High Density Lipoprotein Cholesterol Efflux Capacity and Atherosclerosis in Cardiovascular Disease: Pathophysiological Aspects and Pharmacological Perspectives

Lipid exchange of apolipoprotein A-I amyloidogenic variants in reconstituted high-density lipoprotein with artificial membranes

High-density lipoproteins (HDLs) are responsible for removing cholesterol from arterial walls, through a process known as reverse cholesterol transport. The main protein in HDL, apolipoprotein A-I (ApoA-I), is essential to this process, and changes in its sequence significantly alter HDL structure and functions. ApoA-I amyloidogenic variants, associated with a particular hereditary degenerative disease, are particularly effective at facilitating cholesterol removal, thus protecting carriers from cardiovascular disease. Thus, it is conceivable that reconstituted HDL (rHDL) formulations containing ApoA-I proteins with functional/structural features similar to those of amyloidogenic variants hold potential as a promising therapeutic approach. Here we explored the effect of protein cargo and lipid composition on the function of rHDL containing one of the ApoA-I amyloidogenic variants G26R or L174S by Fourier transformed infrared spectroscopy and neutron reflectometry. Moreover, small-angle x-ray scattering uncovered the structural and functional differences between rHDL particles, which could help to comprehend higher cholesterol efflux activity and apparent lower phospholipid (PL) affinity. Our findings indicate distinct trends in lipid exchange (removal vs. deposition) capacities of various rHDL particles, with the rHDL containing the ApoA-I amyloidogenic variants showing a markedly lower ability to remove lipids from artificial membranes compared to the rHDL containing the native protein. This effect strongly depends on the level of PL unsaturation and on the particles' ultrastructure. The study highlights the importance of the protein cargo, along with lipid composition, in shaping rHDL structure, contributing to our understanding of lipid-protein interactions and their behavior.

Lipids and sudden sensorineural hearing loss: A bidirectional two-sample Mendelian randomization analysis

OBJECTIVE

While numerous observational studies have indicated an association between lipids and Sudden Sensorineural Hearing Loss (SSNHL), it remains uncertain whether dyslipidemia serves as a causal risk factor for SSNHL. Our objective is to elucidate the potential causal relationship between lipid levels and SSNHL through Mendelian randomization analysis.

METHODS

The primary and secondary lipid data used in this study were sourced from the UK Biobank (UKBB) and the Global Lipid Genetics Consortium results (GLGC), respectively. These datasets were obtained from large, publicly available genome-wide association studies (GWAS). The outcome data for sudden sensorineural hearing loss (SSNHL) were acquired from the Finnegan Biobank, consisting of 1491 cases and 196,592 controls. Subsequently, both single-variable Mendelian randomization (SVMR) and multivariate Mendelian randomization (MVMR) methods were employed to evaluate the causal relationship between lipids and the occurrence of SSNHL.

RESULTS

Among the primary lipid data, SVMR analysis showed a significant correlation between high density lipoprotein cholesterol (HDL-C) (OR: 0.822, 95 %CI: 0.694-0.974, p = 0.023) and SSNHL, and triglycerides (TG) (OR: 0.997, 95 %CI: 0.836-1.188, p = 0.975), low density lipoprotein cholesterol (LDL-C) (OR: 1.067, 95 %CI: 0.861-1.322, p = 0.552) did not correlate with SSNHL. In the secondary lipid data, SVMR analysis showed that HDL-C (OR: 0.987, 95 %CI: 0.805-1.210, p = 0.903), TG (OR: 0.991, 95 %CI: 0.787-1.246, p = 0.937) and LDL-C (OR: 1.092, 95 % CI: 0.926-1.287, p = 0.294) did not correlate with SSNHL. MVMR analysis of the primary lipid data showed that HDL-cholesterol (OR: 0.755, 95 % CI: 0.596-0.956, p = 0.019) was significantly associated with SSNHL, while TG (OR: 0.808, 95 %CI: 0.611-1.068, p = 0.134) and LDL-C (OR: 1.146, 95 %CI: 0.869-1.511, p = 0.333) did not correlate with SSNHL, consistent with the results of SVMR. Inverse MR results showed that SSNHL did not correlate with TG (OR: 0.999, 95 %CI: 0.997-1.001, p = 0.835), HDL-C (OR: 1.001, 95 %CI: 0.998-1.003), LDL-C (OR: 0.999, 95 %CI: 0.997-1.002, p = 0.863).

CONCLUSIONS

Mendelian randomization (MR) results suggest that decreased serum HDL-C levels are an independent risk factor for SSNHL. Monitoring and focusing on lipid levels may be of value in the prevention and treatment of SSNHL.

The predictive value of the hs-CRP/HDL-C ratio, an inflammation-lipid composite marker, for cardiovascular disease in middle-aged and elderly people: evidence from a large national cohort study

BACKGROUND AND AIMS

Cardiovascular disease (CVD) is associated with inflammation and abnormal lipid metabolism. However, a single inflammatory index or a single lipid index cannot accurately predict the prognosis of CVD independently because it is prone to be affected by various confounding factors.

METHODS

This population-based cohort study included 6,554 participants from the China Health and Retirement Longitudinal Study (CHARLS) to investigate correlations. In the present study, the occurrence of CVD events such as stroke and heart disease was evaluated by considering self-reported diagnoses at the beginning of the study and during wave 4, and a restricted cubic spline model was used to investigate potential nonlinear relationships in addition to multivariate logistic regression models. Stratified analyses were performed to examine how sociodemographic characteristics may influence the results.

RESULTS

Seven years of follow-up (2011-2018) revealed that 786 people (11.99%) developed CVD. According to the adjusted model, the high-sensitivity C-reactive protein (hs-CRP)-to-high-density lipoprotein cholesterol (HDL-C) ratio is a contributing factor to CVD risk (OR 1.31, 95% CI 1.05-1.64). In addition, a nonlinear relationship was observed between the hs-CRP/HDL-C ratio and the occurrence of new CVD, stroke, or cardiac issues (Poverall <0.05, Pnonlinear <0.05). Moreover, noteworthy associations between the hs-CRP/HDL-C ratio and age were detected in the stratified analysis (P = 0.048), indicating that younger participants had more negative effects of a high hs-CRP/HDL-C ratio.

CONCLUSIONS

According to the present cohort study, a high hs-CRP/HDL-C ratio is a significant risk factor for CVD, new stroke, and heart problems. Early intervention in patients with increased hs-CRP/HDL-C ratios may further reduce the incidence of CVD, in addition to focusing on independent lipid markers or independent inflammatory markers.

Association between Mycoplasma pneumoniae infection, high‑density lipoprotein metabolism and cardiovascular health (Review)

The association between Mycoplasma pneumoniae (M. pneumoniae) infection, high-density lipoprotein metabolism and cardiovascular disease is an emerging research area. The present review summarizes the basic characteristics of M. pneumoniae infection and its association with high-density lipoprotein and cardiovascular health. M. pneumoniae primarily invades the respiratory tract and damages the cardiovascular system through various mechanisms including adhesion, invasion, secretion of metabolites, production of autoantibodies and stimulation of cytokine production. Additionally, the present review highlights the potential role of high-density lipoprotein for the development of prevention and intervention of M. pneumoniae infection and cardiovascular disease, and provides suggestions for future research directions and clinical practice. It is urgent to explore the specific mechanisms underlying the association between M. pneumoniae infection, high-density lipoprotein metabolism, and cardiovascular disease and analyze the roles of the immune system and inflammatory response.

Association between left ventricular remodeling and lipid profiles in obese children: an observational study

Objective

Childhood obesity has become a prominent issue in the society, which can lead to left ventricular remodeling and severe cardiovascular complications in adulthood. It is beneficial to identify the causes of left ventricular remodeling so that targeted measures can be taken to prevent the cardiovascular disease. Therefore, this study aimed to explore the relationship between left ventricular remodeling and changes in blood lipid indexes in obese children.

Methods

This study was conducted on 40 healthy non-obese children and 140 obese children diagnosed in the pediatric health department of our hospital. Clinical data collected from the two groups were compared. Echocardiography was performed to examine left ventricular configuration and cardiac function. Multiple linear regression analysis was conducted to assess the independent effects of blood lipid levels on echocardiographic parameters. Blood lipid indicators among different left ventricular structural patterns which were classified according to left ventricular mass indexes and relative wall thickness were compared.

