Coronary artery disease risk in familial combined hyperlipidemia and familial hypertriglyceridemia: a case-control comparison from the National Heart, Lung, and Blood Institute Family Heart Study

Current Data and New Insights into the Genetic Factors of Atherogenic Dyslipidemia Associated with Metabolic Syndrome

Atherogenic dyslipidemia plays a critical role in the development of metabolic syndrome (MetS), being one of its major components, along with central obesity, insulin resistance, and hypertension. In recent years, the development of molecular genetics techniques and extended analysis at the genome or exome level has led to important progress in the identification of genetic factors (heritability) involved in lipid metabolism disorders associated with MetS. In this review, we have proposed to present the current knowledge related to the genetic etiology of atherogenic dyslipidemia, but also possible challenges for future studies. Data from the literature provided by candidate gene-based association studies or extended studies, such as genome-wide association studies (GWAS) and whole exome sequencing (WES,) have revealed that atherogenic dyslipidemia presents a marked genetic heterogeneity (monogenic or complex, multifactorial). Despite sustained efforts, many of the genetic factors still remain unidentified (missing heritability). In the future, the identification of new genes and the molecular mechanisms by which they intervene in lipid disorders will allow the development of innovative therapies that act on specific targets. In addition, the use of polygenic risk scores (PRS) or specific biomarkers to identify individuals at increased risk of atherogenic dyslipidemia and/or other components of MetS will allow effective preventive measures and personalized therapy.

Association of TCF7L2 Variants in Type 2 Diabetes Mellitus with Hypertriglyceridemia - A Case-Control Study

Background

Type 2 Diabetes Mellitus (T2DM) is a chronic metabolic condition involving various genetic and environmental factors leading to impaired insulin secretion, resulting in hyperglycemia. The transcription factor 7-like 2 (TCF7L2) gene is an element of the Wnt signaling pathway that plays an important role in glucose and lipid metabolism. The aim of this study is to evaluate the association of TCF7L2 rs7903146 and rs12255372 polymorphisms in T2DM with hypertriglyceridemia.

Methods

We investigated the effect of rs7903146 and rs12255372 on T2DM with high triglyceride (TG) levels in 60 patients and 20 controls. The anthropometric measurements and biochemical tests were assessed. Peripheral blood samples were collected, and genomic DNA was extracted. The genotyping of TCF7L2 polymorphisms was carried out using polymerase chain reaction (PCR)-based direct sequencing and allele-specific PCR methods. The T2DM patients and controls were compared by means of the t-test, Chi-square test, odds ratio (OR), and 95% confidence interval (CI) using Epi Info v7.

Results

The HbA1c was found to be 9.7 ± 2.1 and 5.4 ± 0.5% in patients and controls, respectively. The average TG levels (P < 0.005) in patients were 205.2 ± 145.7 and 106.4 ± 27.4mg/dl in controls. Significant evidence of association was found in T2DM patients having high TG levels with rs7903146 CT/TT (OR: 4.89; P = 0.0105) and rs12255372 GT/TT (OR: 5.23; P = 0.0101) genotypes when compared to controls.

Conclusion

The results of this study show that TCF7L2 rs7903146 CT/TT and rs12255372 GT/TT genotypes are significantly associated with the risk of hypertriglyceridemia in individuals with T2DM among the studied population.

The clinical utility of polygenic risk scores for combined hyperlipidemia

PURPOSE OF REVIEW

Combined hyperlipidemia is the most common lipid disorder and is strongly polygenic. Given its prevalence and associated risk for atherosclerotic cardiovascular disease, this review describes the potential for utilizing polygenic risk scores for risk prediction and management of combined hyperlipidemia.

RECENT FINDINGS

Different diagnostic criteria have led to inconsistent prevalence estimates and missed diagnoses. Given that individuals with combined hyperlipidemia have risk estimates for incident coronary artery disease similar to individuals with familial hypercholesterolemia, early identification and therapeutic management of those affected is crucial. With diagnostic criteria including traits such apolipoprotein B, low-density lipoprotein cholesterol, and triglyceride, polygenic risk scores for these traits strongly associate with combined hyperlipidemia and could be used in combination for clinical risk prediction models and developing specific treatment plans for patients.

