apoA-I Levels Research Articles

In vivo PET imaging with [(18)F]FDG to explain improved glucose uptake in an apolipoprotein A-I treated mouse model of diabetes.

Type 2 diabetes is characterised by decreased HDL levels, as well as the level of apolipoprotein A-I (apoA-I), the main apolipoprotein of HDLs. Pharmacological elevation of HDL and apoA-I levels is associated with improved glycaemic control in patients with type 2 diabetes. This is partly due to improved glucose uptake in skeletal muscle. This study used kinetic modelling to investigate the impact of increasing plasma apoA-I levels on the metabolism of glucose in the db/db mouse model. Treatment of db/db mice with apoA-I for 2h significantly improved both glucose tolerance (AUC 2574 ± 70mmol/l × min vs 2927 ± 137mmol/l × min, for apoA-I and PBS, respectively; p < 0.05) and insulin sensitivity (AUC 388.8 ± 23.8mmol/l × min vs 194.1 ± 19.6mmol/l × min, for apoA-I and PBS, respectively; p < 0.001). ApoA-I treatment also increased glucose uptake by skeletal muscle in both an insulin-dependent and insulin-independent manner as evidenced by increased uptake of fludeoxyglucose ([(18)F]FDG) from plasma into gastrocnemius muscle in apoA-I treated mice, both in the absence and presence of insulin. Kinetic modelling revealed an enhanced rate of insulin-mediated glucose phosphorylation (k 3) in apoA-I treated mice (3.5 ± 1.1 × 10(-2) min(-1) vs 2.3 ± 0.7 × 10(-2) min(-1), for apoA-I and PBS, respectively; p < 0.05) and an increased influx constant (3.7 ± 0.6 × 10(-3) ml min(-1) g(-1) vs 2.0 ± 0.3 × 10(-3) ml min(-1) g(-1), for apoA-I and PBS, respectively; p < 0.05). Treatment of L6 rat skeletal muscle cells with apoA-I for 2h indicated that increased hexokinase activity mediated the increased rate of glucose phosphorylation. These findings indicate that apoA-I improves glucose disposal in db/db mice by improving insulin sensitivity and enhancing glucose phosphorylation.

The effect of red grape seed extract on serum paraoxonase activity in patients with mild to moderate hyperlipidemia.

Red grape seed extract (RGSE) contains oligomeric proanthocyanidin complexes as a class of flavonoids. These compounds are potent antioxidants and exert many health-promoting effects. This study aimed to determine the effects of RGSE on serum levels of triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein AI (apo-AI) levels and paraoxonase (PON) activity in patients with mild to moderate hyperlipidemia (MMH). A randomized double-blind placebo-controlled clinical trial was conducted at Shahid-Modarres Hospital (Tehran, Iran) and Tabriz University of Medical Sciences. Seventy MMH patients were randomly assigned to receive treatment (200 mg/day of RGSE) or placebo for eight weeks. Significant elevation in serum levels of apo-AI (P = 0.001), HDL-C (P = 0.001) and PON activity (P = 0.001) and marked decreases in concentrations of TC (P = 0.015), TG (P = 0.011) and LDL-C (P = 0.014) were found in the cases. PON activity was significantly correlated with apo-AI (r = 0.270; P < 0.01) and HDL-C (r = 0.45; P < 0.001). Significant differences between the RGSE and control groups (before and after treatment) for TC (P = 0.001), TG (P = 0.001), PON (P = 0.03), apo-AI (P = 0.001) and LDL-C (P = 0.002) were seen. It is possible that RGSE increases PON activity mostly through increasing HDL-C and apo-AI levels in MMH patients. It may thus have potential beneficial effects in preventing oxidative stress and atherosclerosis in these patients.

