LDL Particles Research Articles

Association between Intermediate-Density Lipoprotein Particles and the Progression of Carotid Atherosclerosis: A Community-Based Cohort Study.

Experimental studies report that intermediate-density lipoprotein (IDL), the precursor of low-density lipoprotein, promotes atherosclerotic plaque formation. However, whether IDL is involved in the development of atherosclerosis in humans is still unclear. The aim of this community-based study is to examine the association between IDL particle (IDL-P) concentrations and the 5-year progression of carotid atherosclerosis. Baseline IDL-P concentrations were measured using nuclear magnetic resonance spectroscopy in 927 participants aged 45-74 years with no history of cardiovascular disease (CVD) at baseline. To estimate the association between baseline IDL-P concentrations and 5-year progression of carotid atherosclerosis, indicated by atherosclerotic plaque progression and changes in total plaque area (TPA), multivariable-adjusted regression was employed. During the 5-year follow-up period, 45.8% of participants developed new plaques. Baseline IDL-P concentrations were significantly associated with the progression of carotid atherosclerosis. Participants in the highest quartile of IDL-P concentrations exhibited 1.36-fold (95% confidence interval [CI]: 1.09-1.68) increased progression of carotid plaque and 1.67-fold (95% CI: 1.04-2.69) higher TPA than those in the lowest quartile. These relationships were independent of baseline concentrations of low-density lipoprotein particles and very-low-density lipoprotein particles and their subclasses. Elevated IDL-P concentrations were independently associated with the progression of carotid atherosclerosis, suggesting that IDL-P is a novel risk factor for the development of atherosclerosis.

Discordant association of nonalcoholic fatty liver disease with lipoprotein(a) and markers of atherogenic dyslipidemia

Nonalcoholic fatty liver disease (NAFLD) is associated with atherogenic dyslipidemia and an increased risk of cardiovascular events. Previous studies have suggested an inverse relationship between NAFLD severity and lipoprotein(a) [Lp(a)] level, but contemporary data from the U.S. are lacking. Lp(a), lipid profile, apolipoproteins, and nuclear magnetic resonance-based lipoprotein particle concentrations were measured in 151 patients with biopsy-proven NAFLD. Levels were compared between those with nonalcoholic fatty liver (NAFL) on histology and non-alcoholic steatohepatitis (NASH). Median age was 55 [48, 62] years, 67% of patients were women, 83% were White, 43% had NAFL, and 57% had NASH. Triglyceride level was higher and high-density lipoprotein-cholesterol (HDL-C) was lower among those with NASH as compared with NAFL. Circulating apolipoprotein-B (ApoB) and low-density lipoprotein particle concentration (LDL-P) were 9% and 17% higher in the NASH group as compared with NAFL, respectively. Contrastingly, Lp(a) concentration was 50% lower in NASH relative to NAFL group. Hepatocyte ballooning, lobular inflammation, and fibrosis on histology were inversely associated with Lp(a) concentration. NAFLD severity has a discordant association with Lp(a) and other markers of atherogenic dyslipidemia. This relationship may have implications for prognosticating cardiovascular disease risk in patients with NAFLD.

Missense variants in SORT1 are associated with LDL-C in an Amish population

Common noncoding variants at the human 1p13.3 locus associated with SORT1 expression are among those most strongly associated with low-density lipoprotein cholesterol (LDL-C) in human genome-wide association studies. However, validation studies in mice and cell lines have produced variable results regarding the directionality of the effect of SORT1 on LDL-C. This, together with the fact that the 1p13.3 variants are associated with expression of several genes, has raised the question of whether SORT1 is the causal gene at this locus. Using whole exome sequencing in members of an Amish population, we identified coding variants in SORT1 that are associated with increased (rs141749679, K302E) and decreased (rs149456022, Q225H) LDL-C. Further, analysis of plasma lipoprotein particle subclasses by ion mobility in a subset of rs141749679 (K302E) carriers revealed higher levels of large LDL particles compared to noncarriers. In contrast to the effect of these variants in the Amish, the sortilin K302E mutation introduced into a C57BL6/J mouse via CRISPR/Cas9 had decreased non-high-density lipoprotein cholesterol, and the sortilin Q225H mutation did not alter cholesterol levels in mice. This is indicative of different effects of these mutations on cholesterol metabolism in the two species. To our knowledge, this is the first evidence that naturally occurring coding variants in SORT1 are associated with LDL-C, thus supporting SORT1 as the gene responsible for the association of the 1p13.3 locus with LDL-C.

