HDL Cholesterol Efflux Capacity Research Articles

High-Density Lipoprotein Cholesterol Efflux Capacity as a Novel Prognostic Surrogate for Coronary Artery Disease.

Aim: We examined the impact of baseline high-density lipoprotein cholesterol efflux capacity (CEC) on major cardiac adverse events (MACE) in patients with coronary artery disease (CAD) during a long-term secondary prevention. Method: CEC was measured using a cell-based efflux system in (3)[H]-cholesterol-labeled J774 macrophages in apolipoprotein B-depleted plasma between January 2011 and January 2013. Patients with CAD were divided into 2 groups as a boundary CEC value of 1: 0.19 ≤ CEC ＜1 (impaired CEC group, mean CEC of 0.76±0.16, n =136), and 1 ≤ CEC ≤ 2.08 (enhanced CEC group, 1.20±0.19, n =44). MACE, comprised the incidence of cardiac death, non-fatal myocardial infarction, and any revascularizations (RV) without restenosis approximately 1 year after vascularization, was retrospectively investigated at September 2019. Impact of enhanced CEC on MACE among 22 variables was examined by applying a Cox proportional hazard model. Result: The frequency of MACE in impaired CEC group (16.9%, mean observational interval of 2111±888 days) was significantly higher than that in enhanced CEC group (2.3%, 2,252±685, p =0.013), largely driven by the significantly higher RV incidence (14.0 % versus 2.3 %, p =0.032). Enhancement of CEC was the significant predictor of MACE (hazard ratio: 0.11; 95% CI: 0.013-0.879; p =0.038). Conclusion: A baseline CEC level of more than 1 in patients with CAD brought favorable long-term clinical outcomes, suggesting that CEC is a useful prognostic and therapeutic surrogate for secondary prevention of CAD.

Diabetes Impairs Cellular Cholesterol Efflux From ABCA1 to Small HDL Particles.

HDL (high-density lipoprotein) may be cardioprotective because it accepts cholesterol from macrophages via the cholesterol transport proteins ABCA1 (ATP-binding cassette transporter A1) and ABCG1 (ATP-binding cassette transporter G1). The ABCA1-specific cellular cholesterol efflux capacity (ABCA1 CEC) of HDL strongly and negatively associates with cardiovascular disease risk, but how diabetes mellitus impacts that step is unclear. To test the hypothesis that HDL's cholesterol efflux capacity is impaired in subjects with type 2 diabetes mellitus. We performed a case-control study with 19 subjects with type 2 diabetes mellitus and 20 control subjects. Three sizes of HDL particles, small HDL, medium HDL, and large HDL, were isolated by high-resolution size exclusion chromatography from study subjects. Then we assessed the ABCA1 CEC of equimolar concentrations of particles. Small HDL accounted for almost all of ABCA1 CEC activity of HDL. ABCA1 CEC-but not ABCG1 CEC-of small HDL was lower in the subjects with type 2 diabetes mellitus than the control subjects. Isotope dilution tandem mass spectrometry demonstrated that the concentration of SERPINA1 (serpin family A member 1) in small HDL was also lower in subjects with diabetes mellitus. Enriching small HDL with SERPINA1 enhanced ABCA1 CEC. Structural analysis of SERPINA1 identified 3 amphipathic α-helices clustered in the N-terminal domain of the protein; biochemical analyses demonstrated that SERPINA1 binds phospholipid vesicles. The ABCA1 CEC of small HDL is selectively impaired in type 2 diabetes mellitus, likely because of lower levels of SERPINA1. SERPINA1 contains a cluster of amphipathic α-helices that enable apolipoproteins to bind phospholipid and promote ABCA1 activity. Thus, impaired ABCA1 activity of small HDL particles deficient in SERPINA1 could increase cardiovascular disease risk in subjects with diabetes mellitus.

HDL Cholesterol Efflux Capacity is Impaired in Severe Short-Term Hypothyroidism Despite Increased HDL Cholesterol.

Severe hypothyroidism has profound effects on lipoprotein metabolism including high-density lipoprotein (HDL) cholesterol elevations but effects on HDL function metrics are unknown. To determine the impact of severe short-term hypothyroidism on HDL particle characteristics, HDL cholesterol efflux capacity (CEC), and HDL antioxidative capacity. Observational study with variables measured during severe short-term hypothyroidism (median TSH 81 mU/L) and after 20 weeks of thyroid hormone supplementation (median TSH 0.03 mU/L) (Netherlands Trial Registry ID 7228). University hospital setting in The Netherlands. Seventeen patients who had undergone a total thyroidectomy for differentiated thyroid carcinoma. HDL particle characteristics (nuclear magnetic resonance spectrometry), CEC (human THP-1-derived macrophage foam cells and apolipoprotein B-depleted plasma), and HDL anti-oxidative capacity (inhibition of low-density lipoprotein oxidation). During hypothyroidism plasma total cholesterol, HDL cholesterol and apolipoprotein A-I were increased (P ≤ 0.001). HDL particle concentration was unchanged, but there was a shift in HDL subclasses toward larger HDL particles (P < 0.001). CEC was decreased (P = 0.035), also when corrected for HDL cholesterol (P < 0.001) or HDL particle concentration (P = 0.011). HDL antioxidative capacity did not change. During severe short-term hypothyroidism CEC, an important antiatherogenic metric of HDL function, is impaired. HDL cholesterol and larger HDL particles are increased but HDL particle concentration is unchanged. Combined, these findings suggest that HDL quality and quantity are not improved, reflecting dysfunctional HDL in hypothyroidism.