Results

Obese children exhibited significantly increased height, weight, body mass index (BMI), body fat percentage (BFP), blood pressure, triglycerides, total cholesterol, left ventricular internal diameter (LVIDd), interventricular septum (IVSd), left ventricular posterior wall diastolic thickness (LVPWd), myocardial mass (LVM) and relative wall thickness (RWT), as well as lower high-density lipoprotein cholesterol (HDL-C) and left ventricular ejection fraction (LVEF) compared to the non-obese children (P < 0.05). Multiple linear correlation analysis showed LVM had a significantly positive correlation with BMI (r = 3.21, P = 0.002) and SBP (r = 2.61, P = 0.01); LVMI had a significantly negative correlation with HDL-C (r = -2.45, P = 0.015); RWT had a significantly positive correlation with SBP (r = 2.50, P = 0.013) but a significantly negative correlation with HDL-C (r = -2.35, P = 0.02). Furthermore, there were significant differences in HDL-C values among children with different ventricular configurations (P < 0.05), with the lowest HDL-C value recorded in the concentric hypertrophy group.

Conclusion

Obese children will develop left ventricular remodeling. The left ventricular configuration indexes are most significantly associated with serum HDL-C. Lower HDL-C level contributes to severer left ventricular hypertrophy, indicating a concentric hypertrophy pattern.

Association between high-density lipoprotein cholesterol and type 2 diabetes mellitus: dual evidence from NHANES database and Mendelian randomization analysis

Background

Low levels of high-density lipoprotein cholesterol (HDL-C) are commonly seen in patients with type 2 diabetes mellitus (T2DM). However, it is unclear whether there is an independent or causal link between HDL-C levels and T2DM. This study aims to address this gap by using the The National Health and Nutrition Examination Survey (NHANES) database and Mendelian randomization (MR) analysis.

Materials and methods

Data from the NHANES survey (2007-2018) with 9,420 participants were analyzed using specialized software. Logistic regression models and restricted cubic splines (RCS) were used to assess the relationship between HDL-C and T2DM incidence, while considering covariates. Genetic variants associated with HDL-C and T2DM were obtained from genome-wide association studies (GWAS), and Mendelian randomization (MR) was used to evaluate the causal relationship between HDL-C and T2DM. Various tests were conducted to assess pleiotropy and outliers.

Results

In the NHANES study, all groups, except the lowest quartile (Q1: 0.28-1.09 mmol/L], showed a significant association between HDL-C levels and reduced T2DM risk (all P < 0.001). After adjusting for covariates, the Q2 [odds ratio (OR) = 0.67, 95% confidence interval (CI): (0.57, 0.79)], Q3 [OR = 0.51, 95% CI: (0.40, 0.65)], and Q4 [OR = 0.29, 95% CI: (0.23, 0.36)] groups exhibited average reductions in T2DM risk of 23%, 49%, and 71%, respectively. In the sensitivity analysis incorporating other lipid levels, the Q4 group still demonstrates a 57% reduction in the risk of T2DM. The impact of HDL-C levels on T2DM varied with age (P for interaction = 0.006). RCS analysis showed a nonlinear decreasing trend in T2DM risk with increasing HDL-C levels (P = 0.003). In the MR analysis, HDL-C levels were also associated with reduced T2DM risk (OR = 0.69, 95% CI = 0.52-0.82; P = 1.41 × 10-13), and there was no evidence of pleiotropy or outliers.

Conclusion

This study provides evidence supporting a causal relationship between higher HDL-C levels and reduced T2DM risk. Further research is needed to explore interventions targeting HDL-C levels for reducing T2DM risk.

Predictive values of novel high‑density lipoprotein‑related inflammatory indices in in‑stent restenosis among patients undergoing elective percutaneous coronary intervention

Inflammation and disorders in lipid metabolism play pivotal roles in the development and progression of in-stent restenosis (ISR). The present study aimed to investigate the association between the high-density lipoprotein (HDL)-related inflammatory indices and the risk of developing ISR among patients undergoing elective percutaneous coronary intervention (PCI). A sum of 1,471 patients undergoing elective PCI were retrospectively included and classified by tertiles of HDL-related inflammatory indices. The study endpoint was ISR. The multivariable Cox proportional hazards regression analysis with restricted cubic splines (RCS) was used to assess the associations. During a median follow-up of 62.27 months, 251 (17.06%) patients experienced ISR. The incidence of ISR increased with the increasing white blood cell-to-HDL ratio (WHR) tertiles (log-rank test, overall P=0.0082). After full adjustment, the highest tertile of WHR was significantly associated with a 1.603-fold risk of ISR (hazard ratio, 1.603; 95% confidence interval, 1.152-2.231; P=0.005) in contrast to the lowest tertile of the WHR. Results of RCS further indicated that the association between WHR and ISR was in a non-linear and dose-dependent manner (non-linear P=0.034; P overall=0.019). The lymphocyte-to-HDL ratio (LHR) and neutrophil-to-HDL ratio (NHR) were also significantly and positively associated with the risk of ISR, of which the third tertiles were at increased risk of 41.2 and 44.7% after full adjustment, respectively. Overall, lipid metabolism disorders and inflammation were interconnected in the development of ISR; therefore, HDL-related inflammatory indices, including WHR, LHR and NHR, might be potential predictors in the prognosis of elective PCI.

Inflammation and immunomodulatory therapies influence the relationship between ATP-binding cassette A1 membrane transporter-mediated cholesterol efflux capacity and coronary atherosclerosis in rheumatoid arthritis

Objectives

High-density lipoprotein (HDL) removes cholesterol from cells in atherosclerotic lesions, a function known as cholesterol efflux capacity (CEC). ATP-binding-cassette A1 (ABCA1) membrane transporter starts cholesterol transfer from macrophages to HDL particles. In rheumatoid arthritis (RA), methotrexate and biologic disease modifying drugs (bDMARDs) are atheroprotective whereas corticosteroids and C-reactive protein (CRP) are proatherogenic. We evaluated the influence of these factors on the relationship of ABCA1-CEC with atherosclerosis and cardiovascular events.

Methods

Atherosclerosis was evaluated with computed tomography angiography in 140 patients with RA and repeated in 99 after 6.9 ± 0.3 years. Events including acute coronary syndromes, stroke, cardiovascular death, claudication, revascularization, and heart failure were recorded. ABCA1-CEC was quantified in J774A.1 murine macrophages and reported as percentage of effluxed over intracellular cholesterol.

Results

Higher ABCA1-CEC associated with (i) more calcified plaques at baseline only in patients with CRP>7 mg/L (median) (p-interaction = 0.001) and methotrexate nonusers (p-interaction = 0.037), and more partially-calcified plaques only in bDMARD nonusers (p-interaction = 0.029); (ii) fewer new calcified plaques in patients with below-median but not higher time-averaged CRP (p-interaction = 0.028); (iii) fewer new total and calcified plaques in prednisone unexposed but not patients exposed to prednisone during follow-up (p-interaction = 0.034 and 0.004) and (iv) more new plaques in baseline bDMARD nonusers and fewer in bDMARD users (p-interaction ≤ 0.001). Also, ABCA1-CEC associated with greater cardiovascular risk only in baseline prednisone users (p-interaction = 0.027).

Conclusion

ABCA1-CEC associated with decreased atherosclerosis in patients with below-median baseline and time-averaged CRP and bDMARD use. Conversely, ABCA1-CEC associated with increased plaque in those with higher CRP, corticosteroid users, methotrexate nonusers, and bDMARD nonusers. While in well-treated and controlled disease ABCA1-CEC appears atheroprotective, in uncontrolled RA its action may be masked or fail to counteract the inflammation-driven proatherogenic state.