ANGPTL3 (Angiopoietin-Like 3) Preferentially Resides on High-Density Lipoprotein in the Human Circulation, Affecting Its Activity.

Background ANGPTL3 (angiopoietin-like protein 3) is an acknowledged crucial regulator of lipid metabolism by virtue of its inhibitory effect on lipoprotein lipase and endothelial lipase. It is currently unknown whether and to which lipoproteins ANGPTL3 is bound and whether the ability of ANGPTL3 to inhibit lipase activity is affected by binding to lipoproteins. Methods and Results Incubation of ultracentrifugation-isolated low-density lipoprotein (LDL) and high-density lipoprotein (HDL) fractions from healthy volunteers with recombinant ANGPTL3 revealed that ANGPTL3 associates with both HDL and LDL particles ex vivo. Plasma from healthy volunteers and a patient deficient in HDL was fractionated by fast protein liquid chromatography, and ANGPTL3 distribution among lipoprotein fractions was measured. In healthy volunteers, ≈75% of lipoprotein-associated ANGPTL3 resides in HDL fractions, whereas ANGPTL3 was largely bound to LDL in the patient deficient in HDL. ANGPTL3 activity was studied by measuring lipolysis and uptake of 3H-trioleate by brown adipocyte T37i cells. Unbound ANGPTL3 did not suppress lipase activity, but when given with HDL or LDL, ANGPTL3 suppressed lipase activity by 21.4±16.4% (P=0.03) and 25.4±8.2% (P=0.006), respectively. Finally, in a subset of the EPIC (European Prospective Investigation into Cancer) Norfolk study, plasma HDL cholesterol and amount of large HDL particles were both positively associated with plasma ANGPTL3 concentrations. Moreover, plasma ANGPTL3 concentrations showed a positive association with incident coronary artery disease (odds ratio, 1.25 [95% CI, 1.01-1.55], P=0.04). Conclusions Although ANGPTL3 preferentially resides on HDL, its activity was highest once bound to LDL particles.

Oxidative Stress, Atherogenic Dyslipidemia, and Cardiovascular Risk.

Oxidative stress is the consequence of an overproduction of reactive oxygen species (ROS) that exceeds the antioxidant defense mechanisms. Increased levels of ROS contribute to the development of cardiovascular disorders through oxidative damage to macromolecules, particularly by oxidation of plasma lipoproteins. One of the most prominent features of atherogenic dyslipidemia is plasma accumulation of small dense LDL (sdLDL) particles, characterized by an increased susceptibility to oxidation. Indeed, a considerable and diverse body of evidence from animal models and epidemiological studies was generated supporting oxidative modification of sdLDL particles as the earliest event in atherogenesis. Lipid peroxidation of LDL particles results in the formation of various bioactive species that contribute to the atherosclerotic process through different pathophysiological mechanisms, including foam cell formation, direct detrimental effects, and receptor-mediated activation of pro-inflammatory signaling pathways. In this paper, we will discuss recent data on the pathophysiological role of oxidative stress and atherogenic dyslipidemia and their interplay in the development of atherosclerosis. In addition, a special focus will be placed on the clinical applicability of novel, promising biomarkers of these processes.

Unveiling the intricate causal nexus between pancreatic cancer and peripheral metabolites through a comprehensive bidirectional two-sample Mendelian randomization analysis.

