Protective effect of high density lipoprotein on endothelium-dependent vasodilatation

Total Outflow of High-Density Lipoprotein-Cholesteryl Esters from Plasma Is Decreased in a Model of 3/4 Renal Mass Reduction

(1) Background: Previous studies have enriched high-density lipoproteins (HDL) using cholesteryl esters in rabbits with a three-quarter reduction in functional renal mass, suggesting that the kidneys participate in the cholesterol homeostasis of these lipoproteins. However, the possible role of the kidneys in lipoprotein metabolism is still controversial. To understand the role of the kidneys in regulating the HDL lipid content, we determined the turnover of HDL-cholesteryl esters in rabbits with a three-quarter renal mass reduction. (2) Methods: HDL subclass characterization was conducted, and the kinetics of plasma HDL-cholesteryl esters, labeled with tritium, were studied in rabbits with a 75% reduction in functional renal mass (Ntx). (3) Results: The reduced renal mass triggered the enrichment of cholesterol, specifically cholesteryl esters, in HDL subclasses. The exchange of cholesteryl esters between HDL and apo B-containing lipoproteins (VLDL/LDL) was not significantly modified in Ntx rabbits. Moreover, the cholesteryl esters of HDL and VLDL/LDL fluxes from the plasmatic compartment tended to decrease, but they only reached statistical significance when both fluxes were added to the Nxt group. Accordingly, the fractional catabolic rate (FCR) of the HDL-cholesteryl esters was lower in Ntx rabbits, concomitantly with its accumulation in HDL subclasses, probably because of the reduced mass of renal cells requiring this lipid from lipoproteins.

Metabolic syndrome and erectile dysfunction: a systematic review and meta-analysis study

PURPOSE

The clinical significance of metabolic syndrome (MetS) versus its single components in erectile dysfunction (ED) is conflicting. Thus, the purpose is to analyze the available evidence on the relationship between MetS-along with its components-and ED.

METHODS

All prospective and retrospective observational studies reporting information on ED and MetS were included. In addition, we here reanalyzed preclinical and clinical data obtained from a previously published animal model of MetS and from a consecutive series of more than 2697 men (mean age: 52.7 ± 12), respectively.

RESULTS

Data derived from this meta-analysis showed that MetS was associated with an up to fourfold increased risk of ED when either unadjusted or adjusted data were considered. Meta-regression analysis, performed using unadjusted statistics, showed that the MetS-related risk of ED was closely associated with all the MetS components. These associations were confirmed when unadjusted analyses from clinical models were considered. However, fully adjusted data showed that MetS-associated ED was more often due to morbidities included (or not) in the algorithm than to the MetS diagnostic category itself. MetS is also associated with low testosterone, but its contribution to MetS-associated ED-as derived from preclinical and clinical models-although independent, is marginal.

CONCLUSIONS

The results of our analysis suggest that MetS is a useless diagnostic category for studying ED. However, treating the individual MetS components is important, because they play a pivotal role in determining ED.

Serum Uric Acid is a Better Indicator of Kidney Impairment Than Serum Uric Acid-to-Creatinine Ratio and Serum Uric Acid-to-High-Density Lipoprotein Ratio: A Cross-Sectional Study of Type 2 Diabetes Mellitus Patients

Background

Type 2 diabetes mellitus (T2DM) patients are likely to develop kidney disease. Early diagnosis, finding predictors and controlling risk factors are of great significance for T2DM patients. This study investigated the ability of uric acid (UA), the uric acid to creatinine (CR) ratio (UA/CR) and the uric acid to high-density lipoprotein cholesterol ratio (UHR) to assess the kidney function of T2DM patients and determined the relationship between the three indicators and the estimated glomerular filtration rate (eGFR).

Methods

A total of 1326 adult T2DM patients were enrolled in the current study. Patients were stratified into three groups according to their eGFRs. Spearman correlation was used to analyze the correlation between three indicators and the clinical variables. Logistic regression analysis was used to assess the association between the three indicators and diabetic kidney disease (DKD) and kidney impairment (eGFR <60 mL/min/1.73 m2). Receiver operating characteristic (ROC) analyses and the area under the ROC curve (AUC) were then used to assess the ability of UA, UA/CR, and UHR to discriminate kidney impairment in T2DM.

Results

UA and UHR demonstrated a positive association with DKD risk (P < 0.05). The odds ratios (ORs) were 1.005 (95% CI, 1.004-1.007) and 1.057 (95% CI, 1.039-1.076), respectively. UA/CR was negatively correlated with DKD risk (OR, 0.922 (95% CI, 0.876, 0.970), P < 0.05). Furthermore, UA and UHR demonstrated a strong positive association with kidney impairment risk, while UA/CR was negatively correlated with kidney impairment risk in T2DM patients (P < 0.05 for all) after adjusting for confounding factors. UA had the highest AUC (0.762) among the three indicators. UHR had a greater AUC (0.713) than UA/CR, which had an AUC value of 0.148 (p < 0.001).

Conclusion

UA is the best indicator of renal impairment (eGFR <60 mL/min/1.73 m2) among the three indicators, and UHR is a better indicator than UA/CR.

The association between arterial hypertension and menarcheal age

OBJECTIVE

Menarche, as a milestone of puberty, may have a long-term effect on health. The present study investigated the association of age at menarche with the incidence of arterial hypertension.

STUDY DESIGN

A total of 4747 post-menarcheal participants of the Tehran Lipid and Glucose Study who met the eligibility criteria were selected. Demographic, lifestyle, reproductive, and anthropometric data, as well as risk factors for cardiovascular diseases, were collected. Participants were classified according to their age at menarche: group I: ≤11 years, group II: 12-15 years, and group III: ≥16 years.

MAIN OUTCOME MEASURES

A Cox proportional hazards regression model was used to estimate the associations between age at menarche and arterial hypertension outcomes. The generalized estimating equation models were used to compare the trend of changes in systolic and diastolic blood pressure between the three groups.

RESULTS

The mean age of participants at baseline was 33.9 (13.0). At the end of the study, 1261 (26.6 %) participants had arterial hypertension. Women in group III had a 2.04-fold higher risk of arterial hypertension than those in group II. The mean changes in systolic and diastolic blood pressure were 29 % (95 % CI: 0.02-0.57) and 16 % (95 % CI: 0.00-0.38) higher for women in group III compared with group II.

CONCLUSIONS

Late menarche could be a risk factor for arterial hypertension, so it is necessary to pay more attention to age at menarche in cardiovascular risk assessment programs.

Endothelial Function in Dyslipidemia: Roles of LDL-Cholesterol, HDL-Cholesterol and Triglycerides

Dyslipidemia is associated with endothelial dysfunction. Endothelial dysfunction is the initial step for atherosclerosis, resulting in cardiovascular complications. It is clinically important to break the process of endothelial dysfunction to cardiovascular complications in patients with dyslipidemia. Lipid-lowering therapy enables the improvement of endothelial function in patients with dyslipidemia. It is likely that the relationships of components of a lipid profile such as low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides with endothelial function are not simple. In this review, we focus on the roles of components of a lipid profile in endothelial function.

Associations between Endothelial Lipase, High-Density Lipoprotein, and Endothelial Function Differ in Healthy Volunteers and Metabolic Syndrome Patients

Metabolic syndrome (MS) is characterized by endothelial- and high-density lipoprotein (HDL) dysfunction and increased endothelial lipase (EL) serum levels. We examined the associations between EL serum levels, HDL (serum levels, lipid content, and function), and endothelial function in healthy volunteers (HV) and MS patients. Flow-mediated dilation (FMD), nitroglycerin-mediated dilation (NMD), serum levels of HDL subclasses (measured by nuclear magnetic resonance (NMR) spectroscopy), and EL serum levels differed significantly between HV and MS patients. The serum levels of triglycerides in large HDL particles were significantly positively correlated with FMD and NMD in HV, but not in MS patients. Cholesterol (C) and phospholipid (PL) contents of large HDL particles, calculated as HDL1-C/HDL1-apoA-I and HDL1-PL/HDL1-apoA-I, respectively, were significantly negatively correlated with FMD in HV, but not in MS patients. Cholesterol efflux capacity and arylesterase activity of HDL, as well as EL, were correlated with neither FMD nor NMD. EL was significantly negatively correlated with HDL-PL/HDL-apoA-I in HV, but not in MS patients, and with serum levels of small dense HDL containing apolipoprotein A-II in MS patients, but not in HV. We conclude that MS modulates the association between HDL and endothelial function, as well as between EL and HDL. HDL cholesterol efflux capacity and arylesterase activity, as well as EL serum levels, are not associated with endothelial function in HV or MS patients.

