Small, dense low-density lipoproteins (LDL) are predictors of cardio- and cerebro-vascular events in subjects with the metabolic syndrome

Association of obesity and LDL subfractions evaluated by body mass index, waist circumference, and diabetes status: the ELSA-Brasil study

Low-density lipoproteins (LDL) comprise a pool of particles with different densities that may have variable impact on atherogenesis. Studies suggest that obese individuals with elevated body mass index (BMI) and waist circumference (WC) have increased small and dense LDL subfractions (sdLDL-c). It is unclear if diabetes (T2D) and insulin resistance (IR) may modify this association. We included 4,111 (50.4 ± 8.6 years of age, 45.5% men) individuals with neither prior cardiovascular disease nor use of lipid-lowering medications. Total LDL-c and its subfractions (LDL1-c, LDL2-c, LDL3-c, and LDL4-c) were measured by vertical zonal ultracentrifugation. We considered the subfractions LDL1-c and LDL2-c as large buoyant LDL (lbLDL-c) and the subfractions LDL3-c and LDL4-c as sdLDL-c. We analyzed the association between LDL-c subclasses, BMI and WC using linear regression analysis and stratified by the presence of T2D and IR. For sdLDL-c, a direct association with hypertension, T2D, fasting plasma glucose, total cholesterol, LDL-c, and triglycerides was observed. In multivariate analysis, after adjustment for age, sex, race and triglycerides, the strong association of sdLDL-c with BMI (β 95% CI 0.16 (0,13-0,19)) and WC (β 95% CI 0.22 (0.19-0.26)) persisted. After stratification, the association of sdLDL-c and WC was present only in those with insulin resistance or diabetes. BMI showed a smaller impact than WC on this association. WC and BMI were strongly associated with sdLDL-c subfractions. Further, this association was modified by diabetes and insulin resistance status.

Association between small dense low-density lipoprotein and carotid intima-media thickness

Cardiovascular disease (CVD) and atherosclerosis are major causes of mortality worldwide. Early and accurate diagnosis of vascular thickening by predictive markers can help reduce the death rate of these diseases. Low-density lipoprotein (LDL) particles, which are rich in cholesterol, are regarded as key biomarkers for CVD and atherosclerosis. Numerous studies have demonstrated that pattern B (small dense LDL, sdLDL) is more atherogenic than LDL and can serve as a superior quantitative marker for CVD than LDL. Furthermore, several studies have indicated that carotid intima-media thickness (cIMT) is a reliable marker for the early detection of CVD and atherosclerosis in various populations. This review examines the relationship between sdLDL concentration and cIMT. It is concluded that sdLDL concentration has a positive correlation with cIMT, and their combined use can facilitate a more precise assessment of the diseases, especially atherosclerosis.

Association of LDL-cholesterol subfractions with cardiovascular disorders: a systematic review

BACKGROUND

Cardiovascular disorders (CVDs) are the leading cause of death worldwide. This study aimed to evaluate the association between low-density lipoprotein (LDL) subfractions and cardiovascular disorders.

METHODS

To ensure the rigor of the systematic review, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used. For this systematic review, a comprehensive search strategy was performed in important databases including PubMed, Scopus, Embase, International Statistical Institute (ISI) Web of Science, and google scholar from 2009 to February 2021. The following terms were used for systematic search: low-density lipoprotein, LDL, subfractions, subclasses, nuclear magnetic resonance, NMR, chromatography, high-pressure liquid, HPLC, cardiovascular disease, cerebrovascular, and peripheral vascular disease. Also, for evaluating the risk of bias, the Newcastle-Ottawa scale was employed.

RESULTS

At the end of the search process, 33 articles were included in this study. The results of most of the evaluated studies revealed that a higher LDL particle number was consistently associated with increased risk for cardiovascular disease, independent of other lipid measurements. Also, small dense LDL was associated with an increased risk of CVDs. There was no association between LDL subfraction and CVDs in a small number of studies.

CONCLUSIONS

Overall, it seems that the evaluation of LDL subclasses can be used as a very suitable biomarker for the assessment and diagnosis of cardiovascular diseases. However, further studies are required to identify the mechanisms involved.

Sex-specific responses in glucose-insulin homeostasis and lipoprotein-lipid components after high-dose supplementation with marine n-3 PUFAs in abdominal obesity: a randomized double-blind crossover study

Background

Clinical studies on effects of marine-derived omega-3 (n-3) polyunsaturated fatty acids (PUFAs), mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and the plant-derived omega-6 (n-6) PUFA linoleic acid (LA) on lipoprotein-lipid components and glucose-insulin homeostasis have shown conflicting results, which may partly be explained by differential responses in females and males. However, we have lacked data on sexual dimorphism in the response of cardiometabolic risk markers following increased consumption of n-3 or n-6 PUFAs.

Objective

To explore sex-specific responses after n-3 (EPA + DHA) or n-6 (LA) PUFA supplementation on circulating lipoprotein subfractions, standard lipids, apolipoproteins, fatty acids in red blood cell membranes, and markers of glycemic control/insulin sensitivity among people with abdominal obesity.

Methods

This was a randomized double-blind crossover study with two 7-week intervention periods separated by a 9-week washout phase. Females (n = 16) were supplemented with 3 g/d of EPA + DHA (fish oil) or 15 g/d of LA (safflower oil), while males (n = 23) received a dose of 4 g/d of EPA + DHA or 20 g/d of LA. In fasting blood samples, we measured lipoprotein particle subclasses, standard lipids, apolipoproteins, fatty acid profiles, and markers of glycemic control/insulin sensitivity.

Results

The between-sex difference in relative change scores was significant after n-3 for total high-density lipoproteins (females/males: -11%*/-3.3%, p = 0.036; *: significant within-sex change), high-density lipoprotein particle size (+2.1%*/-0.1%, p = 0.045), and arachidonic acid (-8.3%*/-12%*, p = 0.012), and after n-6 for total (+37%*/+2.1%, p = 0.041) and small very-low-density lipoproteins (+97%*/+14%, p = 0.021), and lipoprotein (a) (-16%*/+0.1%, p = 0.028). Circulating markers of glucose-insulin homeostasis differed significantly after n-3 for glucose (females/males: -2.1%/+3.9%*, p = 0.029), insulin (-31%*/+16%, p < 0.001), insulin C-peptide (-12%*/+13%*, p = 0.001), homeostasis model assessment of insulin resistance index 2 (-12%*/+14%*, p = 0.001) and insulin sensitivity index 2 (+14%*/-12%*, p = 0.001), and quantitative insulin sensitivity check index (+4.9%*/-3.4%*, p < 0.001).

Conclusion

We found sex-specific responses after high-dose n-3 (but not n-6) supplementation in circulating markers of glycemic control/insulin sensitivity, which improved in females but worsened in males. This may partly be related to the sex differences we observed in several components of the lipoprotein-lipid profile following the n-3 intervention.

Clinical trial registration

https://clinicaltrials.gov/, identifier [NCT02647333].

Remnant cholesterol can identify individuals at higher risk of metabolic syndrome in the general population

Remnant cholesterol (RC) is a highly atherogenic lipid. Previous studies have shown that RC was closely associated with many metabolism-related diseases. However, the relationship of RC with metabolic syndrome (MetS) remains unclear. This study's objective is to investigate the relationship of RC with MetS. A total of 60,799 adults who received health assessments were included in this study. RC was calculated by subtracting the directly measured values for low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) from total cholesterol (TC) and divided into 5 groups according to its quintile. MetS diagnosis according to National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) definitions. Application of receiver operating characteristic (ROC) curve analysis and multivariate logistic regression to assess the association of RC with MetS. In RC quintile groups, the prevalence of MetS was 0.84, 1.10, 1.92, 3.87 and 37.71%, respectively. Multivariate logical regression analysis showed that RC and MetS maintained a stable independent positive correlation between both sexes. An interaction test further showed that the MetS risk associated with RC was significantly higher in women than in men. Moreover, ROC analysis results showed that RC had high accuracy in identifying MetS, especially among young and middle-aged men [(area under the curve: AUC) < 30 years: 0.9572, 30-39 years: 0.9306, 40-49 years: 0.9067]. The current study provided the first evidence of a positive association between RC and MetS, and that this correlation was stronger in women than in man, which may be due to the relative deficiency of estrogen in women.

Associations among carotid plaque progression, cerebrovascular/cardiovascular diseases and LDL-C/non-HDL-C goal achievement in diabetic patients: A retrospective cohort study

BACKGROUND

Impaired glycolipid metabolism can induce vascular injury and plaque formation. It is important to investigate the associations between carotid plaque progression and lipid-lowering goal achievement and cardiovascular disease.

METHODS

Diabetic patients who underwent at least 2 carotid ultrasound scans with intervals ≥0.5 years and were hospitalized in the Department of Endocrinology at Sun Yat-sen Memorial Hospital were included. Patients were divided into 3 groups based on carotid plaque progression: the persistent plaque absence, new-onset plaque and persistent plaque presence groups. The primary outcomes were CHD and stroke, while the secondary outcomes were low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C) goal achievement.