Reactive Dicarbonyl Scavenging Effectively Reduces MPO-Mediated Oxidation of HDL and Restores PON1 Activity.

Atheroprotective functions of high-density lipoproteins (HDL) are related to the activity of HDL-associated enzymes such as paraoxonase 1 (PON1). We examined the impact of inhibition of myeloperoxidase (MPO)-mediated HDL oxidation by PON1 on HDL malondialdehyde (MDA) content and HDL function. In the presence of PON1, crosslinking of apoAI in response to MPO-mediated oxidation of HDL was abolished, and MDA-HDL adduct levels were decreased. PON1 prevented the impaired cholesterol efflux capacity of MPO-oxidized HDL from Apoe−/− macrophages. Direct modification of HDL with MDA increased apoAI crosslinking and reduced the cholesterol efflux capacity. MDA modification of HDL reduced its anti-inflammatory function compared to native HDL. MDA-HDL also had impaired ability to increase PON1 activity. Importantly, HDL from subjects with familial hypercholesterolemia (FH-HDL) versus controls had increased MDA-apoAI adducts, and PON1 activity was also impaired in FH. Consistently, FH-HDL induced a pro-inflammatory response in Apoe−/− macrophages and had an impaired ability to promote cholesterol efflux. Interestingly, reactive dicarbonyl scavengers, including 2-hydroxybenzylamine (2-HOBA) and pentyl-pyridoxamine (PPM), effectively abolished MPO-mediated apoAI crosslinking, MDA adduct formation, and improved cholesterol efflux capacity. Treatment of hypercholesterolemic mice with reactive dicarbonyl scavengers reduced MDA-HDL adduct formation and increased HDL cholesterol efflux capacity, supporting the therapeutic potential of reactive carbonyl scavenging for improving HDL function.

LDL Receptor Regulates the Reverse Transport of Macrophage-Derived Unesterified Cholesterol via Concerted Action of the HDL-LDL Axis: Insight From Mouse Models.

The HDL (high-density lipoprotein)-mediated stimulation of cellular cholesterol efflux initiates macrophage-specific reverse cholesterol transport (m-RCT), which ends in the fecal excretion of macrophage-derived unesterified cholesterol (UC). Early studies established that LDL (low-density lipoprotein) particles could act as efficient intermediate acceptors of cellular-derived UC, thereby preventing the saturation of HDL particles and facilitating their cholesterol efflux capacity. However, the capacity of LDL to act as a plasma cholesterol reservoir and its potential impact in supporting the m-RCT pathway in vivo both remain unknown. We investigated LDL contributions to the m-RCT pathway in hypercholesterolemic mice. Macrophage cholesterol efflux induced in vitro by LDL added to the culture media either alone or together with HDL or ex vivo by plasma derived from subjects with familial hypercholesterolemia was assessed. In vivo, m-RCT was evaluated in mouse models of hypercholesterolemia that were naturally deficient in CETP (cholesteryl ester transfer protein) and fed a Western-type diet. LDL induced the efflux of radiolabeled UC from cultured macrophages, and, in the simultaneous presence of HDL, a rapid transfer of the radiolabeled UC from HDL to LDL occurred. However, LDL did not exert a synergistic effect on HDL cholesterol efflux capacity in the familial hypercholesterolemia plasma. The m-RCT rates of the LDLr (LDL receptor)-KO (knockout), LDLr-KO/APOB100, and PCSK9 (proprotein convertase subtilisin/kexin type 9)-overexpressing mice were all significantly reduced relative to the wild-type mice. In contrast, m-RCT remained unchanged in HAPOB100 Tg (human APOB100 transgenic) mice with fully functional LDLr, despite increased levels of plasma APO (apolipoprotein)-B-containing lipoproteins. Hepatic LDLr plays a critical role in the flow of macrophage-derived UC to feces, while the plasma increase of APOB-containing lipoproteins is unable to stimulate m-RCT. The results indicate that, besides the major HDL-dependent m-RCT pathway via SR-BI (scavenger receptor class B type 1) to the liver, a CETP-independent m-RCT path exists, in which LDL mediates the transfer of cholesterol from macrophages to feces. Graphical Abstract: A graphical abstract is available for this article.