Statins influence the relationship between ATP-binding cassette A1 membrane transporter-mediated cholesterol efflux capacity and coronary atherosclerosis in rheumatoid arthritis

Objectives

Cholesterol efflux capacity (CEC) is the main antiatherogenic function of high-density lipoprotein (HDL). ATP-binding-cassette A1 (ABCA1) membrane transporter initiates cholesterol export from arterial macrophages to pre-β HDL particles fostering their maturation; in turn, those accept cholesterol through ABCG1-mediated export. Impaired pre-β HDL maturation may disrupt the collaborative function of the two transporters and adversely affect atherosclerosis. Statins exert atheroprotective functions systemically and locally on plaque. We here evaluated associations between ABCA1-CEC, coronary atherosclerosis and cardiovascular risk and the influence of statins on those relationships in rheumatoid arthritis (RA).

Methods

Evaluation with computed tomography angiography was undertaken in 140 patients and repeated in 99 after 6.9 ± 0.3 years. Events comprising cardiovascular death, acute coronary syndromes, stroke, claudication, revascularization and heart failure were recorded. ABCA1-CEC and ABCG1-CEC were evaluated in J774A.1 macrophages and Chinese hamster ovary (CHO) cells respectively and expressed as percentage of effluxed over total intracellular cholesterol. Covariates in all cardiovascular event risk and plaque outcome models included atherosclerotic cardiovascular disease (ASCVD) risk score and high-density lipoprotein cholesterol.

Results

ABCA1-CEC negatively correlated with ABCG1-CEC (r = -0.167, p = 0.049). ABCA1-CEC associated with cardiovascular risk (adjusted hazard ratio 2.05 [95%CI 1.20-3.48] per standard deviation [SD] increment). There was an interaction of ABCA1-CEC with time-varying statin use (p = 0.038) such that current statin use inversely associated with risk only in patients with ABCA1-CEC below the upper tertile. ABCA1-CEC had no main effect on plaque or plaque progression; instead, ABCA1-CEC (per SD) associated with fewer baseline total plaques (adjusted rate ratio [aRR] 0.81, [95%CI 0.65-1.00]), noncalcified plaques (aRR 0.78 [95%CI 0.61-0.98]), and vulnerable low-attenuation plaques (aRR 0.41 [95%CI 0.23-0.74]) in statin users, and more low-attenuation plaques (aRR 1.91 [95%CI 1.18-3.08]) in nonusers (p-for-interaction = 0.018, 0.011, 0.025 and < 0.001 respectively). Moreover, ABCA1-CEC (per SD) associated with greater partially/fully-calcified plaque progression (adjusted odds ratio 3.07 [95%CI 1.20-7.86]) only in patients not exposed to statins during follow-up (p-for-interaction = 0.009).

Conclusion

In patients with RA, higher ABCA1-CEC may reflect a proatherogenic state, associated with enhanced cardiovascular risk. Statin use may unmask the protective impact of ABCA1-mediated cholesterol efflux on plaque formation, progression and cardiovascular risk.

Regular Practice of Physical Activity Improves Cholesterol Transfers to High-Density Lipoprotein (HDL) and Other HDL Metabolic Parameters in Older Adults

The effects of regular physical activity on two important anti-atherosclerosis functions of high-density lipoprotein (HDL), namely its capacity to receive both forms of cholesterol and its anti-oxidant function, were investigated in this study comparing older adults with young individuals. One-hundred and eight healthy adult individuals were enrolled and separated into the following groups: active older (60-80 yrs, n = 24); inactive older (60-79 yrs, n = 21); active young (20-34 yrs, n = 39); and inactive young (20-35 yrs, n = 24). All performed cardiopulmonary tests. Blood samples were collected in order to assess the following measures: lipid profile, HDL anti-oxidant capacity, paraoxonase-1 activity, HDL subfractions, and lipid transfer to HDL. Comparing active older and active young groups with inactive older and inactive young groups, respectively, the active groups presented higher HDL-C levels (p < 0.01 for both comparisons), unesterified cholesterol transfer (p < 0.01, p < 0.05), and intermediate and larger HDL subfractions (p < 0.001, p < 0.01) than the respective inactive groups. In addition, the active young group showed higher esterified cholesterol transfer than the inactive young group (p < 0.05). As expected, the two active groups had higher VO2peak than the inactive groups; VO2peak was higher in the two younger than in the two older groups (p < 0.05). No differences in unesterified and esterified cholesterol transfers and HDL subfractions were found between active young and active older groups. HDL anti-oxidant capacity and paraoxonase-1 activity were equal in all four study groups. Our data highlight and strengthen the benefits of regular practice of physical activity on an important HDL function, the capacity of HDL to receive cholesterol, despite the age-dependent decrease in VO2peak.

Effects of different mind-body exercises on glucose and lipid metabolism in patients with type 2 diabetes: A network meta-analysis

BACKGROUND

This study aims to compare the relative effectiveness of different forms of mind-body exercise in improving glycolipid metabolism in patients with T2DM using a network meta-analysis.

METHODS

The relevant literature was systematically searched in Cochrane Library, Embase, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang database and VIP Chinese Science. A network meta-analysis was conducted using a random-effects model within a frequentist framework.

RESULTS

A total of 52 studies with 6 modalities of mind-body exercise involving 4024 patients were included. Compared with controls, all exercise modalities except Yijinjing significantly improved patients' fasting blood glucose (MDs ranged from -0.72(95% CI: -1.20,-0.25) in dance to -2.06(95% CI: -2.59,-1.54) in yoga), glycated hemoglobin (MDs ranged from -0.62 (95% CI: -0.96) in taijiquan to -0.27,-0.27) in Pilates to -1.18(95% CI: 1.80,-0.57)), total cholesterol (MDs ranged from -0.73(95% CI: -1.29,-0.17) in Pilates to -0.41(95% CI: -0.62,-0.19) in Tai Chi), triglycerides (MDs ranged from -0.56 in Pilates (95% CI: -1.07,-0.04) for Pilates to -0.38 (95% CI: -0.67,-0.10)) for dance; only Tai Chi Chuan (MD:0.12 95% CI:0.04,0.20) and Baduanjin (MD:0.14 95% CI:0.06,0.22) significantly increased high-density lipoprotein cholesterol levels in patients; only yoga(MD: 0.78 95%CI: 1.20,-0.37) and Tai Chi Chuan(MD: 0.32 95%CI: 0.60,-0.04) significantly decreased high-density lipoprotein cholesterol levels in patients.

CONCLUSION

All mind-body exercises help to improve blood glucose and lipid levels in T2DM patients, but the ranking of relative effectiveness needs to be rationalized. Our study suggests that T2DM patients should choose appropriate mind-body exercises according to their conditions and stick to them for a long time under their healthcare professionals' guidance to achieve effective diabetes control.

Time-varying effect of postoperative cholesterol profile on long-term outcomes of isolated coronary artery bypass graft surgery

BACKGROUND

Controlling cholesterol levels is one of the primary goals of preventing atherosclerotic plaque progression in patients undergoing coronary artery bypass graft (CABG) surgery. This study aimed to investigate the impact of serum cholesterol profile at multiple time points following isolated CABG surgery on long-term patient outcomes.

METHOD

This retrospective cohort study was conducted on the admission and follow-up data of isolated CABG patients from the Tehran Heart Center registry between 2009 and 2016. The association of low-density lipoprotein (LDL), high-density lipoprotein (HDL), and their ratio as an atherogenic index with major adverse cardiac and cerebrovascular events (MACCE) and all-cause mortality were evaluated using time-varying survival analysis methods.

RESULT

A total of 18657 patients were included in this analysis. After adjusting for known confounding factors, no significant difference in all-cause mortality and MACCE was observed at different LDL levels. The incidence of acute coronary syndrome (ACS) in patients with LDL > 100 mg/dl and LDL < 50 mg/dl was significantly higher than in the control group (P-value = 0.004 and 0.04, respectively). The incidence of cerebrovascular accidents (CVA) at LDL > 100 mg/dl was also significantly higher compared to the control group (P -value = 0.033). Lower HDL levels were significantly associated with a higher MACCE (P -value < 0.001), all-cause mortality (P -value < 0.001), ACS (P -value = 0.00), and CVA (P -value = 0.014). The atherogenic index was also directly related to MACCE and all its components (all P-values < 0.001).