Abstract 201: Maternal HDL-Cholesterol Levels in Women From the Gambia are Directly Related to Infant Birthweight

Babies born with low birthweight are often at a health disadvantage. Previous studies have shown direct relationships between maternal plasma cholesterol and infant birthweight in resource-rich countries. As plasma cholesterol levels are often decreased in resource-poor countries, the purpose of these studies was to evaluate the relationship between plasma cholesterol and birthweight in women enrolled in the ENID trial (ISRCTN49285450) in rural Gambia, West Africa. Plasma was obtained at enrolment (13.6±3.3 wk) and at 20 and 30 weeks of gestation; samples were obtained from women with term infants that weighed &lt;2.75 kg or &gt;3.25 kg at birth. Women with lower HDL-cholesterol (HDL-C) concentrations in mid-pregnancy had lower birthweight infants compared to women with higher HDL-C concentrations. There was no significant association between LDL-C or total cholesterol concentrations and birthweight. The relationship with HDL-C and birthweight was maintained when maternal BMI was included in the model. To begin to elucidate the processes involved in the regulation of fetal growth, placental function was examined in mice with increasing maternal HDL-C concentrations based on apoA-I levels; mice were lacking apoA-I (apoA-I -/- ), were wildtype (apoA-I +/+ ), or had excess apoA-I (apoA-I tg/tg ). HDL decreased in size as plasma apoA-I levels increased, and there were no statistical differences in the proteins carried by HDL, except for apoA-I, in pregnant mice of different genotypes. However, pregnancy alone led to changes in the HDL proteome. Importantly, fetuses of mice with lower concentrations of maternal HDL-C had reduced growth rates, not due to a lack of fetal apoA-I. The murine fetal growth rates were directly related to nutrient uptake by and transport across the placenta. This work suggests that maternal HDL affects placental function leading to enhanced nutrient supply and improved growth in utero, making HDL a potential biomarker for fetal growth and putative target for intervention.

Abstract 159: Synthetic High Density Lipoprotein - a Potential Therapy for Sepsis

Introduction: Sepsis is the leading cause of death in critically ill patients with mortality rates exceeding 30%. The ability of endogenous HDL to neutralize and facilitate elimination of lipopolysaccharides (LPS) is known and synthetic HDLs (sHDL) have been administered in sepsis models with varying success. In the current study we optimized composition of sHDL, apolipoprotein A-I (apoA-I) mimetic peptide-phospholipid particles, to maximize their protective effect against endothelial dysfunction in sepsis, and examined changes in HDL and apoA-I levels in patients with sepsis to select sHDL doses for evaluation in a sepsis animal model. Methods/Results: We first measured HDL cholesterol (HDL-C) and apoA-I in patients at time of intake to the intensive care unit, observing HDL to be 45% lower in septic patients compared to non-septic patients (p&lt;0.01), with HDL levels in non-surviving septic patients being significantly lower compared to those in surviving septic patients (p&lt;0.01). Next, we tested a new generation of sHDL, ETC642, for its efficacy on cecal ligation and puncture (CLP)-challenged mice. We administered sHDL to mice 2h post CLP and found that sHDL treatment significantly increased plasma HDL-C and decreased BUN, plasma IL-6 and IL-10 levels. More importantly, sHDL therapy improved 7d survival rate greater than 2-fold over PBS treated mice (p=0.01). To understand the mechanisms underlying sHDL protection, we investigated the effect of sHDL on endotoxin-induced inflammatory response in vitro . sHDL not only neutralized LPS/LTA but also suppressed TLR4-/TLR2-NF-kB signaling in macrophages, and inhibited LPS/LTA/TNF-α induced endothelial cell activation. Conclusions: In this study, we show that HDL-C levels are markedly decreased in septic patients, which is associated with poor prognosis. We demonstrate that sHDL treatment increases HDL levels and effectively protects against CLP-induced septic death. We further established that sHDL therapy provides multiple protective mechanisms through LPS/LTA detoxification, suppressing inflammatory signaling in macrophages and inhibiting endothelial activation. Together, our findings suggest that targeting the vasculature via sHDL can be an effective platform for sepsis therapy.

Can chronic heart failure induce kidney function damage?