1419-P: Lower Medium and Total HDL Particle Concentrations May Contribute to CVD Risk in Type 1 Diabetes

Although it has long been proposed that HDL is dysfunctional in type 1 diabetes (T1D), this hypothesis has not been formally tested in large cohorts using validated functional and biochemical HDL metrics. We therefore determined whether HDL particle concentration (HDL-P) and function differed between 187 middle-aged adults with childhood-onset T1D (mean age 51 years, T1D duration 43 years, 53% women) and 200 individuals with normal glucose tolerance (NGT) of similar age and sex distribution. HDL-P was assessed by calibrated ion mobility analysis. HDL function, i.e., serum HDL cholesterol efflux capacity, was quantified in J774 cells using a validated assay. Separate stepwise linear regression models were constructed for each HDL metric, allowing for T1D status and potential confounding factors, including HDL cholesterol (HDL-C). The presence of significant effect modification by sex was evaluated. After adjustment, the concentrations of total (T-HDL-P; β=-0.44, p=0.09) and medium-sized (M-HDL-P; β=-0.84, p&amp;lt;0.0001) HDL particles were lower in the T1D compared with the NGT group. In contrast, T1D status was not significantly associated with small (S-HDL-P) and large-sized (L-HDL-P) HDL-P. A significant sex by T1D status interaction term was observed for M-HDL-P (p=0.03), indicating that women had higher M-HDL-P only in NGT; M-HDL-P did not differ by sex in T1D. Moreover, a marginally significant sex by T1D status interaction was observed for L-HDL (p=0.08), suggesting that women had higher L-HDL-P only in T1D. Unexpectedly, serum HDL cholesterol efflux capacity was higher in the T1D compared with the NGT group (β=0.29, p&amp;lt;0.0001). In conclusion, lower levels of T-HDL-P and M-HDL-P in T1D may explain in part the higher cardiovascular risk in T1D, as these metrics were recently shown to be associated with protection from vascular complications. The lack of a difference in M-HDL-P by sex in T1D may contribute to the loss of cardioprotection associated with female sex. Disclosure T. Costacou: None. T. Vaisar: Consultant; Self; AstraZeneca. J. Ju: None. K. Bornfeldt: None. T.J. Orchard: None. J. Heinecke: None. Funding National Institutes of Health (HL130153, DK34818)

Functional pasta consumption in healthy volunteers modulates ABCG1-mediated cholesterol efflux capacity of HDL

Backgrounds and aimsPrevention of cardiovascular (CV) disease is considered a central issue in public health and great attention is payed to nutritional approaches, including consumption of functional foods to reduce CV risk in individuals without indications for anti-atherosclerotic drugs. Cholesterol efflux capacity (CEC) is an important anti-atherogenic property of HDL and a marker of CV risk. We evaluated the effect of a daily consumption of an innovative whole-wheat synbiotic pasta, compared to a control whole-wheat pasta, on serum ATP binding cassette G1 (ABCG1)-mediated CEC in healthy overweight or obese individuals. Methods and resultsStudy participants (n = 41) were randomly allocated to either innovative or control pasta, consumed daily for twelve weeks. Serum CEC was measured before and after the dietary intervention, by a well-established radioisotopic technique on Chinese Hamster Ovary Cells transfected with human ABCG1. The innovative synbiotic pasta consumption was associated to a significantly higher post treatment/baseline ratio of ABCG1-mediated CEC values with respect to control pasta (mean ratio 1.05 ± 0.037 and 0.95 ± 0.042 respectively, p < 0.05). Analysis of the relationship between ABCG1-mediated CEC and glycemia, homocysteine, total folates and interleukin-6 showed specific changes in the correlations between HDL function and glycemia, oxidative and inflammatory markers only after synbiotic pasta consumption. ConclusionThis is the first report on serum CEC improvement obtained by a new synbiotic functional pasta consumption, in absence of lipid profile modifications, in overweight/obese participants. This pilot study suggests that a simple dietary intervention can be a promising approach to CV preservation through improving of athero-protective HDL function.

SAT-LB92 Sex Hormones Therapy Differentially Modulates HDL Function in Transgender Individuals

Background/aim: The main proposed atheroprotective function of high-density lipoproteins (HDL) lays on their role to promote macrophage cholesterol efflux. An insightful way to learn more about the effects of sex hormones on HDL function is to study changes during hormone therapy. The present study was aimed at evaluating the effects of exogenous sex hormones administration on HDL cholesterol efflux capacity (CEC) within transgender individuals. CEC estimates the ability of HDL to remove cholesterol from cells, i.e. the initial step in reverse cholesterol transport. Subjects/Methods: Transmen were treated with testosterone gel, a mix of testosterone esters once every three weeks) or testosterone undecanoate once every twelve weeks, whereas transwomen were treated with either oral estradiol valerate or a transdermal application of estradiol (patches). Cyproterone acetate was prescribed as a testosterone-blocking agent to all transwomen. HDL function was evaluated by a radioisotopic technique. Hormone levels, lipids and HDL function were evaluated after one year of follow-up. Results: In transmen (n= 15), testosterone markedly increased (+ 97%; p < 0.0001), whereas luteinizing hormone (LH) decreased significantly (- 64%; p = 0.049). Total cholesterol and low-density lipoprotein cholesterol (LDL-C) were not affected by testosterone treatment, whilst triglycerides (TG) were raised (+ 11.76%; p = 0.0078) and HDL-C reduced (- 19.6%, p=0.0103). Concerning HDL CEC, only the aqueous diffusion process was lowered (- 9.8%; p = 0.0032), an effect directly correlated with HDL-C changes (r = 0.6242, p = 0.0002). Total-, ATP-binding cassette transporter (ABCA1)-, and ABCG1-mediated CEC were not affected by testosterone treatment. In transwomen (n= 15), estradiol levels were raised (+200%, p=0.013) whereas LH and testosterone significantly reduced, i.e. - 97% for both. Relative to lipids, estradiol supplementation reduced total cholesterol (- 10.7%, p=0.0017), HDL-C (- 14.3%, p = 0.0024) and LDL-C (- 10.9%, p = 0.0058). Total HDL CEC decreased (- 11%, p=0.0001) with a specific decrement in CEC mediated by the ATP-binding cassette transporter (ABCA1) (-24%, p = 0.0003) and aqueous diffusion (-4.7%, p = 0.0014). This last was associated to a reduction in HDL-C (r = 0.4084, p = 0.0251). Conversely, the drop in ABCA1 and total CEC did not associate to reductions in HDL-C levels. Conclusions: In transmen, testosterone supplementation was associated with a reduction in aqueous diffusion-mediated CEC, an effect potentially dependent to HDL-C changes. In transwomen, estrogen significantly decreased HDL function (CEC), independent of HDL-C levels changes.