SUMMARY

Polygenic risk scores are effective tools in risk prediction of combined hyperlipidemia, can provide insight into disease pathophysiology, and may be useful in managing and guiding treatment plans for patients. However, efforts to ensure equitable polygenic risk score performance across different genetic ancestry groups is necessary before clinical implementation in order to prevent the exacerbation of racial disparities in the clinic.

The Inherited Hypercholesterolemias

Inherited hypercholesterolemias include monogenic and polygenic disorders, which can be very rare (eg, cerebrotendinous xanthomatosis (CTX)) or relatively common (eg, familial combined hyperlipidemia [FCH]). In this review, we discuss familial hypercholesterolemia (FH), FH-mimics (eg, polygenic hypercholesterolemia [PH], FCH, sitosterolemia), and other inherited forms of hypercholesterolemia (eg, hyper-lipoprotein(a) levels [hyper-Lp(a)]). The prevalence, genetics, and management of inherited hypercholesterolemias are described and selected guidelines summarized.

Signature pattern of gene expression and signaling pathway in premature diabetic patients uncover their correlation to early age coronary heart disease

BACKGROUND

Coronary Heart Disease (CHD) is the leading cause of death in industrialized countries. There is currently no direct relation between CHD and type 2 diabetes mellitus (T2D), one of the major modifiable risk factors for CHD. This study was carried out for genes expression profiling of T2D associated genes to identify related biological processes/es and modulated signaling pathway/s of male subjects with CHD.

METHOD

the subjects were divided into four groups based on their disease, including control, type 2 diabetes mellitus (T2D), CHD, and CHD + T2D groups. The RNA was extracted from their blood, and RT² Profiler™ PCR Array was utilized to determine gene profiling between groups. Finally, the PCR Array results were validated by using Q-RT-PCR in a more extensive and independent population.

RESULT

PCR Array results revealed that the T2D and T2D + CHD groups shared 11 genes significantly up-regulated in both groups. Further analysis showed that the mRNA levels of AKT2, IL12B, IL6, IRS1, IRS2, MAPK14, and NFKB1 increased. Consequently, the mRNA levels of AQP2, FOXP3, G6PD, and PIK3R1 declined in the T2D + CHD group compared to the T2D group. Furthermore, in silico analysis indicated 36 Gene Ontology terms and 59 signaling pathways were significantly enriched in both groups, which may be a culprit in susceptibility of diabetic patients to CHD development.

CONCLUSION

Finally, the results revealed six genes as a hub gene in altering various biological processes and signaling pathways. The expression trend of these identified genes might be used as potential markers and diagnostic tools for the early identification of the vulnerability of T2D patients to develop premature CHD.

Etiologic Puzzle of Coronary Artery Disease: How Important Is Genetic Component?

In the modern era, coronary artery disease (CAD) has become the most common form of heart disease and, due to the severity of its clinical manifestations and its acute complications, is a major cause of morbidity and mortality worldwide. The phenotypic variability of CAD is correlated with the complex etiology, multifactorial (caused by the interaction of genetic and environmental factors) but also monogenic. The purpose of this review is to present the genetic factors involved in the etiology of CAD and their relationship to the pathogenic mechanisms of the disease. Method: we analyzed data from the literature, starting with candidate gene-based association studies, then continuing with extensive association studies such as Genome-Wide Association Studies (GWAS) and Whole Exome Sequencing (WES). The results of these studies revealed that the number of genetic factors involved in CAD etiology is impressive. The identification of new genetic factors through GWASs offers new perspectives on understanding the complex pathophysiological mechanisms that determine CAD. In conclusion, deciphering the genetic architecture of CAD by extended genomic analysis (GWAS/WES) will establish new therapeutic targets and lead to the development of new treatments. The identification of individuals at high risk for CAD using polygenic risk scores (PRS) will allow early prophylactic measures and personalized therapy to improve their prognosis.

Genetic Lipid Disorders Associated with Atherosclerotic Cardiovascular Disease: Molecular Basis to Clinical Diagnosis and Epidemiologic Burden

Genetic lipid disorders, ranging from common dyslipidemias such as familial hypercholesterolemia, lipoprotein (a), and familial combined hyperlipidemia to rare disorders including familial chylomicronemia syndrome and inherited hypoalphalipoproteinemias (ie, Tangier and fish eye diseases), affect millions of individuals in the United States and tens of millions around the world and are often undiagnosed in the general population. Clinicians should take into consideration the potential of inherited lipid disorders or syndromes when severe derangements in lipid parameters are observed. Patients' combined genotype and phenotype should be evaluated in conjunction with a host of environmental factors impacting their risk of atherosclerotic cardiovascular disease.