Abstract Accelerated atherosclerosis and increased cardiovascular events have been extensively documented in patients with end stage chronic kidney disease. The aim of our work was to find evidence supporting the theory that chronic heart failure (CHF) induces renal function damage. In our work, lipids, apolipoprotein (apo)AI, NTproBNP, hsCRP, lipid hydroperoxide (LPO) and creatinine levels were determined in patients with CHF. A total of 37 patients who were diagnosed with CHF, as well as 15 healthy persons, were recruited for the study. The patients were placed into 2 groups: patients with NYHA class 2 and NYHA class 3. Using routine laboratory methods, NT-proBNP level, and lipids were measured by way of employing a Cobas Integra analyser, while the concentration of hs-CRP was measured by immunonephelometric methods. Moreover, serum LPO concentration was measured using Cayman’s Assay Kit (LPO). The statistical analysis of the obtained results was performed using the nonparametric Kruskal-Wallis test and Spearman’s correlation analysis. Our work demonstrated that the CHF patients had significantly decrease concentration of HDL cholesterol and apoAI, but increased NT-pro-BNP, hsCRP and LPO levels. In all CHF patients, a significant positive correlation between NT-proBNP concentration and creatinine levels, and a significant negative correlation between NT-proBNP concentration and apoAI levels, as well as between concentration of creatinine and apoAI levels, was shown. The study results suggest that variation in the concentration of NT-proBNP, LPO, hsCRP, apoAI, creatinine, in addition to chronic heart failure progression, gradually accompany the progress of chronic renal failure. What is more, the disorders may lead to the occurrence of cardiovascular events, consequently, to patient death.

The effects of apolipoprotein B depletion on HDL subspecies composition and function

HDL cholesterol (HDL-C) efflux function may be a more robust biomarker of coronary artery disease risk than HDL-C. To study HDL function, apoB-containing lipoproteins are precipitated from serum. Whether apoB precipitation affects HDL subspecies composition and function has not been thoroughly investigated. We studied the effects of four common apoB precipitation methods [polyethylene glycol (PEG), dextran sulfate/magnesium chloride (MgCl2), heparin sodium/manganese chloride (MnCl2), and LipoSep immunoprecipitation (IP)] on HDL subspecies composition, apolipoproteins, and function (cholesterol efflux and reduction of LDL oxidation). PEG dramatically shifted the size distribution of HDL and apolipoproteins (assessed by two independent methods), while leaving substantial amounts of reagent in the sample. PEG also changed the distribution of cholesterol efflux and LDL oxidation across size fractions, but not overall efflux across the HDL range. Dextran sulfate/MgCl2, heparin sodium/MnCl2, and LipoSep IP did not change the size distribution of HDL subspecies, but altered the quantity of a subset of apolipoproteins. Thus, each of the apoB precipitation methods affected HDL composition and/or size distribution. We conclude that careful evaluation is needed when selecting apoB depletion methods for existing and future bioassays of HDL function.

Selective PPAR modulators (SPPARs) may fill the need for treatment of the atherogenic dyslipidemia of insulin resistance and type 2 diabetes: Can they reduce the associated cardiac risk?

Selective PPAR modulators (SPPARs) may fill the need for treatment of the atherogenic dyslipidemia of insulin resistance and type 2 diabetes: Can they reduce the associated cardiac risk?

Cholesteryl Ester Transfer Protein Inhibition With Anacetrapib Decreases Fractional Clearance Rates of High-Density Lipoprotein Apolipoprotein A-I and Plasma Cholesteryl Ester Transfer Protein.

Anacetrapib (ANA), an inhibitor of cholesteryl ester transfer protein (CETP) activity, increases plasma concentrations of high-density lipoprotein cholesterol (HDL-C), apolipoprotein A-I (apoA)-I, apoA-II, and CETP. The mechanisms responsible for these treatment-related increases in apolipoproteins and plasma CETP are unknown. We performed a randomized, placebo (PBO)-controlled, double-blind, fixed-sequence study to examine the effects of ANA on the metabolism of HDL apoA-I and apoA-II and plasma CETP. Twenty-nine participants received atorvastatin (ATV) 20 mg/d plus PBO for 4 weeks, followed by ATV plus ANA 100 mg/d for 8 weeks (ATV-ANA). Ten participants received double PBO for 4 weeks followed by PBO plus ANA for 8 weeks (PBO-ANA). At the end of each treatment, we examined the kinetics of HDL apoA-I, HDL apoA-II, and plasma CETP after D3-leucine administration as well as 2D gel analysis of HDL subspecies. In the combined ATV-ANA and PBO-ANA groups, ANA treatment increased plasma HDL-C (63.0%; P<0.001) and apoA-I levels (29.5%; P<0.001). These increases were associated with reductions in HDL apoA-I fractional clearance rate (18.2%; P=0.002) without changes in production rate. Although the apoA-II levels increased by 12.6% (P<0.001), we could not discern significant changes in either apoA-II fractional clearance rate or production rate. CETP levels increased 102% (P<0.001) on ANA because of a significant reduction in the fractional clearance rate of CETP (57.6%, P<0.001) with no change in CETP production rate. ANA treatment increases HDL apoA-I and CETP levels by decreasing the fractional clearance rate of each protein.