Evaluation of the relationship between monocyte to high-density lipoprotein cholesterol ratio and thrombus burden in patients with deep vein thrombosis

OBJECTIVE

The purpose of this study was to evaluate monocyte count and high-density lipoprotein cholesterol levels and their ratio (monocyte/high-density lipoprotein ratio) in patients with deep venous thrombosis as well as to determine whether this ratio at the time of diagnosis can be an indicator of thrombus burden in terms of thrombus location in deep venous thrombosis.

METHODS

We retrospectively analyzed the patient's diagnosis of deep venous thrombosis confirmed with venous Doppler ultrasound, using a database query for outpatients between 2018 and 2022. Of 378 patients included, blood count results at the time of diagnosis were available for 356. We recruited 300 age- and sex-matched patients with appropriate blood counts, without a diagnosis of deep venous thrombosis, as the control group, by querying the outpatient clinic database. The monocyte/high-density lipoprotein ratio was computed from the ratio of monocyte count to high-density lipoprotein-C. Patients were categorized based on the level of thrombus and the number of vein segments involved as evidenced by Doppler ultrasound findings.

RESULTS

The serum level of monocyte/high-density lipoprotein ratio was significantly higher in the patient group compared to the control group (p<0.01). Patients with proximal deep venous thrombosis had a higher mean monocyte/high-density lipoprotein ratio (19.6±5.1 vs. 17.1±5.5; p<0.01) than patients with distal deep venous thrombosis. Monocyte/high-density lipoprotein ratio increased with the number of vein segments involved (p<0.01).

CONCLUSION

Monocyte/high-density lipoprotein ratio is significantly elevated in patients with deep venous thrombosis when compared to the control group. Monocyte/high-density lipoprotein ratio levels were correlated with disease burden reflected by thrombus location and the number of vein segments involved in deep venous thrombosis patients.

Association of monocyte/high-density lipoprotein cholesterol ratio and the carotid intima-media thickness in diabetic patients

OBJECTIVES

The goal of this study was to see whether there was a link between the monocyte/high-density lipoprotein cholesterol ratio (MHR) and carotid intima-media thickness (CIMT) in people with type 2 diabetes.

METHODS

Duplex ultrasonography parameters and demographic, physical, and paraclinical assessments were recorded. Using the t-test, the MHR and CIMT were compared between the two groups. Regression models were also constructed.

RESULTS

A total of 118 diabetics and 126 non-diabetics were included in the cross-sectional research. According to the stated diabetes duration, the observed age difference of 7 years might be considered. The MHR and CIMT were not substantially different between the two groups. In the DM and non-DM groups, the Spearman correlations between MHR and CIMT were 0.32 and - 0.08, respectively (p-values = 0.001 and 0.379). Thus, regression models (stratified for DM/non-DM and male/female) revealed that the MHR is a significant predictor of CIMT, but only in the case of male DM individuals, when crudely adjusted for confounders.

CONCLUSIONS

In diabetes mellitus, the current investigation found a direct link between MHR and CIMT. In addition, in male diabetic subjects, MHR was demonstrated to be a predictor of CIMT.

The monocyte to high-density lipoprotein cholesterol ratio is a risk factor for frequent premature ventricular complexes: a retrospective cohort study

BACKGROUND

Little is known about the link between the monocyte to high-density lipoprotein cholesterol ratio (MHR) and frequent premature ventricular complexes (PVCs). This investigation aimed to evaluate the link between the MHR and frequent PVCs in patients, as well as their outcomes, using the axis, burden, coupling interval-ventricular tachycardia (ABC-VT) risk score (ARS).

METHODS

Two hundred patients with frequent PVCs and 70 controls were retrospectively enrolled, and their general data were gathered. The MHR and ARS were calculated. Then, patients developing frequent PVCs were classified into a medium-/high-risk subgroup and a low-risk subgroup according to ARS. The results were evaluated employing comparative statistical analyses, Spearman's correlation, logistic regression analyses, and receiver operating characteristic (ROC) curves.

RESULTS

The MHR in the controls was obviously lower than that in the frequent PVC group. In addition, the MHR was the lowest in the control group and highest in the medium-/high-risk subgroup, with that of the low-risk subgroup falling in the middle. Spearman's correlation analyses showed that the MHR was positively correlated with the ARS (ρ = 0.307, P < 0.001). Ultimately, the MHR was found to be a risk factor for frequent PVCs in the multivariate analysis. In addition, an MHR cutoff point of 254.6 featured 67.50% sensitivity and 67.14% specificity for predicting frequent PVCs, and the area under the curve (AUC) reached 0.694 (95% confidence interval: 0.623-0.766) (P < 0.001).

CONCLUSIONS

The MHR is positively and independently correlated with frequent PVCs and can be used as a practical, cost-saving and simple biomarker of inflammation owing to its value in predicting frequent PVCs. In addition, the MHR is crucial to risk stratification and prognosis, which may give it clinical value in the prevention and management of frequent PVCs.

Beneficial effects of high-density lipoprotein (HDL) on stent biocompatibility and the potential value of HDL infusion therapy following percutaneous coronary intervention

Several epidemiological studies have shown a clear inverse relationship between serum levels of high-density lipoprotein cholesterol (HDL-C) and the risk of atherosclerotic cardiovascular disease (ASCVD), even at low-density lipoprotein cholesterol levels below 70 mg/dL. There is much evidence from basic and clinical studies that higher HDL-C levels are beneficial, whereas lower HDL-C levels are detrimental. Thus, HDL is widely recognized as an essential anti-atherogenic factor that plays a protective role against the development of ASCVD. Percutaneous coronary intervention is an increasingly common treatment choice to improve myocardial perfusion in patients with ASCVD. Although drug-eluting stents have substantially overcome the limitations of conventional bare-metal stents, there are still problems with stent biocompatibility, including delayed re-endothelialization and neoatherosclerosis, which cause stent thrombosis and in-stent restenosis. According to numerous studies, HDL not only protects against the development of atherosclerosis, but also has many anti-inflammatory and vasoprotective properties. Therefore, the use of HDL as a therapeutic target has been met with great interest. Although oral medications have not shown promise, the developed HDL infusions have been tested in clinical trials and have demonstrated viability and reproducibility in increasing the cholesterol efflux capacity and decreasing plasma markers of inflammation. The aim of the present study was to review the effect of HDL on stent biocompatibility in ASCVD patients following implantation and discuss a novel therapeutic direction of HDL infusion therapy that may be a promising candidate as an adjunctive therapy to improve stent biocompatibility following percutaneous coronary intervention.