Polygenic architecture and cardiovascular risk of familial combined hyperlipidemia

BACKGROUND AND AIMS

Familial combined hyperlipidemia (FCHL) is one of the most common inherited lipid phenotypes, characterized by elevated plasma concentrations of apolipoprotein B-100 and triglycerides. The genetic inheritance of FCHL remains poorly understood. The goals of this study were to investigate the polygenetic architecture and cardiovascular risk associated with FCHL.

METHODS AND RESULTS

We identified individuals with an FCHL phenotype among 349,222 unrelated participants of European ancestry in the UK Biobank using modified versions of 5 different diagnostic criteria. The prevalence of the FCHL phenotype was 11.44% (n = 39,961), 5.01% (n = 17,485), 1.48% (n = 5,153), 1.10% (n = 3,838), and 0.48% (n = 1,688) according to modified versions of the Consensus Conference, Dutch, Mexico, Brunzell, and Goldstein criteria, respectively. We performed discovery, case-control genome-wide association studies for these different FCHL criteria and identified 175 independent loci associated with FCHL at genome-wide significance. We investigated the association of genetic and clinical risk with FCHL and found that polygenic susceptibility to hypercholesterolemia or hypertriglyceridemia and features of metabolic syndrome were associated with greater prevalence of FCHL. Participants with an FCHL phenotype had a similar risk of incident coronary artery disease compared to participants with monogenic familial hypercholesterolemia (adjusted hazard ratio vs controls [95% confidence interval]: 2.72 [2.31-3.21] and 1.90 [1.30-2.78]).

CONCLUSIONS

These results suggest that, rather than being a single genetic entity, the FCHL phenotype represents a polygenic susceptibility to dyslipidemia in combination with metabolic abnormalities. The cardiovascular risk associated with an FCHL phenotype is similar to that of monogenic familial hypercholesterolemia, despite being ∼5x more common.

Familial Hypercholesterolemia, Familial Combined Hyperlipidemia, and Elevated Lipoprotein(a) in Patients With Premature Coronary Artery Disease

BACKGROUND

Familial hypercholesterolemia (FH), familial combined hyperlipidemia (FCHL), and elevated lipoprotein (a) (Lp[a]) increase risk of premature coronary artery disease (CAD). The objective of this study was to assess the prevalence of FH, FCHL, elevated Lp(a) and their impact on management in patients with premature CAD.

METHODS

We prospectively recruited men ≤ 50 years and women ≤ 55 with obstructive CAD. FH was defined as Dutch Lipid Clinic Network scores ≥ 6. FCHL was defined as apolipoprotein B > 1.2 g/L, triglyceride and total cholesterol > 90th population percentile, and family history of premature cardiovascular disease. Lp(a) ≥ 50 mg/dL was considered to be elevated.

RESULTS

Among 263 participants, 9.1% met criteria for FH, 12.5% for FCHL, and 19.4% had elevated Lp(a). Among patients with FH, 37.5% had FH-causing DNA variants. Patients with FH, but not other dyslipidemias, were more likely than nondyslipidemic patients to have received lipid-lowering therapy before presenting with CAD (33.3% vs 12.3%, P = 0.04) and combined lipid-lowering therapy after the presentation (41.7% vs 7.7%, P < 0.001). One year after presentation, 58.3%, 54.5%, and 58.8% of patients with FH, FCHL, and elevated Lp(a) had low-density lipoprotein cholesterol (LDL-C) < 1.8 mmol/L, respectively, compared with 68.0 % in reference group. Patients with FCHL were more likely to have non-high-density lipoprotein (HDL) and apolipoprotein B above recommended lipid goals (70.0% and 87.9%, respectively).

CONCLUSIONS

FH, FCHL, and elevated Lp(a) are common in patients with premature CAD and have differing impact on treatment and achievement of lipid targets. Assessment for these conditions in patients with premature CAD provides valuable information for individualized management.

