An overview of the new frontiers in the treatment of atherogenic dyslipidemias

Association between atherogenic index of plasma and prehypertension or hypertension among normoglycemia subjects in a Japan population: a cross-sectional study

OBJECTIVE

The atherogenic index of plasma (AIP), consisting of triglycerides and high-density lipoprotein cholesterol, is applied to estimate the cardiovascular disease risk. The evidence regarding the association between AIP and prehypertension or hypertension remains inconclusive. This study was conducted to investigate the association of AIP and prehypertension or hypertension in normoglycemic subjects in Japan.

METHODS

In the present cross-sectional study, 15,453 normoglycemic participants aged 18 years or older in Gifu, Japan, were evaluated. The selected participants were separated into four groups in the light of AIP quartiles, ranging from the lowest quartile (Q1) to the highest quartile (Q4). And the association between AIP and prehypertension or hypertension was explored with multivariate logistic regression by gradually adjusting model.

RESULTS

Among the 15,453 participants, aged of 43.7 ± 8.9 years, and of whom 45.5% were females, the prevalence rates of prehypertension or hypertension were 27.68% (4,278) and 6.23% (962) respectively. In multivariate logistic regression analyses, participants in the highest AIP quartile had an increase risk in prehypertension and hypertension, compared with participants the lowest one, the odds ratios (OR) were 1.15 (95%CI: 1.00-1.13, P = 0.045) for prehypertension and 1.54 (95%CI:1.16-2.04, P = 0.003) for hypertension after adjusting confounders. In subgroup analyses, the high risk of hypertension was also observed for female participants in the highest AIP quartile (Q4) (OR = 2.19, 95%CI: 1.37-3.49, P = 0.001), especially between the ages of 40 and 60 years (OR = 2.20, 95%CI: 1.24-3.88, P = 0.007).

CONCLUSIONS

Higher AIP is significantly and positively associated with the risk of prehypertension or hypertension in normoglycemic subjects in Gifu, Japan, which was more pronounced in the female population, especially between the years of 40 and 60.

Dyslipidemia and the Prevalence of Hypertension: A Cross-Sectional Study Based on Chinese Adults Without Type 2 Diabetes Mellitus

Background

In clinical practice, it is frequently observed that patients with hypertension often coexist with dyslipidemia. However, studies on atherosclerotic indices and the prevalence of hypertension are still limited. The purpose of this study was to assess the relationship between atherosclerotic indices and the prevalence of hypertension in Chinese adults without type 2 diabetes mellitus.

Methods

In this paper, a cross-sectional study was conducted based on 117,056 adults in 11 Chinese cities (Shanghai, Beijing, Wuhan, Suzhou, Shenzhen, Changzhou, Nantong, Guangzhou, Hefei, Nanjing, and Chengdu) from 2010 to 2016. Besides, the raw data was obtained from the public database (www.Datadryad.org), while eight atherosclerosis indices namely the atherogenic coefficient (AC), Castelli's risk index I (CRI-I) and II (CRI-II), the atherogenic index of plasma (AIP), the cholesterol index, the lipoprotein combined index (LCI), non-high-density lipoprotein cholesterol (non-HDL-C) and triglycerides/high-density lipoprotein cholesterol (TG/HDL-C) were analyzed in this study. Apart from that, two groups of continuous variables were measured using the Mann-Whitney test, and categorical variables were analyzed using the Chi-square test. Differences between multiple groups of continuous variables were investigated using Kruskal-Wallis one-way analysis of variance (ANOVA) and Dunn's test. Furthermore, Spearman correlation analysis and multivariate logistic regression analyses were performed to assess the relationship between atherosclerotic indices and blood pressure levels, and the prevalence of hypertension, respectively. The results of multivariate logistic regression analyses were expressed as the odds ratio (OR) and their corresponding 95% confidence intervals (CIs). Moreover, the receiver operating characteristic (ROC) curve was depicted to further analyze the predictive value of the atherosclerotic indices on the prevalence of hypertension.

Results

The atherosclerosis indices were higher in the hypertensive population compared to those in the normotensive population. Meanwhile, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were linearly and positively correlated with atherosclerotic indices. In addition, multivariate logistic regression analysis showed that the cholesterol index and non-HDL-C were observed to be positively associated with the prevalence of hypertension (p for trend < 0.05). Moreover, the prevalence of hypertension increased by 3.7% (OR: 1.037; 95% CI: 1.009-1.065; p = 0.009) and 6.1% (OR: 1.06; 95% CI: 1.033–1.091; p < 0.001), respectively, as per 1-standard deviation (SD) increase in the cholesterol index and non-HDL-C. Beyond that, ROC analysis demonstrated that the cholesterol index and non-HDL-C have a good predictive value for the prevalence of hypertension in women, with under the ROC curve (AUC) of 0.659 and 0.684 and cut-off values of 47.94 and 134.34 mg/dl, accordingly.