Oxidized high-density lipoprotein promotes CD36 palmitoylation and increases lipid uptake in macrophages

Oxidized high-density lipoprotein (oxHDL) reduces the ability of cells to mediate reverse cholesterol transport and also shows atherogenic properties. Palmitoylation of cluster of differentiation 36 (CD36), an important receptor mediating lipoprotein uptake, is required for fatty acid endocytosis. However, the relationship between oxHDL and CD36 has not been described in mechanistic detail. Here, we demonstrate using acyl-biotin exchange analysis that oxHDL activates CD36 by increasing CD36 palmitoylation, which promotes efficient uptake in macrophages. This modification increased CD36 incorporation into plasma lipid rafts and activated downstream signaling mediators, such as Lyn, Fyn, and c-Jun N-terminal kinase, which elicited enhanced oxHDL uptake and foam cell formation. Furthermore, blocking CD36 palmitoylation with the pharmacological inhibitor 2-bromopalmitate decreased cell surface translocation and lowered oxHDL uptake in oxHDL-treated macrophages. We verified these results by transfecting oxHDL-induced macrophages with vectors expressing wildtype or mutant CD36 (mCD36) in which the cytoplasmic palmitoylated cysteine residues were replaced. We show that cells containing mCD36 exhibited less palmitoylated CD36, disrupted plasma membrane trafficking, and reduced protein stability. Moreover, in ApoE^−/−CD36^−/− mice, lipid accumulation at the aortic root in mice receiving the mCD36 vector was decreased, suggesting that CD36 palmitoylation is responsible for lipid uptake in vivo. Finally, our data indicated that palmitoylation of CD36 was dependent on DHHC6 (Asp-His-His-Cys) acyltransferase and its cofactor selenoprotein K, which increased the CD36/caveolin-1 interaction and membrane targeting in cells exposed to oxHDL. Altogether, our study uncovers a causal link between oxHDL and CD36 palmitoylation and provides insight into foam cell formation and atherogenesis.

Clusterin, paraoxonase 1, and myeloperoxidase alterations induce high-density lipoproteins dysfunction and contribute to peripheral artery disease; aggravation by type 2 diabetes mellitus

Peripheral artery disease (PAD) is an atherosclerotic disorder affecting arteries of the lower limbs, the major risk factors including dyslipidemia and diabetes mellitus (DM). We aimed to identify alterations of the proteins in high-density lipoproteins (HDL) associated with HDL dysfunction in PAD patients. HDL₂ and HDL₃ were isolated from plasma of PAD patients with/without DM (PAD-DM/PAD) and healthy subjects (N). Apolipoprotein AI (ApoAI), ApoAII, ApoCIII, clusterin (CLU), paraoxonase 1 (PON1), myeloperoxidase (MPO), and ceruloplasmin (CP) were measured in HDL₂ /HDL₃ and plasma. Oxidation and glycation of the analyzed proteins were assessed as malondialdehyde-protein adducts (MDA) and advanced glycation end-products (AGE), respectively. The anti-inflammatory effect of HDL₃ was estimated as its potential to reduce monocyte adhesion to tumor necrosis factor α-activated endothelial cells. We show that in PAD patients compared to N subjects: (i) HDL₂ presented increased levels of MDA-PON1, AGE-PON1, AGE-ApoAI, ApoAII, ApoCIII, and CP levels, and decreased PON1 levels; (ii) HDL₃ had increased levels of MDA- and AGE-CLU and -ApoAI, MDA-PON1, ApoCIII, CLU, MPO, CP, and reduced PON1 levels. All these alterations were exacerbated by DM. These changes were more pronounced in HDL₃ , which had reduced anti-inflammatory potential in PAD and became pro-inflammatory in PAD-DM. In PAD patients' plasma, CLU levels and MPO specific activity increased, while PON1 specific activity decreased. In conclusion, HDL function is altered in PAD patients due to multiple modifications of associated proteins that are aggravated by DM. Plasma CLU, MPO, and PON1 could constitute indicators of HDL dysfunction and contribute to risk stratification in PAD patients.

Reproducible Determination of High-Density Lipoprotein Proteotypes

High-density lipoprotein (HDL) is a heterogeneous mixture of blood-circulating multimolecular particles containing many different proteins, lipids, and RNAs. Recent advancements in mass spectrometry-based proteotype analysis show promise for the analysis of proteoforms across large patient cohorts. In order to create the required spectral libraries enabling these data-independent acquisition (DIA) strategies, HDL was isolated from the plasma of more than 300 patients with a multiplicity of physiological HDL states. HDL proteome spectral libraries consisting of 296 protein groups and more than 786 peptidoforms were established, and the performance of the DIA strategy was benchmarked for the detection of HDL proteotype differences between healthy individuals and a cohort of patients suffering from diabetes mellitus type 2 and/or coronary heart disease. Bioinformatic interrogation of the data using the generated spectral libraries showed that the DIA approach enabled robust HDL proteotype determination. HDL peptidoform analysis enabled by using spectral libraries allowed for the identification of post-translational modifications, such as in APOA1, which could affect HDL functionality. From a technical point of view, data analysis further shows that protein and peptide quantities are currently more discriminative between different HDL proteotypes than peptidoforms without further enrichment. Together, DIA-based HDL proteotyping enables the robust digitization of HDL proteotypes as a basis for the analysis of larger clinical cohorts.

The association between monocyte HDL ratio and albuminuria in diabetic nephropathy

Objectives:

We aimed to investigate whether Monocyte-to-HDL ratio (MHR) had an association with albuminuria in patients with diabetic nephropathy (DN).

Methods:

Diabetic patients, who had admitted to the outpatient clinic of general internal disease department between September 2017 - February 2018 and had their spot urinary albumin/creatinine ratio measured, were examined retrospectively. Patients were separated based on the presence of DN. Patients with DN were grouped as Stage-I, Stage-II and Stage-III chronic kidney disease (CKD). Groups were compared in terms of MHR. The presence of a correlation between MHR and albuminuria was investigated.

Results:

MHR was found to be higher in the DN (n=85) group compared to Non- DN group. (16.2±5.5 vs. 14.3±4, p=0.037) And there was no significant difference in Stage-I, Stage-II and Stage-III CKD groups in terms of MHR. (15.2± 3.4, 16.1±6.0, 17.1±6.0, p=0.485). No significant correlation was found between MHR and albuminuria in DN and non-DN groups (p=0.634, r=0.052; p=0.553, r=-0.059).

Conclusions:

DN group had higher MHR than non-nephropathy group, whereas, there was no correlation between albuminuria and MHR.

An elevated monocyte-to-high-density lipoprotein-cholesterol ratio is associated with mortality in patients with coronary artery disease who have undergone PCI

Background: The aim of the present study was to investigate the association between the monocyte-to-high-density lipoprotein–cholesterol ratio (MHR) and the outcomes of patients with coronary artery disease (CAD) who were treated with percutaneous coronary intervention (PCI).

Methods: A total of 5679 CAD patients from CORFCHD-PCI, a retrospective cohort study (identifier: ChiCTR-ORC-16010153), who underwent PCI were included in the study and divided into three tertiles according to their MHR values. The primary outcome was long-term mortality after PCI. The main secondary endpoints were stroke, readmission, and major adverse cardiovascular events (MACEs), defined as the combination of cardiac death, recurrent myocardial infarction, and target vessel reconstruction. The average follow-up time was 35.9 ± 22.6 months.

Results: Patients were divided into three groups according to MHR tertiles: the first tertile (MHR < 0.4; n=1290), second tertile (MHR ≥ 0.4–0.61; n=1878) and third tertile (MHR > 0.61; n=1870). The all-cause mortality (ACM) incidence was significantly lower in the first and second tertiles than in the third tertile (adjusted HR = 0.658, [95% CI: 0.408–0.903], P=0.009 and HR = 0.712, [95% CI: 0.538–0.941], P=0.017, respectively). Cardiac mortality (CM) occurred in 235 patients: 60 (3.1%) in the first tertile group, 74 (3.9%) in the second tertile group and 101 (5.4%) in the third tertile group. There was a significant difference in the CM incidence between the first tertile group and the third tertile group (HR = 0.581, [95% CI: 0.406–0.832], P=0.003), and there was also a difference in the CM incidence between the second tertile group and the third tertile group (HR = 0.690, [95% CI: 0.506–0.940], P=0.019).

Conclusion: The present study indicated that an increased MHR was independently associated with long-term mortality in CAD patients who have undergone PCI.