High density lipoprotein functionality and cardiovascular events and mortality: A systematic review and meta-analysis

Background and aimsThe aim of this systematic review and meta-analysis is to synthesize studies assessing the associations between high-density lipoprotein functionality and risk of cardiovascular disease and mortality. MethodsWe searched Medline and Embase for the identification of observational studies meeting the inclusion criteria. This meta-analysis was conducted following the PRISMA statement and was registered in PROSPERO (CRD42017065857). We pooled risk estimates with a random-effect model separately for cardiovascular disease (fatal and non-fatal) and all-cause mortality. ResultsOut of 29 manuscripts, 20 articles investigated cholesterol efflux capacity (13 prospective and 7 cross-sectional), 10 antioxidant capacity (7 prospective and 3 cross-sectional) and two anti-inflammatory capacity of high-density lipoprotein (1 prospective and 1 cross-sectional). A greater cholesterol efflux capacity was associated with lower risk of cardiovascular disease in 8 studies (RR for 1SD increase: 0.86; 95% CI: 0.76–0.98) and of mortality in 5 studies (RR for 1SD increase: 0,77; 0.60–1.00). Better antioxidant capacity was non-significantly associated with lower cardiovascular disease risk in 2 studies (RR for 1SD increase 0.70; 0.32–1.53) and significantly with mortality in 3 studies (RR for 1SD increase 0.48; 0.28–0.81). High-density lipoprotein anti-inflammatory ability was associated with a lower cardiovascular disease risk in the only prospective study. ConclusionsGreater high-density lipoprotein cholesterol efflux capacity and antioxidant/anti-inflammatory capacities were associated with lower risk of cardiovascular disease. However, the heterogeneity between studies and evidence of publication bias warrants caution and highlights the need for larger prospective studies with standardized assays and specific outcomes.

HDL functions and their interaction in patients with ST elevation myocardial infarction: a case control study

BackgroundRecent studies emphasize the importance of HDL function over HDL cholesterol measurement, as an important risk for cardiovascular diseases (CVD). We compared the HDL function of patients with acute coronary syndrome (ACS) and healthy controls.MethodsWe measured cholesterol efflux capacity of HDL using THP-1 macrophages labelled with fluorescently tagged (BODIPY) cholesterol. PON1 activities toward paraoxon and phenyl acetate were assessed by spectrophotometric methods.ResultsWe recruited 150 ACS patients and 110 controls. The HDL function of all patients during acute phase and at six month follow-up was measured. The mean age of the patients and controls was 51.7 and 43.6 years respectively. The mean HDL cholesterol/apolipoprotein A-I levels (ratio) of patients during acute phase, follow-up and of controls were 40.2 mg/dl/ 112.5 mg/dl (ratio = 0.36), 38.3 mg/dl/ 127.2 mg/dl (ratio = 0.30) and 45.4 mg/dl/ 142.1 mg/dl (ratio = 0.32) respectively. The cholesterol efflux capacity (CEC) of HDL was positively correlated with apolipoprotein A-I levels during acute phase (r = 0.19, p = 0.019), follow-up (r = 0.26, p = 0.007) and of controls (r = 0.3, p = 0.0012) but not with HDL-C levels (acute phase: r = 0.07, p = 0.47; follow-up: r = 0.1, p = 0.2; control: r = 0.02, p = 0.82). Higher levels of cholesterol efflux capacity, PON1 activity and apolipoprotein A-I were associated with lower odds of development of ACS. We also observed that low CEC is associated with higher odds of having ACS if PON1 activity of HDL is also low and vice versa.ConclusionACS is associated with reduced HDL functions which improves at follow-up. The predicted probability of ACS depends upon individual HDL functions and the interactions between them.

Temporal Dynamics of High-Density Lipoprotein Proteome in Diet-Controlled Subjects with Type 2 Diabetes.