The novel selective PPARα modulator (SPPARMα) pemafibrate improves dyslipidemia, enhances reverse cholesterol transport and decreases inflammation and atherosclerosis

BackgroundAtherosclerosis is characterized by lipid accumulation and chronic inflammation in the arterial wall. Elevated levels of apolipoprotein (apo) B-containing lipoproteins are a risk factor for cardiovascular disease (CVD). By contrast, plasma levels of functional high-density lipoprotein (HDL) and apoA-I are protective against CVD by enhancing reverse cholesterol transport (RCT). Activation of peroxisome proliferator-activated receptor-α (PPARα), a ligand-activated transcription factor, controls lipid metabolism, cellular cholesterol trafficking in macrophages and influences inflammation. ObjectiveTo study whether pharmacological activation of PPARα with a novel highly potent and selective PPARα modulator, pemafibrate, improves lipid metabolism, macrophage cholesterol efflux, inflammation and consequently atherosclerosis development in vitro and in vivo using human apolipoprotein E2 Knock-In (apoE2KI) and human apoA-I transgenic (hapoA-I tg) mice. Approach and resultsPemafibrate treatment decreases apoB secretion in chylomicrons by polarized Caco-2/TC7 intestinal epithelium cells and reduces triglyceride levels in apoE2KI mice. Pemafibrate treatment of hapoA-I tg mice increases plasma HDL cholesterol, apoA-I and stimulates RCT to feces. In primary human macrophages, pemafibrate promotes macrophage cholesterol efflux to HDL and exerts anti-inflammatory activities. Pemafibrate also reduces markers of inflammation and macrophages in the aortic crosses as well as aortic atherosclerotic lesion burden in western diet-fed apoE2KI mice. ConclusionsThese results demonstrate that the novel selective PPARα modulator pemafibrate exerts beneficial effects on lipid metabolism, RCT and inflammation resulting in anti-atherogenic properties.

The Effect of Preoperative Apolipoprotein A-I on the Prognosis of Surgical Renal Cell Carcinoma: A Retrospective Large Sample Study.

The prognostic value of serum lipid-profile in renal cell cancer (RCC) remains unknown. The purpose of the study is to explore the association between the serum lipid-profile and RCC patients.The levels of preoperative serum lipid-profile (including cholesterol, triglycerides, high-density lipoprotein-cholesterol [HDL-C], low-density lipoprotein-cholesterol [LDL-C], apolipoprotein A-I [ApoA-I], and apolipoprotein B [ApoB]) were retrospectively performed in 786 patients with RCC. The cutoff values of the lipids were determined by the receiver-operating characteristic (ROC) curve analysis. Univariate and multivariate Cox regression analyses were performed to investigate the prognostic value of serum lipids in RCC.Combined ROC analysis and univariate and multivariate Cox regression analyses, for overall survival (OS), revealed patients with low ApoA-I (<1.04) had significantly lower OS than the high ApoA-I (≥1.04) group (multivariate Cox regression analyses, hazard ratio [HR], 0.57; P = 0.003). Not only in the whole RCC cohort but also in the subgroups stratified according to the pT1-2 (P = 0.002), pN0 (P < 0.001), and pM0 (P = 0.001) status, respectively. Moreover, in the 755 patients with nonmetastasis, the low ApoA-I group was also associated with shortened disease-free survival (DFS) time compared to the high ApoA-I group (multivariate Cox regression analyses, HR, 0.65; P = 0.033). However, the other lipids were not independent prognostic factors for surgical RCC.An elevated level of preoperative ApoA-I was demonstrated to be related with better survival in patients with surgical RCC. Measuring the preoperative ApoA-I might be a simple way for finding the poor prognostic patients who should enrolled in further clinical trials and management.

Apolipoprotein A-I interactions with insulin secretion and production.

