretrovirus genome organization of 5'LTR-gag-pro-pol-env-3'LTR and with a characteristic mouse mammary tumor virus-like (MMTV) betaretrovirus dUTPase domain but without a sag gene. The BSHRV gag (534aa), pro/pol (~1099aa) and env (672aa) proteins had 56%/63%/50% aa identity to the corresponding proteins of MMTV (AF228552). The proviral DNA is detectable in tumor as well as in tumor-free cells by conventional PCR and qPCR but only visible in the tumor cells by in situ hybridization. Low level retroviral RNA expression was found only in the DNase-treated RNA tumor samples using RT/nested PCR. BSHRV/2013/HUN-like betaretrovirus DNA was also identified from a faecal and tissue samples from 1 of the further 3 tested individuals by nested-PCR and qPCR. Further research is needed to investigate the distribution, activity and etiological role of this novel MMTV-like betaretrovirus species in hamster.

High-density lipoprotein: our elusive friend.

PURPOSE OF REVIEW: Despite advances in the research on HDL composition (lipidomics and proteomics) and functions (cholesterol efflux and antioxidative capacities), the relationship between HDL compositional and functional properties is not fully understood. We have reviewed the recent literature on this topic and pointed out the difficulties which limit our understanding of HDL's role in cardiovascular disease (CVD). RECENT FINDINGS: Though current findings strongly support that HDL has a significant role in CVD, the underlying mechanisms by which HDL mitigates CVD risk are not clear. This review focuses on studies that investigate the cell-cholesterol efflux capacity and the proteomic and lipidomic characterization of HDL and its subfractions especially those that analyzed the relationship between HDL composition and functions. SUMMARY: Recent studies on HDL composition and HDL functions have greatly contributed to our understanding of HDL's role in CVD. A major problem in HDL research is the lack of standardization of both the HDL isolation and HDL functionality methods. Data generated by different methods often produce discordant results on the particle number, size, lipid and protein composition, and the various functions of HDL.

Local immune parameters as potential predictive markers in head and neck squamous cell carcinoma patients receiving induction chemotherapy and cetuximab.

BACKGROUND: The aim of this study was to determine whether tumor-associated immune cells may predict response to therapy and disease outcome in head and neck squamous cell carcinoma (HNSCC) patients receiving induction chemotherapy and cetuximab. METHODS: Paraffin-embedded pretreatment biopsy samples from 45 patients with stage III-IV resectable HNSCC were investigated retrospectively by immunohistochemistry for density of different immune cell types based on expression of CD8, FOXP3, CD134, CD137, PD-1, CD20, NKp46, dendritic cell lysosomal-associated membrane protein (DC-LAMP), CD16, CD68, and myeloperoxidase. Results were analyzed for possible correlations with clinicopathologic parameters, response to therapy, and survival. RESULTS: Of the immune cell types studied, we found significant association with response to induction chemotherapy only in the case of DC-LAMP+ mature dendritic cells and PD-1+ lymphocytes; density of DC-LAMP+ cells also correlated with progression-free survival. CONCLUSION: DC-LAMP+ mature dendritic cells and PD-1+ cells may be implicated in response to induction chemotherapy and cetuximab in HNSCC patients.

[Dosimetric evaluation of intracavitary-interstitial image-guided adaptive brachytherapy of cervical cancer and comparison with conventional treatment techniques]. / Méhnyakdaganatok képvezérelt adaptív intersticiális-intrakavitális brahiterápiájának dozimetriai elemzése és a hagyományos kezelési technikákkal való összehasonlítása.

Our aim was the dosimetric evaluation of intracavitary-interstitial high-dose-rate image-guided adaptive cervix brachytherapy, implemented in Hungary. Between 2016 and 2018, 21 patients with cervical cancer were treated with overall 72 fractions. Graphical optimized treatment plans were compared to inverse optimized plans, 3D optimized plans (without needles) and conventional intracavitary 2D plans. Significant difference was found in almost all dose-volume parameters. The most advantageous values came from interstitial plans, inverse optimized plans did not differ dosimetrically from the treatment plans, while intracavitary optimized plans disposed of less appropriate dose-volume parameters, the least of all were intracavitary 2D plans. Needle number showed correlation with conformality, but inverse correlation with Dose Nonuniformity Ratio and D2cm3 of rectum. Volume of High Risk CTV correlated with D2cm3 of bladder, rectum and sigmoid. Although 3D optimization improved the quality of conventional 2D plans, interstitial plans resulted in even more homogeneous dose distribution and significantly lower doses to organs at risks.

[Clinical results of combined intracavitary-interstitial image-guided adaptive brachytherapy in locally advanced cervical cancer]. / Elõrehaladott méhnyakdaganatok képvezérelt adaptív kombinált intrakavitális-intersticiális brahiterápiájának bevezetése Magyarországon.