We examined the effect of mild hyperglycemia on high-density lipoprotein (HDL) metabolism and kinetics in diet-controlled subjects with type 2 diabetes (T2D). 2H2O-labeling coupled with mass spectrometry was applied to quantify HDL cholesterol turnover and HDL proteome dynamics in subjects with T2D (n = 9) and age- and BMI-matched healthy controls (n = 8). The activities of lecithin–cholesterol acyltransferase (LCAT), cholesterol ester transfer protein (CETP), and the proinflammatory index of HDL were quantified. Plasma adiponectin levels were reduced in subjects with T2D, which was directly associated with suppressed ABCA1-dependent cholesterol efflux capacity of HDL. The fractional catabolic rates of HDL cholesterol, apolipoprotein A-II (ApoA-II), ApoJ, ApoA-IV, transthyretin, complement C3, and vitamin D-binding protein (all p < 0.05) were increased in subjects with T2D. Despite increased HDL flux of acute-phase HDL proteins, there was no change in the proinflammatory index of HDL. Although LCAT and CETP activities were not affected in subjects with T2D, LCAT was inversely associated with blood glucose and CETP was inversely associated with plasma adiponectin. The degradation rates of ApoA-II and ApoA-IV were correlated with hemoglobin A1c. In conclusion, there were in vivo impairments in HDL proteome dynamics and HDL metabolism in diet-controlled patients with T2D.

Correlates and Predictors of Cerebrospinal Fluid Cholesterol Efflux Capacity from Neural Cells, a Family of Biomarkers for Cholesterol Epidemiology in Alzheimer's Disease.

Basic research has implicated intracellular cholesterol in neurons, microglia, and astrocytes in the pathogenesis of Alzheimer's disease (AD), but there is presently no assay to access intracellular cholesterol in neural cells in living people in the context of AD. To devise and characterize an assay that can access intracellular cholesterol and cholesterol efflux in neural cells in living subjects. We modified the protocol for high-density lipoprotein cholesterol efflux capacity (CEC) from macrophages, a biomarker that accesses cholesterol in macrophages in atherosclerosis. To measure cerebrospinal fluid (CSF) CECs from neurons, microglia, and astrocytes, CSF was exposed to, correspondingly, neuronal, microglial, and astrocytic cholesterol source cells. Human neuroblastoma SH-SY5Y, mouse microglial N9, and human astroglial A172 cells were used as the cholesterol source cells. CSF samples were screened for contamination with blood. CSF CECs were measured in a small cohort of 22 individuals. CSF CECs from neurons, microglia, and astrocytes were moderately to moderately strongly correlated with CSF concentrations of cholesterol, apolipoprotein A-I, apolipoprotein E, and clusterin (Pearson's r = 0.53-0.86), were in poor agreement with one another regarding CEC of the CSF samples (Lin's concordance coefficient rc = 0.71-0.76), and were best predicted by models consisting of, correspondingly, CSF phospholipid (R2 = 0.87, p < 0.0001), CSF apolipoprotein A-I and clusterin (R2 = 0.90, p < 0.0001), and CSF clusterin (R2 = 0.62, p = 0.0005). Characteristics of the CSF CEC metrics suggest a potential for independent association with AD and provision of fresh insight into the role of cholesterol in AD pathogenesis.

HDL-related biomarkers are robust predictors of survival in patients with chronic liver failure

High-density lipoprotein cholesterol (HDL-C) levels are reduced in patients with chronic liver disease and inversely correlate with disease severity. During acute conditions such as sepsis, HDL-C levels decrease rapidly and HDL particles undergo profound changes in their composition and function. We aimed to determine whether indices of HDL quantity and quality associate with progression and survival in patients with advanced liver disease. HDL-related biomarkers were studied in 508 patients with compensated or decompensated cirrhosis (including acute-on-chronic liver failure [ACLF]) and 40 age- and gender-matched controls. Specifically, we studied levels of HDL-C, its subclasses HDL2-C and HDL3-C, and apolipoprotein A1 (apoA-I), as well as HDL cholesterol efflux capacity as a metric of HDL functionality. Baseline levels of HDL-C and apoA-I were significantly lower in patients with stable cirrhosis compared to controls and were further decreased in patients with acute decompensation (AD) and ACLF. In stable cirrhosis (n= 228), both HDL-C and apoA-I predicted the development of liver-related complications independently of model for end-stage liver disease (MELD) score.In patients with AD, with or without ACLF (n= 280), both HDL-C and apoA-I were MELD-independent predictors of 90-day mortality. On ROC analysis, both HDL-C and apoA-I had high diagnostic accuracy for 90-day mortality in patients with AD (AUROCs of 0.79 and 0.80, respectively, similar to that of MELD 0.81). On Kaplan-Meier analysis, HDL-C <17 mg/dl and apoA-I <50 mg/dl indicated poor short-term survival. The prognostic accuracy of HDL-C was validated in a large external validation cohort of 985 patients with portal hypertension due to advanced chronic liver disease (AUROCs HDL-C: 0.81 vs. MELD: 0.77). HDL-related biomarkers are robust predictors of disease progression and survival in chronic liver failure. People who suffer from cirrhosis (scarring of the liver) have low levels of cholesterol carried by high-density lipoproteins (HDL-C). These alterations are connected to inflammation, which is a problem in severe liver disease. Herein, we show that reduced levels of HDL-C and apolipoprotein A-I (apoA-I, the main protein carried by HDL) are closely linked to the severity of liver failure, its complications and survival. Both HDL-C and apoA-I can be easily measured in clinical laboratories and are as good as currently used prognostic scores calculated from several laboratory values by complex formulas.