Effect of high-density lipoprotein on penile erection: A cross-sectional study

Previous studies have shown that elevated levels of high-density lipoprotein (HDL) could inhibit penile erection, but the relationship between HDL and the erection of the penile tip or base has not been extensively researched. We investigated the effects of HDL on erection of the penile tip and base through a cross-sectional study of 113 patients with erectile dysfunction, using a cut-off score of ≤21 on the International Index of Erectile Function-5. The following patient data were collected: nocturnal penile tumescence; blood pressure; platelet count; platelet distribution width; mean platelet volume; plateletcrit; and levels of serum glucose, total cholesterol, triglyceride, HDL, and low-density lipoprotein. Univariate and multivariate analyses were used to assess the association between HDL levels and the erection of the penile tip and base. We confirmed that HDL had a beneficial effect on penile erectile function. We also found that when the HDL level exceeded the normal range, the change in HDL had a significant effect on the penile base. In addition, our study did not find any relationship between platelet parameters and erection of the penile tip or penile base.

Investigation of monocyte HDL ratio as an indicator of inflammation and complete blood count parameters in patients with acne vulgaris

AIMS

Acne vulgaris is a common inflammatory skin disease that affects the pilosebaceous unit. Increased sebum production, hyperkeratosis in follicular infundibulum, inflammation and Propionibacterium acnes are among aetiological factors. Complete blood count (CBC) parameters are used as diagnosis biomarkers for many diseases related with inflammatory processes. Although monocyte/HDL ratio (MHR) has been defined as an inflammatory marker recently, we did not come across any studies about MHR in acne, which is known to be an inflammatory disease. The present study was conducted to compare CBC parameters and MHR levels in acne vulgaris patients and healthy controls (HCs).

METHODS

Sixty-five acne vulgaris patients followed in our clinic between January 2018 and December 2019 and 36 HCs matching in terms of age and sex were included in the study. Patients and HCs were compared in terms of CBC parameters [neutrophil, monocyte, platelet, lymphocyte, neutrophil/lymphocyte (NLR), monocyte/lymphocyte (MLR), platelet/lymphocyte (PLR)], HDL and MHR ratio.

RESULTS

When compared with the HCs, acne vulgaris patients had statistically significantly higher neutrophil, NLR ratio and HDL (P = .042, P = .011 and P = .014, respectively). No statistically significant difference was found between acne vulgaris patients and the HCs in terms of other CBC parameters and MHR ratio (P > .05).

CONCLUSIONS

We believe that prospective studies consisting of large patient series are needed to understand whether CBC parameters and MHR ratio can be used as an inflammatory marker in acne vulgaris patients.

Monocyte to High-Density Lipoprotein Ratio in Patients with Arteritic and Non-Arteritic Anterior Ischaemic Optic Neuropathy

The purpose of this study was to evaluate the monocyte to high-density lipoprotein (HDL) ratio (MHR) in patients with arteritic anterior ischaemic optic neuropathy (A-AION) and non-arteritic anterior ischaemic optic neuropathy (NA-AION). A total of 98 subjects were included in the study. Patients were divided into three groups: 16 patients with A-AION regarded as group one; 41 patients with NA-AION regarded as group two and 41 healthy subjects regarded as the control group. The MHR was calculated in all participants and compared between the patient and control groups. The mean age of subjects with A-AION, NA-AION and the control group were 75.9 ± 8.9 years, 67.1 ± 9.2 years, and 66.6 ± 6.7 years, respectively. Baseline clinical characteristics, such as diabetes mellitus and hypertension, were similar among groups. The mean MHR was significantly higher only in the A-AION group compared with the NA-AION and control group (p < .001), whereas there was no difference between NA-AION group and control group (p = .110). On receiver operating characteristic analysis, the area under the curve was 0.755, and the best cut- off value was 12.2 with a sensitivity of 72% and a specificity of 80%. An elevated MHR ratio is significantly associated with A-AION and MHR might be used to differentiate A-AION from NA-AION.

Can monocyte to HDL cholesterol ratio and monocyte to lymphocyte ratio be markers for inflammation and oxidative stress in patients with vitiligo? A preliminary study

Both systemic inflammation and oxidative stress play crucial roles in the pathogenesis of vitiligo. In recent studies, monocyte to high-density lipoprotein cholesterol ratio (MHR), monocyte to lymphocyte ratio (MLR), neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), mean platelet volume (MPV) and plateletcrit (PCT) have been shown to reflect inflammation and oxidative stress in chronic inflammatory and autoimmune diseases. In this study, we aimed to investigate the hematological and inflammatory parameters in patients with vitiligo and to evaluate their possible relationship with disease severity. The parameters including MHR, MLR, NLR, PLR, MPV, and PCT were retrospectively investigated in patients with vitiligo and healthy controls. Disease severity was evaluated using the vitiligo extent tensity index (VETI) score. A total of 180 patients with vitiligo, and age-gender-matched 180 healthy controls were enrolled in the study. MHR, MLR, PLR, PCT values were found to be significantly higher in patients with vitiligo (p < 0.05). MPV and NLR values showed no statistically significant difference between the two groups. A positive correlation was also detected between MHR and MLR values, disease duration, and VETI score (p < 0.05). We suggest that MHR and MLR can be used as markers of inflammation and oxidative stress in patients with vitiligo. Both markers may also reflect disease severity.

Endothelial Dysfunction in Chronic Kidney Disease, from Biology to Clinical Outcomes: A 2020 Update

The vascular endothelium is a dynamic, functionally complex organ, modulating multiple biological processes, including vascular tone and permeability, inflammatory responses, thrombosis, and angiogenesis. Endothelial dysfunction is a threat to the integrity of the vascular system, and it is pivotal in the pathogenesis of atherosclerosis and cardiovascular disease. Reduced nitric oxide (NO) bioavailability is a hallmark of chronic kidney disease (CKD), with this disturbance being almost universal in patients who reach the most advanced phase of CKD, end-stage kidney disease (ESKD). Low NO bioavailability in CKD depends on several mechanisms affecting the expression and the activity of endothelial NO synthase (eNOS). Accumulation of endogenous inhibitors of eNOS, inflammation and oxidative stress, advanced glycosylation products (AGEs), bone mineral balance disorders encompassing hyperphosphatemia, high levels of the phosphaturic hormone fibroblast growth factor 23 (FGF23), and low levels of the active form of vitamin D (1,25 vitamin D) and the anti-ageing vasculoprotective factor Klotho all impinge upon NO bioavailability and are critical to endothelial dysfunction in CKD. Wide-ranging multivariate interventions are needed to counter endothelial dysfunction in CKD, an alteration triggering arterial disease and cardiovascular complications in this high-risk population.

Increased monocyte to HDL cholesterol ratio in vitamin B12 deficiency: Is it related to cardiometabolic risk?

Vitamin B12 deficiency may have indirect cardiovascular effects in addition to hematological and neuropsychiatric symptoms. It was shown that the monocyte count-to-high density lipoprotein cholesterol (HDL-C) ratio (MHR) is a novel cardiovascular marker. In this study, the aim was to evaluate whether MHR was high in patients with vitamin B12 deficiency and its relationship with cardiometabolic risk factors. The study included 128 patients diagnosed with vitamin B12 deficiency and 93 healthy controls. Patients with vitamin B12 deficiency had significantly higher systolic blood pressure (SBP), diastolic blood pressure (DBP), MHR, C-reactive protein (CRP) and uric acid levels compared with the controls (median 139 vs 115 mmHg, p < 0.001; 80 vs 70 mmHg, p < 0.001; 14.2 vs 9.5, p < 0.001; 10.2 vs 4 mg/dl p < 0.001; 6.68 vs 4.8 mg/dl, p < 0.001 respectively). The prevalence of left ventricular hypertrophy was higher in vitamin B12 deficiency group (43.8%) than the control group (8.6%) (p < 0.001). In vitamin B12 deficiency group, a positive correlation was detected between MHR and SBP, CRP and uric acid (p < 0.001 r:0.34, p < 0.001 r:0.30, p < 0.001 r:0.5, respectively) and a significant negative correlation was detected between MHR and T-CHOL, LDL, HDL and B12 (p < 0.001 r: -0.39, p < 0.001 r: -0.34, p < 0.001 r: -0.57, p < 0.04 r: -0.17, respectively). MHR was high in vitamin B12 deficiency group, and correlated with the cardiometabolic risk factors in this group, which were SBP, CRP, uric acid and HDL. In conclusion, MRH, which can be easily calculated in clinical practice, can be a useful marker to assess cardiovascular risk in patients with vitamin B12 deficiency.