CONCLUSION

LDL/HDL ratio is suggested as a better marker for secondary prevention goals compared to LDL alone in patients undergoing CABG surgery.

Insulin Resistance and Hypertension: Mechanisms Involved and Modifying Factors for Effective Glucose Control

Factors such as aging, an unhealthy lifestyle with decreased physical activity, snacking, a standard Western diet, and smoking contribute to raising blood pressure to a dangerous level, increasing the risk of coronary artery disease and heart failure. Atherosclerosis, or aging of the blood vessels, is a physiological process that has accelerated in the last decades by the overconsumption of carbohydrates as the primary sources of caloric intake, resulting in increased triglycerides and VLDL-cholesterol and insulin spikes. Classically, medications ranging from beta blockers to angiotensin II blockers and even calcium channel blockers were used alone or in combination with lifestyle modifications as management tools in modern medicine to control arterial blood pressure. However, it is not easy to control blood pressure or the associated complications. A low-carbohydrate, high-fat (LCHF) diet can reduce glucose and insulin spikes, improve insulin sensitivity, and lessen atherosclerosis risk factors. We reviewed articles describing the etiology of insulin resistance (IR) and its impact on arterial blood pressure from databases including PubMed, PubMed Central, and Google Scholar. We discuss how the LCHF diet is beneficial to maintaining arterial blood pressure at normal levels, slowing down the progression of atherosclerosis, and reducing the use of antihypertensive medications. The mechanisms involved in IR associated with hypertension are also highlighted.

Effect of the JAK/STAT Inhibitor Tofacitinib on Macrophage Cholesterol Metabolism

The impact of JAK/STAT inhibitors, which are used in various inflammatory diseases, on cardiovascular risk is controversial and has recently raised safety concerns. Our study investigates the direct effects of tofacitinib on macrophage cholesterol metabolism, which is crucial for atherosclerosis plaque development and stability. Cultured human macrophages THP-1 were used to assess the impact of tofacitinib on cell cholesterol efflux and synthesis via radioisotopic methods, and on cholesterol uptake by measuring the cell cholesterol content with a fluorometric assay. The cholesterol acceptors and donors were either standard lipoproteins or sera from patients with juvenile idiopathic arthritis (JIA) and from control subjects. Tofacitinib significantly increased the macrophage cholesterol efflux to all acceptors; it reduced cholesterol uptake from both the normal and hypercholesterolemic sera; and it reduced cholesterol synthesis. The treatment of macrophages with tofacitinib was able to increase the cholesterol efflux and decrease cholesterol uptake when using sera from untreated JIA patients with active disease as cholesterol acceptors and donors, respectively. In conclusion, our in vitro data support the concept that tofacitinib has a favorable impact on macrophage cholesterol metabolism, even in the presence of sera from rheumatologic patients, and suggest that other mechanisms may be responsible for the cardiovascular risk associated with tofacitinib use in selected patient populations.

Increased plasma lipids in triple-negative breast cancer and impairment in HDL functionality in advanced stages of tumors

The association between plasma lipids and breast cancer (BC) has been extensively explored although results are still conflicting especially regarding the relationship with high-density lipoprotein cholesterol (HDLc) levels. HDL mediates cholesterol and oxysterol removal from cells limiting sterols necessary for tumor growth, inflammation, and metastasis and this may not be reflected by measuring HDLc. We addressed recently diagnosed, treatment-naïve BC women (n = 163), classified according to molecular types of tumors and clinical stages of the disease, in comparison to control women (CTR; n = 150) regarding plasma lipids and lipoproteins, HDL functionality and composition in lipids, oxysterols, and apo A-I. HDL was isolated by plasma discontinuous density gradient ultracentrifugation. Lipids (total cholesterol, TC; triglycerides, TG; and phospholipids, PL) were determined by enzymatic assays, apo A-I by immunoturbidimetry, and oxysterols (27, 25, and 24-hydroxycholesterol), by gas chromatography coupled with mass spectrometry. HDL-mediated cell cholesterol removal was determined in macrophages previously overloaded with cholesterol and ¹⁴C-cholesterol. Lipid profile was similar between CTR and BC groups after adjustment per age. In the BC group, lower concentrations of TC (84%), TG (93%), PL (89%), and 27-hydroxicholesterol (61%) were observed in HDL, although the lipoprotein ability in removing cell cholesterol was similar to HDL from CRT. Triple-negative (TN) BC cases presented higher levels of TC, TG, apoB, and non-HDLc when compared to other molecular types. Impaired HDL functionality was observed in more advanced BC cases (stages III and IV), as cholesterol efflux was around 28% lower as compared to stages I and II. The altered lipid profile in TN cases may contribute to channeling lipids to tumor development in a hystotype with a more aggressive clinical history. Moreover, findings reinforce the dissociation between plasma levels of HDLc and HDL functionality in determining BC outcomes.

Plasma and cerebrospinal fluid cholesterol esterification is hampered in Alzheimer's disease

OBJECTIVE

The purpose of this study was to evaluate cholesterol esterification and HDL subclasses in plasma and cerebrospinal fluid (CSF) of Alzheimer's disease (AD) patients.

METHODS

The study enrolled 70 AD patients and 74 cognitively normal controls comparable for age and sex. Lipoprotein profile, cholesterol esterification, and cholesterol efflux capacity (CEC) were evaluated in plasma and CSF.

RESULTS

AD patients have normal plasma lipids but significantly reduced unesterified cholesterol and unesterified/total cholesterol ratio. Lecithin:cholesterol acyltransferase (LCAT) activity and cholesterol esterification rate (CER), two measures of the efficiency of the esterification process, were reduced by 29% and 16%, respectively, in the plasma of AD patients. Plasma HDL subclass distribution in AD patients was comparable to that of controls but the content of small discoidal preβ-HDL particles was significantly reduced. In agreement with the reduced preβ-HDL particles, cholesterol efflux capacity mediated by the transporters ABCA1 and ABCG1 was reduced in AD patients' plasma. The CSF unesterified to total cholesterol ratio was increased in AD patients, and CSF CER and CEC from astrocytes were significantly reduced in AD patients. In the AD group, a significant positive correlation was observed between plasma unesterified cholesterol and unesterified/total cholesterol ratio with Aβ1-42 CSF content.

CONCLUSION

Taken together our data indicate that cholesterol esterification is hampered in plasma and CSF of AD patients and that plasma cholesterol esterification biomarkers (unesterified cholesterol and unesterified/total cholesterol ratio) are significantly associated to disease biomarkers (i.e., CSF Aβ1-42).

High-Density Lipoprotein function is modulated by the SARS-CoV-2 spike protein in a lipid-type dependent manner

There is a close relationship between the SARS-CoV-2 virus and lipoproteins, in particular high-density lipoprotein (HDL). The severity of the coronavirus disease 2019 (COVID-19) is inversely correlated with HDL plasma levels. It is known that the SARS-CoV-2 spike (S) protein binds the HDL particle, probably depleting it of lipids and altering HDL function. Based on neutron reflectometry (NR) and the ability of HDL to efflux cholesterol from macrophages, we confirm these observations and further identify the preference of the S protein for specific lipids and the consequent effects on HDL function on lipid exchange ability. Moreover, the effect of the S protein on HDL function differs depending on the individuals lipid serum profile. Contrasting trends were observed for individuals presenting low triglycerides/high cholesterol serum levels (LTHC) compared to high triglycerides/high cholesterol (HTHC) or low triglycerides/low cholesterol serum levels (LTLC). Collectively, these results suggest that the S protein interacts with the HDL particle and, depending on the lipid profile of the infected individual, it impairs its function during COVID-19 infection, causing an imbalance in lipid metabolism.

ATP-binding cassette G1 membrane transporter-mediated cholesterol efflux capacity influences coronary atherosclerosis and cardiovascular risk in Rheumatoid Arthritis

OBJECTIVES

Cholesterol efflux capacity (CEC) measures the ability of high-density lipoprotein (HDL) to remove cholesterol from macrophages and reduce the lipid content of atherosclerotic plaques. CEC inversely associated with cardiovascular risk beyond HDL-cholesterol levels. CEC through the ATP-binding-cassette G1 (ABCG1) membrane transporter is impaired in rheumatoid arthritis (RA). We evaluated associations of ABCG1-CEC with coronary atherosclerosis, plaque progression and cardiovascular risk in RA.