Conclusions

In Chinese adults without type 2 diabetes mellitus, atherosclerotic indices were significantly higher in hypertensive populations compared with those in normotensive populations, regardless of hypertension levels. Meanwhile, SBP and DBP were linearly and positively related to atherosclerotic indices. Besides, the cholesterol index and non-HDL-C were independent risk factors for the prevalence of hypertension, and they could be adopted for effectively predicting the prevalence of hypertension in women.

Salsalate reduces atherosclerosis through AMPKβ1 in mice

Objective

Salsalate is a prodrug of salicylate that lowers blood glucose in people with type 2 diabetes. AMP-activated protein kinase (AMPK) is an αβγ heterotrimer which inhibits macrophage inflammation and the synthesis of fatty acids and cholesterol in the liver through phosphorylation of acetyl-CoA carboxylase (ACC) and HMG-CoA reductase (HMGCR), respectively. Salicylate binds to and activates AMPKβ1-containing heterotrimers that are highly expressed in both macrophages and liver, but the potential importance of AMPK and ability of salsalate to reduce atherosclerosis have not been evaluated.

Methods

ApoE^−/− and LDLr^−/− mice with or without (−/−) germline or bone marrow AMPKβ1, respectively, were treated with salsalate, and atherosclerotic plaque size was evaluated in serial sections of the aortic root. Studies examining the effects of salicylate on markers of inflammation, fatty acid and cholesterol synthesis and proliferation were conducted in bone marrow–derived macrophages (BMDMs) from wild-type mice or mice lacking AMPKβ1 or the key AMPK-inhibitory phosphorylation sites on ACC (ACC knock-in (KI)-ACC KI) or HMGCR (HMGCR-KI).

Results

Salsalate reduced atherosclerotic plaques in the aortic roots of ApoE^−/− mice, but not ApoE^−/− AMPKβ1^−/− mice. Similarly, salsalate reduced atherosclerosis in LDLr^−/− mice receiving wild-type but not AMPKβ1^−/− bone marrow. Reductions in atherosclerosis by salsalate were associated with reduced macrophage proliferation, reduced plaque lipid content and reduced serum cholesterol. In BMDMs, this suppression of proliferation by salicylate required phosphorylation of HMGCR and the suppression of cholesterol synthesis.

Conclusions

These data indicate that salsalate suppresses macrophage proliferation and atherosclerosis through an AMPKβ1-dependent pathway, which may involve HMGCR phosphorylation and cholesterol synthesis. Since rapidly-proliferating macrophages are a hallmark of atherosclerosis, these data indicate further evaluation of salsalate as a potential therapeutic agent for treating atherosclerotic cardiovascular disease.

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Salsalate (a dimer of salicylate) activates AMPK in macrophages and reduces atherosclerosis.

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Salicylate-induced reductions in atherosclerosis are associated with reduced macrophage proliferation and serum cholesterol.

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AMPK phosphorylation of HMG-CoA reductase is required for suppressing cholesterol synthesis and macrophage proliferation.

Atherogenic indices in clinical practice and biomedical research: A short review

Cardiovascular diseases (CVD) represent a major cause of mortality and morbidity worldwide. To date, many physicians still requesting traditional lipid profile tests (TG, TC, HDL-C, and LDL-C) to confirm the clinical diagnosis related to CVD. However, using these tests may be inadequate for the prediction of CVD risk, especially in intermediate risk. For better clinical practice, laboratory diagnostic alternatives should constantly be evaluated and developed by physicians and laboratory scientists. In this review, we sought to focus on the benefits of lipid ratios (CRI-, CRI-II, AIP, AC, and CHOLindex) in supporting clinical diagnosis and how they can be calculated. To attain this aim, a literature search in reputed databases (PubMed and Scopus) was performed and peer-reviewed research articles were included to conduct this review. Short theoretical and practical notes about each index were accordingly included along with calculation formulas. Thus, the current article can assist new researchers and young physicians to review what supports their knowledge in managing early CVDs.    