Aim: Pancreatic cancer (PC) is a devastating malignancy characterized by its aggressive nature and poor prognosis. However, the relationship of PC with peripheral metabolites remains not fully investigated. The study aimed to explore the causal linkage between PC and peripheral metabolite profiles. Methods: Employing publicly accessible genome-wide association studies (GWAS) data, we conducted a bidirectional two-sample Mendelian randomization (MR) analysis. The primary analysis employed the inverse-variance weighted (IVW) method. To address potential concerns about horizontal pleiotropy, we also employed supplementary methods such as maximum likelihood, weighted median, MR-Egger regression, and MR pleiotropy residual sum and outlier (MR-PRESSO). Results: We ascertained 20 genetically determined peripheral metabolites with causal linkages to PC while high-density lipoprotein (HDL) and very low-density lipoprotein (VLDL) particles accounted for the vast majority. Specifically, HDL particles exhibited an elevated PC risk while VLDL particles displayed an opposing pattern. The converse MR analysis underscored a notable alteration in 17 peripheral metabolites due to PC, including branch chain amino acids and derivatives of glycerophospholipid. Cross-referencing the bidirectional MR results revealed a reciprocal causation of PC and X-02269 which might form a self-perpetuating loop in PC development. Additionally, 1-arachidonoylglycerophosphocholine indicated a reduced PC risk and an increase under PC influence, possibly serving as a negative feedback regulator. Conclusion: Our findings suggest a complex interplay between pancreatic cancer and peripheral metabolites, with potential implications for understanding the etiology of pancreatic cancer and identifying novel early diagnosis and therapeutic targets. Moreover, X-02269 may hold a pivotal role in PC onset and progression.

Lipid variability in patients with diabetes mellitus

Diabetic dyslipidemia is characterized by hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL-C), elevated low-density lipoprotein cholesterol (LDL-C), and the predominance of small dense LDL particles caused by insulin resistance in patients with type 2 diabetes mellitus (DM) or insulin deficiency in patients with type 1 DM. Dyslipidemia is a major risk factor for atherosclerotic cardiovascular disease in individuals with DM, and lowering lipid levels can reduce the associated morbidity and mortality. The current guidelines for dyslipidemia management recommend an LDL-C goal lower than 55 to 100 mg/dL, depending on the underlying risk factors. However, greater visit-to-visit variability in cholesterol levels might be an independent predictor of major adverse cardiovascular events, high incidence of atrial fibrillation, poor renal outcomes, and cognitive dysfunction in patients with DM. This review focuses on the clinical implications of lipid variability in patients with DM.

A pilot retrospective study of a physician-directed and genomics-based model for precision lifestyle medicine.

Precision lifestyle medicine is a relatively new field in primary care, based on the hypothesis that genetic predispositions influence an individual's response to specific interventions such as diet, exercise, and prescription medications. Despite the increase in commercially available genomic testing, few studies have investigated effects of a physician-directed program to optimize chronic disease using genomics-based precision medicine. We performed an pilot, observational cohort study to evaluate effects of the Wild Health program, a physician and health coach service offering genomics-based lifestyle and medical interventions, on biomarkers indicative of chronic disease. 871 patients underwent genomic testing, biomarker testing, and ongoing health coaching after initial medical consultation by a physician. Improvements in several clinically relevant out-of-range biomarkers at baseline were identified in a large proportion of patients treated through lifestyle intervention without the use of prescription medication. Notably, normalization of several biomarkers associated with chronic disease occurred in 47.5% (hemoglobin A1c [HbA1c]), 33.3% (low density lipoprotein particle number [LDL-P]), and 33.2% (C-reactive protein [CRP]). However, due to the inherent limitations of our observational study design and use of retrospective data, ongoing work will be crucial for continuing to shed light on the effectiveness of physician-led, genomics-based lifestyle coaching programs. Future studies would benefit from implementing a randomized controlled study design, tracking specific interventions, and evaluating physiological data, such as BMI.

When Bigger Is Better: Can Bariatric Surgery Boost Low-Density Lipoprotein Particle Size for Improved Health?

When Bigger Is Better: Can Bariatric Surgery Boost Low-Density Lipoprotein Particle Size for Improved Health?

Effect of PCSK9 inhibition on plasma levels of small dense low density lipoprotein-cholesterol and 7-ketocholesterol