Polysaccharide MCP extracted from Morchella esculenta reduces atherosclerosis in LDLR-deficient mice

The pharmaceutical application of fungal polysaccharides has been extensively studied based on their multiple biological activities. However, the effect of Morchella esculenta polysaccharides on the development of atherosclerosis remains unknown. This study aims to investigate the anti-atherosclerotic effect of a novel polysaccharide (MCP) extracted from Morchella esculenta. The average molecular weight of MCP is 1.69 × 10⁵ Da, and it is composed of glucose, mannose and galactose in the molar ratio of 1 : 1.9 : 0.51. LDLR-deficient (LDLR^-/-) mice were fed high-fat diet (HFD) and administered intragastrically (i.g.) with saline or MCP dissolved in saline for 15 weeks. We found that MCP inhibited en face and sinus lesions. Moreover, serum levels of total and low-density lipoprotein cholesterol and triglyceride were decreased by MCP. The HFD-induced hepatic lipid accumulation was also attenuated by MCP. The underlying molecular mechanisms of anti-atherogenic and lipogenic effects of MCP might be attributed to reduced cholesterol synthesis by activating AMPKα signaling pathway and inhibiting SREBP2 expression. In addition, MCP-decreased serum triglyceride level is related to inhibiting LXRα expression. Taken together, these results indicate that MCP markedly alleviates atherosclerosis and M. esculenta can be used as a functional food additive to benefit patients with atherosclerosis.

Triglyceride-lowering and anti-inflammatory mechanisms of omega-3 polyunsaturated fatty acids for atherosclerotic cardiovascular risk reduction

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of death globally. Omega-3 polyunsaturated fatty acids (PUFAs) including eicosapentaenoic acid and docosahexaenoic acid have been extensively studied as both dietary supplement and pharmaceutical agent for the prevention of ASCVD. Epidemiological and retrospective studies have long shown the inverse relationship of omega-3 PUFA consumption and ASCVD event but results of previous large randomized controlled trials have not consistently shown the same effect. Meta-analysis and a recent clinical trial using a high dose of eicosapentaenoic acid showed convincing protective effects of omega-3 PUFAs on ASCVD. Emerging evidence shows that both chronic inflammation and hypertriglyceridemia increase the risk of atherosclerosis. Amelioration of the inflammatory process and reduction of hypertriglyceridemia provide two mechanisms on the prevention and management of ASCVD, and agents with both of these effects are more potent and desirable. Omega-3 PUFAs exert anti-hypertriglyceridemia effect, ameliorate inflammation, and maintain the resolution of inflammation homeostasis pleiotropically through multiple molecular and cellular mechanisms. This review presents the pathophysiology of atherosclerosis, the mechanisms of omega-3 PUFAs on the reduction of the atherosclerotic risk, and the current clinical utilities of omega-3 PUFAs on the prevention of ASCVD.

Exploration of Blood Lipoprotein and Lipid Fraction Profiles in Healthy Subjects through Integrated Univariate, Multivariate, and Network Analysis Reveals Association of Lipase Activity and Cholesterol Esterification with Sex and Age

In this study, we investigated blood lipoprotein and lipid fraction profiles, quantified using nuclear magnetic resonance, in a cohort of 844 healthy blood donors, integrating standard univariate and multivariate analysis with predictive modeling and network analysis. We observed a strong association of lipoprotein and lipid main fraction profiles with sex and age. Our results suggest an age-dependent remodulation of lipase lipoprotein activity in men and a change in the mechanisms controlling the ratio between esterified and non-esterified cholesterol in both men and women.

Familial combined hyperlipidaemia/polygenic mixed hyperlipidaemia

Familial combined hyperlipidaemia (FCH) is the most prevalent form of familial hyperlipidaemia with a multigenic origin and a complex pattern of inheritance. In this respect, FCH is an oligogenic primary lipid disorder due to interaction of genetic variants and mutations with environmental factors. Patients with FCH are at increased risk of cardiovascular disease and often have other associated metabolic conditions. Despite its relevance in cardiovascular prevention, FCH is frequently underdiagnosed and very often undertreated. In this review, emphasis is placed on the most recent advances in FCH, in order to increase its awareness and ultimately contribute to improving its clinical control.