The SGLT2 inhibitor canagliflozin suppresses lipid synthesis and interleukin-1 beta in ApoE deficient mice

Sodium-glucose cotransporter 2 inhibitors such as canagliflozin lower blood glucose and reduce cardiovascular events in people with type 2 diabetes through mechanisms that are not fully understood. Canagliflozin has been shown to increase the activity of the AMP-activated protein kinase (AMPK), a metabolic energy sensor important for increasing fatty acid oxidation and energy expenditure and suppressing lipogenesis and inflammation, but whether AMPK activation is important for mediating some of the beneficial metabolic effects of canagliflozin has not been determined. We, therefore, evaluated the effects of canagliflozin in female ApoE-/- and ApoE-/-AMPK β1-/- mice fed a western diet. Canagliflozin increased fatty acid oxidation and energy expenditure and lowered adiposity, blood glucose and the respiratory exchange ratio independently of AMPK β1. Canagliflozin also suppressed liver lipid synthesis and the expression of ATP-citrate lyase, acetyl-CoA carboxylase and sterol response element-binding protein 1c independently of AMPK β1. Canagliflozin lowered circulating IL-1β and studies in bone marrow-derived macrophages indicated that in contrast with the metabolic adaptations, this effect required AMPK β1. Canagliflozin had no effect on the size of atherosclerotic plaques in either ApoE-/- and ApoE-/-AMPK β1-/- mice. Future studies investigating whether reductions in liver lipid synthesis and macrophage IL-1β are important for the cardioprotective effects of canagliflozin warrant further investigation.

Pilates training improves aerobic capacity, but not lipid or lipoprotein levels in elderly women with dyslipidemia: A controlled trial

INTRODUCTION

The aim of the present study was to verify the effects of a Pilates training on total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), glucose and C-reactive protein (CRP) levels, as well as on functionality of postmenopausal women with dyslipidemia.

METHOD

This randomized study involved 35 sedentary women with dyslipidemia, aged between 60 and 75 years. One group participated in a Pilates exercises training with two to four weekly sessions during 10 weeks (Pilates group, n = 20) and the other group did not perform any intervention (control group, n = 6). Biochemical analyses and functionality parameters were measured before and after the 10 weeks.

RESULTS

No significant differences were observed in TC, TG, LDL and HDL for both groups. Regarding glucose and CRP levels, significant reductions were observed in both groups after the intervention period. In functional parameters, both groups significantly increased their 30-s chair stand test values. On the other hand, only the Pilates group presented significant increments in the 6-min walk test (p < 0.05).

CONCLUSION

Pilates training did not change lipid or lipoprotein levels, but improved cardiorespiratory fitness of elderly women with dyslipidemia.

Atherogenic Index of Plasma (AIP) a Tool to Assess Changes in Cardiovascular Disease Risk Post Laparoscopic Sleeve Gastrectomy

Predictive indices like the atherogenic index of plasma (AIP) have been developed to estimate the risk of cardiovascular disease (CVD). Metabolic surgery is the most effective treatment for a rapid improvement of morbid obesity and its comorbidities such as type 2 diabetes (T2D) and CVD. A decreased reoccurrence of CVD after metabolic surgery has been reported by several studies. However, studies utilizing predictive indices for CVD risk in CVD-free morbid-obese patients who undertook laparoscopic sleeve gastrectomy (LSG) are lacking. Here, we use AIP as a tool to evaluate the improvement in CVD risk post-LSG in morbid-obese people who had no history of CVD. Method. We compared baseline, 6- and 12-month post-LSG score of AIP, vascular age, circulating biochemical markers related to CVD in two groups of BMI and age-matched morbid-obese participants with and without T2D. Results. At baseline, people with T2D had significantly higher AIP both, with morbid obesity (0.23 ± 0.06, p < 0.001) and normal weight (0.022 ± 0.05, p < 0.001) compared to their BMI-matched without T2D group. People with morbid obesity had low AIP (-0.083 ± 0.06). Vascular age was significantly higher in people with morbid obesity and T2D (65.8 ± 3.7year, p < 0.0001) compared to morbid obesity (37.9 ± 2.6 year). After one year, AIP was significantly reduced compared to baseline score in people with morbid obesity with/without T2D, respectively (-0.135 ± 0.07, p = 0.003; and -0.36 ± 0.04, p = 0.0002). Conclusion. Our data illuminates AIP as a reliable predictive index for CVD risk in morbid-obese people who had no history of CVD. Moreover, AIP accurately distinguishes between morbid obesity with T2D and morbid obesity and showed a rapid and significant reduction in CVD risk after LSG in people who had no history of CVD. This is a ClinicalTrials.gov registered trial (Reference NCT03038373).

Water-Based Aerobic Training Successfully Improves Lipid Profile of Dyslipidemic Women: A Randomized Controlled Trial

PURPOSE

This study aimed to investigate the effects of water-based aerobic training on the lipid profile and lipoprotein lipase (LPL) levels in premenopausal women with dyslipidemia.

METHOD

Forty women were randomly assigned to: aquatic training (WA; n = 20) or a control group (CG; n = 20). The WA group underwent 12 weeks of water-based interval aerobic training twice a week at intensities ranging from 9 to 15 on the Borg Scale of Perceived Exertion. Total cholesterol (TC), triglycerides (TG), high- (HDL) and low- (LDL) density lipoprotein, TC/HDL ratio, LPL levels, and peak oxygen consumption (VO₂peak) were evaluated before and after 12 weeks in both groups.