Relationship between high-density lipoprotein cholesterol levels and endothelial function in women: a cross-sectional study

OBJECTIVES

The purpose of this study was to evaluate the relationship between high-density lipoprotein cholesterol (HDL-C) levels and endothelial function in women.

DESIGN

Cross-sectional study.

SETTING

22 university hospitals and affiliated clinics in Japan.

PARTICIPANTS

1719 Japanese women aged 17-90 years who were not receiving lipid-lowering therapy.

MEASURES

We evaluated flow-mediated vasodilation (FMD) and serum levels of HDL-C. All participants were divided into four groups by HDL-C level: low HDL-C (<40 mg/dL), moderate HDL-C (40-59 mg/dL), high HDL-C (60-79 md/dL) and extremely high HDL-C (≥80 mg/dL).

RESULTS

Univariate regression analysis revealed a significant relationship between FMD and HDL-C (r=0.12, p<0.001). FMD values were significantly smaller in the low HDL-C group (5.2%±3.8%) and moderate HDL-C group (5.2%±3.8%) than in the extremely high HDL-C group (6.7%±3.4%) (p=0.024 and p=0.003, respectively), while there was no significant difference in FMD between the high HDL-C group and the extremely high HDL-C group. Multiple logistic regression analysis did not show a significant association between HDL-C levels and FMD.

CONCLUSIONS

Endothelial function increased in relation to HDL-C levels. However, there was no association of HDL-C levels with endothelial function after adjustment of traditional cardiovascular risk factors in women.

TRIAL REGISTRATION NUMBER

UMIN000012950; Results.

The relationship between monocyte to high-density lipoprotein cholesterol ratio and diabetic nephropathy

Objective:

This study aims to investigate the relationship of monocyte to high-density lipoprotein cholesterol ratio (MHR) with diabetes mellitus (DM) and diabetic nephropathy.

Methods:

This study included 262 Type-2 diabetes mellitus patients, of which 60 had diabetic nephropathy and 202 did not have diabetic nephropathy who presented to the internal diseases polyclinic at Firat University Medical Faculty Hospital between May 2018 and October 2018 and 50 healthy control subjects. A retrospective scan of patient files was conducted and information relevant to nephropathy such as hemoglobin, glycated hemoglobin levels (HbA1c), hematocrit count (HCT), monocyte count, LDL, HDL, triglyceride levels, and microvascular complications were acquired.

Results:

We determined MHR values as 11.9±5.5 and 8.4±2.9 respectively for the diabetic and healthy groups. There was a statistically significant difference between the two groups in terms of MHR, with a positive correlation between diabetes and MHR (< 0.001; r: 0.241). Moreover, glucose, HDL, and triglyceride levels were different between the two groups with statistical significance (respectively, p< 0.001; p< 0.001; p< 0.001). Our study found higher MHR levels for patients with diabetic nephropathy compared to those without diabetic nephropathy (respectively, 17.1±7.9 and 10.3±3.3) and determined statistical significance and a negative correlation (p< 0.001; r: -0.512).

Conclusion:

Our results suggest that an elevated MHR can be a biomarker for diabetic nephropathy, allowing the detection of diabetic nephropathy with simple and inexpensive laboratory tests.

Alcohol Consumption, High-Density Lipoprotein Cholesterol, Antithrombin III, and Body Mass Index Are Associated with Great Saphenous Vein Reflux in the Thigh

BACKGROUND

Venous valvular reflux is the main cause of chronic venous dysfunction. However, the etiology of valvular reflux is not completely understood. We conducted this study to investigate new risk factors for venous reflux of the great saphenous vein (GSV) in the thigh.

METHODS

We studied 139 consecutive patients (278 legs) who underwent Doppler ultrasonography at our hospital between March 2015 and February 2016 for leg discomfort with visible varicosities, edema, skin changes, or venous ulcer in the legs. Continuous variables included age, body mass index (BMI), hematological and blood chemistry parameters, smoking (pack-years), and alcohol consumption (days). Nominal variables included sex, comorbidities, smoking status, alcohol drinking status, and specific antibodies. The relationship of GSV reflux with pregnancy and number of children was investigated in 184 legs of 92 patients among 96 female patients.

RESULTS

On logistic regression analysis, independent factors determining GSV reflux were BMI (B = 0.126, P = 0.012), high-density lipoprotein (HDL) cholesterol level (B = 0.029, P = 0.025), duration of alcohol consumption (B = 1.237 E^-4, P = 0.016), and antithrombin III level (B = -0.036, P = 0.011).

CONCLUSIONS

In this study, the factors determining GSV reflux were higher HDL cholesterol level, longer duration of alcohol consumption, lower antithrombin III level, and higher BMI.

Elevated Monocyte to High-Density Lipoprotein Cholesterol Ratio and Endothelial Dysfunction in Behçet Disease

Behçet disease (BD) is a multisystemic disorder characterized by endothelial dysfunction and inflammation. Monocyte to high-density lipoprotein cholesterol ratio (MHR) is a recently emerged indicator of inflammation and oxidative stress. Sixty patients with BD and 50 control individuals were included to investigate the relationship between MHR and endothelial dysfunction. Endothelial function was assessed by flow- and nitroglycerin-mediated dilatation technique (FMD and NMD, respectively). Serum high-sensitivity C-reactive protein (hsCRP) levels were measured in all study participants. The MHR and hsCRP levels were significantly higher in patients with active BD than in controls. Brachial artery FMD was significantly lower in patients with active BD than in controls. Brachial artery NMD was similar between groups. There was a strong inverse correlation between MHR and FMD and a strong positive correlation between MHR and serum hsCRP levels. Thus, elevated MHR may be a useful marker reflecting impaired endothelial function and systemic inflammation in patients with BD.

Is In-Stent Restenosis After a Successful Coronary Stent Implantation Due to Stable Angina Associated With TG/HDL-C Ratio?

We examined the impact of the preprocedural triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C) ratio on risk of in-stent restenosis (ISR). Patients with typical anginal symptoms and/or positive treadmill or myocardial perfusion scintigraphy test results who underwent successful coronary stent implantation due to stable angina were examined; 1341 patients were enrolled. The hospital files of the patients were used to gather data. Cox regression analysis showed that the TG/HDL-C ratio was independently associated with the presence of ISR ( P < .001). Moreover, diabetes mellitus ( P = .007), smaller stent diameter ( P = .046), and smoking status ( P = .001) were also independently associated with the presence of ISR. Using a cutoff of 3.8, the TG/HDL-C ratio predicted the presence of ISR with a sensitivity of 71% and a specificity of 68%. Also, the highest quartile of TG/HDL-C ratio had the highest rate of ISR ( P < .001). Measuring preprocedural TG/HDL-C ratio, in fasting or nonfasting samples, could be beneficial for the risk assessment of ISR. However, further large-scale prospective studies are required to establish the exact role of this simple, easily calculated, and reproducible parameter in the pathogenesis of ISR.

Monocyte Count/HDL Cholesterol Ratio and Cardiovascular Disease in Patients With Obstructive Sleep Apnea Syndrome: A Multicenter Study

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is an independent risk factor for cardiovascular disease (CVD). Although monocyte to high-density lipoprotein cholesterol ratio (MHR) is increasingly being implicated in cardiovascular morbidity and mortality, no study has attempted to determine the role of MHR in cardiovascular morbidity of patients with OSAS. We aimed to investigate the association between MHR and CVD in patients with OSAS and the relationship between severity of OSAS, polysomnographic parameters, and MHR.