RESULTS

There were 304 diabetic patients included, with a median follow-up period of 2.15 years. In multivariable logistic regression analysis, persistent plaque presence was positively associated with a 2.285-fold increase in coronary heart disease (CHD) prevalence, while new-onset plaque was associated with a 3.225-fold increase in stroke prevalence compared to persistent plaque absence in patients with follow-up periods ≥ 0.5 years. The association remained significant in patients with a follow-up period ≥ 1 year and ≥2 years. The velocity of average plaque length change was independently associated with increased ΔLDL-C (last - goal) (β = 0.073, P = 0.048).

CONCLUSION

Carotid plaque progression had long-term association with CHD and stroke starting from 0.5 years, while the velocity of average plaque length associated with increased ΔLDL-C (last - goal) might reflect patient response to statins. Repeated carotid plaque measurements might guide lipid-lowering therapies.

Anorexia Nervosa Is Associated with a Shift to Pro-Atherogenic Low-Density Lipoprotein Subclasses

Anorexia nervosa (AN) is a severe eating disorder affecting primarily female adolescents and younger adults. The energy deprivation associated with AN has been shown to alter lipoprotein metabolism, which may affect cardiovascular risk. However, the mechanisms leading to alterations in the composition, structure, and function of lipoproteins in AN patients are not well-understood yet. Here, we investigated the lipid abnormalities associated with AN, particularly changes in the distribution, composition, metabolism, and function of lipoprotein subclasses. In this exploratory study, we analyzed serum samples of 18 women diagnosed with AN (BMI < 17.5 kg/m2) and 24 normal-weight women (BMI from 18.5−24.9 kg/m2). Using the Quantimetrix Lipoprint® system, we determined low-density lipoprotein (LDL) subclass distribution, including quantitative measurements of very low-density lipoprotein (VLDL), intermediate density lipoprotein (IDL) and high-density lipoprotein (HDL) subclass distribution. We quantified the most abundant apolipoproteins of HDL and assessed lecithin-cholesterol acyltransferase (LCAT) and cholesteryl-ester transfer protein (CETP) activities. In addition, anti-oxidative capacity of apoB-depleted serum and functional metrics of HDL, including cholesterol efflux capacity and paraoxonase activity were assessed. The atherogenic lipoprotein subclasses VLDL and small LDL particles were increased in AN. Levels of VLDL correlated significantly with CETP activity (rs = 0.432, p = 0.005). AN was accompanied by changes in the content of HDL-associated apolipoproteins involved in triglyceride catabolism, such as apolipoprotein C-II (+24%) and apoA-II (−27%), whereas HDL-associated cholesterol, phospholipids, and triglycerides were not altered. Moreover, AN did not affect HDL subclass distribution, cholesterol efflux capacity, and paraoxonase activity. We observed a shift to more atherogenic lipoprotein subclasses in AN patients, whereas HDL functionality and subclass distribution were not altered. This finding underpins potential detrimental effects of AN on lipid metabolism and the cardiovascular system by increasing atherosclerotic risk factors.

Association between small dense low-density lipoprotein cholesterol and neuroimaging markers of cerebral small vessel disease in middle-aged and elderly Chinese populations

BACKGROUND

Cerebral small vascular disease (CSVD) is one of the leading causes of death in the aged population and is closely related to abnormalities in low-density lipoprotein cholesterol (LDL-C). Our study aims to clarify the relationship between small and dense low-density lipoprotein cholesterol (sdLDL-C) (a subcomponent of LDL-C) and neuroimaging markers of CSVD.

METHODS

In total, 1211 Chinese adults aged ≥45 years with cranial magnetic resonance imaging (MRI) were recruited in this retrospective study from January 2018 to May 2021. Serum lipids and other baseline characteristics were investigated in relation to the occurrence of CSVD. A logistic regression model was performed to analyze the relationships between LDL subtypes and CSVD risk, and the Pearson correlation coefficient was used to analyze the correlation between clinical characteristics and CSVD risk. ROC curves and AUCs were created and depicted to predict the best cutoff value of LDL-C subtypes for CSVD risk. Based on these data, we performed comprehensive analyses to investigate the risk factors for CSVD.

RESULTS

Ultimately, 623 eligible patients were included in the present study. Of the 623 eligible patients, 487 were included in the CSVD group, and 136 were included in the group without CSVD (control group). We adjusted for confounders in the multivariate logistic regression model, and LDL-C3 was still higher in the CSVD patients than in the group of those without CSVD (OR (95% CI), 1.22(1.08-1.38), P < 0.05). Pearson correlation showed that there was a positive correlation between the levels of LDL-C3, LDL-C4, LDL-C5, glucose, age, hypertension, previous ischemic stroke and CSVD risk (r > 0.15, P < 0.01). Moreover, the best cutoff value of LDL-C3 to predict CSVD was 9.5 mg/dL with 68.4% sensitivity and 72.8% specificity, and the best cutoff value of LDL-C4 to predict CSVD was 5.5 mg/dL with 50.5% sensitivity and 90.4% specificity.

CONCLUSION

The results indicate that LDL-C3 is an independent risk factor for CSVD. A new prediction model based on LDL-C3 and LDL-C4 can help clinicians identify high-risk CSVD, even in people with normal LDL-C levels. The levels of sdLDL-C should be considered in the assessment and management of CSVD.

Group-Based Lifestyle Intervention Strategies for Metabolic Syndrome: A Scoping Review and Strategic Framework for Future Research

Background and Objectives: Group-based lifestyle interventions reap social support benefits and have been implemented among individuals with various chronic diseases. However, there is a lack of consolidated evidence on its approaches to prevent or manage metabolic syndrome (MetS). This scoping review aims to assess the group-based lifestyle interventional strategies for MetS and provide a strategic framework for future research in this area. Materials and Methods: Scholarly databases (OVID Medline, SCOPUS, PUBMED, PsycINFO, EMBASE, and Cochrane Central Register of Controlled Trials) and reference lists of included publications were systematically searched using appropriate keywords and MeSH terms. Peer-reviewed articles published from the start of indexing to 31 December 2020 focused on individuals with or at risk for MetS were included. Results: Thirteen interventions were identified, with seven conducted among adults with MetS and six in the population at risk for MetS. Three study designs were reported-randomised controlled trials (RCTs), pre-post interventions, and quasi-experiments. Most of the interventions were based in the community or community organisations, multifaceted, led by a multidisciplinary healthcare team, and assisted by peer educators. Waist circumference showed the most promising MetS-related improvement, followed by blood pressure. Conclusions: There is growing evidence supporting group-based lifestyle interventions to improve MetS-related risk factors. In summary, four strategies are recommended for future research to facilitate group-based interventions in preventing and managing MetS.

Small dense low-density lipoprotein-lowering agents

Metabolic disorders, including obesity, diabetes, and hyperlipidemia, as well as cardiovascular diseases (CVD), particularly atherosclerosis, are still leading causes of death worldwide. Plasma levels of low-density lipoprotein (LDL) are currently being considered as a critical risk factor for the diseases mentioned above, especially atherosclerosis. Because of the heterogeneous nature of LDL, many studies have already been conducted on its subclasses, especially small dense LDL (sdLDL). According to available evidence, sdLDL levels can be considered as an ideal alternative to LDL levels for monitoring CVD and early diagnosis of atherosclerosis. Recently, several researchers have focused on factors that are able to decrease sdLDL levels and improve health quality. Therefore, the purpose of this study is to describe the production process of sdLDL particles and review the effects of pharmaceutical and dietary agents as well as lifestyle on sdLDL plasma levels. In brief, their mechanisms of action are discussed. Apparently, cholesterol and LDL-lowering compounds are also effective in the reduction of sdLDL levels. In addition, improving lipid profile, especially the reduction of triglyceride levels, appropriate regimen, and lifestyle can decrease sdLDL levels. Therefore, all the aforementioned parameters should be taken into consideration simultaneously in sdLDL levels reducing strategies.

A spontaneously hypertensive diet-induced atherosclerosis-prone mouse model of metabolic syndrome

Metabolic Syndrome (MetS) is a complex and multifactorial condition often characterised by obesity, hypertension, hyperlipidaemia, insulin resistance, glucose intolerance and fasting hyperglycaemia. Collectively, MetS can increase the risk of atherosclerotic-cardiovascular disease, which is the leading cause of death worldwide. However, no animal model currently exists to study MetS in the context of atherosclerosis. In this study we developed a pre-clinical mouse model that recapitulates the spectrum of MetS features while developing atherosclerosis. When BPHx mice were placed on a western type diet for 16 weeks, all the classical characteristics of MetS were observed. Comprehensive metabolic analyses and atherosclerotic imaging revealed BPHx mice to be obese and hypertensive, with elevated total plasma cholesterol and triglyceride levels, that accelerated atherosclerosis. Altogether, we demonstrate that the BPHx mouse has all the major components of MetS, and accelerates the development of atherosclerosis.