RESULTS

The WA group elicited decreases in TC (9%; effect size [ES] = 0.69; 95% CI [0.05, 1.33]), LDL (16%; ES = 0.78; 95% CI [0.13, 1.42]), and the TC/HDL ratio (17%; ES = 1.13; 95% CI [0.46, 1.79]), as well as increases in VO₂peak (10%; ES = 0.64; 95% CI [0.002, 1.27]) and HDL (10%; ES = 0.28; 95% CI [-0.35. 0.90]), without significant changes in TG (ES = 0.16; 95% CI [-0.46, 1.79]) and LPL (ES = 0.36; 95% CI [-0.27, 0.98]) levels. In the CG, no statistically significant changes in any of these variables were found (TC, ES = 0.19, 95% CI [-0.43, 0.82]; LDL, ES = 0.22, 95% CI [-0.40, 0.85]; HDL, ES = 0.05, 95% CI [-0.57, 0.67]; TG, ES = 0.09, 95% CI [-0.53, 0.71]; TC/HDL ratio, ES = 0.20, 95% CI [-0.42, 0.82]; LPL, ES = 0.02, 95% CI [-0.60, 0.64]; VO₂peak, ES = 0.20, 95% CI [-0.42, 0.82]).

CONCLUSION

Water-based interval aerobic training positively affected the lipid profile in premenopausal dyslipidemic women.

Genetics of familial hypercholesterolemia: a tool for development of novel lipid lowering pharmaceuticals?

PURPOSE OF REVIEW

Familial hypercholesterolemia is characterized by high LDL cholesterol and an elevated risk to develop coronary heart disease. Mutations in LDL receptor-mediated cholesterol uptake are the main cause of familial hypercholesterolemia. However, multiple mutations in various other genes are also associated with high LDL cholesterol and even familial hypercholesterolemia. Thus, pharmaceuticals that target these genes and proteins might be attractive treatment options to reduce LDL cholesterol. This review provides an overview of the recent developments and clinical testing of such pharmaceuticals.

RECENT FINDINGS

About 80 genes are associated with hypercholesterolemia but only pharmaceuticals that inhibit cholesteryl ester transfer protein (CETP), angiopoietin-related protein 3 (ANGPTL3), and apolipoprotein C-III (apoC-III) have recently been tested in clinical trials. Inhibition of CETP and ANGPTL3 lowered LDL cholesterol. ANGPTL3 inhibition had the largest effect and was even effective in familial hypercholesterolemia patients. The effect of apoC-III inhibition on LDL cholesterol is not conclusive.

SUMMARY

Of the many potential pharmaceutical targets involved in LDL cholesterol, only a few have been studied so far. Of these, pharmaceuticals that inhibit CETP or ANGPTL3 are promising novel treatment options to reduce LDL cholesterol but the effect of apoC-III inhibition requires more research.

Evaluation of dyslipidemia, lipid ratios, and atherogenic index as cardiovascular risk factors among semi-urban dwellers in Nigeria

Background and Objectives:

The increasing frequency of cardiovascular disease (CVD) rests on the presence of major cardiovascular risk factors including dyslipidemia. This dyslipidemia is also a target for the prevention and treatment of many cardiovascular diseases. Hence, identification of individuals at risk of CVD is needed for early identification and prevention. The study was carried out to evaluate dyslipidemia using the lipid ratios and indices instead of just the conventional lipid profile.

Methodology:

It was a cross-sectional study with 699 participants recruited from semi-urban communities in Nigeria. Anthropometric indices, blood pressure, and fasting lipid profiles were determined. Abnormalities in lipid indices and lipid ratios with atherogenic index were also determined. SPSS software version 17.0 were used for analysis, P < 0.05 was considered statistically significant.

Results:

There were 699 participants with a mean age of 64.45 ± 15.53 years. Elevated total cholesterol, high low-density lipoprotein-cholesterol, elevated triglyceride, and low high-density lipoprotein were seen in 5.3%, 19.3%, 4.4%, and 76.3% of the participants, respectively. The Castelli's risk index-I (CRI-I) predicted the highest prevalence of predisposition to cardiovascular risk (47.8%) with females being at significantly higher risk (55.2% vs. 29.3%, P < 0.001). Atherogenic coefficient, CRI-II, CHOLIndex, atherogenic index of plasma (AIP) predicted a cardiovascular risk prevalence of 22.5%, 15.9%, 11.2%, and 11.0%, respectively, with no significant difference in between the sexes.

Conclusions:

Serum lipid ratios and AIP may be used in addition to lipid parameters in clinical practice to assess cardiovascular risks even when lipid profiles are apparently normal. AIP was more gender specific amidst the lipid ratios.