Oxidized forms of cholesterol (oxysterols) are implicated in atherogenesis and can accumulate in the body via direct absorption from food or through oxidative reactions of endogenous cholesterol, inducing the formation of LDL particles loaded with oxidized cholesterol. It remains unknown whether drastic reductions in LDL-cholesterol (LDL-C) are associated with changes in circulating oxysterols and whether small dense LDL (sdLDL) are more likely to carry these oxysterols and susceptible to the effects of PCSK9 inhibition (PCSK9i). We investigate the effect of LDL-C reduction accomplished via PCSK9i on changes in plasma levels of sdLDL-cholesterol (sdLDL-C) and a common, stable oxysterol, 7-ketocholesterol (7-KC), among 134 patients referred to our Preventive Cardiology clinic. Plasma lipid panel, sdLDL-C, and 7-KC measurements were obtained from patients before and after initiation of PCSK9i. The intervention caused a significant lowering of LDL-C (-55.4 %). The changes in sdLDL-C levels (mean reduction 51.4 %) were highly correlated with the reductions in LDL-C levels (R = 0.829, p < 0.001). Interestingly, whereas changes in plasma free 7-KC levels with PCSK9i treatment were much smaller than (-6.6 %) and did not parallel those of LDL-C and sdLDL-C levels, they did significantly correlate with changes in triglycerides and very low-density lipoprotein-cholesterol (VLDL-C) levels (R = 0.219, p = 0.025). Our findings suggest a non-preferential clearance of LDL subparticles as a consequence of LDL receptor upregulation caused by PCSK9 inhibition. Moreover, the lack of significant reduction in 7-KC with PCSK9i suggests that 7-KC may be in part carried by VLDL and lost during lipoprotein processing leading to LDL formation.

Low-Density Lipoprotein Contributes to Endometrial Carcinoma Cell Proliferation, Migration, and Invasion by Activating the JAK-STAT Signaling Pathway.

Cholesterol-rich low-density lipoprotein (LDL) particles have been demonstrated to regulate breast cancer cell proliferation and migration, but their biological function and relevant mechanisms in endometrial carcinoma (EC) remain unclear. Serum and tissue samples were collected from EC patients (n = 50) and patients with benign endometrial hyperplasia (n = 50). Ishikawa and RL95-2 cells were stimulated with different concentrations of LDL, followed by treatment with a JAK2 inhibitor (SD-1029). LDL concentrations were determined by ELISA. The in vitro biological behavior of cells was examined using the CCK-8 assay, EdU staining, and Transwell assay. The tumorigenicity of LDL in vivo was examined using a xenograft mouse model. western blotting, immunofluorescence, and immunohistochemistry studies were performed to measure related protein expression. The LDL concentrations and levels of p-JAK2 and p-STAT3 expression were elevated in the clinical samples. Similar trends in expression were detected in EC cells after LDL stimulation. LDL treatment significantly promoted EC cell proliferation, migration, and invasion, and also upregulated p-JAK2 and p-STAT3 expression in a dose-dependent manner. Moreover, SD-1029 dramatically blocked the LDL-mediated effects on EC cells. Intravenous injection of LDLs promoted tumor growth in the xenograft nude mice, and also increased p-JAK2, p-STAT3, and Ki-67 expression, and downregulated caspase-3 expression. These findings indicate that LDLs exert an oncogenic effect in EC cells by activating the JAK/STAT signaling pathway, and also suggest the JAK/STAT pathway as a possible therapeutic target for EC.

Lipoprotein Characteristics and Incident Coronary Heart Disease: Prospective Cohort of Nearly 90 000 Individuals in UK Biobank.

Background Associations of coronary heart disease (CHD) with plasma lipids are well described, but the associations with characteristics of lipoproteins (which transport lipids) remain unclear. Methods and Results UK Biobank is a prospective study of 0.5 million adults. Analyses were restricted to 89 422 participants with plasma lipoprotein and apolipoprotein measures from Nightingale nuclear magnetic resonance spectroscopy and without CHD at baseline. CHD risk was positively associated with concentrations of very-low-density lipoproteins, intermediate-density lipoproteins, and low-density lipoproteins (LDL), and inversely associated with high-density lipoproteins. Hazard ratios (99% CIs) per SD were 1.22 (1.17-1.28), 1.16 (1.11-1.21), 1.20 (1.15-1.25), and 0.90 (0.86-0.95), respectively. Larger subclasses of very-low-density lipoproteins were less strongly associated with CHD risk, but associations did not materially vary by size of LDL or high-density lipoprotein. Given lipoprotein particle concentrations, lipid composition (including cholesterol) was not strongly related to CHD risk, except for triglyceride in LDL particles. Apolipoprotein B was highly correlated with LDL concentration (r=0.99), but after adjustment for apolipoprotein B, concentrations of very-low-density lipoprotein and high-density lipoprotein particles remained strongly related to CHD risk. Conclusions This large-scale study reliably quantifies the associations of nuclear magnetic resonance-defined lipoprotein characteristics with CHD risk. CHD risk was most strongly related to particle concentrations, and separate measurements of lipoprotein concentrations may be of greater value than the measurement by apolipoprotein B, which was largely determined by LDL concentration alone. Furthermore, there was strong evidence of positive association with mean triglyceride molecules per LDL particle but little evidence of associations with total triglycerides or other lipid and lipoprotein fractions after accounting for lipoprotein concentrations.