We present the early clinical results achieved with image-guided adaptive brachytherapy (IGABT) with combined intracavitary-interstitial (IC-IS) technique recently implemented in Hungary in the treatment of locally advanced cervical cancer (LACC). Twenty-one patients were treated with radio-chemotherapy (RCT) followed by combined IC-IS BT. At the end of the RCT we assessed the residual tumour with pelvic MRI. On CT images registered with the applicator in place we contoured the organs at risk and the high-risk clinical target volume, which included the whole cervix and the eventual residual tumour in the parametria. No grade 4 toxicity was noticed. At 11 months follow-up the local control rate was 92.3%, the pelvic control rate 86.5%, the distant metastasis free survival and the disease-free survival were 74%. The combined IC-IS treatment was well tolerated. Our clinical results are similar to those reported in the literature.

[Role of MRI and CT in the evaluation of postirradiation status and complications in head and neck cancer]. / Az MRI és a CT szerepe a sugárterápia utáni státusz értékelésében, szövõdményeinek vizsgálatában, fej-nyaki daganatoknál.

Most head and neck cancer patients are treated with combined modalities such as surgery, radiotherapy (RT), chemotherapy (ChT). Concurrent chemo-radiation has improved treatment outcomes with increased toxic effects. Reactions after RT are divided into early and late changes. Early reactions are seen during the course of therapy or within 3 months; these are reversible in most cases. Late complications are observed 3 months to years after RT and they are generally irreversible. As typical late reaction radiation induced necrosis may occur in soft tissues, cartilage, bones and brain. Tumor recurrence and post-radiation necrosis typically appear at the same time, within 2-3 years after RT; the differentiation may be difficult. Computed tomography (CT) and magnetic resonance imaging (MRI) have become the gold standards not only for staging and assessing tumor response, but also to evaluate posttreatment status, to distinguish residual or recurrent tumor and RT complications. Using baseline CT or MRI between 2-3 months after treatment and performing standard follow-up imaging with strict clinical follow-up are required to establish early salvage treatment.

High-Density Lipoprotein Particles, Cell-Cholesterol Efflux, and Coronary Heart Disease Risk.

Objective- The cell-cholesterol efflux capacity of HDL (high-density lipoprotein) is inversely associated with coronary heart disease risk. ABCA1 (ATP-binding cassette transporter A1) plays a crucial role in cholesterol efflux from macrophages to preß-1-HDL. We tested the hypothesis that coronary heart disease patients have functionally abnormal preß-1-HDL. Approach and Results- HDL cell-cholesterol efflux capacity via the ABCA1 and the SR-BI (scavenger receptor class B type I) pathways, HDL antioxidative capacity, apo (apolipoprotein) A-I-containing HDL particles, and inflammatory- and oxidative-stress markers were measured in a case-control study of 100 coronary heart disease cases and 100 sex-matched controls. There were significant positive correlations between ABCA1-dependent cholesterol efflux and the levels of small lipid-poor preß-1 particles ( R2=0.535) and between SR-BI-dependent cholesterol efflux and the levels of large lipid-rich (α-1+α-2) HDL particles ( R2=0.712). Cases had significantly higher (87%) preß-1 concentrations than controls, but the functionality of their preß-1 particles (preß-1 concentration normalized ABCA1-dependent efflux capacity) was significantly lower (-31%). Cases had significantly lower (-12%) mean concentration of large HDL particles, but the functionality of their particles (α-1+α-2 concentration normalized SR-BI-dependent efflux capacity) was significantly higher (22%) compared with that of controls. HDL antioxidative capacity was significantly lower (-16%) in cases than in controls. There were no significant correlations between either preß-1 functionality or large HDL particle functionality with HDL antioxidative capacity or the concentrations of inflammatory- and oxidative-stress markers. Conclusions- HDL cell-cholesterol efflux capacity is significantly influenced by both the concentration and the functionality of specific HDL particles participating in cell-cholesterol efflux. Coronary heart disease patients have higher than normal preß-1 concentrations with decreased functionality and lower than normal large HDL particle concentrations with enhanced functionality.

Where next with HDL assays?

PURPOSE OF REVIEW: The inverse association between HDL cholesterol (HDL-C) and cardiovascular disease (CVD) has been unequivocally proven in the past several decades. However, some interventions aiming to increase HDL-C failed to reduce CVD risk. HDL is structurally and functionally complex and HDL-associated metrics other than HDL-C, such as the concentration, composition, and functionality of HDL particles, have been considered as better determinants of CVD risk. A large body of recent research has addressed changes in HDL functions and HDL subpopulations in CVD with the goal of discovering novel and reliable biomarkers and targets for the treatment or prevention of CVD. RECENT FINDINGS: We have reviewed recent findings on HDL composition, HDL particle concentrations, and cell-cholesterol efflux capacity that have lately contributed to our understanding of HDL's role in CVD. SUMMARY: We point out that a major problem in HDL research is the lack of standardization of HDL assays that has led to discrepancies among studies. Therefore, there is a need for new standardized assays that capture the complexities of key HDL parameters.