Novel Therapeutical Approaches to Managing Atherosclerotic Risk

Atherosclerosis is a multifactorial vascular disease that leads to inflammation and stiffening of the arteries and decreases their elasticity due to the accumulation of calcium, small dense Low Density Lipoproteins (sdLDL), inflammatory cells, and fibrotic material. A review of studies pertaining to cardiometabolic risk factors, lipids alterations, hypolipidemic agents, nutraceuticals, hypoglycaemic drugs, atherosclerosis, endothelial dysfunction, and inflammation was performed. There are several therapeutic strategies including Proprotein Convertase Subtilisin/Kexin 9 (PCSK9) inhibitors, inclisiran, bempedoic acid, Glucagon-Like Peptide-1 Receptor agonists (GLP-1 RAs), and nutraceuticals that promise improvement in the atheromatous plaque from a molecular point of view, because have actions on the exposure of the LDL-Receptor (LDL-R), on endothelial dysfunction, activation of macrophages, on lipid oxidation, formations on foam cells, and deposition extracellular lipids. Atheroma plaque reduction both as a result of LDL-Cholesterol (LDL-C) intensive lowering and reducing inflammation and other residual risk factors is an integral part of the management of atherosclerotic disease, and the use of valid therapeutic alternatives appear to be appealing avenues to solving the problem.

Relationship between small dense low-density lipoprotein cholesterol with carotid plaque in Chinese individuals with abnormal carotid artery intima-media thickness

Aim

To investigate the relationship of small dense low-density lipoprotein cholesterol (sdLDL-C) to carotid artery intima-media thickness (CA-IMT) and carotid plaque (CAP) in Chinese general population, and to evaluate whether sdLDL-C could be an independent risk factor for individuals with subclinical atherosclerosis.

Methods

A total of 729 subjects were randomly collected from consecutive individuals from April 2019 to April 2020 for an annual health checkup. CA-IMT > 1.0 mm was defined as abnormal IMT. Plaque stability was measured by ultrasound examination based on the property of the echo. And sdLDL-C levels were detected by LipoPrint system. Multivariate logistic regression analysis was performed to identify factors associated with CA-IMT and carotid plaque.

Results

The abnormal IMT group had significantly higher sdLDL-C levels than control group (p < 0.0001). And sdLDL-C levels were significantly positively correlated with IMT value (r = 0.1396, p = 0.0021) and presence of carotid plaque (r = 0.14, p = 0.002) in the subjects with abnormal IMT. In addition, subjects with higher levels of sdLDL-C (r = 0.11, p = 0.035) tended to have unstable CAP. After adjustment for age, gender and blood glucose, sdLDL-C level was an independent risk factor of the presence of CAP (OR = 1.59, 95% CI: 1.02–1.83, p = 0.034) in subjects with abnormal IMT.

Conclusion

SdLDL-C is an independent risk factor of the occurrence of CAP in the Chinese subjects with abnormal IMT. Our findings provide supporting evidence that sdLDL-C might be an alternative way to predict CVD in early stage.

Estimation of the LDL subclasses in ischemic stroke as a risk factor in a Chinese population

Background

Acute ischemic stroke (AIS) is one of the leading causes of mortality and long-term disability worldwide. Our study aims to clarify the role of low-density lipoproteins (LDL) subclasses in the occurrence of AIS and develop a risk xprediction model based on these characteristics to identify high-risk people.

Methods

Five hundred and sixty-six patients with AIS and 197 non-AIS controls were included in this study. Serum lipids and other baseline characteristics including fasting blood glucose (GLU), serum creatinine (Scr), and blood pressure were investigated in relation to occurrence of AIS. The LDL subfractions were classified and measured with the Lipoprint System by a polyacrylamide gel electrophoresis technique.

Results

Levels of LDL-3, LDL-4 and LDL-5 subclasses were significantly higher in the AIS group compared to the non-AIS group and lower level of LDL-1 was prevalent in the AIS patients. Consistently, Spearman correlation coefficient demonstrated that sd-demonevels, especially LDL-3 and LDL-4 levels, were significantly positively correlated with AIS. Furthermore, there is a significant positive correlation between small dense LDL (sd-LDL, that is LDL-3 to 7) levels and serum lipids including total cholesterol (TC), Low density lipoprotein cholesterol (LDL-C), and Triglyceride (TG). Increased LDL-3 and LDL-4 as well as decreased LDL-1 and LDL-2 were correlated to the occurrence of AIS, even in the people with normal LDL-C levels. A new prediction model including 12 variables can accurately predict the AIS risk in Chinese patients (AUC = 0.82 ± 0.04).

Conclusions

Levels of LDL subclasses should be considered in addition to serum LDL-C in assessment and management of AIS. A new prediction model based on clinical variables including LDL subtractions can help clinicians identify high of AIS, even in the people with norm.

Increased ABCA1 (ATP-Binding Cassette Transporter A1)-Specific Cholesterol Efflux Capacity in Schizophrenia

Objective:

Patients with schizophrenia have increased long-term mortality attributable to cardiovascular disease and commonly demonstrate features of mixed dyslipidemia with low HDL-C (high-density lipoprotein cholesterol). The removal of cholesterol from cells by HDL via specific ATP-binding cholesterol transporters is a major functional property of HDL, and its measurement as cholesterol efflux capacity (CEC) can predict cardiovascular risk. Whether HDL function is impaired in patients with schizophrenia is unknown.

Approach and Results:

We measured basal and ABCA1 (ATP-binding cassette transporter A1)- and ABCG1 (ATP-binding cassette transporter G1)-dependent CEC, comparing patients with schizophrenia with age- and sex-matched healthy controls, and related our findings to nuclear magnetic resonance analysis of lipoprotein subclasses. Total plasma cholesterol and LDL-C (low-density lipoprotein cholesterol) were comparable between healthy controls (n=51) and patients (n=120), but patients with schizophrenia had increased total plasma triglyceride, low HDL-C and apo (apolipoprotein) A-I concentrations. Nuclear magnetic resonance analysis indicated a marked (15-fold) increase in large triglyceride-rich lipoprotein particle concentration, increased small dense LDL particles, and fewer large HDL particles. Despite lower HDL-C concentration, basal CEC was 13.7±1.6% higher, ABCA1-specific efflux was 35.9±1.6% higher, and ABCG1 efflux not different, in patients versus controls. In patients with schizophrenia, ABCA1-specific efflux correlated with the abundance of small 7.8 nm HDL particles but not with serum plasminogen or triglyceride levels.

Conclusions:

Patients with schizophrenia have increased concentrations of atherogenic apoB-containing lipoproteins, decreased concentrations of large HDL particles, but enhanced ABCA1-mediated CEC. In this population, preventative strategies should focus on reducing atherogenic lipoproteins rather than increasing CEC.

Daily Use of Extra Virgin Olive Oil with High Oleocanthal Concentration Reduced Body Weight, Waist Circumference, Alanine Transaminase, Inflammatory Cytokines and Hepatic Steatosis in Subjects with the Metabolic Syndrome: A 2-Month Intervention Study

Extra virgin olive oil (EVOO) intake is associated with reduced cardiovascular risk, and its phenolic compound oleocanthal (OC) has anti-oxidant and anti-inflammatory properties. The cardiometabolic effects of EVOO with a high OC concentration have not been fully elucidated. We administered EVOO with a high OC concentration daily to 23 subjects with the metabolic syndrome (MetS) and hepatic steatosis (15 men and 8 women, age: 60 ± 11 years) for 2 months. Anthropometric data, metabolic parameters, hepatic steatosis (by fatty liver index, FLI), abdominal fat distribution (by ultrasound), and pro- and anti-inflammatory cytokines were assessed before and after the intervention. EVOO supplementation was associated with a reduction in body weight, waist circumference, body mass index (BMI), alanine transaminase and FLI, as well as interleukin (IL)-6, IL-17A, tumor necrosis factor-α and IL-1B, while IL-10 increased. Maximum subcutaneous fat thickness (SFT max) also increased, with a concomitant decrease in the ratio of visceral fat layer thickness/SFT max. Correlation analysis revealed positive associations between changes in body weight and BMI and those in SFT max, along with an inverse association between changes in IL-6 and those in SFT max. In conclusion, ingestion of EVOO with a high OC concentration had beneficial effects on metabolic parameters, inflammatory cytokines and abdominal fat distribution in MetS subjects with hepatic steatosis, a category of patients at high cardiometabolic risk.

High-Risk Atherosclerosis and Metabolic Phenotype: The Roles of Ectopic Adiposity, Atherogenic Dyslipidemia, and Inflammation

Current algorithms for assessing risk of atherosclerotic cardiovascular disease (ASCVD) and, in particular, the reliance on low-density lipoprotein (LDL) cholesterol in conditions where this measurement is discordant with apoB and LDL-particle concentrations fail to identify a sizeable part of the population at high risk for adverse cardiovascular events. This results in missed opportunities for ASCVD prevention, most notably in those with metabolic syndrome, prediabetes, and diabetes. There is substantial evidence that accumulation of ectopic fat and associated metabolic traits are markers for and pathogenic components of high-risk atherosclerosis. Conceptually, the subset of advanced lesions in high-risk atherosclerosis that triggers vascular complications is closely related to a set of coordinated high-risk traits clustering around a distinct metabolic phenotype. A key feature of this phenotype is accumulation of ectopic fat, which, coupled with age-related muscle loss, creates a milieu conducive for the development of ASCVD: atherogenic dyslipidemia, nonresolving inflammation, endothelial dysfunction, hyperinsulinemia, and impaired fibrinolysis. Sustained vascular inflammation, a hallmark of high-risk atherosclerosis, impairs plaque stabilization in this phenotype. This review describes how metabolic and inflammatory processes that are promoted in large measure by ectopic adiposity, as opposed to subcutaneous adipose tissue, relate to the pathogenesis of high-risk atherosclerosis. Clinical biomarkers indicative of these processes provide incremental information to standard risk factor algorithms and advanced lipid testing identifies atherogenic lipoprotein patterns that are below the discrimination level of standard lipid testing. This has the potential to enable improved identification of high-risk patients who are candidates for therapeutic interventions aimed at prevention of ASCVD.