METHODS

Coronary atherosclerosis (noncalcified, partially, fully-calcified, low-attenuation plaque) was assessed with computed tomography angiography in 140 patients and reevaluated in 99 after 6.9 ± 0.3 years. Cardiovascular events including acute coronary syndromes, stroke, cardiovascular death, claudication, revascularization and hospitalized heart failure were recorded. ABCG1-CEC was measured in Chinese hamster ovary cells as percentage of effluxed over total intracellular cholesterol.

RESULTS

ABCG1-CEC inversely associated with extensive atherosclerosis (≥5 plaques) (adjusted odds ratio 0.50 [95% CI 0.28-0.88]), numbers of partially-calcified (rate ratio [RR] 0.71 [0.53-0.94]) and low-attenuation plaques (RR 0.63 [0.43-0.91] per standard deviation increment). Higher ABCG1-CEC predicted fewer new partially-calcified plaques in patients with lower baseline and time-averaged CRP and fewer new noncalcified and calcified plaques in those receiving higher mean prednisone dose. ABCG1-CEC inversely associated with events in patients with but not without noncalcified plaques, with <median but not higher CRP and in prednisone users but not nonusers (p-for-interaction = 0.021, 0.033 and 0.008 respectively).

CONCLUSION

ABCG1-CEC inversely associated with plaque burden and vulnerability, and plaque progression conditionally on cumulative inflammation and corticosteroid dose. ABCG1-CEC inversely associated with events specifically in patients with noncalcified plaques, lower inflammation and in prednisone users.

Lipids at the Nexus between Cerebrovascular Disease and Vascular Dementia: The Impact of HDL-Cholesterol and Ceramides

Cerebrovascular diseases and the subsequent brain hypoperfusion are at the basis of vascular dementia. Dyslipidemia, marked by an increase in circulating levels of triglycerides and LDL-cholesterol and a parallel decrease in HDL-cholesterol, in turn, is pivotal in promoting atherosclerosis which represents a common feature of cardiovascular and cerebrovascular diseases. In this regard, HDL-cholesterol has traditionally been considered as being protective from a cardiovascular and a cerebrovascular prospective. However, emerging evidence suggests that their quality and functionality play a more prominent role than their circulating levels in shaping cardiovascular health and possibly cognitive function. Furthermore, the quality of lipids embedded in circulating lipoproteins represents another key discriminant in modulating cardiovascular disease, with ceramides being proposed as a novel risk factor for atherosclerosis. This review highlights the role of HDL lipoprotein and ceramides in cerebrovascular diseases and the repercussion on vascular dementia. Additionally, the manuscript provides an up-to-date picture of the impact of saturated and omega-3 fatty acids on HDL circulating levels, functionality and ceramide metabolism.

Atherosclerotic Cardiovascular Risk Stratification in the Rheumatic Diseases:: An Integrative, Multiparametric Approach

Cardiovascular disease (CVD) risk is increased in most inflammatory rheumatic diseases (IRDs), reiterating the role of inflammation in the initiation and progression of atherosclerosis. An inverse association of CVD risk with body weight and lipid levels has been described in IRDs. Coronary artery calcium scores, plaque burden and characteristics, and carotid plaques on ultrasound optimize CVD risk estimate in IRDs. Biomarkers of cardiac injury, autoantibodies, lipid biomarkers, and cytokines also improve risk assessment in IRDs. Machine learning and deep learning algorithms for phenotype and image analysis hold promise to improve CVD risk stratification in IRDs.

Role of Lipoprotein Levels and Function in Atherosclerosis Associated with Autoimmune Rheumatic Diseases

Immune and inflammatory mediators in autoimmune rheumatic diseases induce modification in the activity of enzymes pivotal for lipid metabolism and promote a proatherogenic serum lipid profile. However, disturbances in low- and high-density lipoprotein composition and increased lipid oxidation also occur. Therefore, lipoprotein dysfunction causes intracellular cholesterol accumulation in macrophages, smooth muscle cells, and platelets. Overall, both plaque progression and acute cardiovascular events are promoted. Single rheumatic diseases may present a particular pattern of lipid disturbances so that standard methods to evaluate cardiovascular risk may not be accurate enough. In general, antirheumatic drugs positively affect lipid metabolism in these patients.

Circadian Rhythm of Subspecies of Low-Density Lipoprotein-Cholesterol and High-Density Lipoprotein-Cholesterol in Healthy Subjects and Patients with Type 2 Diabetes

AIMS

We established automated assay kits for quantifying small dense low-density lipoprotein (sdLDL)-cholesterol (C), LDL-triglyceride (TG), and high-density lipoprotein (HDL)3-C, and apolipoprotein (apo)E-rich HDL-C, and these have been recognized as sensitive biomarkers for predicting coronary artery disease. We investigated the circadian rhythms of these novel lipids to determine if fasting is required to determine basal levels.

METHODS

Forty-eight inpatients with type 2 diabetes and 19 healthy volunteers were studied. Blood samples were collected at seven time points, which were obtained after an overnight fast, before and 2 h after each meal, and before the next breakfast. sdLDL-C, LDL-TG, remnant-like particle (RLP)-C, TG-rich lipoprotein (TRL-C), HDL3-C, and apoE-rich HDL-C were measured by the homogeneous methods. NonHDL-C, large buoyant (lb)LDL-C and HDL2-C were calculated by subtracting sdLDL-C from LDL-C or HDL3-C from HDL-C, respectively.

RESULTS

Serum TG levels were significantly increased after meals in both healthy participants and patients with diabetes. RLP-C and TRL-C were also increased postprandially. LDL-TG, LDL-C, nonHDL-C, HDL2,3-C, and apoE-rich HDL-C did not exhibit significant fluctuation during the day in healthy participants and patients with diabetes. sdLDL-C was slightly increased postprandially in subjects with diabetes (1-2 mg/dl, 3%-9%), though its increase was not significant compared to the baseline (fasting) level. Significant postprandial reduction was observed with LDL-C and lbLDL-C. There was no influence of statin therapy or oral anti-diabetes drugs on the circadian rhythm of LDL-C subspecies.

CONCLUSIONS

Subtle postprandial increase in sdLDL-C is considered a negligible level in general clinical practice. Fasting is not mandatory to measure basal concentrations of LDL and HDL subspecies.

Serum adenosine deaminase activity and acute cerebral infarction: a retrospective case-control study based on 7913 participants

BACKGROUND

Adenosine deaminase (ADA) is a key enzyme that catalyzes the deamination of adenosine into inosine, which eventually decomposes into uric acid (UA). A body of papers have reported that adenosine and UA are closely related to cerebrovascular events. However, the association between serum ADA activity and acute cerebral infarction (ACI) remains unclear.

METHODS

7913 subjects were enrolled, including 3968 ACI patients and 3945 controls, in this study. An automatic biochemistry analyzer was used to determine serum activity.

RESULTS

Serum ADA activity was found that was significantly decreased in patients with ACI (10.10 ± 3.72 U/L) compared to those without ACI (11.07 ± 2.85 U/L, p < 0.001). After Logistic regression analysis, ADA concentrations were negatively correlated with ACI (OR = 1.161, 95% CI: 1.140-1.183, p < 0.001). Smoking and alcohol consumption decreased serum ADA concentrations in patients with ACI, whereas diabetes and hypertension had the opposite effect.

CONCLUSIONS

Serum ADA concentrations in patients with ACI are markedly decreased, suggesting that the decreased ADA concentrations may be involved in the pathogenesis of ACI. We hypothesized that decreased ADA activity may be an adaptive mechanism to maintain adenosine levels and protect against ischemic brain injury.

Lipidomics in nutrition research

PURPOSE OF REVIEW

This review focuses on the recent findings from lipidomics studies as related to nutrition and health research.