Human population studies have established that an elevated plasma high-density lipoprotein cholesterol (HDL-C) level is associated with a decreased risk of developing cardiovascular disease. In addition to having several potentially cardioprotective functions, HDLs and apolipoprotein (apo)A-I, the main HDL apolipoprotein, also have antidiabetic properties. Interventions that elevate plasma HDL-C and apoA-I levels improve glycemic control in people with type 2 diabetes mellitus by enhancing pancreatic β-cell function and increasing insulin sensitivity. This review is concerned with recent advances in understanding the mechanisms by which HDLs and apoA-I improve pancreatic β-cell function. HDLs and apoA-I increase insulin synthesis and secretion in pancreatic β cells. The underlying mechanism of this effect is similar to what has been reported for intestinally derived incretins, such as glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide, which both increase β-cell insulin secretion under high glucose conditions. This involves the activation of a heterotrimeric G protein Gαs subunit on the β-cell surface that leads to induction of a transmembrane adenylyl cyclase, increased intracellular cyclic adenosine monophosphate and Ca levels, and activation of protein kinase A. Protein kinase A increases insulin synthesis by excluding FoxO1 from the β-cell nucleus and derepressing transcription of the insulin gene.

Correlation Between ABCA1 Gene Polymorphism and aopA-I and HDL-C in Abdominal Aortic Aneurysm.

BackgroundAs the most common type of aneurysm, abdominal aortic aneurysm (AAA) has an unfavorable prognosis due to the high frequency of rupture. Studies have indicated a close relationship between the pathogenesis and progression of AAA and abnormal serum lipid levels. ATP-binding cassette transport protein A1 (ABCA1) is a cell-surface protein facilitating cellular efflux of cholesterol. The single-nucleotide polymorphism (SNP) of ABCA1 gene has been suggested to be correlated with abnormal metabolism of lipids. Therefore, this study aimed to investigate the relationship between ABCA1 polymorphism and apoA-I and HDL-C in an attempt to elucidate its correlation with AAA occurrence.Material/MethodsWe included 126 AAA patients and 119 healthy controls in this study. PCR and restriction fragment length polymorphism (RFLP) were used to detect the SNP pattern of ABCA1 gene at locus rs2230806 from both AAA patients and healthy controls. The distribution pattern and correlation with apoA-I and HDL-C was analyzed.ResultsThe distribution of KK/RR genotype of ABCA1 gene had significant difference between disease and control group, with lower rates of RR genotype and R allele in the disease group (p<0.05). Levels of apoA-I and HDL-C, but not triglyceride and LDL-C levels, in AAA patients who carried R allele in ABCA1 gene (including RR and RK genotypes) were higher than in non-carriers (p<0.05). The R allele of ABCA1 gene was shown to be related with the occurrence of AAA (p<0.05).ConclusionsPolymorphism of ABCA1 gene is correlated with AAA occurrence, possibly via the regulation of serum lipid metabolism by R allele.

Hyperhomocysteinemia is associated with decreased apolipoprotein AI levels in normal healthy people.

BackgroundHyperhomocysteinemia (HHcy) is an independent risk factor for various cardiovascular diseases. Animal studies have shown that homocysteine (Hcy) inhibits hepatic expression of apolipoprotein AI (apoAI). Our recent clinical study showed that increased plasma Hcy levels were associated with decreased apoAI levels in patients with impaired glucose tolerance. In this study, we assessed a potential association between Hcy and apoAI levels in normal healthy people.MethodsA total of 1768 normal healthy individuals were divided into two groups: the control group (subjects without HHcy) and the HHcy group (subjects with HHcy).ResultsHHcy subjects exhibited significantly lower high-density lipoprotein cholesterol (HDL-C) and apoAI levels than the control group (HDL-C: 1.18 ± 0.25 vs. 1.29 ± 0.32 mmol/L; apoAI: 1.38 ± 0.19 vs. 1.47 ± 0.25 g/L; all P < 0.01). Plasma Hcy levels were negatively associated with HDL-C and apoAI levels after adjustments for age, BMI and TG (HDL-C: r = –0.10; apoAI: r = –0.11; all P < 0.05). Multivariate regression analysis showed that the plasma Hcy levels were an independent influencing factor for apoAI (β = –0.065, P < 0.05).ConclusionsIncreased plasma Hcy levels were associated with decreased apoAI levels in normal healthy people, and the inhibition of apoAI synthesis might be a mechanism through which Hcy is linked with the development of atherosclerosis in HHcy subjects.