METHODS

In this cohort study, patients who had undergone a full-night polysomnography for the diagnosis of OSAS were recruited. Included patients were grouped according to the apnea-hypopnea index (AHI) as mild (5-15), moderate (15-30), and severe (>30) OSAS. Patients with AHI < 5 served as the control group. The presence of heart failure, coronary artery disease, or arrhythmia was defined as CVD.

RESULTS

A total of 1050 patients were included (131 controls, 222 mild, 228 moderate, and 469 severe OSAS). The severe group had higher MHR compared with the control and other OSAS groups (9.99, 12.11, 13.65, and 20.67 in control, mild, moderate, and severe OSAS groups, respectively, P < .001). The MHRs were significantly correlated with AHI, oxygen desaturation index, and minimum O₂ saturation values ( P < .001). Values of MHR were significantly higher in patients with CVD compared with those without ( P < .001). Multiple regression analysis demonstrated that MHR is an independent predictor of CVD.

CONCLUSION

The MHR is strongly associated with CVD and the severity of OSAS and might be used as a biomarker to predict CVD in patients with OSAS.

The evaluation of endothelial function and structure in hirsute patients in reproductive age

OBJECTIVE

To evaluate the endothelial function and structure in patients with hirsutism in reproductive age.

STUDY DESIGN

The study was conducted on 69 consecutive women admitted with complaints of hirsutism and 63 voluntary healthy women, as controls. A total of 132 subjects who applied to the Gynecology and Infertility Outpatient Clinics were included. Participants with modified Ferriman Gallway (mFG) score over 8 were considered to be hirsute. The demographic, metabolic, hormonal characteristics, risk factors of cardiovascular disease, CIMT (carotis intima media thickness) and FMD (flow-mediated dilatation) were compared between hirsute women and those in the control group. A prospective case-control study was performed.

RESULTS

There was no statistically significant difference in CIMT (0,50±0,08 vs 0,52±0,08, p=0.38) and FMD (10,80±6,83 vs 9,57±6,52, p=0.34) values between the study and control groups, respectively. There was no statistically significant correleation between CIMT and FMD values with age, body mass index (BMI), waist circumference, hip circumference, waist/hip ratio, CRP (C-reactive protein), total cholesterol, LDL (low density lipoprotein), HDL (high density lipoprotein), total testosteron, FAI (free androjen index), androstenedion, SHBG (sex hormone binding globuline), DHEA-S, hirsutism score, sistolic blood pressure, diastolic blood pressure, HOMA-IR (homeostatic model of assesment insuline resistance) value.

CONCLUSION

The effect of the presence of hirsutism on either CIMT and FMD values, among young patients was not significant. Since endothelial dysfunction might became evident after a long period of physio-pathological process, our findings obtained from younger patients may not really show the impact of hirsutism on endothelial function in short term.

Endoglin and obestatin levels, cardiometabolic risk factors and subclinical atherosclerosis in children aged 10-18 years

BACKGROUND

The aim of this study was to investigate the early signs of atherosclerosis and to evaluate serum endoglin and obestatin levels as predictors of subclinical atherosclerosis in obese children.

METHODS

A total of 95 children (60 obese and 35 controls) aged 10-18 years were included in the study. Their endoglin and obestatin levels and biochemical parameters were measured. The carotid intima media thickness (cIMT) and brachial artery flow-mediated dilatation (FMD) responses were evaluated.

RESULTS

The cIMT values were higher (p < 0.001) and FMD responses were lower (p = 0.003) in the obese group than in the control group. A logistic regression multivariate analysis revealed that cIMT was independently associated with the body mass index (BMI) Z-score (β = 0.323, p = 0.003) and low density lipoprotein (LDL) (β = 0.29, p = 0.008), while FMD % was independently associated with waist circumference (β = -0.36, p = 0.002). The obese and control groups were similar in endoglin (p = 0.67) and obestatin levels (p = 0.70). The endoglin level was inversely correlated with the cholesterol and LDL levels (r = -0.23, p = 0.032; rho = -0.25, p = 0.019).

CONCLUSIONS

The cIMT and brachial artery FMD response in obese children are significantly different compared to healthy controls. Circulating endoglin and obestatin levels are not predictive markers for subclinical atherosclerosis in obese children aged 10-18 years old.

Usefulness of the monocyte-to-high-density lipoprotein cholesterol ratio to predict bare metal stent restenosis

Aim: The aim of the present study was to investigate the predictive value of preprocedural monocyte count-to-high-density lipoprotein cholesterol ratio (MHR) on development of in-stent restenosis in patients undergoing coronary bare-metal stent (BMS) implantation. Patients & methods: Data from 705 patients who had undergone BMS implantation and additional control coronary angiography were analyzed. Results: Patients were divided into three tertiles based on preprocedural MHR. Restenosis occurred in 59 patients (25%) in the lowest tertile, 84 (35%) in the middle tertile and 117 (50%) in the highest MHR tertile (p < 0.001). Using multiple logistic regression analysis, smoking, diabetes mellitus, stent length, preprocedural MHR and C-reactive protein levels emerged as independent predictors of in-stent restenosis. Conclusion: High preprocedural MHR is related to BMS restenosis.

Association of the Monocyte to HDL Cholesterol Ratio With Thrombus Burden in Patients With ST-Segment Elevation Myocardial Infarction

Intracoronary thrombus burden is associated with some adverse events and poor prognosis in patients with ST-segment elevation myocardial infarction (STEMI). Identifying predictors of the intracoronary thrombus burden may contribute to the management of STEMI. In this study, we evaluated whether monocyte count to high-density lipoprotein cholesterol ratio (MHR) is a predictor of intracoronary thrombus burden in patients with STEMI. The study population consisted of 414 patients with STEMI who underwent primary percutaneous coronary intervention (PCI). Angiographic thrombus burden was classified based on thrombolysis in myocardial infarction (TIMI) thrombus grades. The patients were grouped into 2 categories of low thrombus burden and high thrombus burden. The MHR was significantly higher in the high thrombus burden group compared with the low thrombus group (16.0 [9.2-22.1] vs 25.4 [13.5-44.6]; P < .001). In multivariate logistic regression analysis, MHR was an independent predictor of high thrombus burden (odds ratio: 1.067, 95% CI: 1.031-1.105; P < .001). The area under the receiver–operating characteristic curve of the MHR was 0.688 (0.641-0.733; P < .001) to predict high thrombus burden. In conclusion, MHR was independent predictor of high thrombus burden in patients with STEMI who underwent primary PCI.

Defects of High-Density Lipoproteins in Coronary Artery Disease Caused by Low Sphingosine-1-Phosphate Content: Correction by Sphingosine-1-Phosphate-Loading

BACKGROUND

Sphingosine-1-phosphate (S1P) is a constituent of high-density lipoproteins (HDL) that contributes to their beneficial effects. We have shown decreased HDL-S1P in coronary artery disease (CAD) but its functional relevance remains unclear.

OBJECTIVES

This study investigated the functional consequences of reduced HDL-S1P content in CAD and tested if increasing it may improve or restore HDL function.

METHODS

Human HDL from healthy and CAD subjects, as well as mouse HDL, were isolated by ultracentrifugation. HDL-S1P-dependent activation of cell-signaling pathways and induction of vasodilation were examined in vitro and in isolated arteries using native and S1P-loaded HDL, S1P receptor antagonists, and S1P-blocking antibodies.

RESULTS

HDL-S1P-dependent signaling was clearly impaired and S1P content reduced in CAD-HDL as compared to healthy HDL. Both healthy and CAD-HDL could be efficiently and equally well loaded with S1P from cellular donors and plasma. S1P-loading greatly improved HDL signaling and vasodilatory potential in pre-contracted arteries and completely corrected the defects inherent to CAD-HDL. HDL-S1P content and uptake was reduced by oxidation and was lower in HDL3 than HDL2. Loading with S1P in vitro and in vivo fully replenished the virtually absent S1P content of apolipoprotein M-deficient HDL and restored their defective signaling. Infusion of erythrocyte-associated C17-S1P in mice led to its rapid and complete uptake by HDL providing a means to directly S1P-load HDL in vivo.