Association of Small Dense Low-Density Lipoprotein Cholesterol with Stroke Risk, Severity and Prognosis

Aim: To investigate the association of small dense low-density lipoprotein cholesterol (sdLDL-C) and acute ischemic stroke (AIS) in terms of risk, severity, and outcomes. Prediction models were established to screen high-risk patients and predict prognosis of AIS patients.

Methods: We enrolled in this study 355 AIS patients and 171 non-AIS controls. AIS was subtyped according to TOAST criteria, and the severity and outcomes of AIS were measured. Blood glucose and lipid profiles including total cholesterol, triglyceride, and lipoproteins were measured in all patients using automatic measure. Lipoprotein subfractions were detected by the Lipoprint LDL system.

Results: As compared with the non-AIS control group, the AIS group had higher sdLDL-C levels. Pearson correlation analysis revealed that the sdLDL-C level and risk of AIS, especially non-cardioembolic stroke, were positively correlated. The area under the curve of sdLDL-C for AIS risk was 0.665, better than that of other lipids. Additionally, the sdLDL-C level was significantly correlated with AIS severity and bad outcomes. A logistic regression model for assessing the probability of AIS occurrence and a prognostic prediction model were established based on sdLDL-C and other variables.

Conclusions: Elevated levels of sdLDL-C were associated with a higher prevalence of AIS, especially in non-cardioembolic stroke subtypes. After adjustment for other risk factors, sdLDL-C was found to be an independent risk factor for AIS. Also, sdLDL-C level was strongly associated with AIS severity and poor functional outcomes. Logistic regression models for AIS risk and prognosis prediction were established to help clinicians provide better prevention for high-risk subjects and monitor their prognosis.

Polyglycolic acid sutures embedded in abdominal acupoints for treatment of simple obesity in adults: a randomized control trial

Background

Acupoint catgut embedding therapy characterized by acupoint, needle and catgut are superior to traditional acupuncture, due to exerting more comprehensive therapeutic efficacy. However, it is still deficient in clinical evidence for polyglycolic acid sutures, a novel biodegradable material instead of catgut, embedded for the treatment of simple obesity. In our study, we investigate the efficacy and related mechanism of polyglycolic acid sutures embedded in abdominal acupoints on simple obese persons by a randomized control trial.

Methods

A total of 51 eligible participators were randomly allocated to a polyglycolic acid sutures embedding therapy (PASET) group (n = 28) or control group (n = 23). Participators in PASET group received polyglycolic acid sutures alternatively embedded in abdominal I group and II group acupoints in odd and even number therapeutic courses, and participators in control group were required to perform lifestyle modification. The duration of the study was 10 weeks.

Results

It suggested that PASET significantly reduced weight, body mass index, hip circumference, waist circumference, waist/hip ratio, waist-to-height ratio and thickness of abdominal subcutaneous fat tissue compared with those before treatment (p < 0.01), but lifestyle modification only illustrated downward trend of weight (p < 0.05). Moreover, PASET group also improved the evaluated scores in aspects of physical function, self-esteem, public distress and sexual life, as well as decreased blood pressure, glycemia, low density lipoprotein, uric acid and the levels of tumor necrosis factor-alpha, interleukin-1β, and increased high density lipoprotein in comparison with those before treatment (p < 0.05), whose efficacies are superior to control group. Additionally, our results also indicate PASET is relative safe and its pain and discomfort can be tolerable.

Conclusions

PASET distinctly ameliorates anthropometric data and quality of life in obese population, which associates with improvements of metabolic profile and inflammatory response. Based on the advantageous actions, we think PASET is an effective therapeutic approach to simple obesity treatment.

Trial registration ChiCTR, ChiCTR1800015591. Registered 10 April 2018, http://www.chictr.org.cn/showproj.aspx?proj=23258

The Atherogenic Role of Circulating Modified Lipids in Atherosclerosis

Lipid accumulation in the arterial wall is a crucial event in the development of atherosclerotic lesions. Circulating low-density lipoprotein (LDL) is the major source of lipids that accumulate in the atherosclerotic plaques. It was discovered that not all LDL is atherogenic. In the blood plasma of atherosclerotic patients, LDL particles are the subject of multiple enzymatic and non-enzymatic modifications that determine their atherogenicity. Desialylation is the primary and the most important atherogenic LDL modification followed by a cascade of other modifications that also increase blood atherogenicity. The enzyme trans-sialidase is responsible for the desialylation of LDL, therefore, its activity plays an important role in atherosclerosis development. Moreover, circulating modified LDL is associated with immune complexes that also have a strong atherogenic potential. Moreover, it was shown that antibodies to modified LDL are also atherogenic. The properties of modified LDL were described, and the strong evidence indicating that it is capable of inducing intracellular accumulation of lipids was presented. The accumulated evidence indicated that the molecular properties of modified LDL, including LDL-containing immune complexes can serve as the prognostic/diagnostic biomarkers and molecular targets for the development of anti-atherosclerotic drugs.

Effects of Fructose or Glucose on Circulating ApoCIII and Triglyceride and Cholesterol Content of Lipoprotein Subfractions in Humans

ApoCIII and triglyceride (TG)-rich lipoproteins (TRL), particularly, large TG-rich lipoproteins particles, have been described as important mediators of cardiovascular disease (CVD) risk. The effects of sustained consumption of dietary fructose compared with those of sustained glucose consumption on circulating apoCIII and large TRL particles have not been reported. We measured apoCIII concentrations and the TG and cholesterol content of lipoprotein subfractions separated by size in fasting and postprandial plasma collected from men and women (age: 54 ± 8 years) before and after they consumed glucose- or fructose-sweetened beverages for 10 weeks. The subjects consuming fructose exhibited higher fasting and postprandial plasma apoCIII concentrations than the subjects consuming glucose (p < 0.05 for both). They also had higher concentrations of postprandial TG in all TRL subfractions (p < 0.05, effect of sugar), with the highest increases occurring in the largest TRL particles (p < 0.0001 for fructose linear trend). Compared to glucose consumption, fructose consumption increased postprandial TG in low-density lipoprotein (LDL) particles (p < 0.05, effect of sugar), especially in the smaller particles (p < 0.0001 for fructose linear trend). The increases of both postprandial apoCIII and TG in large TRL subfractions were associated with fructose-induced increases of fasting cholesterol in the smaller LDL particles. In conclusion, 10 weeks of fructose consumption increased the circulating apoCIII and postprandial concentrations of large TRL particles compared with glucose consumption.

Efficacy of a nutraceutical combination on lipid metabolism in patients with metabolic syndrome: a multicenter, double blind, randomized, placebo controlled trial

Background

Nutraceuticals represent a new therapeutic frontier in the treatment of metabolic syndrom (MetS) and related cardiovascular risk factors. The aim of this study was to evaluate the potential beneficial effects of Armolipid Plus (AP) (berberine 500 mg, red yest rice, monacolin K 3 mg and policosanol 10 mg) on insulin resistance, lipid profile, particularly on small and dense LDL cholesterol (sdLDL-C), representing the most atherogenic components, as well as its effects on high sensitivity C-reactive protein, a notable marker of cardiovascular risk, blood pressure and cardiac remodeling in subjects affected by MetS, with left ventricular hypertrophy.

Methods

The study was a prospective, multi-center, randomized, double blind, placebo-controlled trial. One hundred and fifty eight patients, aged between 28 and 76 years old, were enrolled and randomized to receive either one tablet of AP or placebo (PL) once daily for 24 weeks. Anthropometric and vital parameters, total cholesterol (tot-C), low-density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), triglyceridemia (TG), non-HDL cholesterol (NHDL-C) and sdLDL-C were evaluated.

Results

After 24 weeks of treatment, the analysis performed on 141 subjects (71 in AP arm and 70 in PL arm), showed a significant improvement of lipid profile in the AP group, with reduction in tot-C (− 13.2 mg/dl), LDL-C (− 13.9 mg/dl) and NHDL-C (− 15.3 mg/dl) and increase in HDL-C (+ 2.0 mg/dl). These changes were equally significant compared with placebo (tot-C: AP − 13.2 mg/dL vs PL + 2.7 mg/dL, p < 0.01; LDL-C: AP -13.9 mg/dl vs PL + 1.5 mg/dl, p < 0.01; NHDL-C: AP -15.3 mg/dl vs PL + 2.8 mg/dl, p < 0.01), Although no significant difference was observed between the two arms in the reduction of HDL-C nevertheless it increased significantly in the AP group (AP + 2 mg/dL p < 0.05, PL 0.13 mg/dL).