Dairy food products: good or bad for cardiometabolic disease?

Prevalence of type 2 diabetes mellitus (T2DM) is rapidly increasingly and is a key risk for CVD development, now recognised as the leading cause of death globally. Dietary strategies to reduce CVD development include reduction of saturated fat intake. Milk and dairy products are the largest contributors to dietary saturated fats in the UK and reduced consumption is often recommended as a strategy for risk reduction. However, overall evidence from prospective cohort studies does not confirm a detrimental association between dairy product consumption and CVD risk. The present review critically evaluates the current evidence on the association between milk and dairy products and risk of CVD, T2DM and the metabolic syndrome (collectively, cardiometabolic disease). The effects of total and individual dairy foods on cardiometabolic risk factors and new information on the effects of the food matrix on reducing fat digestion are also reviewed. It is concluded that a policy to lower SFA intake by reducing dairy food consumption to reduce cardiometabolic disease risk is likely to have limited or possibly negative effects. There remain many uncertainties, including differential effects of different dairy products and those of differing fat content. Focused and suitably designed and powered studies are needed to provide clearer evidence not only of the mechanisms involved, but how they may be beneficially influenced during milk production and processing.

The biological activity of high-density lipoprotein fractions and their role in the development of cardiovascular diseases

Increasing the human plasma concentration of high-density lipoproteins (HDL) may be part of strategy for control of cardiovascular diseases (CVD). HDL particles vary in their structure, metabolism, and biological activity. The review describes major HDL fractions (subpopulations) and discusses new findings on the antiatherogenic properties of HDL particles. The whole spectrum of HDL fractions, small, dense, protein-rich lipoproteins, has atheroprotective properties that are determined by the presence of specialized groups of proteins and lipids; however, this activity may be decreased in atherogenic lesion. Comprehensive structural and compositional analysis of HDL may provide key information to identify the fractions that have characteristic biological properties and lose their functionality in CVD. These fractions may be also biomarkers for the risk of CVD and hence represent pharmacological targets.

Low-density lipoprotein cholesterol in a global cohort of 57,885 statin-treated patients

BACKGROUND AND AIMS

There is an inconsistency between international guidelines on lipid-lowering treatment regarding whether to pursue LDL-C treatment targets or to focus on the intensity of treatment. While either approach is attractive, there is no recent global data on actual LDL-C values, treatment targets attained, and the intensity of treatment in statin-treated patients. We aimed to determine and compare the extent of treatment target attainment globally using standardized data collection.

METHODS

Analyses were based on the Dyslipidemia International Study (DYSIS), a cross-sectional study documenting statin-treated outpatients throughout 30 countries worldwide (across Europe, the Middle East, Canada, Africa, and Asia). Patients were classified as being at very high, high, or non-high cardiovascular risk based on the 2011 European Society of Cardiology (ESC)/European Atherosclerosis Society (EAS) guidelines.

RESULTS

Data were available for a total of 57,885 patients with a median LDL-C value of 98.2 mg/dl (IQR: 76.6, 125.7 mg/dl). Overall, only 26.8% of patients were documented to have attained their risk-based target LDL-C level. Of the 76% of patients who were classified as being at very high risk, only 21.7% attained their LDL-C goal. Globally, the median distance to target was 33.0 mg/dl, ranging from 18.8 to 42.1 mg/dl across countries. We calculated that a further LDL-C reduction of just 10 mg/dl would result in an 11% increase in the proportion of very-high-risk and high-risk patients attaining their target level (9% for non-high risk patients).

CONCLUSIONS

In spite of statin therapy, LDL-C values were high, with a substantial distance to target that was even more pronounced in (very) high risk patients. These results call for the optimization of existing treatment strategies and a collaborative effort to improve the impact of treatment guidance on clinical practice.

Assessment of postprandial triglycerides in clinical practice: Validation in a general population and coronary heart disease patients

BACKGROUND

Previous studies have suggested that for clinical purposes, subjects with fasting triglycerides (TGs) between 89-180 mg/dl (1-2 mmol/l) would benefit from postprandial TGs testing.

OBJECTIVE

To determine the postprandial TG response in 2 independent studies and validate who should benefit diagnostically from an oral-fat tolerance test (OFTT) in clinical practice.

METHODS

A population of 1002 patients with coronary heart disease (CHD) from the CORDIOPREV clinical trial and 1115 white US subjects from the GOLDN study underwent OFTTs. Subjects were classified into 3 groups according to fasting cut points of TGs to predict the usefulness of OFTT: (1) TG < 89 mg/dl (<1 mmol/l); (2) TG, 89-180 mg/dl (1-2 mmol/l); and (3) TG > 180 mg/dl (>2 mmol/l). Postprandial TG concentration at any point > 220 mg/dl (>2.5 mmol/l) has been pre-established as an undesirable postprandial response.