HDL cholesterol efflux capacity is related to disease activity in psoriatic arthritis patients.

Cholesterol efflux capacity (CEC) is the ability of high-density lipoprotein (HDL) cholesterol to accept cholesterol from macrophages. CEC is linked to cardiovascular events in the general population, and it has been shown to be disrupted in inflammatory states. The aim of this study was to establish whether CEC is impaired in PsA patients and if this could be explained by disease-related features like disease activity. Case-control study that encompassed 105 individuals: 52 PsA patients and 53 controls. CEC, using an in vitro assay, and lipoprotein serum concentrations were assessed in patients and controls. Disease activity in patients with PsA was measured using the Disease Activity Index for Psoriatic Arthritis (DAPSA). Multivariate analysis was performed to study the differences between CEC in patients and controls, and the relation of CEC with PsA activity-related data and lipid profile. Total cholesterol, apolipoprotein A1, and LDL cholesterol serum levels were downregulated in PsA patients. CEC did not differ between controls and patients (17 ± 10 vs. 18 ± 2%, p = 0.15) after adjusting for traditional cardiovascular risk factors or other variations in the lipid profile related to the disease. Traditional cardiovascular risk factors, both in patients and controls, were not related to CEC. After multivariate regression analysis, the DAPSA score was inversely and independently associated with CEC (beta coefficient - 0.75 [95%CI - 1.39-- 0.11] %, p = 0.023). CEC is inversely associated with disease activity in PSA patients, reinforcing the role of disease activity as a key factor in the development of accelerated atherosclerosis in these patients.Key Points• Cholesterol efflux capacity is linked to cardiovascular events in the general population.• In patients with psoriatic arthritis, cholesterol efflux capacity is inversely associated with disease activity (beta coefficient - 0.75[95% CI - 1.39-- 0.11] %, p = 0.023).• This finding reinforces the role of disease activity as a key factor in increasing cardiovascular risk in psoriatic arthritis patients.

LCK inhibitor attenuates atherosclerosis in ApoE−/− mice via regulating T cell differentiation and reverse cholesterol transport

Lots of studies demonstrated that CD4+ T cells regulate the development of atherosclerosis (AS). Previously, we reported that LCK, a key molecule in activation of T cell receptor (TCR) signalling and T cells, adversely affects reverse cholesterol transport (RCT), which ameliorates AS in vitro. To investigate the effect of LCK on AS in vivo, we injected the LCK inhibitor, PP2, into ApoE−/− mice fed a chow diet or a high-fat diet (HFD). Although, AS plaques were not affected by PP2 in chow diet-fed mice, PP2 significantly reduced the lesion percentage and necrotic core areas in HFD-fed mice. We further analysed the plaque contents and found that the accumulation of lipids and macrophages were decreased, while the contents of collagen and smooth muscle cells were increased by the LCK inhibitor. Thus, inhibiting LCK enhanced the plaque stability. We also found the LCK inhibitor improved cholesterol efflux capacity of HDL and up-regulated RCT regulatory proteins in the spleen. Moreover, inhibiting LCK regulated differentiation of T cells by increasing regulatory T (Treg) cells and decreasing the number of T helper 1 (Th1) cells in the aorta, thymus and spleen. Consistent with these results, infiltration of CD4+ T cells in plaques, secretion of pro-atherosclerotic cytokines, INF-γ and TNF-α synthesized mostly by Th1 cells, and the activation of PI3K/AKT/mTOR signalling were inhibited by the LCK inhibitor. Moreover, the effect of LCK inhibitor on the ratio of Th1 to Treg cells were compromised by activation of mTOR. Together, these data indicate that inhibiting LCK in TCR signalling attenuated the development of AS and promoted plaque stability. Improving RCT by upregulating RCT regulatory proteins and decreasing the Th1/Treg ratio by inhibiting PI3K/AKT/mTOR signalling may contribute to the anti-atherosclerotic effects of LCK inhibition.