CONCLUSIONS

Reduced HDL-S1P content contributes to HDL dysfunction in CAD. It can be efficiently increased by S1P-loading in vitro and in vivo, providing a novel approach to correcting HDL dysfunction in CAD.

Relation Between Monocyte to High-Density Lipoprotein Cholesterol Ratio With Presence and Severity of Isolated Coronary Artery Ectasia

The aim of this study was to investigate an easily available inflammatory and oxidative stress marker and monocyte to high-density lipoprotein cholesterol ratio (MHR) in patients with coronary artery ectasia (CAE). The study population included 405 patients of which 135 patients had isolated CAE, 135 patients had obstructive coronary artery disease (CAD), and 135 patients had normal coronary angiograms (NCAs). The severity of isolated CAE was determined according to the Markis classification. The MHR was significantly greater in patients with isolated CAE than those with obstructive CAD and NCAs: 14.8 (11.6 to 19.8), 11.4 (9.6 to 13.5), 9.8 (7.5 to 11.9), respectively. Linear regression analyses showed that MHR and C-reactive protein were significantly related with the severity of isolated CAE. In conclusion, the MHR is significantly greater in patients with CAE compared to controls with obstructive CAD and NCAs, and MHR is associated with the severity of CAE.

HDL-S1P: cardiovascular functions, disease-associated alterations, and therapeutic applications

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid contained in High-density lipoproteins (HDL) and has drawn considerable attention in the lipoprotein field as numerous studies have demonstrated its contribution to several functions inherent to HDL. Some of them are partly and some entirely due to the S1P contained in HDL (HDL-S1P). Despite the presence of over 1000 different lipids in HDL, S1P stands out as it possesses its own cell surface receptors through which it exercises key physiological functions. Most of the S1P in human plasma is associated with HDL, and the amount of HDL-S1P influences the quality and quantity of HDL-dependent functions. The main binding partner of S1P in HDL is apolipoprotein M but others may also exist particularly under conditions of acute S1P elevations. HDL not only exercise functions through their S1P content but have also an impact on genuine S1P signaling by influencing S1P bioactivity and receptor presentation. HDL-S1P content is altered in human diseases such as atherosclerosis, coronary artery disease, myocardial infarction, renal insufficiency and diabetes mellitus. Low HDL-S1P has also been linked to impaired HDL functions associated with these disorders. Although the pathophysiological and molecular reasons for such disease-associated shifts in HDL-S1P are little understood, there have been successful approaches to circumvent their adverse implications by pharmacologically increasing HDL-S1P as means to improve HDL function. This mini-review will cover the current understanding of the contribution of HDL-S1P to physiological HDL function, its alteration in disease and ways for its restoration to correct HDL dysfunction.

Association of Monocyte-to-HDL Cholesterol Ratio with Slow Coronary Flow is Linked to Systemic Inflammation

BACKGROUND

Previous studies proposed that both inflammation, oxidative stress, and impaired endothelial dysfunction have a significant role in occurrence of slow coronary flow (SCF). monocyte-to-high density lipoprotein cholesterol ratio (MHR) is a recently emerged indicator of inflammation and oxidative stress, which have been studied only in patients with chronic kidney disease.

HYPOTHESIS

We aimed to assess the relationship between MHR and SCF.

METHODS

Patients who had angiographically normal coronary arteries were enrolled in this retrospective study (n = 253 as SCF group and n = 176 as control group). Patients who had corrected thrombolysis in myocardial infarction frame counts (cTFCs) above the normal cutoffs were defined as with SCF.

RESULTS

The MHR and high-sensitivity C-reactive protein (hsCRP) were significantly higher in the SCF group. In correlation analysis, MHR has a significantly positive correlation with cTFC and serum hsCRP levels (P < .001). In multivariate logistic regression analysis, MHR was found as independently associated with the presence of SCF (odds ratio: 1.24, P < .001).

CONCLUSION

Higher MHR which indicates an enhanced inflammation and oxidative stress was significantly and independently associated with the presence of SCF. Besides, MHR was positively correlated with serum hsCRP level as a conventional marker for systemic inflammation.

Citrulline increases cholesterol efflux from macrophages in vitro and ex vivo via ATP-binding cassette transporters

Reverse cholesterol transport (RCT) is a mechanism critical to the anti-atherogenic property of HDL. Although citrulline contributes to the amelioration of atherosclerosis via endothelial nitric oxide production, it remains unclear whether it affects RCT. This study was undertaken to clarify the effects of citrulline on expressions of specific transporters such as ATP binding cassette transporters (ABC)A1 and ABCG1, and the cholesterol efflux from macrophages to apolipoprotein (apo) A-I or HDL in vitro and ex vivo. Citrulline increased ABCA1 and ABCG1 mRNA and protein levels in THP-1 macrophages, translating into enhanced apoA-I- and HDL-mediated cholesterol efflux. In the human crossover study, 8 healthy male volunteers (age 30-49 years) consumed either 3.2 g/day citrulline or placebo for 1 week. Citrulline consumption brought about significant increases in plasma levels of citrulline and arginine. Supporting the in vitro data, monocyte-derived macrophages (MDM) differentiated under autologous post-citrulline sera demonstrated enhancement of both apoA-I- and HDL-mediated cholesterol efflux through increased ABCA1 and ABCG1 expressions, compared to MDM differentiated under pre-citrulline sera. However, the placebo did not modulate these parameters. Therefore, in addition to improving endothelium function, citrulline might have an anti-atherogenic property by increasing RCT of HDL.

High levels of asymmetric dimethylarginine are strongly associated with low HDL in patients with acute myocardial infarction

Objectives

Low levels of high-density lipoprotein (HDL) cholesterol are associated with an increased risk of acute myocardial infarction possibly through impaired endothelial atheroprotection and decreased nitric oxide (NO) bioavailability. Asymmetric dimethylarginine (ADMA) mediates endothelial function by inhibiting nitric oxide synthase activity. In patients with acute myocardial infarction, we investigated the relationship between serum levels of HDL and ADMA.

Approach and Results

Blood samples from 612 consecutive patients hospitalized for acute MI <24 hours after symptom onset were taken on admission. Serum levels of ADMA, its stereoisomer, symmetric dimethylarginine (SDMA) and L-arginine were determined using high-performance liquid chromatography. Patients with low HDL (<40 mg/dL for men and <50 mg/dL for women) were compared with patients with higher HDL. Most patients (59%) had low HDL levels. Median ADMA levels were markedly higher in the low HDL group (0.69 vs. 0.50 µmole/L, p<0.001). In contrast, SDMA and L-arginine levels were similar for the two groups (p = 0.120 and p = 0.064). Notably, ADMA, but not SDMA or L-arginine, was inversely correlated with HDL (r = −0.311, p<0.001). In stratified analysis, this relationship was only found for low HDL levels (r = −0.265, p<0.001), but not when HDL levels were higher (r = −0.077, p = 0.225). By multivariate logistic regression analysis, ADMA level was strongly associated with low HDL levels (OR(95%CI):6.06(3.48–10.53), p<0.001), beyond traditional confounding factors.

Conclusions

Our large population-based study showed for the first time a strong inverse relationship between HDL and ADMA in myocardial infarction patients, suggesting a functional interaction between HDL and endothelium, beyond metabolic conditions associated with low HDL levels.