Conclusion

The results of this study, applicable to a specific local population show that, in a population of subjects affected by MetS, treatment with AP improves the lipid profile and the most atherogenic factors, thus suggesting a reduction in the risk of development and progression of atherosclerosis, particularly in subjects with high atherogenic risk, due to the presence of sdLDL-C.

Small Dense Low-Density Lipoprotein as Biomarker for Atherosclerotic Diseases

Low-density lipoprotein (LDL) plays a key role in the development and progression of atherosclerosis and cardiovascular disease. LDL consists of several subclasses of particles with different sizes and densities, including large buoyant (lb) and intermediate and small dense (sd) LDLs. It has been well documented that sdLDL has a greater atherogenic potential than that of other LDL subfractions and that sdLDL cholesterol (sdLDL-C) proportion is a better marker for prediction of cardiovascular disease than that of total LDL-C. Circulating sdLDL readily undergoes multiple atherogenic modifications in blood plasma, such as desialylation, glycation, and oxidation, that further increase its atherogenicity. Modified sdLDL is a potent inductor of inflammatory processes associated with cardiovascular disease. Several laboratory methods have been developed for separation of LDL subclasses, and the results obtained by different methods can not be directly compared in most cases. Recently, the development of homogeneous assays facilitated the LDL subfraction analysis making possible large clinical studies evaluating the significance of sdLDL in the development of cardiovascular disease. Further studies are needed to establish guidelines for sdLDL evaluation and correction in clinical practice.

Hypertriglyceridemia is a major factor associated with elevated levels of small dense LDL cholesterol in patients with metabolic syndrome

BACKGROUND

We aimed to determine the major contributing component of metabolic syndrome (MetS) that results in an elevated small dense LDL cholesterol (sdLDL-C) concentration and sdLDL-C/LDL-C ratio.

METHODS

Four hundred and forty-seven subjects (225 men; 222 women) with MetS were randomly selected from the Korean Metabolic Syndrome Research Initiatives-Seoul cohort study. Age- and sex-matched healthy controls (181 men; 179 women) were also randomly selected from the same cohort.

RESULTS

A comparison of the median values of the sdLDL-C concentration between subgroups, divided according to whether subjects met or did not meet the criteria for each MetS component in patients with MetS, revealed a significant difference in the sdLDL-C concentration only between subgroups divided according to whether subjects met or did not meet the triglyceride (TG) criteria (P<0.05 for each gender). The TG level showed a good correlation with sdLDL-C concentration (correlation coefficients [r]=0.543 for men; 0.653 for women) and the sdLDL-C/LDL-C ratio (r=0.789 for men; 0.745 for women). Multiple linear regression analyses conducted for the MetS group concordantly identified TG as one of the most significant contributors to sdLDL-C concentration (β=0.1747±0.0105, P<0.0001) and the sdLDL-C/LDL-C ratio (β=6.9518±0.3011, P<0.0001).

CONCLUSIONS

Among five MetS components, only the abnormal TG level was a differentiating factor for sdLDL-C concentration and sdLDL-C/LDL-C ratio. These results were reproducible in both genders, with or without MetS.

Estimation of LDL Particle Size Using Lipid Indices: A Population-Based Study of 1578 Schoolchildren

BACKGROUND

Low-density lipoprotein (LDL) is atherogenic and LDL particles are reduced in diameter in the presence of insulin resistance, forming small, dense LDL. This study was conducted to assess the relationship between commonly used lipid indices and LDL particle size and furthermore to clarify the best surrogate lipid markers that could conveniently be used to estimate LDL particle size in children.

METHODS

We determined LDL particle diameter by gradient gel electrophoresis in 1578 children aged 10-12 years. At the fasting state, the relationships between measured LDL particle size and lipid variables [total cholesterol (TC), triglycerides (TG), LDL-cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), atherogenic index [(TC-HDL-C)/HDL-C, TG/HDL-C, LDL-C/HDL-C, and LDL-C/apolipoprotein B (Apo B) and non-HDL-C (TC-HDL-C)] were analyzed.

RESULTS

The LDL particle diameter was 26.64 (mean) ± 0.48 (SD) nm in boys (n = 820) and 26.66 ± 0.49 nm in girls (n = 758); there was not a statistically significant difference. There were statistically significant correlations between LDL particle size and TG or HDL-C concentrations (r = 0.28∼0.37), but the correlations with LDL-C and ApoB were very weak. The combined lipid measures, such as atherogenic index, TC/HDL-C, TG/HDL-C, and LDL-C/HDL-C showed moderate correlations (r = 0.33∼0.38) with LDL particle size; however, the correlation of non-HDL-C with LDL particle size was weak (r = 0.18∼0.19). Simple HDL-C measure appeared to be of comparable value to combined lipid measures.

CONCLUSIONS

Our data indicate that various lipid indices are not superior to HDL-C levels alone as a clinical tool for estimating LDL particle size. Non-HDL-C was less valuable in this aspect.

Associations of ApoAI and ApoB-containing lipoproteins with AngII-induced abdominal aortic aneurysms in mice

OBJECTIVE

Dyslipidemia is implicated in abdominal aortic aneurysms (AAAs) in humans and angiotensin (Ang) II-infused mice. This study determined effects of major lipoprotein classes on AngII-induced AAAs using multiple mouse strains with dietary and pharmacological manipulations.

APPROACH AND RESULTS

Western diet had minor effects on plasma cholesterol concentrations and the low incidence of AngII-induced AAAs in C57BL/6J mice. Low incidence of AAAs in this strain was not attributed to protection from high-density lipoprotein, because apolipoprotein (apo) AI deficiency did not increase AngII-induced AAAs. ApoAI deletion also failed to alter AAA occurrence in hypercholesterolemic mice. Low-density lipoprotein receptor-/- mice fed normal diet had low incidence of AngII-induced AAAs. Western diet feeding of this strain provoked pronounced hypercholesterolemia because of increased apoB-containing lipoproteins with attendant increases of atherosclerosis in both sexes, but AAAs only in male mice. ApoE-deficient mice fed normal diet were modestly hypercholesterolemic, whereas this strain fed Western diet was severely hypercholesterolemic because of increased apoB-containing lipoprotein concentrations. The latter augmented atherosclerosis, but did not change the high incidence of AAAs in this strain. To determine whether reductions in apoB-containing lipoproteins influenced AngII-induced AAAs, ezetimibe was administered at a dose that partially reduced plasma cholesterol concentrations to ApoE-deficient mice fed Western diet. This decreased atherosclerosis, but not AAAs. This ezetimibe dose in ApoE-deficient mice fed normal diet significantly decreased plasma apoB-containing lipoprotein concentrations and reduced AngII-induced AAAs.

CONCLUSIONS

ApoB-containing lipoproteins contribute to augmentation of AngII-induced AAA in male mice. However, unlike atherosclerosis, AAA occurrence was not correlated with increases in plasma apoB-containing lipoprotein concentrations.

Lipoprotein profile, lipoprotein-associated phospholipase A2 and cardiovascular risk in hemodialysis patients

BACKGROUND

Cardiovascular disease is the leading cause of morbidity and mortality in hemodialysis patients; the increased risk of cardiovascular disease is due to accelerated atherosclerosis, inflammation and impaired lipoprotein metabolism. We aimed to evaluate lipoprotein-associated phospholipase A2 (Lp-PLA2) and some pro-inflammatory aspects of the lipoprotein profile in dialyzed patients in order to evaluate the relationship with the accelerated atherosclerosis and vascular accidents.

METHODS

In 102 dialysis patients and 40 non-uremic controls, we investigated the lipoprotein plasma profile, high sensitivity C-reactive protein (CRP), ceruloplasmin and serum amyloid A protein (SAA), and followed patients for 1 year to analyze the risk of acute cardiovascular events.

RESULTS

Total cholesterol, low-density lipoprotein and high-density lipoprotein plasma levels were significantly lower in uremic patients than controls, whereas CRP, SAA, ceruloplasmin, Lp-PLA2 and their ratio with apolipoprotein A1 were significantly higher. Patients with Lp-PLA2 levels >194 nmol/min/ml had more acute cardiovascular events than patients with lower values.

CONCLUSION

Our results show that in dialysis subjects: (1) low-density lipoproteins show a more atherogenic phenotype than in the general population; (2) high-density lipoproteins are less anti-inflammatory; (3) Lp-PLA2 could potentially be used to evaluate cardiovascular risk.

A longitudinal study examining the effects of a season of American football on lipids and lipoproteins

Background

Dyslipidemia is one factor cited for increased risk of cardiovascular disease (CVD) in American football players. However, American football players undergo physical conditioning which is known to influence lipids. This study examined if the physical activity of an American football season is associated with changes in lipids and if a relationship exists between lipids and body composition.

Methods

Fourteen division I freshmen American football players had blood drawn prior to summer training (T1), end of competition (T2), and end of spring training (T3). Samples were analyzed for total cholesterol (TCHL), HDL-C, LDL-C, and triglycerides (TG). Body composition was assessed via dual-x-ray absorptiometry. National Cholesterol Education Program (NCEP) lipid categorization was used to characterize participants. Pearson correlations were computed to determine relationships.