739 Moderate and High Intensity Exercise Improve Cholesterol Efflux Capacity, Lipoprotein Profile and Increase HDL Particle Size in Healthy Young Men

Exercise is associated with increased HDL-C and a reduced risk of CVD. The type, intensity and mechanism by which exercise impacts on risk is not completely understood. We investigated the effects of moderate and high intensity exercise on HDL function, particle size, lipid/lipoprotein profile in a highly homogeneous population. 115 male army recruits (21+/-3 y) underwent a 12-week moderate-intensity exercise program. Of these, 51 then completed a 15-week higher-intensity program. Fitness increased, %bodyfat, and BMI decreased post-moderate intensity exercise (all p<0.01) and were sustained post-high intensity exercise. Lipid/lipoprotein profile, HDL function and particle size improved with exercise (see Table). In healthy young men, moderate and high intensity exercise improved fitness, body composition, lipid/ lipoprotein profile, HDL particle size and cholesterol efflux capacity. High intensity exercise resulted in sustained or further improvements. Improved HDL function may contribute to exercise-related reductions in CVD risk.Tabled 1Baseline (phase 1)Moderate intensity (phase 2)High intensity (phase 3)HDL-C (mmol/L)1.46±0.051.58±0.06*1.71±0.06# +LDL-C (mmol/L)2.49±0.102.39±0.092.49±0.10Apolipoprotein AI (mg/ml)1.41±0.031.60±0.04*1.70±0.04#+Apolipoprotein AII (mg/ml)0.82±0.030.79±0.030.82±0.03apoB/apoA-I (mg/mL)0.58±0.020.50±0.02*0.50±0.02#apoA-I/apoA-II (mol/mol)1.85±0.062.23±0.07*2.09±0.06#Cholesterol Efflux (%)0.52±0.010.59±0.01*0.61±0.02#HDL diameter (mm)7.89±0.148.47±0.11*8.48±0.03#∗P1 vs P2: p<0.05, #P1 vs P3: p<0.05, +P2 vs P3: p<0.05. Open table in a new tab

High-density lipoprotein cholesterol efflux capacity is not associated with atherosclerosis and prevalence of cardiovascular outcome: The CODAM study

Cholesterol Efflux Capacity (CEC) is considered to be a key atheroprotective property of high-density lipoproteins (HDL). However, the role of HDL-CEC in atherosclerosis and cardiovascular (CV) risk is still controversial, and data in individuals with diabetes are limited. In this study, we have investigated the relationship of CEC and other HDL characteristics with clinical and subclinical atherosclerosis in subjects with elevated cardiovascular diseases (CVD) risk and Type 2 Diabetes Mellitus (T2DM). Using multiple linear regression analyses, we determined the relationship of HDL-CEC with carotid intima-media thickness (cIMT, Z-Score), an endothelial dysfunction (EnD) Score (Z-Score), prevalent CVD (n=150 cases) and history of CV events (CVE, n=85 cases) in an observational cohort (CODAM, n=574, 59.6±0.3yr, 61.3% men, 24.4% T2DM). Stratified analyses were performed to determine if the associations differed between individuals with normal glucose metabolism (NGM) and those with disturbed glucose metabolism. HDL-CEC was not associated with either marker of atherosclerosis (cIMT, EnD Score) nor with CVD or CVE. In contrast, other HDL characteristics that is, HDL-Cholesterol (HDL-C, Z-Score), apolipoprotein A-I (apoA-I, Z-Score), HDL size (Z-Score) and HDL particle number (HDL-P, Z-Score) were inversely and significantly associated with the EnD Score (s -0.226 to -0.097, P<.05) and CVE (ORs 0.61 to 0.68, P<.05). In stratified analyses, HDL size and HDL-P were significantly associated with the EnD Score in individuals with NGM (Pinteraction .039 and .005, respectively), but not in those with (pre)diabetes. HDL-C and apoA-I were inversely associated with prevalent CVD in individuals with (pre)diabetes (Pinteraction=.074 and .034, respectively), but not in those with NGM. HDL-CEC is not associated with clinical or subclinical atherosclerosis, neither in the whole population nor in individuals with (pre)diabetes, while other HDL characteristics show atheroprotective associations. The atheroprotective associations of HDL-size and HDL-P are lost in (pre)diabetes, while higher concentrations of HDL-C and apoA-I are associated with a lower prevalence of CVD in (pre)diabetes.

Lower than average HDL cholesterol efflux capacity in Lithuanian population

BackgroundThe aim of our study was to evaluate high-density lipoprotein cholesterol (HDL-C) efflux capacity in healthy controls and patients with severe dyslipidemia. Evaluation of HDL function may be beneficial for better understanding of cardiovascular diseases, as well as for taking actions to minimize residual cardiovascular risk.MethodsDuring 2016–2017 a total of 93 participants – 48 (51.6%) women and 45 (48.4%) men – were included in this cross-sectional study. Data of 45 (48.4%) participants with severe dyslipidemia (SD) and 48 (51.6%) controls without dyslipidemia was used for statistical analysis. Total lipid panel, concentration of lipoprotein (a) and apolipoproteins were measured, data about cardiovascular risk factors were collected and detailed evaluation of HDL-C quality was performed for all patients.ResultsIncreased HDL-C concentration was associated with higher ApoA1 (r = 0.866 in controls, r = 0.63 in SD group), ApoA2 (r = 0.41 in controls, r = 0.418 in SD group) and LDL-C concentrations (r = − 0.412 in SD group), lower ApoE (r = − 0.314 in SD group) and TG concentrations (r = − 0.38 in controls, r = − 0.608 in SD group), lower ApoB/ApoA1 ratio (r = − 0.567 in control group), below average HDL-C efflux capacity (r = − 0.335 in SD group), lower BMI (r = − 0.327 in controls, r = − 0.531 in SD group) and abdominal circumference (r = − 0.309 in women with SD). Below-average HDL-C efflux capacity was found in 67.7% (N = 63) of participants. It was more often found among patients with normal weight or BMI 30–31 kg/m2. HDL-C efflux capacity was inversely associated with HDL-C concentration (r = − 0.228).ConclusionAbnormal HDL function may be associated with residual cardiovascular risk in Lithuanian population.