Relationship of depression, stress and endothelial function in stable angina patients

Endothelial dysfunction has been considered as one of potential mechanisms by which depression and stress might contribute to the development of coronary artery disease (CAD). Recent studies suggest that circulating endothelial progenitor cells (EPCs) and brachial artery flow-mediated dilation (FMD) are related to endothelial function and progression of CAD. We investigated the relationships between the level of circulating CD34/KDR(+) EPCs and CD133/KDR(+) EPCs, brachial FMD, and scores of depression and stress measured with the Depression Anxiety Stress Scales in 288 stable angina patients without major psychiatric disorders. As defined by the ≥75th percentile, 100 (35%) subjects had high depression score (≥8), and 84 (29%) subjects had high stress score (≥10). Subjects with high depression or stress score had significantly lower FMD (1.86±0.14 vs. 3.63±0.17%, p<0.001; 2.05±0.18 vs. 3.48±0.17%, p<0.001) and percentage of circulating CD34/KDR(+) EPCs (0.97±0.11 vs. 1.94±0.17%, p<0.001; 1.09±0.13 vs. 1.68±0.16%, p=0.005), but not CD133/KDR(+) EPCs (0.52±0.04 vs. 0.66±0.06%, p=0.057; 0.61±0.05 vs. 0.59±0.05%, p=0.833), as compared with subjects with normal depression or stress score. Multivariate regression analysis indicated that high depression score (OR 1.09, 95% CI: 1.04-1.15, p<0.001), but not stress score or percentage of circulating EPCs, independently predicted impaired brachial FMD. In conclusions, our results demonstrated that in stable angina patients without major psychiatric disorders, a high depression or stress score was related to attenuated brachial FMD and depletion of circulating EPCs. However, only the depression score, but not the stress score or the level of EPCs, was an independent predictor for decreased brachial FMD.

The Role of Endocannabinoid System Blockade in the Treatment of the Metabolic Syndrome

This review considers the use of the first selective blocker of the cannabinoid receptor type 1, rimonabant, to reduce weight and improve cardiovascular disease risk factors in obese patients with metabolic syndrome or multiple cardiovascular disease risk factors. In 4 large trials-Rimonabant in Obesity (RIO)-Lipids, RIO-Europe, RIO-North America, and RIO-Diabetes-after 1 to 2 years of treatment, rimonabant (20 mg/day) led to a significantly greater weight loss and reduction in waist circumference compared with placebo. Treatment with rimonabant was also associated with other favorable changes, including better glycemic control in type 2 diabetes mellitus, improved lipid profile, reduced blood pressure, increased adiponectin levels, fall in high-sensitivity C-reactive protein concentrations, and an overall decrease in the prevalence of the metabolic syndrome. Initial experience with rimonabant shows that it is generally well tolerated with the most common side effect of mild nausea. Rimonabant may be a useful adjunct to lifestyle and behavior modification in the treatment of obese subjects with metabolic syndrome or multiple cardiometabolic risk factors.

Novel biological functions of high-density lipoprotein cholesterol

In addition to its role in reverse cholesterol transport, high-density lipoprotein (HDL) cholesterol has direct action on numerous cell types that influence cardiovascular and metabolic health. Cellular responses to HDL entail its capacity to invoke cholesterol efflux that causes signal initiation via scavenger receptor class B, type I, and plasma membrane receptor activation by HDL cargo molecules. In endothelial cells and their progenitors, HDL attenuates apoptosis and stimulates proliferation and migration. HDL also has diverse anti-inflammatory actions in both endothelial cells and leukocytes. In vascular smooth muscles, HDL tempers proinflammatory, promigratory, and degradative processes, and through actions on endothelium and platelets HDL is antithrombotic. There are additional actions of HDL of potential cardiovascular consequence that are indirect, including the capacities to promote pancreatic β-cell insulin secretion, to protect pancreatic β cells from apoptosis, and to enhance glucose uptake by skeletal muscle myocytes. Furthermore, HDL decreases white adipose tissue mass, increases energy expenditure, and promotes the production of adipose-derived cytokine adiponectin that has its own vascular-protective properties. Many of these numerous actions of HDL have been observed not only in cell culture and animal models but also in human studies, and assessments of these functions are now being applied to patient populations to better-elucidate which actions of HDL may contribute to its cardioprotective potential and how they can be quantified and targeted. Further work on the many mechanisms of HDL action promises to reveal new prophylactic and therapeutic strategies to optimize both cardiovascular and metabolic health.

Novel biological functions of high-density lipoprotein cholesterol

In addition to its role in reverse cholesterol transport, high-density lipoprotein (HDL) cholesterol has direct action on numerous cell types that influence cardiovascular and metabolic health. Cellular responses to HDL entail its capacity to invoke cholesterol efflux that causes signal initiation via scavenger receptor class B, type I, and plasma membrane receptor activation by HDL cargo molecules. In endothelial cells and their progenitors, HDL attenuates apoptosis and stimulates proliferation and migration. HDL also has diverse anti-inflammatory actions in both endothelial cells and leukocytes. In vascular smooth muscles, HDL tempers proinflammatory, promigratory, and degradative processes, and through actions on endothelium and platelets HDL is antithrombotic. There are additional actions of HDL of potential cardiovascular consequence that are indirect, including the capacities to promote pancreatic β-cell insulin secretion, to protect pancreatic β cells from apoptosis, and to enhance glucose uptake by skeletal muscle myocytes. Furthermore, HDL decreases white adipose tissue mass, increases energy expenditure, and promotes the production of adipose-derived cytokine adiponectin that has its own vascular-protective properties. Many of these numerous actions of HDL have been observed not only in cell culture and animal models but also in human studies, and assessments of these functions are now being applied to patient populations to better-elucidate which actions of HDL may contribute to its cardioprotective potential and how they can be quantified and targeted. Further work on the many mechanisms of HDL action promises to reveal new prophylactic and therapeutic strategies to optimize both cardiovascular and metabolic health.

Improving Total-Cholesterol/HDL-Cholesterol Ratio Results in an Endothelial Dysfunction Recovery in Peripheral Artery Disease Patients

Aims. To evaluate the effects of variations of total-cholesterol/HDL-cholesterol ratio and the effects of the atorvastatin on endothelial function in peripheral artery disease (PAD). Material and Methods. A prospective, randomised controlled study was carried out in 150 PAD patients. Patients randomized to the control group (n = 75) were treated with antiplatelet drugs, angiotensin-converting-enzyme inhibitors and cardiovascular-risk-factor control. Experimental group (n = 75) also received treatment with atorvastatin for a month. It was determined baseline nitrite plasma levels and total-cholesterol/HDL-cholesterol ratio and after one month of treatment in both groups. It was also analysed the correlation between the gradient of nitrite levels and the differential of total-cholesterol/HDL ratio in treatment group. Results. After a month, a reduction in nitrite levels was detected in treatment group (11.88 ± 7.8 μM versus 5.7 ± 1.8 μM, P < 0.0001). It was shown a higher decrease in nitrite plasma levels in the atorvastatin group finding lower levels assessments (5.7 ± 1.8 μM versus 13.1 ± 9.1 μM, resp., P < 0.001). A significant reduction in total-cholesterol/HDL-cholesterol ratio was observed in statin group after treatment (P < 0.0001). A strong correlation was found between the gradient of nitrite levels and the differential of total-cholesterol/HDL-cholesterol ratio in atorvastatin group (r = 0.7; P < 0.001). Conclusions. Improvement of nitrite levels are associated with decreased total cholesterol/HDL ratio values in PAD patients treated with atorvastatin.

Relationship between concentration difference of different density lipoproteins and shear stress in atherosclerosis

Previous research has observed concentration polarization in LDL and HDL in the arterial system. However, there is no report that links this concentration polarization to the development of vascular atherosclerosis (AS). Therefore, the purpose of this study is to establish the relationship between concentration difference of LDL and HDL and shear stress using a carotid bifurcation vascular model. PTFE was employed to create the carotid bifurcation model. Endothelial cells were coated on the inner wall of the graft. In a recirculation system, HDL and LDL concentration were measured under two different ICA flow velocities at 5 different locations within our model. We report the following: (1) LDL and HDL concentration difference was observed in both high flow and low flow environments; (2) the degree of LDL and HDL concentration polarization varied depending of high flow and low flow environment; (3) absolute values of concentration difference between LDL and HDL at the inner wall surface decreased with the increase in shear stress when shear stress was more than 1.5 Pa. This variation trend would be more pronounced if shear stress were less than 0.5 Pa. Our study suggests that under the action of shear stress, concentration differences of LDL or HDL create a disturbance in the balance of atherogenic factors and anti-As factors, resulting in the occurrence of AS.