Results

Body mass increased T2 (p = 0.008) as a result of increase in fat mass (p = 0.005) and remained high despite a decrease T3. Lean mass did not differ significantly at any time. No significant time effects were observed for lipids measured. The number of participants presenting with risk factors attributed to dyslipidemia varied. By T3, no participant was categorized as “low” for HDL-C. TCHL was moderately correlated (r = 0.60) with fat mass at T1; whereas a moderate correlation (r = −0.57) was observed between BMI and HDL-C at T2. TG was strongly correlated with fat mass at each time point (T1, r = 0.83; T2, r = 0.94; T3, r = 0.70).

Conclusion

The physical activity associated with a season of football results in little change in blood lipids and CVD risk. Further, TG are strongly related to fat mass. Future research should focus on examining the cause of dyslipidemia in American football players.

Effect of colesevelam HCl monotherapy on lipid particles in type 2 diabetes mellitus

Purpose

In addition to lowering hemoglobin A1C, colesevelam has been shown to improve the atherogenic lipoprotein profile of subjects with type 2 diabetes mellitus (T2DM) when used in combination with metformin and/or sulfonylureas. A recent study evaluated the effects of colesevelam as antidiabetes monotherapy in adults with T2DM who had inadequate glycemic control (hemoglobin A1C ≥7.5 to ≤9.5 %) with diet and exercise alone; we report here the effects on lipoprotein particle subclasses.

Methods

Subjects were randomized to receive oral colesevelam 3.75 g/day (n = 176) or placebo (n = 181) for 24 weeks. Changes in lipoprotein particle subclasses were determined by nuclear magnetic resonance spectroscopy.

Results

At Week 24 with last observation carried forward, colesevelam produced a reduction in total low-density lipoprotein (LDL) particle concentration (baseline: 1,611 nmol/L; least-squares [LS] mean treatment difference: −143 nmol/L, p < 0.0001) versus placebo; reductions were also seen in large, small, and very small LDL particle concentrations (all p < 0.05). There was also a reduction in total very low-density lipoprotein (VLDL) and chylomicron particle concentration (baseline: 88 nmol/L; LS mean treatment difference: −1 nmol/L, p = 0.82) that resulted from a lowering in small VLDL particle concentration (baseline: 45 nmol/L; LS mean treatment difference: −5 nmol/L, p = 0.03). In addition, with colesevelam there was an increase in total high-density lipoprotein (HDL) particle concentration versus placebo (baseline: 31 μmol/L; LS mean treatment difference: +0.6 μmol/L, p = 0.20), due to increases in the large (baseline: 5 μmol/L; LS mean treatment difference: +0.5 μmol/L, p = 0.007) and medium (baseline: 3 μmol/L; LS mean treatment difference: +0.8 μmol/L, p = 0.02) HDL subclasses.

Conclusions

Colesevelam monotherapy in subjects with T2DM resulted in generally favorable changes in certain lipoprotein subclass profiles compared with placebo.

Low-density-lipoprotein particle size predicts a poor outcome in patients with atherothrombotic stroke

BACKGROUND AND PURPOSE

Low-density lipoprotein (LDL) particle size is considered to be one of the more important cardiovascular risk factors, and small LDL particles are known to have atherogenic potential. The aim of this study was to determine whether LDL particle size is associated with stroke severity and functional outcome in patients with atherothrombotic stroke.

METHODS

Between January 2009 and May 2011, 248 patients with first-episode cerebral infarction who were admitted to our hospital within 7 days after symptom onset were prospectively enrolled. LDL particle size was measured using the nondenaturing polyacrylamide gradient gel electrophoresis assay. Stroke severity was assessed by applying the National Institutes of Health Stroke Scale (NIHSS) at admission. Functional outcome was investigated at 3 months after the index stroke using the modified Rankin Scale (mRS), and poor functional outcome was defined as an mRS score of ≥3.

RESULTS

The LDL particle size in the 248 patients was 25.9±0.9 nm (mean±SD). LDL particle size was inversely correlated with the degree of cerebral artery stenosis (p=0.010). Multinomial multivariate logistic analysis revealed that after adjustment for age, sex, and variables with p<0.1 in univariate analysis, LDL particle size was independently and inversely associated with stroke severity (NIHSS score ≥5; reference, NIHSS score 0-2; odds ratio=0.38, p=0.028) and poor functional outcome (odds ratio=0.44, p=0.038).

CONCLUSIONS

The results of this study demonstrate that small LDL particles are independently correlated with stroke outcomes. LDL particle size is thus a potential biomarker for the prognosis of atherothrombotic stroke.

Circulating Lp-PLA₂ activity correlates with oxidative stress and cytokines in overweight/obese postmenopausal women not using hormone replacement therapy

Controversy remains regarding whether there is an association between circulating lipoprotein-associated phospholipase A2 (Lp-PLA2), cytokines, and oxidative stress in healthy postmenopausal women. We investigated the influence of age on Lp-PLA2 activity in postmenopausal women not using hormone therapy and the relationship of Lp-PLA2 enzyme activity to serum cytokine levels and oxidative stress indices. Normal weight (n = 1284) and overweight/obese (n = 707) postmenopausal women not using hormone therapy were categorized into five age groups: 50-54, 55-59, 60-64, 65-69, and 70-89 years. Overweight-obese women showed higher plasma Lp-PLA2 activity, urinary 8-epi-prostaglandin F2α (8-epi-PGF2α), serum interleukin (IL)-6, and smaller LDL particles than normal-weight women after adjusting for age, years postmenopause, smoking, drinking, blood pressure, glucose, insulin, lipid profiles, BMI, and waist circumference. Overweight/obese women 70-89 years old showed higher Lp-PLA2 activity than those aged 50-54 years, whereas no significant difference in Lp-PLA2 activity existed across normal-weight female age groups. Overweight/obese women aged ≥ 65 years showed higher Lp-PLA2, oxidized LDL (ox-LDL), IL-6, and 8-epi-PGF2α than age-matched normal-weight controls. Overweight/obese women aged ≥ 70 years had higher ox-LDL levels than those aged 50-59, and overweight/obese women aged 65-89 showed higher IL-6 and 8-epi-PGF2α. There were strong positive correlations between Lp-PLA2 and ox-LDL (r = 0.385, P < 0.001), Lp-PLA2 and IL-6 (r = 0.293, P < 0.001), and ox-LDL and IL-6 (r = 0.303, P < 0.001) in overweight/obese women; however, these relationships were weak in normal-weight women. These results suggest that aging and obesity-related oxidative and inflammatory mediators are associated with Lp-PLA2 activity in overweight/obese postmenopausal women not using hormone therapy.

Comparison of a direct enzymatic assay and polyacrylamide tube gel electrophoresis for measurement of small, dense low-density lipoprotein cholesterol

BACKGROUND

Small, dense low-density lipoprotein cholesterol (sdLDL-C) has been linked to the progression of cardiovascular disease. We compared two methods for determination of sdLDL-C, a direct enzymatic (ENZ) method and a polyacrylamide tube gel electrophoresis (PGE) assay, and investigated the associations of both sdLDL-C measurements with metabolic syndrome.

METHODS

We analyzed 242 patient sera for sdLDL and atherosclerosis-related markers. The PGE method separates the intermediate-density lipoprotein particles into three midbands (MID-A to MID-C) and the LDL particles into seven subfractions (LDL1 to LDL7); the sdLDL-PGE result is calculated as the sum of cholesterol concentrations from LDL3 to LDL7.

RESULTS

The regression equation for sdLDL-C was [ENZmmol/L]=0.779[PGE]+0.67, r=0.713. ENZ showed higher sdLDL-C concentrations than PGE (0.86±0.33 vs. 0.24±0.32 mmol/L); however, the difference was not associated with sdLDL-C concentration (p=0.290). sdLDL-C, as measured with the enzymatic assay, exhibited significant positive correlations with very-low-density lipoprotein, MID-C, MID-B, and LDL2 (all p<0.001), considered atherogenic lipoproteins, but did not correlate with the less atherogenic lipoproteins MID-A and LDL1 (all p>0.600). The ENZ and PGE methods yielded similar patterns of correlation between sdLDL-C, and atherosclerosis-related markers. Using logistic regression, sdLDL-ENZ and apolipoprotein B were identified as significant predictors of metabolic syndrome (p<0.03).

CONCLUSIONS

The ENZ assay for sdLDL-C correlated well with the PGE method. The ENZ method measures a broader range of atherogenic lipoprotein particles than PGE and has the potential to identify subjects with vascular risk, thus contributing in directing specific interventions for cardiovascular prevention.

Association of serum 25-hydroxyvitamin D with lifestyle factors and metabolic and cardiovascular disease markers: population-based cross-sectional study (FIN-D2D)

Objectives

Low serum 25-hydroxyvitamin D (25OHD) level has been associated with an increased risk of several chronic diseases. Our aim was to determine lifestyle and clinical factors that are associated with 25OHD level and to investigate connection of 25OHD level with metabolic and cardiovascular disease markers.

Design

In total, 2868 Finnish men and women aged 45–74 years participated in FIN-D2D population-based health survey in 2007. Participants that had a serum sample available (98.4%; n = 2822) were included in this study. 25OHD was measured with chemiluminescent microparticle immunoassay method.