FRI181 Increased LDL Particle And Apolipoprotein B Concentrations In Patients With Nonfunctioning And Cortisol Secreting Adrenal Adenomas

Abstract Disclosure: R. Sandooja: None. A. Kittithaworn: None. P. Dogra: None. D. Gruppen: None. E. Atkinson: None. S. Achenbach: None. K. Yu: None. M. Connelly: None. V. Simha: None. R.P. Dullaart: None. I. Bancos: None. INTRODUCTION: Based on the spectrum of cortisol excess, adrenal adenomas are classified as adenomas with Cushing syndrome (CS), adenomas with mild autonomous cortisol secretion (MACS), and non-functioning adenomas (NFA). Patients with adrenal adenomas demonstrate a high prevalence of cardiovascular morbidity and mortality proportional to the degree of hypercortisolism. Evidence on whether dyslipidemia is a contributing cardiovascular risk factor in patients with NFA and MACS is discrepant. We aimed to characterize (apo) lipoprotein abnormalities across the spectrum of cortisol excess in patients with adenomas as compared to referent subjects. METHODS: Study Design: Single center cross sectional study between 01/2015 - 05/2021.Patients: Adults with NFA, MACS, or CS were consecutively enrolled. MACS was diagnosed based on post-dexamethasone cortisol &amp;gt;1.8 mcg/dL. Referent subjects were recruited from local population of patients with available abdominal imaging and no adrenal disorders. All subjects provided fasting ethylenediaminetetraacetic acid (EDTA) venous samples. Measurements: Nuclear magnetic resonance (NMR) spectroscopy measurements included total cholesterol (TC), low-density lipoprotein (LDL) and LDL particle concentrations, high-density lipoprotein (HDL) subclasses, apolipoprotein B (apo B), triglycerides (TG) and TG-rich lipoprotein concentrations. RESULTS: Participants included 101 patients with CS (median age 44 years, IQR 31-58, 85% women), 158 patients with MACS (median age 62 years, IQR 51-70, 62% women), 166 patients with NFA (median age 60 years, IQR 53--66, 63% women) and 136 referent subjects (median age 68 years, IQR 57-77, 52% women). Patients had higher BMI (32 vs 27 kg/m2), higher prevalence of hypertension (72% vs 46%) and diabetes mellitus (27% vs 9%) as compared to reference subjects. Statin therapy was used in 32% of patients and referent subjects. After adjusting for age, sex, BMI, smoking, diabetes, hypertension, and statin therapy, as compared to referent subjects, we found inconsistent increase in TC, LDL cholesterol and TG across CS, MACS and NFA and no consistent differences in LDL size, HDL variables, TG and TG-rich lipoproteins. However, when compared to referent subjects, LDL particle concentrations- CS(OR 1.78, 95% CI 1.33-2.39), MACS (OR 1.31, 95% CI 1.03-1.67), and NFA (OR 1.43, 95% CI 1.12-1.82) and Apo B levels were higher in all patient categories: CS (OR 2.26, 95% CI 1.57-3.24), MACS (OR 1.36 95% CI 1.00-1.85 ), and NFA (OR 1.54 95% CI 1.13-2.09). These differences were particularly evident in patients not on statin therapy. CONCLUSIONS: We found that LDL particle and Apo B concentrations were elevated in all patient groups, including those with MACS and NFA. In comparison to conventional lipid measurements, LDL particle and Apo B may serve as a better biomarker of the future cardiovascular risk in patients with adrenal adenomas. Presentation: Friday, June 16, 2023