P3767Progressive left atrial remodeling associates with cholesterol efflux capacity of HDL in atrial fibrillation patients

Abstract Background The clinical significance of high-density lipoprotein (HDL) function, represented by cholesterol efflux capacity (CEC), in addition to serum HDL cholesterol (HDL-C) levels, has been recognized in the pathogenesis and prognosis in patients with atherosclerotic cardiovascular diseases. However, the roles of HDL in the development and the progression of atrial fibrillation (AF), has been rarely evaluated. In this study, we thus hypothesized that the compromised HDL function may be associated with the progression of pathological structural remodeling in left atrium (LA). Objective We explored the association between CEC of HDL and the left atrial dimension (LAD), a maker of structural remodeling in the LA, in patients with AF and control. Methods This is a single center case-control study including consecutive 260 AF patients (AF group) and 34 paroxysmal supraventricular tachycardia (PSVT) patients (PSVT group, served as a control group), who underwent catheter ablation from July 2017 to December 2018. Blood samples were collected before catheter ablation procedure. CEC of HDL was measured by using ex vivo radiotracer system that involved incubation of [3H] cholesterol-loaded J774.1 murine macrophage-like cells with apoB-depleted serum. Results Serum HDL-C level was lower in AF group compared to those of PSVT group (55.3±15.3mg/dl vs 61.7±13.3mg/dl: p=0.024). As a marker of HDL function, CEC of HDL was significantly lower in patients with AF group compared to those in PSVT patients (4.74±0.84% vs 5.20±0.99%: p=0.005, Fig 1). In all patients including both groups, CEC of HDL was inversely correlated with LAD (r=−0.25; p&lt;0.001, Fig 2), indicating the inverse association between HDL function and the progression of structural remodeling in AF. Moreover, multivariate logistic regression analysis adjusted by age, gender, body mass index, ejection fraction, and HDL-C demonstrated that increase in CEC of HDL was associated with the lower risk to be highest quartiles of LAD (&gt;42mm), even adjusted by serum HDL-C levels (odds ratio of 1-SD elevation in CEC of HDL for LAD&gt;42mm: 0.63; 95% confidence interval: 0.40–0.97, p=0.037), which implicated the link between HDL function and progression of left atrial structural remodeling. Conclusion Findings in this study may suggest that compromised HDL functionality is associated with the pathogenesis of left atrial structural remodeling in AF patients.

Relationship between HDL Cholesterol Efflux Capacity, Calcium Coronary Artery Content, and Antibodies against ApolipoproteinA-1 in Obese and Healthy Subjects.

Aims: To explore the associations between cholesterol efflux capacity (CEC), coronary artery calcium (CAC) score, Framingham risk score (FRS), and antibodies against apolipoproteinA-1 (anti-apoA-1 IgG) in healthy and obese subjects (OS). Methods and Results: ABCA1-, ABCG1-, passive diffusion (PD)-CEC and anti-apoA-1 IgG were measured in sera from 34 controls and 35 OS who underwent CAC score determination by chest computed tomography. Anti-apoA-1 IgG ability to modulate CEC and macrophage cholesterol content (MCC) was tested in vitro. Controls and OS displayed similar ABCG1-, ABCA1-, PD-CEC, CAC and FRS scores. Logistic regression analyses indicated that FRS was the only significant predictor of CAC lesion. Overall, anti-apoA-1 IgG were significantly correlated with ABCA1-CEC (r = 0.48, p < 0.0001), PD-CEC (r = −0.33, p = 0.004), and the CAC score (r = 0.37, p = 0.03). ABCA1-CEC was correlated with CAC score (r = 0.47, p = 0.004) and FRS (r = 0.18, p = 0.29), while PD-CEC was inversely associated with the same parameters (CAC: r = −0.46, p = 0.006; FRS: score r = −0.40, p = 0.01). None of these associations was replicated in healthy controls or after excluding anti-apoA-1 IgG seropositive subjects. In vitro, anti-apoA-1 IgG inhibited PD-CEC (p < 0.0001), increased ABCA1-CEC (p < 0.0001), and increased MCC (p < 0.0001). Conclusions: We report a paradoxical positive association between ABCA1-CEC and the CAC score, with the latter being inversely associated with PD in OS. Corroborating our clinical observations, anti-apoA-1 IgG enhanced ABCA1 while repressing PD-CEC, leading to MCC increase in vitro. These results indicate that anti-apoA-1 IgG have the potential to interfere with CEC and macrophage lipid metabolism, and may underpin paradoxical associations between ABCA1-CEC and cardiovascular risk.