Lipid-lowering and anti-inflammatory effects of omega 3 ethyl esters and krill oil: a randomized, cross-over, clinical trial.

IntroductionPolyunsaturated fatty acids (PUFAs) derived from different sources could have different lipid-lowering effects in humans. The main aim of our study was to compare the short-term triglyceride-lowering efficacy of krill oil and purified omega 3 ethyl ester PUFAs in mildly overweight hypertriglyceridemic subjects.Material and methodsThis double-blind, randomized clinical trial was carried out in 25 moderately hypertriglyceridemic subjects (TG = 150–500 mg/dl). After a 4-week run-in, participants were allocated to treatment with similar pills containing omega 3 ethyl ester PUFAs 1000 mg twice a day vs. krill oil 500 mg twice a day. After 4 weeks of treatment, participants were asked to observe a 4-week wash-out period, and they were then assigned to the alternative treatment for a further period of 4 weeks.ResultsAlthough both PUFA sources were able to improve TG plasma levels, esterified omega 3 PUFAs were more efficacious than krill oil (p < 0.05). Nonetheless, only krill oil treatment was able to significantly improve high-density lipoprotein cholesterol and apolipoprotein AI levels, compared to both baseline (p < 0.05) and end of treatment with esterified omega 3 PUFAs (p < 0.05) values. Both treatments were able to significantly reduce high-sensitivity C-reactive protein (hs-CRP) levels from the baseline (p < 0.05), but krill oil improved it more efficaciously than esterified omega 3 PUFAs (p < 0.05).ConclusionsKrill oil has lipid-lowering effects comparable with those obtained through a 4-fold higher dose of purified omega 3 ethyl ester PUFAs in mildly overweight hypertriglyceridemic subjects, while more efficaciously reducing hs-CRP.

Lipids and lipoproteins and inflammatory markers in patients with chronic apical periodontitis.

BackgroundSince chronic apical periodontitis (CAP) appears to be a risk factor for coronary heart disease, the aim of the study was to determine the relationship between the size of CAP lesion and inflammatory markers (hsCRP, IL-6, TNF-α), as well as lipids and lipoproteins (LpPLA2, apoAI, apoB level) in blood serum of patients with CAP.MethodsThe patients studied (n = 43) were divided into groups: patients under 50 and over 50 years of age, and a separate subgroup of the oldest age with the largest size of CAP lesions. Apolipoprotein AI (apoAI) above 150 mg/dL and below 150 mg/dL was used as an important criterion for the division of patients into groups. The CAP lesion size was measured using the Kodak digital imaging system software. The control group consisted of clinically healthy volunteers (n = 20) without CAP. Lipids were measured on a Siemens analyzer (Germany), apoAI, apoB, hsCRP levels were determined by immunonephelometric method, using the Health Care Diagnostic Product (Siemens GmbH, Germany), and IL-6, TNF-α and LpPLAG7 assay kits (ELISA, R&D Systems) were used.ResultsThe findings suggested that in patients with CAP and their age increase, the CAP lesion size, the concentration of inflammatory markers and LpPLA2 mass increased. Correlations between the CAP lesion size and LpPLA2 mass and between the CAP lesion size and TG level in patients with apoAI 150 ≤ mg/dL showed increase TG in atherogenic apoB-containing triglyceride-rich lipoprotein and TC in cholesterol-rich lipoprotein. The patients with a low apoAI and high LpPLA2 level can have a higher risk of odontogenic disease and progression of atherosclerosis and coronary heart disease.ConclusionWe have found a positive correlation between apoAI level and the CAP lesion size and a negative correlation between LpPLA2 level and the CAP lesion size. The results suggest that apoAI and LpPLA2 in HDL particles have antiinflammatory action and together can limit the CAP lesion size in patient with a higher apoAI level. The literature data on the distribution of lipoprotein particles in subjects are still insufficient, so this problem requires further studies.

Structural and Functional Analysis of the ApolipoproteinA-I A164S Variant.