FRI099 Advanced Lipoprotein Analysis In Patients With Cushing’s Syndrome

Abstract Disclosure: R.T. Varghese: None. R. McGlotten: None. M. Sampson: None. A. Prakash: None. R. Shamburek: None. A.T. Remaley: None. R. Muniyappa: None. L.K. Nieman: None. Introduction: Cushing syndrome (CS) patients have a higher mortality rate due to increased cardiovascular disease (CVD). Analysis of lipoprotein particles with nuclear magnetic resonance (NMR) spectroscopy provides additional insights into CVD risk beyond the standard lipid panel. The goal of the study was to better characterize the lipid abnormalities in patients with CS by using high-resolution separation of lipoprotein particles. Methods: We measured plasma lipids (Cholesterol, TC; calculated low density lipoprotein, LDL; triglycerides, TG; high density lipoprotein, HDL) by the traditional enzymatic assay and lipoprotein particles by NMR spectroscopy. Measures of inflammation and insulin resistance were also derived from NMR spectra. Values are shown as mean ± SEM or median [IQR]. Results: After initial evaluation, 42 subjects (mean age 47.4 ± 2.5 years; 28 females; weight 85.0 ± 3.1 kg) had Cushing's disease (n=23), ectopic ACTH secretion (n=17), or adrenal adenoma (n=2). Ten patients were on chronic statin therapy, and 14 subjects had type 2 diabetes mellitus (T2DM). The control group comprised 45 subjects without T2DM [mean age 45.4 ± 2.1 years and weight (83.5 ± 2.7) kg]. None in the control group were on statin therapy. Compared to controls, CS patients had significantly higher systolic (135 ±2 vs. 119 ±2 mm Hg, p&amp;lt;0.001) and diastolic blood pressure (79 ±2 vs. 71 ±1 mm Hg, p&amp;lt;0.001), HbA1c (6.1 [5.4-7.5] vs. 5.4 [5.0-5.7], p&amp;lt;0.001), plasma glucose (103 [90-137] vs 94 [89-100] mg/dL, p=0.003), and insulin (17[12-26] vs 11[7-15] uU/mL, p=0.01) levels. Compared to controls, patients with CS had significantly higher triglyceride concentration (116 [84 -146] vs 87 [62-120] mg/dL, p=0.02) and lower LDL concentration (90 [69 -113] vs 108 [90 -125] mg/dL, p=0.04). However, total cholesterol and HDL cholesterol concentrations were not different. LDL particle size in CS was smaller (20.5[20.0-21.0] vs 21.0 [20.7-21.2] nm, p=0.01) and VLDL particle size was larger (49.8 ± 0.9 vs 45.7 ± 1.0 nm, p=0.002) than in controls. No difference was noted between groups in HDL particle number or size or in LDL and VLDL particle number. In the group with CS, a marker of inflammation, GlycA (Glycan N-acetylglucosamine) (494.5 ± 18.2 vs. 382.5 ± 9.0 µmol/L, p&amp;lt;0.001) and Lipoprotein Insulin Resistance score (LPIR) (46.4 ± 3.1 vs. 36.2 ± 3.1, p=0.02) were significantly higher. There were no group differences in branch-chained amino acids (BCCA) levels. These differences remained even when patients with type 2 diabetes and those on statin therapy were excluded. Conclusions: These data suggest that the higher inflammatory and insulin resistance state, dysglycemia, hypertension, and altered lipoprotein profiles may contribute to the increased CV risk in patients with Cushing’s syndrome. Early detection and treatment for these abnormalities may attenuate CV risk. Presentation: Friday, June 16, 2023

Association between exposure to air pollution and blood lipids in the general population of Spain.

We aimed to assess the associations of exposure to air pollutants and standard and advanced lipoprotein measures, in a nationwide sample representative of the adult population of Spain. We included 4647 adults (>18 years), participants in the national, cross-sectional, population-based di@bet.es study, conducted in 2008-2010. Standard lipid measurements were analysed on an Architect C8000 Analyzer (Abbott Laboratories SA). Lipoprotein analysis was made by an advanced 1 H-NMR lipoprotein test (Liposcale®). Participants were assigned air pollution concentrations for particulate matter <10 μm (PM10 ), <2.5 μm (PM2.5 ) and nitrogen dioxide (NO2 ), corresponding to the health examination year, obtained by modelling combined with measurements taken at air quality stations (CHIMERE chemistry-transport model). In multivariate linear regression models, each IQR increase in PM10 , PM2.5 and NO2 was associated with 3.3%, 3.3% and 3% lower levels of HDL-c and 1.3%, 1.4% and 1.1% lower HDL particle (HDL-p) concentrations (p < .001 for all associations). In multivariate logistic regression, there was a significant association between PM10 , PM2.5 and NO2 concentrations and the odds of presenting low HDL-c (<40 mg/dL), low HDL-p (<p25) and higher LDL particle (LDL-p) concentrations (≥p75). In subgroup analyses there were stronger associations between PM10 and NO2 and low HDL-p in men (p for interaction .008 and .034), and between NO2 and low HDL-p in individuals with obesity (p for interaction .015). Our study shows an association between the exposure to air pollutants and blood lipids in the general population of Spain, suggesting a link to atherosclerosis.