RESULTS

Of the total, 49% patients with CHD and 42% from the general population showed an undesirable response after the OFTT. The prevalence of undesirable postprandial TG in the CORDIOPREV clinical trial was 12.8, 50.3, and 89.7%, in group 1, 2, and 3, respectively (P < .001) and 11.2, 58.1, and 97.5% in group 1, 2, and 3, respectively (P < .001) in the GOLDN study.

CONCLUSIONS

These two studies validate the predictive values reported in a previous consensus. Moreover, the findings of the CORDIOPREV and GOLDN studies show that an OFTT is useful to identify postprandial hyperlipidemia in subjects with fasting TG between 1-2 mmol/l (89-180 mg/dL), because approximately half of them have hidden postprandial hyperlipidemia, which may influence treatment. An OFTT does not provide additional information regarding postprandial hyperlipidemia in subjects with low TG (<1 mmol/l, <89 mg/dL) or increased TG (>2 mmol/l, >180 mg/dl).

Glucagon-like peptide-1, glucagon-like peptide-2, and lipid metabolism

PURPOSE OF REVIEW

Glucagon-like peptide-1 (GLP-1) is the best known incretin hormone able to potentiate glucose-induced insulin secretion. Moreover, GLP-1 is currently under intensive investigation as a potential crucial mediator of beneficial metabolic effects after bariatric surgery, because of its eating inhibitory, antiobesity, and antidiabetes effects. This review briefly summarizes recent findings on the specific effects of GLP-1 on lipoprotein metabolism. The related hormone GLP-2 is derived from the same precursor gene; its effects on lipoprotein metabolism will also be discussed briefly.

RECENT FINDINGS

Pharmacological activation of the GLP-1 system has beneficial effects on obesity-induced alterations of lipoprotein metabolism. These benefits can be observed with direct GLP-1 receptor agonists like liraglutide or exendin-4, but also with inhibitors of dipeptidyl peptidase IV (DPP-IV), which reduce the breakdown of endogenous GLP-1. The role of GLP-2-related pathways on lipid levels and metabolism are less clear, but some effects (e.g. increased intestinal chylomicron output) are opposite to GLP-1.

SUMMARY

Activation of the GLP-1-dependent pathways may perhaps translate into a lower cardiovascular risk. Understanding how GLP-1 and GLP-2 regulate and interact in the control of lipoprotein metabolism will set the stage for the development of new strategies to treat dyslipidaemia in obesity, diabetes, and other cardiometabolic diseases.

Hepatic Transmembrane 6 Superfamily Member 2 Regulates Cholesterol Metabolism in Mice

BACKGROUND & AIMS

The rs58542926 C>T variant of the transmembrane 6 superfamily member 2 gene (TM6SF2), encoding an E167K amino acid substitution, has been correlated with reduced total cholesterol (TC) and cardiovascular disease. However, little is known about the role of TM6SF2 in metabolism. We investigated the long-term effects of altered TM6SF2 levels in cholesterol metabolism.

METHODS

C57BL/6 mice (controls), mice that expressed TM6SF2 specifically in the liver, and mice with CRISPR/Cas9-mediated knockout of Tm6sf2 were fed chow or high-fat diets. Blood samples were collected from all mice and plasma levels of TC, low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol, and triglycerides were measured. Liver tissues were collected and analyzed by histology, real-time polymerase chain reaction, and immunoblot assays. Adenovirus vectors were used to express transgenes in cultured Hep3B hepatocytes.

RESULTS

Liver-specific expression of TM6SF2 increased plasma levels of TC and LDL-c, compared with controls, and altered liver expression of genes that regulate cholesterol metabolism. Tm6sf2-knockout mice had decreased plasma levels of TC and LDL-c, compared with controls, and consistent changes in expression of genes that regulate cholesterol metabolism. Expression of TM6SF2 promoted cholesterol biosynthesis in hepatocytes.

CONCLUSIONS

TM6SF2 regulates cholesterol metabolism in mice and might be a therapeutic target for cardiovascular disease.

Camphene, a Plant Derived Monoterpene, Exerts Its Hypolipidemic Action by Affecting SREBP-1 and MTP Expression