Apolipoprotein A-I (apoA-I) is the main protein involved in the formation of high-density lipoprotein (HDL), it is the principal mediator of the reverse cholesterol transfer (RCT) pathway and provides cardio-protection. In addition to functional wild-type apoA-I, several variants have been shown to associate with hereditary amyloidosis. In this study we have performed biophysical and biochemical analyses of the structure and functional properties of the A164S variant of apoA-I (1:500 in the Danish general population), which is the first known mutation of apoA-I that leads to an increased risk of ischaemic heart disease (IHD), myocardial infarction and mortality without associated low HDL cholesterol levels. Despite the fact that epidemiologically IHD is associated with low plasma levels of HDL, the A164S mutation is linked to normal plasma levels of lipids, HDL and apoA-I, suggesting impaired functionality of this variant. Using biophysical techniques (e.g., circular dichroism spectroscopy and electron microscopy) to determine secondary structure, stability and pro-amyloidogenic property of the lipid free A164S apoA-I variant, our observations suggest similarity in structural properties between apoA-I WT and apoA-I A164S. However, the A164S apoA-I variant exhibits lower binding affinity to lipids but forms similar sized HDL particles to those produced by WT.

Nitrated apolipoprotein AI/apolipoprotein AI ratio is increased in diabetic patients with coronary artery disease

Aims/hypothesisRecent studies have suggested that determination of HDL function may be more informative than its concentration in predicting its protective role in coronary artery disease (CAD). Apolipoprotein AI (apoAI), the major protein of HDL, is nitrosylated in vivo to nitrated apoAI (NT-apoAI) that might cause dysfunction. We hypothesized that NT-apoAI/apoAI ratio might be associated with diabetes mellitus (DM) in CAD patients. MethodsWe measured plasma NT-apoAI and apoAI levels in 777 patients with coronary artery disease (CAD) by ELISA. Further, we measured plasma cholesterol efflux potential in subjects with similar apoAI but different NT-apoAI levels. ResultsWe found that median NT-apoAI/apoAI ratio was significantly higher in diabetes mellitus (DM) (n = 327) versus non-diabetic patients (n = 450). Further analysis indicated that DM, thiobarbituric acid-reactive substances and C-reactive protein levels were independent predictors of higher NT-apoAI/apoAI ratio. There was negative correlation between NT-apoAI/apoAI and use of anti-platelet and lipid lowering drugs. The cholesterol efflux capacity of plasma from 67 individuals with differing NT-apoAI but similar apoAI levels from macrophages in vitro was negatively correlated with NT-apoAI/apoAI ratio. ConclusionsHigher NT-apoAI/apoAI ratio is significantly associated with DM in this relatively large German cohort with CAD and may contribute to associated complications by reducing cholesterol efflux capacity.

Dyslipidemia in patients with systemic lupus erythematosus: Association with disease activity and B-type natriuretic peptide levels.

The aim of the present study was to evaluate the association between the levels of lipids and B-type natriuretic peptide (BNP) in systemic lupus erythematosus (SLE) patients with heart failure (HF). A total of 46 patients with active SLE and 40 healthy, age-matched control subjects were studied. BNP was measured by an immunofluorescence assay in fresh plasma. Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, apolipoprotein (Apo) B, ApoA-I and lipoprotein(a) were assessed. Compared with the control subjects, HDL-C and ApoA-I levels were considerably decreased and TG level increased markedly from SLE patients. The average concentration of HDL-C and ApoA-I in the SLE group with HF was significantly reduced compared to those patients without HF. The results showed that the levels of HDL-C and ApoA-I in SLE patients were negatively correlated with BNP. Disease activity was associated with the TC and TG levels. The present data indicated the presence of a cardiovascular (CV) risk in active SLE with high disease activity, which was demonstrated by the high frequency of dyslipidemia and higher BNP concentrations. Therefore, dyslipoproteinemia may underlie some of the increased risk for CV disease and HF in patients with SLE.