Low-density lipoprotein subclasses over the menopausal transition and risk of coronary calcification and carotid atherosclerosis: the SWAN Heart and HDL ancillary studies.

Perimenopausal women experience a steep increase in low-density lipoprotein cholesterol (LDL-C) that is related to a higher risk of carotid plaque later in life. Low-density lipoprotein subclasses have been linked to cardiovascular diseases beyond LDL-C, promising a better risk stratification. We aim to characterize changes in LDL subclasses and assess their associations with presence of coronary artery calcium (CAC score ≥10) and carotid intima-media thickness (cIMT) over the menopausal transition (MT) and by menopause stage. Nuclear magnetic resonance spectroscopy LDL subclasses were measured for a maximum of five time points. Coronary artery calcification and cIMT were measured for a maximum of two time points. LOESS (locally weighted regression with scatter smoothing) plots, linear mixed-effects models, and generalized estimating equations were used for analyses. The study included 471 women (baseline: age, 50.2 ± 2.7 years; 79.0% premenopausal/early perimenopausal), of whom 221 had data on CAC or cIMT. Low-density lipoprotein subclasses increased over the MT, whereas intermediate density-lipoprotein particles declined. In adjusted models, higher total LDL particles (LDL-P) and apolipoprotein B were associated with greater CAC prevalence and greater cIMT. Although none of the associations were modified by menopause stage, higher LDL-C, apolipoprotein B, and total LDL-P were associated with greater cIMT during the perimenopause or postmenopause stages, whereas higher LDL-C and small LDL-P were associated with greater CAC prevalence, mainly during perimenopause. During the MT, women experience significant increases in LDL subclasses found to be related to greater cIMT levels and CAC prevalence. Whether these changes could better predict future risk of hard cardiovascular disease events beyond LDL-C remains a research question to address.

Lipoprotein (a) in atherosclerosis: A bibliometric and visualization analysis

Abstract: Lipoprotein (a) [Lp (a)] is a complex polymorphic lipoprotein consisting of one low-density lipoprotein particle with one molecule of apolipoprotein B100 and another apolipoprotein (a) linked by a disulfide bond. In recent years, due to its causal role in premature atherosclerotic cardiovascular diseases and calcified aortic stenosis, Lp (a) has attracted more and more attention. Our study aimed to illustrate the trend of Lp (a) research in atherosclerosis (AS) through bibliometric analysis. The Science Citation Index-Expanded was used to locate Lp (a) and AS studies published between December 1, 2012 and December 1, 2022. VOSviewer and CiteSpace bibliometric software packages were used to analyze literature information. LP (a) has seen an overall increase in annual publications. The United States had the highest number of publications worldwide, with 192 publications. The University of California, San Diego, has contributed significantly to Lp (a) with 29 publications and led research collaboration. In the past few decades, there has been close collaboration between countries or regions, institutions, and authors. In addition, the European Heart Journal was the most cited, followed by the Journal of Lipid Research and AS with 2033, 1096, and 806 citations, respectively. Recent studies were on genes and lipid-lowering therapies. Our study comprehensively evaluated the research status and trends of Lp (a) in AS worldwide for the first time and provided a valuable reference for clinical researchers.

Dyslipidemia poses a significant risk of many complications for Type 2 Diabetes Mellitus Patients: Article Review.