The control of hyperlipidemia plays a central role in cardiovascular disease. Previously, we have shown that camphene, a constituent of mastic gum oil, lowers cholesterol and triglycerides (TG) in the plasma of hyperlipidemic rats without affecting HMG-CoA reductase activity, suggesting that its hypocholesterolemic and hypotriglyceridemic effects are associated with a mechanism of action different than that of statins. In the present study, we examine the mechanism by which camphene exerts its hypolipidemic action. We evaluated the effect of camphene on the de novo synthesis of cholesterol and TG from [14C]-acetate in HepG2 cells, along with the statin mevinolin. Camphene inhibited the biosynthesis of cholesterol in a concentration-dependent manner, and a maximal inhibition of 39% was observed at 100 μM while mevinolin nearly abolished cholesterol biosynthesis. Moreover, treatment with camphene reduced TG by 34% and increased apolipoprotein AI expression. In contrast, mevinolin increased TG by 26% and had a modest effect on apolipoprotein AI expression. To evaluate the mode of action of camphene, we examined its effects on the expression of SREBP-1, which affects TG biosynthesis and SREBP-2, which mostly affects sterol synthesis. Interestingly, camphene increased the nuclear translocation of the mature form of SREBP-1 while mevinolin was found to increase the amount of the mature form of SREBP-2. The effect of camphene is most likely regulated through SREBP-1 by affecting MTP levels in response to a decrease in the intracellular cholesterol. We propose that camphene upregulates SREBP-1 expression and MTP inhibition is likely to be a probable mechanism whereby camphene exerts its hypolipidemic effect.

Global Overview of the Epidemiology of Atherosclerotic Cardiovascular Disease

Atherosclerotic cardiovascular disease (ACD) is the leading cause of mortality worldwide. The objective of this paper is to provide an overview of the global burden of ACD and its risk factors and to discuss the main challenges and opportunities for prevention. Publicly available data from the Global Burden of Disease Study were analyzed for ischemic heart disease (IHD), ischemic stroke and ACD risk factors. Data from the WHO Global Health Observatory were used to describe prevalence of diverse cardiometabolic risk factors. World Bank Gross Domestic Product per capita (GDPc) information was used to categorize countries according to income level. Cardiovascular mortality decreased globally from 1990-2010 with important differences by GDPc; during 1990 there was a positive association between IHD mortality and GDPc. Higher-income countries had higher rates compared to those of lower-income countries. High levels of body mass index (BMI), blood pressure, glucose and cholesterol have a differential contribution to mortality by income group over time; high-income countries have been able to reduce the contribution from these risk factors in the last 20 years, whereas lower/middle income countries show an increasing trend in mortality attributable to high BMI and glucose. Although age-adjusted ACD mortality rate trends decreased globally, the absolute number of ACD deaths is increasing in part due to the growth of the population and aging, as well as to important lifestyle and food-system changes that likely attenuate gains in prevention. Population and individual level preventable causes of ACD must be aggressively and efficiently targeted in countries of lower economic development in order to reduce the growing burden of disease due to ACD.

Innovative pharmaceutical interventions in cardiovascular disease: Focusing on the contribution of non-HDL-C/LDL-C-lowering versus HDL-C-raising: A systematic review and meta-analysis of relevant preclinical studies and clinical trials

Non-HDL-cholesterol is well recognised as a primary causal risk factor in cardiovascular disease. However, despite consistent epidemiological evidence for an inverse association between HDL-C and coronary heart disease, clinical trials aimed at raising HDL-C (AIM-HIGH, HPS2-THRIVE, dal-OUTCOMES) failed to meet their primary goals. This systematic review and meta-analysis investigated the effects of established and novel treatment strategies, specifically targeting HDL, on inhibition of atherosclerosis in cholesteryl ester transfer protein-expressing animals, and the prevention of clinical events in randomised controlled trials. Linear regression analyses using data from preclinical studies revealed associations for TC and non-HDL-C and lesion area (R(2)=0.258, P=0.045; R(2)=0.760, P<0.001), but not for HDL-C (R(2)=0.030, P=0.556). In clinical trials, non-fatal myocardial infarction risk was significantly less in the treatment group with pooled odd ratios of 0.87 [0.81; 0.94] for all trials and 0.85 [0.78; 0.93] after excluding some trials due to off-target adverse events, whereas all-cause mortality was not affected (OR 1.05 [0.99-1.10]). Meta-regression analyses revealed a trend towards an association between between-group differences in absolute change from baseline in LDL-C and non-fatal myocardial infarction (P=0.066), whereas no correlation was found for HDL-C (P=0.955). We conclude that the protective role of lowering LDL-C and non-HDL-C is well-established. The contribution of raising HDL-C on inhibition of atherosclerosis and the prevention of cardiovascular disease remains undefined and may be dependent on the mode of action of HDL-C-modification. Nonetheless, treatment strategies aimed at improving HDL function and raising apolipoprotein A-I may be worth exploring.

Methyl-γ-butyrobetaine decreases levels of acylcarnitines and attenuates the development of atherosclerosis

OBJECTIVE

The elevation of the levels of l-carnitine and its fatty acid esters, acylcarnitines, in tissue or plasma has been linked to the development of atherosclerosis. Recently, a potent inhibitor of l-carnitine biosynthesis and transport, methyl-γ-butyrobetaine (methyl-GBB), was discovered. In this study, we evaluated the effects of γ-butyrobetaine (GBB), l-carnitine and methyl-GBB administration on the progression of atherosclerosis.