Abstract 12788: Adiponectin Modulates the Cardiovascular Risk Associated With Obesity: Results From the Framingham Offspring Study

Objectives: Our objective was to examine the interrelationships of cardiovascular disease (CVD) risk factors with obesity, lipoproteins and their subfractions, markers of glucose homeostasis, and the inflammation markers adiponectin, and C reactive protein (hs-CRP). Methods: We measured fasting plasma lipids, low-density lipoprotein (LDL)-C, small dense LDL-C (sdLDL-C), high-density lipoprotein (HDL)-C, HDL subfractions, triglycerides, glucose, insulin, adiponectin, and hs-CRP in 2,691 male and female participants (median age 58 years) in cycle 6 of the Framingham Offspring Study. We carried out univariate and multivariate statistical analyses. Results: In both men and women the presence of obesity compared to those of normal weight was significantly (P&lt;0.05) associated with: 1) a 60% increase in the prevalence of CVD, 2) a two to three fold higher prevalence of major CVD risk factors (hypertension, diabetes, and low HDL-C &lt; 40 mg/dL), 3) a doubling of plasma levels of hsCRP, insulin, and triglycerides, 4) increased sdLDL-C, and 5) significant decreases in adiponectin and the levels of apoA-I in very large protective α-1 HDL. Surprisingly there was no relationship of obesity with levels of LDL-C in men. By multivariate analysis, in both men and women, adiponectin level emerged as the statistically most important parameter determining the variability of HDL-C and apoA-I levels in very large α-1 HDL, and sdLDL-C, while for systolic blood pressure age was the most important determinant, and for hsCRP levels it was plasma insulin levels. Interestingly over half of obese subjects were not hypertensive or prediabetic, and less than 20% had premature CVD or diabetes. By tertile analysis in obese subjects, low adiponectin was associated with a doubling of the prevalence of diabetes, and significant increases in triglycerides, and sdLDL-C (men only), and significant decreases in HDL-C and apoA-I in large α-1 HDL. Conclusions: Our data indicate that the prevalence of CVD and its risk factors increases with body mass index, and that the level of circulating adiponectin is a significant determinant of cardiovascular risk, especially diabetes prevalence, and levels of LDL and HDL subfractions in obese subjects.

Abstract 18449: Apolipoprotein B/Apolipoprotein A-I Ratio and Progression of Aortic Valve Stenosis - Results From the PROGRESSA Study

Introduction: Calcific aortic stenosis (AS) is an active and complex disorder, which involves atherosclerotic-like processes. However, previous studies reported that the association between atherosclerotic risk factors and AS progression appears to be stronger in younger middle-aged patients compared to elderly ones. Hypothesis: Apolipoprotein B/apolipoprotein A-I (apoB/apoA-I) ratio reflects the balance between proatherogenic versus antiatherogenic lipid profile. The objective of this study was to examine the association between apoB/apoA-I ratio and progression of AS according to patient’s age. Methods: One hundred sixty five patients with AS were prospectively recruited in the PROGRESSA study. AS progression was assessed by increase in peak aortic jet velocity (Vpeak) measured by Doppler echocardiography between baseline and 2-year follow-up. Blood samples were collected to measure plasma levels of apoB and apoA-I. Results: The mean age was 66±13 years and 72% were male. During the 2-year follow-up, AS progression was similar in younger patients (age &lt;69 y.o. [median age for the whole cohort]; n=82) and older patients (Vpeak: +0.24±0.04 vs +0.25±0.03 m/s; p=0.82). There was a significant interaction (p&lt;0.01) between patient’s age and baseline apoB/apoA-I ratio for AS progression. Younger patients with high baseline apoB/apoA-I ratio (i.e. apoB/apoA-I ≥0.53; n=41) had faster AS progression compared to those with lower apoB/apoA-I ratio (Vpeak: +0.32±0.06 vs +0.16±0.04 m/s; p=0.03). In older patients, there was no significant association between apoB/apoA-I ratio and AS progression (Vpeak: +0.23±0.05 vs +0.27±0.04 m/s; p=0.55). After adjustment for sex, hypertension, dyslipidemia, diabetes, metabolic syndrome, creatinine level, degree of aortic valve calcification and baseline Vpeak, higher apoB/apoA-I ratio remained independently associated with faster progression of AS in younger patients (p=0.003). Conclusions: This prospective study shows for the first time that higher apoB/apoA-I ratio is a powerful and independent predictor of faster AS progression in younger patients. These findings suggest that the pathological processes involved in the progression of AS are different in younger versus older patients.