Results

The mean 25OHD level was 58.2 nmol/l in men (n = 1348) and 57.1 nmol/l in women (n = 1474). Mean 25OHD level was lower in the younger age groups than in the older ones (p<0.0001 both in men and women). This study confirmed that low physical activity (p<0.0001 both in men and women), smoking (p = 0.0002 in men and p = 0.03 in women) and high BMI (p<0.0001 in women) are factors that independently associate with low 25OHD level. Of the metabolic and cardiovascular disease markers high triglyceride concentration (p = 0.02 in men and p = 0.001 in women) and high apolipoprotein B/apolipoprotein A1 ratio (p = 0.04 in men and p = 0.03 in women) were independently associated with low 25OHD level.

Conclusions

Higher age did not predict lower 25OHD level in this study population of aged 45–74 years which may derive from a healthy life-style of “active pensioners”. Low physical activity and smoking came up as independent lifestyle factors associated with low 25OHD level. Defining the molecular mechanisms behind the associations of 25OHD with low physical activity and smoking are important objective in future studies. The association of 25OHD with BMI, high triglyceride concentration and apolipoprotein B/apolipoprotein A1 ratio may be related to the role of vitamin D in inflammation, but more detailed studies are needed.

Obesity and its metabolic complications: the role of adipokines and the relationship between obesity, inflammation, insulin resistance, dyslipidemia and nonalcoholic fatty liver disease

Accumulating evidence indicates that obesity is closely associated with an increased risk of metabolic diseases such as insulin resistance, type 2 diabetes, dyslipidemia and nonalcoholic fatty liver disease. Obesity results from an imbalance between food intake and energy expenditure, which leads to an excessive accumulation of adipose tissue. Adipose tissue is now recognized not only as a main site of storage of excess energy derived from food intake but also as an endocrine organ. The expansion of adipose tissue produces a number of bioactive substances, known as adipocytokines or adipokines, which trigger chronic low-grade inflammation and interact with a range of processes in many different organs. Although the precise mechanisms are still unclear, dysregulated production or secretion of these adipokines caused by excess adipose tissue and adipose tissue dysfunction can contribute to the development of obesity-related metabolic diseases. In this review, we focus on the role of several adipokines associated with obesity and the potential impact on obesity-related metabolic diseases. Multiple lines evidence provides valuable insights into the roles of adipokines in the development of obesity and its metabolic complications. Further research is still required to fully understand the mechanisms underlying the metabolic actions of a few newly identified adipokines.

Elevated small dense low-density lipoprotein cholesterol as a predictor for future cardiovascular events in patients with stable coronary artery disease

AIM

The aim of the present study was to investigate how small dense low-density lipoprotein cholesterol (sdLDL-C) compared with LDL-C affect the long-term prognosis in patients with stable coronary artery disease (CAD).

METHODS

sdLDL-C measured by heparin magnesium precipitation and LDL particle size measured by non-denatured gradient-gel electrophoresis were compared in 190 consecutive CAD patients who underwent coronary arteriography between 2003 and 2004 who did or did not develop cardiovascular events during a seven-year follow-up period. Cardiovascular events were death caused by cardiovascular diseases(CVDs), onset of acute coronary syndrome, need for coronary and peripheral arterial revascularization, hospitalization for heart failure, surgical procedure for any CVDs, and/or hospitalization for stroke.

RESULTS

First-time cardiovascular events were observed in 72 patients. Those who experienced cardiovascular events were older and had higher prevalence rates of hypertension and diabetes; significantly higher Gensini coronary atherosclerotic scores; significantly higher levels of sdLDL-C, sdLDL-C/LDL-C, and LDL-C/high-density lipoprotein cholesterol (HDL-C) ratios; and greater glycated hemoglobin(Hb)A1c and brain natriuretic peptide (BNP) levels. They also had significantly smaller LDL particle sizes, HDL-C, apolipoprotein A-1, and estimated glomerular filtration rate (GFR) compared with patients without cardiovascular events. Conversely, LDL-C, non-HDL-C, apolipoprotein B, remnantlike particle cholesterol, and high-sensitivity C-reactive protein (hs-CRP) levels were similar between the two groups. A Kaplan-Meyer event-free survival curve demonstrated that patients with sdLDL-C≥35 mg/dL (median level) had significantly poorer prognosis compared with those with lower sdLDL-C levels, while patients with LDL-C ≥100 mg/dL had a non-significantly lower survival rate.

CONCLUSION

These results confirm that sdLDL-C is a very promising biomarker to predict future cardiovascular events in the secondary prevention of stable CAD.

Correlation between serum levels of small, dense low-density lipoprotein cholesterol and carotid stenosis in cerebral infarction patients >65 years of age

BACKGROUND

We studied the relationship between serum levels of small, dense low-density lipoprotein cholesterol (sdLDL-C) and carotid stenosis in elderly patients with ischemic cerebral infarction.

METHODS

All patients >65 years of age with newly diagnosed ischemic cerebral infarction were enrolled. None received statins before enrollment. Patients were examined for carotid stenosis by ultrasound color Doppler, and serum sdLDL-C levels were measured using an automated method.

RESULTS

The 149 patients were distributed according to their carotid stenosis as without (n = 61) or with mild (n = 30), moderate (n = 34), or severe (n = 24) carotid stenosis. sdLDL-C levels increased significantly with increasing stenosis severity (0.54 ± 0.19, 0.71 ± 0.18, 0.98 ± 0.19, and 1.32 ± 0.17 mmol/L, respectively). Spearman rank correlation analysis revealed that sdLDL-C levels and degree of carotid stenosis were positively correlated (r = 0.411; P < 0.001). Male sex, body mass index, diabetes, hypertension, hyperlipidemia, drinking, smoking, and sdLDL-C levels were positively correlated with carotid stenosis. Logistic regression analysis revealed that sdLDL-C levels are an independent risk factor of carotid stenosis (P = 0.041).

CONCLUSIONS

sdLDL-C levels are positively correlated with the severity of carotid stenosis, and are an independent risk factor in elderly patients with ischemic cerebral infarction.

Effect of age on atherogenicity of LDL and inflammatory markers in healthy women

BACKGROUND AND AIM

Since using LDL level alone is insufficient as a method to identify individuals with incident coronary artery disease (CAD), other factors may be implicated in the pathogenesis of CAD. Additionally, controversy still remains regarding whether there is an age-related increase in circulating cytokines in healthy individuals. We investigated the influence of age on atherogenicity of LDL and inflammatory markers in healthy women.

METHODS AND RESULTS

Two thousand nine hundred forty four healthy women form 30-79 years old (23.3 ± 0.05 kg/m²) were categorized into 5 age groups: 30-39, 40-49, 50-59, 60-69 and 70-79 years. BMI, smoking, drinking, and metabolic syndrome prevalence adjusted mean values of total-cholesterol progressively increased from the group age 30-39 years to the group age 40-49 and 50-59 years and thereafter decreased in the group age 60-69 and 70-79 years. Serum concentrations of C-reactive protein (CRP), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were higher in women aged 60-79 years than women aged 30-59 years. Plasma ox-LDL levels increased in the group age 50-59 years compared with the group age 30-39 and 40-49 years and further increased in the group age 60-69 and 70-79 years. Mean values of LDL particle size were smaller in women aged 60-79 years than those in women aged 30-59 years. After adjustment for BMI, smoking, drinking, and metabolic syndrome status, age was positively correlated with LDL-cholesterol (r = 0.095, P < 0.001), oxidized LDL (r = 0.305, P < 0.001), hs-CRP (r = 0.150, P < 0.001), TNF-α (r = 0.171, P < 0.001) and IL-6 (r = 0.294, P < 0.001) and negatively with LDL particle size (r = -0.239, P < 0.001).

CONCLUSION

Our results indicate that LDL atherogenicity and inflammatory mediators can be better markers of CAD risk than known risk factors such as elevated concentrations of total- and LDL-cholesterol, decreased HDL-cholesterol levels and smoking in old healthy women.

Small-dense LDL cholesterol/large-buoyant LDL cholesterol ratio as an excellent marker for indicating lipodystrophy in HIV-infected patients

OBJECTIVES

To examine whether the lipid parameters are predicting factors for human immunodeficiency virus (HIV)-associated lipodystrophy.

METHODS

Whole-body fat compositions of HIV-positive patients receiving stavudine-containing antiretroviral regimens (n = 79) were determined. Lipodystrophy was defined as a ratio of trunk fat mass/lower limb fat mass greater than 2.28. Blood samples were analyzed for total cholesterol (TC), triglycerides, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), small-dense LDL-C (sdLDL-C), apoAI, apoB, lipoprotein(a), and CD4 cell counts. Large-buoyant LDL-C (lbLDL-C) was calculated (LDL-C minus sdLDL-C).

RESULTS

Twenty-six patients were classified as having lipodystrophy. The mean values of triglycerides, HDL-C, sdLDL-C, apoB, TC/HDL-C, apolipoprotein (apo) B/apoAI, and sdLDL-C/lbLDL-C showed significant differences between patients with and without lipodystrophy (P < .02). Using logistic regression analysis, sdLDL-C/lbLDL-C was identified as a significant predictor of lipodystrophy (P < .001). At a ratio of 0.554, the odds ratio was 17.8 with a likelihood ratio of 5.5.