HDL Particle Measurement: Comparison of 5 Methods.

BACKGROUND: HDL cell cholesterol efflux capacity has been documented as superior to HDL cholesterol (HDL-C) in predicting cardiovascular disease risk. HDL functions relate to its composition. Compositional assays are easier to perform and standardize than functional tests and are more practical for routine testing. Our goal was to compare measurements of HDL particles by 5 different separation methods. METHODS: HDL subfractions were measured in 98 samples using vertical auto profiling (VAP), ion mobility (IM), nuclear magnetic resonance (NMR), native 2-dimensional gel electrophoresis (2D-PAGE), and pre-ß1-ELISA. VAP measured cholesterol in large HDL2 and small HDL3; IM measured particle number directly in large, intermediate, and small HDL particles; NMR measured lipid signals in large, medium, and small HDL; 2D-PAGE measured apolipoprotein (apo) A-I in large (α1), medium (α2), small (α3-4), and pre-ß1 HDL particles; and ELISA measured apoA-I in pre-ß1-HDL. The data were normalized and compared using Passing-Bablok, Lin concordance, and Bland-Altman plot analyses. RESULTS: With decreasing HDL-C concentration, NMR measured a gradually lower percentage of large HDL, compared with IM, VAP, and 2D-PAGE. In the lowest HDL-C tertile, NMR measured 8% of large HDL, compared with IM, 22%; VAP, 20%; and 2D-PAGE, 18%. There was strong discordance between 2D-PAGE and NMR in measuring medium HDL (R2 = 0.356; rc = 0.042) and small HDL (R2 = 0.376; rc = 0.040). The 2D-PAGE assay measured a significantly higher apoA-I concentration in pre-ß1-HDL than the pre-ß1-ELISA (9.8 vs 1.6 mg/dL; R2 = 0.246; rc = 0.130). CONCLUSIONS: NMR agreed poorly with the other methods in measuring large HDL, particularly in low HDL-C individuals. Similarly, there was strong discordance in pre-ß1-HDL measurements between the ELISA and 2D-PAGE assays.

EVALUATION OF BONE MINERALIZATION BY COMPUTED TOMOGRAPHY IN WILD AND CAPTIVE EUROPEAN COMMON SPADEFOOTS (PELOBATES FUSCUS), IN RELATION TO EXPOSURE TO ULTRAVIOLET B RADIATION AND DIETARY SUPPLEMENTS.

Captive rearing programs have been initiated to save the European common spadefoot (Pelobates fuscus), a toad species in the family of Pelobatidae, from extinction in The Netherlands. Evaluating whether this species needs ultraviolet B (UVB) radiation and/or dietary supplementation for healthy bone development is crucial for its captive management and related conservation efforts. The bone mineralization in the femurs and the thickest part of the parietal bone of the skulls of European common spadefoots (n = 51) was measured in Hounsfield units (HUs) by computed tomography. One group, containing adults (n = 8) and juveniles (n = 13), was reared at ARTIS Amsterdam Royal Zoo without UVB exposure. During their terrestrial lifetime, these specimens received a vitamin-mineral supplement. Another group, containing adults (n = 8) and juveniles (n = 10), was reared and kept in an outdoor breeding facility in Münster, Germany, with permanent access to natural UVB light, without vitamin-mineral supplementation. The HUs in the ARTIS and Münster specimens were compared with those in wild specimens (n = 12). No significant difference was found between the HUs in the femurs of both ARTIS and Münster adults and wild adults (P = 0.537; P = 0.181). The HUs in the skulls of both captive-adult groups were significantly higher than in the skulls of wild specimens (P = 0.020; P = 0.005). The HUs in the femurs of the adult ARTIS animals were significantly higher than the HUs in the femurs of the adult Münster animals (P = 0.007). The absence of UVB radiation did not seem to have a negative effect on the bone development in the terrestrial stage. This suggests that this nocturnal, subterrestrial amphibian was able to extract sufficient vitamin D3 from its diet and did not rely heavily on photobiosynthesis through UVB exposure.

Clinical signs, diagnostics and successful treatment of a myocarditis in an adult chimpanzee (Pan troglodytes).

A chimpanzee (Pan troglodytes) was presented with lethargic behaviour. Echocardiography and abnormal cardiac and inflammatory biomarkers revealed a myocarditis. The animal fully recovered after prolonged treatment with losartan and carvedilol. This is the first report of the diagnosis and successful treatment of myocarditis in this species.

Influence of HDL particles on cell-cholesterol efflux under various pathological conditions.