Abstract: The most prevalent chronic illnesses to be identified and treated collectively are dyslipidemias. They are typically identified by triglycerides serum, cholesterol, or both, Atypical levels of related lipoprotein species, including high of very low density lipoproteins VLDL, low HDL cholesterol, high LDL cholesterol, and a predominance of small dense LDL particles, are also present. are all signs of diabetic dyslipidemia. Chronic Kidney disease (CKD) alone may result in dyslipidemia due to disruption of lipids metabolism. Hyperglycemia and insulin resistance may exacerbate dyslipidemia in diabetic patients with CKD. Patients with type 2 diabetes mellitus bear a disproportionately high burden of cardiovascular disease , the primary global origin of morbidity and mortality, with the proportion of CVD attributed to diabetes rising in the general population . A significant microvascular consequence of diabetes is diabetic retinopathy (DR). among developed countries, it is the most frequent cause of blindness among people of working age. The most prevalent neuropathy, diabetic neuropathy, has a variety of clinical symptoms connected with it. After the age of 50, it typically occurs, and people with long-term diabetes mellitus are more likely to experience it. However, macrovascular pathogenesis is also involved. It begins with microvascular damage to the tiny blood arteries that nourish the nerves. The aim of writing this article is that the imbalance of fats and their high concentrations in the human body of a patient with type 2 diabetes generates many complications, which over time are dangerous complications that threaten the life of a diabetic patient and lead to his death if these complications are not controlled because the high levels of sugar and fat in the human body It plays an important role in the development of the patient's condition.

The Anti-Thrombotic Effects of PCSK9 Inhibitors.

Atherosclerosis is the primary process that underlies cardiovascular disease. The connection between LDL cholesterol and the formation of atherosclerotic plaques is established by solid evidence. PCSK9 inhibitors have proven to be a valuable and practical resource for lowering the LDL cholesterol of many patients in recent years. Their inhibitory effect on atherosclerosis progression seems to be driven not just by lipid metabolism modification but also by LDL-independent mechanisms. We review the effect of PCSK9 inhibitors on various mechanisms involving platelet activation, inflammation, endothelial dysfunction, and the resultant clot formation. The main effectors of PCSK9 activation of platelets are CD36 receptors, lipoprotein(a), oxidised LDL particles, tissue factor, and factor VIII. Many more molecules are under investigation, and this area of research is growing rapidly.

The LDL receptor is regulated by membrane cholesterol as revealed by fluorescence fluctuation analysis

Membrane cholesterol-rich domains have been shown to be important for regulating a range of membrane protein activities. Low-density lipoprotein receptor (LDLR)-mediated internalization of cholesterol-rich LDL particles is tightly regulated by feedback mechanisms involving intracellular sterol sensors. Since LDLR plays a role in maintaining cellular cholesterol homeostasis, we explore the role that membrane domains may have in regulating LDLR activity. We expressed a fluorescent LDLR-mEGFP construct in HEK293T cells and imaged the unligated receptor or bound to an LDL/DiI fluorescent ligand using total internal reflection fluorescence microscopy. We studied the receptor’s spatiotemporal dynamics using fluorescence fluctuation analysis methods. Image cross correlation spectroscopy reveals a lower LDL-to-LDLR binding fraction when membrane cholesterol concentrations are augmented using cholesterol esterase, and a higher binding fraction when the cells are treated with methyl-β-cyclodextrin) to lower membrane cholesterol. This suggests that LDLR’s ability to metabolize LDL particles is negatively correlated to membrane cholesterol concentrations. We then tested if a change in activity is accompanied by a change in membrane localization. Image mean-square displacement analysis reveals that unligated LDLR-mEGFP and ligated LDLR-mEGFP/LDL-DiI constructs are transiently confined on the cell membrane, and the size of their confinement domains increases with augmented cholesterol concentrations. Receptor diffusion within the domains and their domain-escape probabilities decrease upon treatment with methyl-β-cyclodextrin, consistent with a change in receptor populations to more confined domains, likely clathrin-coated pits. We propose a feedback model to account for regulation of LDLR within the cell membrane: when membrane cholesterol concentrations are high, LDLR is sequestered in cholesterol-rich domains. These LDLR populations are attenuated in their efficacy to bind and internalize LDL. However, when membrane cholesterol levels drop, LDL has a higher binding affinity to its receptor and the LDLR transits to nascent clathrin-coated domains, where it diffuses at a slower rate while awaiting internalization.