CONCLUSIONS

The sdLDL-C/lbLDL-C ratio is an excellent marker for indicating lipodystrophy in HIV-infected patients.

Small, dense LDL particles predict changes in intima media thickness and insulin resistance in men with type 2 diabetes and prediabetes--a prospective cohort study

The association of small, dense low-density lipoprotein (sdLDL) particles with an increased cardiovascular risk is well established. However, its predictive value with regard to glucose metabolism and arterial disease in patients with type 2 diabetes has not been thoroughly investigated. We conducted a prospective longitudinal cohort study in patients with (pre)diabetes who were seen at baseline and after two years. sdLDL particles were determined by gradient gel electrophoresis. Insulin resistance was estimated by using the homeostatic model assessment 2 (HOMA2). Intima media thickness (IMT) and flow-mediated dilation (FMD) were assessed by ultrasound measurements. Fifty-nine patients (mean age 63.0 ± 12.2 years) were enrolled and 39 were seen at follow-up. IMT increased in the whole cohort during follow-up. The change in IMT was predicted by the proportion of sdLDL particles at baseline (p=0.03), and the change in FMD was predicted by LDL-cholesterol levels at baseline (p=0.049). HOMA2 and changes in HOMA2 correlated with the proportion of sdLDL particles and changes in this proportion, respectively (p<0.05 for both). Serum resistin levels increased in parallel with the increasing sdLDL particle number, while serum adiponectin increased only in patients with unaltered sdLDL particle number at follow-up (p<0.01 for both). In conclusion, the proportion of small, dense LDL particles and changes in this proportion are predictive of changes in intima media thickness and insulin resistance, and are closely associated with other determinants of an adverse metabolic status. Thus, this parameter extends the individual risk assessment beyond the limitations of traditional risk markers in patients with dysglycemia.

Heterogeneous properties of intermediate- and low-density lipoprotein subpopulations

OBJECTIVE

Intermediate-density lipoprotein (IDL) and low-density lipoprotein (LDL) consist of heterogeneous particles whose subpopulations may have different atherogenic characteristics. This study investigated the associations between these subpopulations and other lipids, lipoproteins and atherosclerosis-related markers.

DESIGN AND METHODS

A total of 416 subjects (124 males and 292 females, mean age: 50.8 years) were enrolled in this study. Using polyacrylamide gel electrophoresis, serum lipoproteins were separated according to their specific electrophoretic mobility based on particle size. The IDL particles were separated into three midbands (MID-A to C), and the LDL particles were separated into seven subfractions (LDL1 to 7).

RESULTS

MID-B, MID-C, LDL2 and LDL3 to 6 (as a small LDL fraction) were significantly and positively correlated with very LDL (VLDL), while MID-A and LDL1 were significantly and inversely correlated with VLDL. MID-A and LDL1 were significantly and positively correlated with high-density lipoprotein (HDL). The correlation patterns between MID-A or LDL1 and triglycerides, apolipoprotein A-I, glucose, the insulin resistance index, creatinine and the mean LDL particle size had similar trends to those between HDL and these parameters.

CONCLUSIONS

The respective subpopulations of IDL and LDL particles can vary in their ability to predict cardiovascular disease risks. These variations may partially explain why quantitative assessments using LDL-cholesterol concentrations, as typically performed in conventional practice, are not perfect predictors of cardiovascular disease. Further studies are required to determine the clinical relevance of analyzing the IDL and LDL subpopulations.

Relation between lipoprotein subfractions and TSH levels in the cardiovascular risk among women with subclinical hypothyroidism

OBJECTIVE

Subclinical hypothyroidism (SCH) is a common condition associated with increased cardiovascular risk. A standard treatment is yet to be established, as there is no consensus on the TSH cut-off values which should be used as indicators. Thus, the aim of this study was to assess cardiovascular risk in patients with SCH and to differentiate it according to TSH levels.

DESIGN

This was an observational study conducted in an academic medical centre.

PATIENTS

The study population consisted of 95 middle-aged women recently diagnosed with SCH and 65 euthyroid controls.

MEASUREMENTS

We measured anthropometric parameters, lipid cardiovascular risk markers and lipoprotein subclasses of HDL and LDL.

RESULTS

Patients with SCH exhibited a significant increase in triglycerides and atherogenic index of plasma and a significant reduction in HDL-cholesterol with respect to the control group after adjusted by age and BMI. A similar lipid profile was observed in both SCH groups. However, patients with TSH levels higher than 10 mIU/l showed a significant reduction in LDL particle size, which was associated with a higher prevalence of atherogenic pattern B.

CONCLUSIONS

Our findings indicate that cardiovascular risk is affected in patients with TSH levels over 10 mIU/l, who have a lipid profile characteristic of atherogenic dyslipidemia.

Colesevelam improved lipoprotein particle subclasses in patients with prediabetes and primary hyperlipidaemia

BACKGROUND

A randomised, double-blind, placebo-controlled study evaluated lipid- and glucose-lowering effects of colesevelam in patients with prediabetes and primary hyperlipidaemia. We report the effect of colesevelam on lipoprotein particle concentration and particle size (determined by nuclear magnetic resonance spectroscopy) in these patients.

METHODS

Adults with prediabetes (World Health Organization criteria), low-density lipoprotein cholesterol (LDL-C) ≥ 100 mg/dL (≥2.6 mmol/L) and triglycerides < 500 mg/dL (<5.6 mmol/L) were randomised to colesevelam 3.75 g/day or placebo for 16 weeks. The intent-to-treat population comprised 103 colesevelam and 106 placebo recipients.

RESULTS

At the end of the study, mean reduction from baseline in total LDL particle concentration was significantly greater with colesevelam versus placebo (mean treatment difference: -113 nmol/L; p = 0.02). Increases in total very low-density lipoprotein particle concentration (VLDL-P) and high-density lipoprotein particle concentration (HDL-P) did not differ significantly between the groups; however, with colesevelam versus placebo, there were significantly (p < 0.05) greater increases in large and medium VLDL-P and large HDL-P and reductions in small VLDL-P. Mean size increases were significantly greater with colesevelam for VLDL (mean treatment difference: 5.3 nm; p < 0.0001) and HDL (0.1 nm; p = 0.002).

CONCLUSIONS

Colesevelam improved the overall atherogenic lipoprotein profile in adults with prediabetes and primary hyperlipidaemia, despite potentially less favourable changes in VLDL particles.

Lipoprotein subfractions in metabolic syndrome and obesity: clinical significance and therapeutic approaches

Small, dense low density lipoprotein (sdLDL) represents an emerging cardiovascular risk factor, since these particles can be associated with cardiovascular disease (CVD) independently of established risk factors, including plasma lipids. Obese subjects frequently have atherogenic dyslipidaemia, including elevated sdLDL levels, in addition to elevated triglycerides (TG), very low density lipoprotein (VLDL) and apolipoprotein-B, as well as decreased high density lipoprotein cholesterol (HDL-C) levels. Obesity-related co-morbidities, such as metabolic syndrome (MetS) are also characterized by dyslipidaemia. Therefore, agents that favourably modulate LDL subclasses may be of clinical value in these subjects. Statins are the lipid-lowering drug of choice. Also, anti-obesity and lipid lowering drugs other than statins could be useful in these patients. However, the effects of anti-obesity drugs on CVD risk factors remain unclear. We review the clinical significance of sdLDL in being overweight and obesity, as well as the efficacy of anti-obesity drugs on LDL subfractions in these individuals; a short comment on HDL subclasses is also included. Our literature search was based on PubMed and Scopus listings. Further research is required to fully explore both the significance of sdLDL and the efficacy of anti-obesity drugs on LDL subfractions in being overweight, obesity and MetS. Improving the lipoprotein profile in these patients may represent an efficient approach for reducing cardiovascular risk.

Lipoprotein subfractions in metabolic syndrome and obesity: clinical significance and therapeutic approaches

Small, dense low density lipoprotein (sdLDL) represents an emerging cardiovascular risk factor, since these particles can be associated with cardiovascular disease (CVD) independently of established risk factors, including plasma lipids. Obese subjects frequently have atherogenic dyslipidaemia, including elevated sdLDL levels, in addition to elevated triglycerides (TG), very low density lipoprotein (VLDL) and apolipoprotein-B, as well as decreased high density lipoprotein cholesterol (HDL-C) levels. Obesity-related co-morbidities, such as metabolic syndrome (MetS) are also characterized by dyslipidaemia. Therefore, agents that favourably modulate LDL subclasses may be of clinical value in these subjects. Statins are the lipid-lowering drug of choice. Also, anti-obesity and lipid lowering drugs other than statins could be useful in these patients. However, the effects of anti-obesity drugs on CVD risk factors remain unclear. We review the clinical significance of sdLDL in being overweight and obesity, as well as the efficacy of anti-obesity drugs on LDL subfractions in these individuals; a short comment on HDL subclasses is also included. Our literature search was based on PubMed and Scopus listings. Further research is required to fully explore both the significance of sdLDL and the efficacy of anti-obesity drugs on LDL subfractions in being overweight, obesity and MetS. Improving the lipoprotein profile in these patients may represent an efficient approach for reducing cardiovascular risk.