RECENT FINDINGS

Several lipidomics studies have investigated malnutrition, including both under- and overnutrition. Focus has been both on the early-life nutrition as well as on the impact of overfeeding later in life. Multiple studies have investigated the impact of different macronutrients in lipidome on human health, demonstrating that overfeeding with saturated fat is metabolically more harmful than overfeeding with polyunsaturated fat or carbohydrate-rich food. Diet rich in saturated fat increases the lipotoxic lipids, such as ceramides and saturated fatty-acyl-containing triacylglycerols, increasing also the low-density lipoprotein aggregation rate. In contrast, diet rich in polyunsaturated fatty acids, such as n-3 fatty acids, decreases the triacylglycerol levels, although some individuals are poor responders to n-3 supplementation.

SUMMARY

The results highlight the benefits of lipidomics in clinical nutrition research, also providing an opportunity for personalized nutrition. An area of increasing interest is the interplay of diet, gut microbiome, and metabolome, and how they together impact individuals' responses to nutritional challenges.

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

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

HDL Cholesterol Efflux and Serum Cholesterol Loading Capacity Alterations Associate to Macrophage Cholesterol Accumulation in FH Patients with Achilles Tendon Xanthoma

Achilles tendon xanthoma (ATX) formation involves macrophage cholesterol accumulation within the tendon, similar to that occurring in atheroma. Macrophage cholesterol homeostasis depends on serum lipoprotein functions, namely the high-density lipoprotein (HDL) capacity to promote cell cholesterol efflux (cholesterol efflux capacity, CEC) and the serum cholesterol loading capacity (CLC). We explored the HDL-CEC and serum CLC, comparing 16 FH patients with ATX to 29 FH patients without ATX. HDL-CEC through the main efflux mechanisms mediated by the transporters ATP binding cassette G1 (ABCG1) and A1 (ABCA1) and the aqueous diffusion (AD) process was determined by a cell-based radioisotopic technique and serum CLC fluorimetrically. Between the two groups, no significant differences were found in terms of plasma lipid profile. A trend toward reduction of cholesterol efflux via AD and a significant increase in ABCA1-mediated HDL-CEC (+18.6%) was observed in ATX compared to no ATX patients. In ATX-presenting patients, ABCG1-mediated HDL-CEC was lower (−11%) and serum CLC was higher (+14%) compared to patients without ATX. Considering all the patients together, ABCG1 HDL-CEC and serum CLC correlated with ATX thickness inversely (p = 0.013) and directly (p < 0.0001), respectively. In conclusion, lipoprotein dysfunctions seem to be involved in ATX physiopathology and progression in FH patients.

Effects of PCSK9 inhibitors on HDL cholesterol efflux and serum cholesterol loading capacity in familial hypercholesterolemia subjects: a multi-lipid-center real-world evaluation

Proprotein convertase subtilisin/kexin type 9 (PCSK9), beyond regulating LDL cholesterol (LDL-c) plasma levels, exerts several pleiotropic effects by modulating lipid metabolism in extrahepatic cells such as macrophages. Macrophage cholesterol homeostasis depends on serum lipoprotein functions, including the HDL capacity to promote cell cholesterol efflux (CEC) and the serum capacity to promote cell cholesterol loading (CLC). The aim of this observational study was to investigate the effect of PCSK9 inhibitors (PCSK9-i) treatment on HDL-CEC and serum CLC in patients with familial hypercholesterolemia (FH). 31 genetically confirmed FH patients were recruited. Blood was collected and serum isolated at baseline and after 6 months of PCSK9-i treatment. HDL-CEC was evaluated through the main pathways with a radioisotopic cell-based assay. Serum CLC was assessed fluorimetrically in human THP-1 monocyte-derived macrophages. After treatment with PCSK9-i, total cholesterol and LDL-c significantly decreased (−41.6%, p < 0.0001 and −56.7%, p < 0.0001, respectively). Total HDL-CEC was not different between patients before and after treatment. Conversely, despite no changes in HDL-c levels between the groups, ABCG1 HDL-CEC significantly increased after treatment (+22.2%, p < 0.0001) as well as HDL-CEC by aqueous diffusion (+7.8%, p = 0.0008). Only a trend towards reduction of ABCA1 HDL-CEC was observed after treatment. PCSK9-i significantly decreased serum CLC (−6.6%, p = 0.0272). This effect was only partly related to the reduction of LDL-c levels. In conclusion, PCSK9-i treatment significantly increased HDL-CEC through ABCG1 and aqueous diffusion pathways and reduced the serum CLC in FH patients. The favorable effect of PCSK9-i on functional lipid profile could contribute to the cardiovascular benefit of these drugs in FH patients.

Effect of a PCSK9 inhibitor and a statin on cholesterol efflux capacity: A limitation of current cholesterol-lowering treatments?

BACKGROUND

Cellular cholesterol efflux is a key step in reverse cholesterol transport that may impact on atherosclerotic cardiovascular risk. The process may be reliant on the availability of apolipoprotein (apo) B-100-containing lipoproteins to accept cholesterol from high-density lipoprotein. Evolocumab and atorvastatin are known to lower plasma apoB-100-containing lipoproteins that could impact on cholesterol efflux capacity (CEC).

METHODS

We conducted a 2-by-2 factorial trial of the effects of subcutaneous evolocumab (420 mg every 2 weeks) and atorvastatin (80 mg daily) for 8 weeks on CEC in 81 healthy, normolipidaemic men. The capacity of whole plasma and apoB-depleted plasma, including ATP-binding cassette transporter A1 (ABCA1)-mediated and passive diffusion, to efflux cholesterol, was measured.

RESULTS

Evolocumab and atorvastatin independently decreased whole plasma CEC (main effect p < .01 for both). However, there were no significant effects of evolocumab and atorvastatin on apoB-depleted plasma, ABCA1-mediated and passive diffusion-mediated CEC (p > .05 in all). In the three intervention groups combined, the reduction in whole plasma CEC was significantly correlated with the corresponding reduction in plasma apoB-100 concentration (r = .339, p < .01). In the evolocumab monotherapy group, the reduction in whole plasma CEC was also significantly correlated with the corresponding reduction in plasma lipoprotein(a) concentration (r = .487, p < .05).

CONCLUSIONS

In normolipidaemic men, evolocumab and atorvastatin decrease the capacity of whole plasma to efflux cellular cholesterol. These effects may be chiefly owing to a fall in the availability of apoB-100-containing lipoproteins. Reduction in circulating lipoprotein(a) may also contribute to the decrease in whole plasma cholesterol efflux with evolocumab monotherapy.

Association of blood lipids with coronary artery plaque among Saudi patients referred to computed tomography

Background

Blood lipids are strong risk factors for the progression of atherosclerotic plaques. However, data on gender-specific associations are limited.

Objectives

To examine gender-specific associations of coronary plaque with blood lipids among a large sample of Saudi patients without CAD.

Methods

Retrospective cross-sectional study was conducted among adult patients referred to (64 multidetector spiral) computed tomography (CT) for standard indications at the Prince Sultan Cardiac Centre (Riyadh, Saudi Arabia) between July 2007 and December 2017. Those with pre-existing CAD were excluded. Plaques were determined based on quantification of coronary calcium and Coronary CT angiography.

Results

A total 2421 patients (1498 males and 923 females) were included. The prevalence of any plaque was 36.6% with higher burden in males than females (41.3% versus 28.9%, p < 0.001). Approximately 78.9% of all plaques were calcified. Blood lipids (mmol/L) were 4.75 ± 1.14 for total cholesterol, 2.90 ± 0.96 for LDL cholesterol, 1.20 ± 0.36 for HDL cholesterol, and 1.64 ± 1.09 for triglycerides. Males had significantly higher triglycerides and lower HDL cholesterol compared with females. In adjusted models in males and all patients, soft and/or calcified plaques were significantly associated with lower HDL cholesterol and higher triglycerides. In females, the only significant association was between soft plaques and higher triglycerides.

Conclusions

Middle-aged patients without clinical CAD in Saudi Arabia have a high burden of plaques, specially calcified ones. The findings may impact the use of lipid lowering mediations, by underscoring the importance of assessing the risk of CAD in patients without clinical CAD even in case of lack of coronary calcification.