It has been reported that low cell-cholesterol efflux capacity (CEC) of HDL is an independent risk factor for CVD. To better understand CEC regulation, we measured ABCA1- and scavenger receptor class B type I (SR-BI)-dependent cell-cholesterol efflux, HDL anti-oxidative capacity, HDL particles, lipids, and inflammatory- and oxidative-stress markers in 122 subjects with elevated plasma levels of triglyceride (TG), serum amyloid A (SAA), fibrinogen, myeloperoxidase (MPO), or ß-sitosterol and in 146 controls. In controls, there were strong positive correlations between ABCA1-dependent cholesterol efflux and small preß-1 concentrations (R2 = 0.317) and SR-BI-dependent cholesterol efflux and large (α-1 + α-2) HDL particle concentrations (R2 = 0.774). In high-TG patients, both the concentration and the functionality (preß-1 concentration-normalized ABCA1 efflux) of preß-1 particles were significantly elevated compared with controls; however, though the concentration of large particles was significantly decreased, their functionality (large HDL concentration-normalized SR-BI efflux) was significantly elevated. High levels of SAA or MPO were not associated with decreased functionality of either the small (preß-1) or the large (α-1 + α-2) HDL particles. HDL anti-oxidative capacity was negatively influenced by high plasma ß-sitosterol levels, but not by the concentrations of HDL particles, TG, SAA, fibrinogen, or MPO. Our data demonstrate that under certain conditions CEC is influenced not only by quantitative (concentration), but also by qualitative (functional) properties of HDL particles.

Effects of eicosapentaenoic acid and docosahexaenoic acid on cardiovascular disease risk factors: a randomized clinical trial.

BACKGROUND: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the primary omega-3 fatty acids in fish oil, have been shown to reduce cardiovascular disease (CVD) risk. OBJECTIVE: This study aimed to examine the independent effects of EPA and DHA on lipid and apolipoprotein levels, as well as on inflammatory biomarkers of CVD risk, using doses often used in the general population. DESIGN: A blinded, randomized 6-week trial was performed in 121 healthy, normolipidemic subjects who received olive oil placebo 6g/d, EPA 600mg/d, EPA 1800mg/d, or DHA 600mg/d. The EPA was derived from genetically modified yeast. RESULTS: The subjects tolerated the supplements well with no safety issues; and the expected treatment-specific increases in plasma EPA and DHA levels were observed. Compared to placebo, the DHA group had significant decreases in postprandial triglyceride (TG) concentrations (-20%, -52.2mg/dL, P=0.03), significant increases in fasting and postprandial low-density lipoprotein cholesterol (LDL-C) (+18.4%, 17.1mg/dL, P=0.001), with no significant changes in inflammatory biomarkers. No significant effects were observed in the EPA 600mg/d group. The high-dose EPA group had significant decreases in lipoprotein-associated phospholipase A2 concentrations (Lp-PLA2) (-14.1%, -21.4ng/mL, P=0.003). CONCLUSIONS: The beneficial effects of EPA 1800mg/d on CVD risk reduction may relate in part to the lowering of Lp-PLA2 without adversely affecting LDL-C. In contrast, DHA decreased postprandial TG, but raised LDL-C. Our observations indicate that these dietary fatty acids have divergent effects on cardiovascular risk markers.

Comparing fluorescence-based cell-free assays for the assessment of antioxidative capacity of high-density lipoproteins.

BACKGROUND: Population studies have shown an inverse association between high-density lipoprotein (HDL) cholesterol levels and risk of coronary heart disease (CHD). HDL has different functions, including the ability to protect biological molecules from oxidation. Our aim was to evaluate the performance of two fluorescence-based assays in assessing the antioxidative capacity of HDL. METHODS: We compared the antioxidative capacity of HDL with the phospholipid 2',7'-dichlorodihydrofluorescein (DCF) assay and the dihydrorhodamine 123 (DHR) assay in controls and in subjects at increased risk of CHD, including subjects with established CHD, and subjects with elevated plasma triglycerides (TG), serum amyloid A (SAA), or myeloperoxidase (MPO) levels. RESULTS: The antioxidative capacity of HDL, as measured by the DCF assay, was significantly lower in both CHD and high-TG patients than in controls (p < 0.001 and p = 0.004, respectively). Interestingly, the mean antioxidative capacity of HDL in high-SAA subjects was significantly higher (p < 0.03), while in high-MPO subjects was similar to controls. When the DHR assay was used we did not find differences in HDL's antioxidative capacity between CHD patients and controls but we found higher antioxidative capacity in high-SAA subjects compared to controls. CONCLUSIONS: Only the DCF assay could detect significant differences in the antioxidative capacity of HDL between controls and CHD subjects. Practical use of both assays for the assessment of antioxidative capacity of HDL is limited by the large overlap in values among groups. The antioxidative activity of HDL in patients who have elevated SAA levels needs to be reassessed.