METHODS

Apolipoprotein E knockout (apoE(-/-)) mice were treated with methyl-GBB, l-carnitine or GBB for 4months. Following the treatment, the amount of atherosclerotic lesions, the number of immune cells in atherosclerotic lesions and the plasma lipid profile were analysed. The l-carnitine and acylcarnitine levels were determined in the aortic tissues of CD-1 outbred mice 2weeks after treatment with methyl-GBB at the dose of 10mg/kg.

RESULTS

Treatment with methyl-GBB decreased the acylcarnitine and l-carnitine levels in the aortic tissues by seventeen- and ten-fold, respectively. Methyl-GBB treatment at a dose of 10mg/kg reduced the size of atherosclerotic plaques by 36%. Neither l-carnitine nor GBB treatment affected the development of atherosclerosis.

CONCLUSIONS

Methyl-GBB administration significantly attenuated the development of atherosclerosis in apoE(-/-)mice. Our results demonstrate that decreasing the acylcarnitine pools can attenuate the development of atherosclerosis.

Lipids, blood pressure and kidney update 2014

This paper is an effort to review all the most important studies and guidelines in the topics of lipid, blood pressure and kidney published in 2014. Irrespective of advances, the options for improving simultaneous hypercholesterolemia and hypertension management (as well as its complication - chronic kidney disease) remain a problem. Recommending hypolidemic, hypotensive and kidney disease drugs to obtain therapy targets in cardiovascular, diabetic, elderly and kidney disease (=high risk) patients might strengthen risk factor control, improve compliance and the therapy efficacy, and in the consequence reduce the risk of cardiovascular events and mortality rate. That is why the authors have decided to summary and discuss the recent scientific achievements in the field of lipid, blood pressure and kidney.

Amyloid-Forming Properties of Human Apolipoproteins: Sequence Analyses and Structural Insights

Apolipoproteins are protein constituents of lipoproteins that transport cholesterol and fat in circulation and are central to cardiovascular health and disease. Soluble apolipoproteins can transiently dissociate from the lipoprotein surface in a labile free form that can misfold, potentially leading to amyloid disease. Misfolding of apoA-I, apoA-II, and serum amyloid A (SAA) causes systemic amyloidoses, apoE4 is a critical risk factor in Alzheimer's disease, and apolipoprotein misfolding is also implicated in cardiovascular disease. To explain why apolipoproteins are over-represented in amyloidoses, it was proposed that the amphipathic α-helices, which form the lipid surface-binding motif in this protein family, have high amyloid-forming propensity. Here, we use 12 sequence-based bioinformatics approaches to assess amyloid-forming potential of human apolipoproteins and to identify segments that are likely to initiate β-aggregation. Mapping such segments on the available atomic structures of apolipoproteins helps explain why some of them readily form amyloid while others do not. Our analysis shows that nearly all amyloidogenic segments: (i) are largely hydrophobic, (ii) are located in the lipid-binding amphipathic α-helices in the native structures of soluble apolipoproteins, (iii) are predicted in both native α-helices and β-sheets in the insoluble apoB, and (iv) are predicted to form parallel in-register β-sheet in amyloid. Most of these predictions have been verified experimentally for apoC-II, apoA-I, apoA-II and SAA. Surprisingly, the rank order of the amino acid sequence propensity to form amyloid (apoB>apoA-II>apoC-II≥apoA-I, apoC-III, SAA, apoC-I>apoA-IV, apoA-V, apoE) does not correlate with the proteins' involvement in amyloidosis. Rather, it correlates directly with the strength of the protein-lipid association, which increases with increasing protein hydrophobicity. Therefore, the lipid surface-binding function and the amyloid-forming propensity are both rooted in apolipoproteins' hydrophobicity, suggesting that functional constraints make it difficult to completely eliminate pathogenic apolipoprotein misfolding. We propose that apolipoproteins have evolved protective mechanisms against misfolding, such as the sequestration of the amyloidogenic segments via the native protein-lipid and protein-protein interactions involving amphipathic α-helices and, in case of apoB, β-sheets.

Reducing elevated plasma LDL cholesterol: the central role of the LDL receptor

Elevated low-density lipoprotein cholesterol (LDL-C) is an established risk factor for cardiovascular disease (CVD), and reduction of elevated LDL-C reduces mortality in patients at risk. This benefit has evolved from the use of statins and knowledge of the LDL receptor (LDLR). The most potent drugs used for dyslipidemias act by mechanisms that involve this receptor. Advances in molecular genetics and understanding of the regulation of this receptor have revealed several pharmacological targets that are being explored to develop more targeted therapies for dyslipidemias.