High-density lipoprotein cholesterol efflux capacity and incidence of coronary artery disease and cardiovascular mortality: a systematic review and meta-analysis

Background

The preventive effect of cholesterol efflux capacity (CEC) on the progression of atherosclerotic lesions has been confirmed in animal models, but findings in the population are inconsistent. Therefore, this meta-analysis aimed to systematically investigate the relationship of CEC with coronary artery disease (CAD) and cardiovascular mortality in a general population.

Methods

Four electronic databases (PubMed, Embase database, Cochrane Library, Web of Science) were searched from inception to February 1st, 2022 for relevant studies, without any language restriction. For continuous variables, the mean and standard deviation (SD), maximum adjusted odds ratios (ORs), relative risks (RRs), or hazard ratios (HRs) and 95% confidence intervals (CIs) were extracted. The random-effects model was adopted to calculate the pooled results, and dose-response analyses were conducted. All pooled results were expressed by standardized mean difference (SMD) and ORs.

Results

Finally, 18 observational studies were included. Compared with the non-CAD group, the CAD group (SMD -0.48, 95% CI − 0.66 to − 0.30; I² 88.9%) had significantly lower CEC. In the high-CEC population, the risks of CAD (OR 0.52, 95% CI 0.37 to 0.71; I² 81%) significantly decreased, and a linear negative dose-response was detected. However, an association between CEC and the risk of cardiovascular mortality was not found (OR 0.44, 95% CI 0.18 to 1.06; I² 83.2%).

Conclusions

This meta-analysis suggests that decreased CEC is strongly associated with the risk of CAD, independent of HDL-C level. However, a decreased CEC seems not to be related to cardiovascular mortality. Meanwhile, CEC is linearly negatively correlated with the risk of CAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01657-3.

Atherogenic index of plasma for non-diabetic, coronary artery disease patients after percutaneous coronary intervention: a prospective study of the long-term outcomes in China

Background

Non-diabetic coronary artery disease (CAD) patients are thought to encounter metabolic dysfunction and while these changes may be imperceptible to the patient they probably influence outcomes. At present, there is no system to support patients sensing these subtle changes, nor is there an established model for prognoses. The Atherogenic Index of Plasma (AIP) index has already proven useful for atherosclerosis although further research is needed, especially for those without hyperglycemia.

Methods

This is a prospective study of 5538 non-diabetic CAD patients who had received percutaneous coronary intervention (PCI). Participants were assigned to one of three groups according to their AIP index. High AIP index cases were then compared to low index patients according to major adverse cardiac events (MACE). Restricted cubic spline (RCS) analysis was also conducted to investigate interrelations between AIP index levels and hazard ratios (HR) for MACEs.

Results

Patients with a high AIP index encountered metabolic dysfunction compared to those with a low AIP index i.e., higher Body Mass Index (BMI), Total Cholesterol (TC), Triglycerides (TG), and uric acid as well as lower HDL-C. Each of the aforementioned interrelations were significant with p values of less than 0.001. There was also a significant increase in the number of MACEs in the high AIP index group compared to the low AIP index group (HR: 1.37, 95% CI 1.04–1.81; p = 0.025). A J-shaped RCS curve highlighted a change in the HR after the 0.18 juncture (HR per SD: 1.20, 95% CI 0.96–1.50). Further subgroup analysis supported the main findings, all with HRs greater than one.

Conclusion

The AIP index could be used in prognostics for non-diabetic CAD patients 2 years after PCI. The relationship between hazard ratio and the AIP index appears to be J-shaped. Although, further multi-center studies designed for non-diabetic patients with potential metabolic dysfunction should be conducted to determine the value of the AIP index.

Emerging role of HDL in brain cholesterol metabolism and neurodegenerative disorders

High-density lipoproteins (HDLs play a key role in cholesterol homeostasis maintenance in the central nervous system (CNS), by carrying newly synthesized cholesterol from astrocytes to neurons, to support their lipid-related physiological functions. As occurs for plasma HDLs, brain lipoproteins are assembled through the activity of membrane cholesterol transporters, undergo remodeling mediated by specific enzymes and transport proteins, and finally deliver cholesterol to neurons by a receptor-mediated internalization process. A growing number of evidences indicates a strong association between alterations of CNS cholesterol homeostasis and neurodegenerative disorders, in particular Alzheimer's disease (AD), and a possible role in this relationship may be played by defects in brain HDL metabolism. In the present review, we summarize and critically examine the current state of knowledge on major modifications of HDL and HDL-mediated brain cholesterol transport in AD, by taking into consideration the individual steps of this process. We also describe potential and encouraging HDL-based therapies that could represent new therapeutic strategies for AD treatment. Finally, we revise the main plasma and brain HDL modifications in other neurodegenerative disorders including Parkinson's disease (PD), Huntington's disease (HD), and frontotemporal dementia (FTD).

Cholesterol Transport Dysfunction and Its Involvement in Atherogenesis

Atherosclerosis is the cause of the development of serious cardiovascular disorders, leading to disability and death. Numerous processes are involved in the pathogenesis of atherosclerosis, including inflammation, endothelial dysfunction, oxidative stress, and lipid metabolism disorders. Reverse transport of cholesterol is a mechanism presumably underlying the atheroprotective effect of high-density lipoprotein. In this review, we examined disorders of cholesterol metabolism and their possible effect on atherogenesis. We paid special attention to the reverse transport of cholesterol. Transformed cholesterol metabolism results in dyslipidemia and early atherosclerosis. Reverse cholesterol transport is an endogenous mechanism by which cells export cholesterol and maintain homeostasis. It is known that one of the main factors leading to the formation of atherosclerotic plaques on the walls of blood vessels are multiple modifications of low-density lipoprotein, and the formation of foam cells following them.

New Strategies to Promote Macrophage Cholesterol Efflux

The capacity of macrophages to dispose of cholesterol deposited in the atherosclerotic plaque depends on their ability to activate cholesterol efflux pathways. To develop athero-protective therapies aimed at promoting macrophage cholesterol efflux, cholesterol metabolism in THP-1 monocyte-derived macrophages has been extensively studied, but the intrinsic sensitivity of monocytes and the lack of a standardized procedure to differentiate THP-1 monocytes into macrophages have made it difficult to utilize THP-1 macrophages in the same or similar degree of differentiation across studies. The variability has resulted in lack of understanding of how the differentiation affects cholesterol metabolism, and here we review and investigate the effects of THP-1 differentiation on cholesterol efflux. The degree of THP-1 differentiation was inversely associated with ATP binding cassette A1 (ABCA1) transporter-mediated cholesterol efflux. The differentiation-associated decrease in ABCA1-mediated cholesterol efflux occurred despite an increase in ABCA1 expression. In contrast, DSC1 expression decreased during the differentiation. DSC1 is a negative regulator of the ABCA1-mediated efflux pathway and a DSC1-targeting agent, docetaxel showed high potency and efficacy in promoting ABCA1-mediated cholesterol efflux in THP-1 macrophages. These data suggest that pharmacological targeting of DSC1 may be more effective than increasing ABCA1 expression in promoting macrophage cholesterol efflux. In summary, the comparison of THP-1 macrophage subtypes in varying degrees of differentiation provided new insights into cholesterol metabolism in macrophages and allowed us to identify a viable target DSC1 for the promotion of cholesterol efflux in differentiated macrophages. Docetaxel and other pharmacological strategies targeting DSC1 may hold significant potential for reducing atherogenic cholesterol deposition.

Detection of lipid efflux from foam cell models using a label-free infrared method

Synchrotron-based microFTIR spectroscopy was used to study the process of lipid efflux in a foam cell model. The anti-atherosclerotic drug, atorvastatin, removed low-density lipoprotein from the foam cells in a dose, and time dependent manner.

The HDL Proteome Watch: Compilation of studies leads to new insights on HDL function

PURPOSE OF REVIEW

High density lipoproteins (HDL) are a heterogeneous family of particles that contain distinct complements of proteins that define their function. Thus, it is important to accurately and sensitively identify proteins associated with HDL. Here we highlight the HDL Proteome Watch Database which tracks proteomics studies from different laboratories across the world.

RECENT FINDINGS

In 45 published reports, almost 1000 individual proteins have been detected in preparations of HDL. Of these, 251 have been identified in at least three different laboratories. The known functions of these consensus HDL proteins go well beyond traditionally recognized roles in lipid transport with many proteins pointing to HDL functions in innate immunity, inflammation, cell adhesion, hemostasis and protease regulation, and even vitamin and metal binding.

SUMMARY

The HDL proteome derived across multiple studies using various methodologies provides confidence in protein identifications that can offer interesting new insights into HDL function. We also point out significant issues that will require additional study going forward.

Cholesterol efflux promoting function of high-density lipoproteins in calcific aortic valve stenosis

Background and aims

Cholesterol efflux capacity is a functional property of high-density lipoproteins (HDL) reflecting the efficiency of the atheroprotective reverse cholesterol transport process in humans. Its relationship with calcific aortic valve stenosis (CAVS) has not been fully assessed yet.

Methods

We evaluated HDL-CEC in a patient population with varying degrees of aortic valvular calcific disease, assessed using echocardiography and cardiac computed tomography. Measurement of biomarkers that reflect osteogenic and tissue remodeling, along with dietary and gut microbiota-derived metabolites were performed.

Results

Patients with moderate-severe CAVS had significantly lower HDL-CEC compared to both control and aortic sclerosis subjects (mean: 6.09%, 7.32% and 7.26%, respectively). HDL-CEC displayed negative correlations with peak aortic jet velocity and aortic valve calcium score, indexes of CAVS severity (ρ = -0.298, p = 0.002 and ρ = -0.358, p = 0.005, respectively). In multivariable regression model, HDL-CEC had independent association with aortic valve calcium score (B: -0.053, SE: 0.014, p < 0.001), GFR (B: -0.034, SE: 0.012, p = 0.007), as well as with levels of total cholesterol (B: 0.018, SE: 0.005, p = 0.002).

Conclusion

These results indicate an impairment of HDL-CEC in moderate-severe CAVS and may contribute to identify potential novel targets for CAVS management.

The impact of statins on coronary atherosclerosis progression and long-term cardiovascular disease risk in rheumatoid arthritis

OBJECTIVES

To evaluate whether statins lower cardiovascular disease (CVD) risk in rheumatoid arthritis (RA) and if tentative benefits are related to changes in coronary plaque burden or composition.

METHODS

In an observational cohort study, 150 patients without CVD underwent coronary atherosclerosis evaluation (total, noncalcified, partially and fully calcified plaque) with computed tomography angiography. Prespecified cardiovascular events including cardiac death, myocardial infarction, unstable angina, revascularization, stroke, claudication, and heart failure were prospectively recorded. Change in plaque burden and composition was re-assessed in 102 patients within 6.9±0.3 years.

RESULTS

Time varying statin therapy, modeled using inverse probability treatment and censoring weights, did not significantly attenuate CVD risk in RA overall (adjusted- OR = 0.39 [95%CI=0.15-1.07], p = 0.067). However, statins associated with lower CVD risk in patients with baseline CRP>0.5mg/dL (adjusted-OR=0.09 [95%CI=0.03-0.30], p < 0.001) but not in those with CRP<0.5mg/dL (p-interaction=0.023), after controlling for Framingham-CVD score and time-varying bDMARD use. In patients treated with statin >50% of follow-up time, CRP did not associate with new plaque formation (adjusted-OR=0.42 [95%CI=0.09-1.94]), in contrast to statin-naïve (adjusted-OR=1.89 [95%CI=1.41-2.54]) and statin-treated <50% time (adjusted-OR=1.41 [95%CI=1.03-1.95], p-interaction=0.029). Statin therapy >50% follow-up time predicted dissipation (adjusted-OR=5.84 [95%CI=1.29-26.55]) and calcification of prevalent noncalcified lesions (adjusted-OR=4.16 [95%CI=1.11-15.54]), as well as new calcified plaque formation in segments without baseline plaque (adjusted-OR=2.84 [95%CI=1.09-7.41]).

CONCLUSION

Statin therapy associated with lower long-term cardiovascular risk in RA patients with higher inflammation. Moreover, statin therapy modified the impact of inflammation on new coronary plaque formation and predicted both regression and calcification of prevalent noncalcified lesions.

Mitochondrial Lipid Homeostasis at the Crossroads of Liver and Heart Diseases

The prevalence of NAFLD (non-alcoholic fatty liver disease) is a rapidly increasing problem, affecting a huge population around the globe. However, CVDs (cardiovascular diseases) are the most common cause of mortality in NAFLD patients. Atherogenic dyslipidemia, characterized by plasma hypertriglyceridemia, increased small dense LDL (low-density lipoprotein) particles, and decreased HDL-C (high-density lipoprotein cholesterol) levels, is often observed in NAFLD patients. In this review, we summarize recent genetic evidence, proving the diverse nature of metabolic pathways involved in NAFLD pathogenesis. Analysis of available genetic data suggests that the altered operation of fatty-acid β-oxidation in liver mitochondria is the key process, connecting NAFLD-mediated dyslipidemia and elevated CVD risk. In addition, we discuss several NAFLD-associated genes with documented anti-atherosclerotic or cardioprotective effects, and current pharmaceutical strategies focused on both NAFLD treatment and reduction of CVD risk.

Association between Serum Concentrations of Apolipoprotein A-I (ApoA-I) and Alzheimer's Disease: Systematic Review and Meta-Analysis

Background: A wealth of experimental and epidemiological evidence suggest that Apolipoprotein A-I (ApoA-I), the main protein constituent of high-density lipoprotein (HDL), may protect against Alzheimer disease (AD). To investigate this potential role, we conducted a meta-analysis of the published studies on the relationship between serum ApoA-I and AD occurrence. Methods: We screened MEDLINE, EMBASE, Web of Science, and Scopus, for cross-sectional studies published from inception to 1 March 2021, comparing the ApoA-I serum levels between patients with AD and cognitively normal controls. Results: From an initial screening of 245 articles, 5 studies, including 397 AD patients (mean age 75.0 years, 234 females) and 367 controls (mean age 69.2 years, 182 females), met the inclusion criteria. Compared to healthy controls, AD subjects had a lower ApoA-I serum level. The pooled weighted mean difference from a random-effects model was −0.31 g/L (p < 0.0001) (95% Confidence Interval: [−0.62–0.01], with high heterogeneity (I² = 100%). The Egger’s test confirmed an absence of publication bias (t = 0.62, p = 0.576). Conclusions: Our study showed that AD patients present lower serum levels of ApoA-I compared to cognitively normal individuals. Further studies on large population samples are required to support this finding.

Identification of Docetaxel as a Potential Drug to Promote HDL Biogenesis

Objective: Our recent studies showed that desmocollin 1 (DSC1) binds to apoA-I in order to inhibit apoA-I-mediated high density lipoprotein (HDL) biogenesis in atherosclerotic plaques. To promote HDL biogenesis in the plaque, here we search for small molecules that block apoA-I-DSC1 interactions. Approach and Results: We combined mutational and computational mapping methods to show that amino acid residues 442-539 in the mature DSC1 protein form an apoA-I binding site (AIBS). Using a crystal structure of the AIBS, we carried out virtual screening of 10 million small molecules to estimate their binding affinities to the AIBS, followed by the selection of 51 high-affinity binding molecules as potential inhibitors of apoA-I-DSC1 interactions. Among the 51, the chemotherapy drug docetaxel showed the highest potency in promoting apoA-I-mediated HDL biogenesis in primary human skin fibroblasts with the half-maximal effective concentration of 0.72 nM. In silico docking studies suggest that the taxane ring in docetaxel binds to the AIBS and that the carbon-13 sidechain of the taxane tightens/stabilizes the binding. The HDL biogenic effect of docetaxel was also observed in two predominant cell types in atherosclerosis, macrophages and smooth muscle cells. Importantly, docetaxel promoted HDL biogenesis at concentrations much lower than those required for inducing cytotoxicity. Conclusion: Determination of the AIBS in DSC1 and AIBS structure-based virtual screening allowed us to identify docetaxel as a strong HDL biogenic agent. With the remarkable potency in promoting HDL biogenesis, a chemotherapy drug docetaxel may be repurposed to enhance atheroprotective HDL functions.