Intracoronary monocyte expression pattern and HDL subfractions after non-ST elevation myocardial infarction

AIMS

Coronary artery disease (CAD) is described as a range of clinical conditions including myocardial infarction (MI) and unstable angina. Lipid and apolipoprotein profiles together with the study of cholesterol deposit and efflux serve to identify novel pre and post infarct scenarios for the treatment of these patients. In (non-ST elevation myocardial infarction) NSTEMI patients, we analysed both systemic and intracoronary serum ability to accept cholesterol as well as cholesterol efflux capacity (CEC) of monocytes in terms of expression of genes involved in the reverse cholesterol transport (RCT).

METHODS AND RESULTS

While HDL-C quantity was similar between systemic and coronary arterial blood, in 21 NSTEMI patients we observed a significant reduction of the preβ-HDL fraction and the levels of Apolipoproteins AI, AII, B and E in coronary versus systemic serum. These data are complemented with the observed reduction of CEC. On the contrary, compared to systemic arterial monocytes, in coronary microenvironment of NSTEMI patients after myocardial infarction, the monocytes exhibited a higher mRNA expression of nuclear receptor LXRα and its targets ABCA1 and APOE, which drive cholesterol efflux capacity.

CONCLUSION

In this cross-sectional study we observe that in the immediate post infarction period, there is a spontaneous bona fide ligand-induced activation of the LXR driven cholesterol efflux capacity of intracoronary monocytes to overcome the reduced serum ability to accept cholesterol and to inhibit the post-infarction pro-inflammatory local microenvironment.

Familial hypertriglyceridemia: an entity with distinguishable features from other causes of hypertriglyceridemia

BACKGROUND

Familial hypertriglyceridemia (FHTG) is a partially characterized primary dyslipidemia which is frequently confused with other forms hypertriglyceridemia. The aim of this work is to search for specific features that can help physicians recognize this disease.

METHODS

This study included 84 FHTG cases, 728 subjects with common mild-to-moderate hypertriglyceridemia (CHTG) and 609 normotriglyceridemic controls. All subjects underwent genetic, clinical and biochemical assessments. A set of 53 single nucleotide polymorphisms (SNPs) previously associated with triglycerides levels, as well as 37 rare variants within the five main genes associated with hypertriglyceridemia (i.e. LPL, APOC2, APOA5, LMF1 and GPIHBP1) were analyzed. A panel of endocrine regulatory proteins associated with triglycerides homeostasis were compared between the FHTG and CHTG groups.

RESULTS

Apolipoprotein B, fibroblast growth factor 21(FGF-21), angiopoietin-like proteins 3 (ANGPTL3) and apolipoprotein A-II concentrations, were independent components of a model to detect FHTG compared with CHTG (AUC 0.948, 95%CI 0.901-0.970, 98.5% sensitivity, 92.2% specificity, P < 0.001). The polygenic set of SNPs, accounted for 1.78% of the variance in triglyceride levels in FHTG and 6.73% in CHTG.

CONCLUSIONS

The clinical and genetic differences observed between FHTG and CHTG supports the notion that FHTG is a unique entity, distinguishable from other causes of hypertriglyceridemia by the higher concentrations of insulin, FGF-21, ANGPTL3, apo A-II and lower levels of apo B. We propose the inclusion of these parameters as useful markers for differentiating FHTG from other causes of hypertriglyceridemia.

Management of hypertriglyceridemia

Hypertriglyceridemia is one of the most common lipid abnormalities encountered in clinical practice. Many monogenic disorders causing severe hypertriglyceridemia have been identified, but in most patients triglyceride elevations result from a combination of multiple genetic variations with small effects and environmental factors. Common secondary causes include obesity, uncontrolled diabetes, alcohol misuse, and various commonly used drugs. Correcting these factors and optimizing lifestyle choices, including dietary modification, is important before starting drug treatment. The goal of drug treatment is to reduce the risk of pancreatitis in patients with severe hypertriglyceridemia and cardiovascular disease in those with moderate hypertriglyceridemia. This review discusses the various genetic and acquired causes of hypertriglyceridemia, as well as current management strategies. Evidence supporting the different drug and non-drug approaches to treating hypertriglyceridemia is examined, and an easy to adopt step-by-step management strategy is presented.

Familial combined hyperlipidemia: An overview of the underlying molecular mechanisms and therapeutic strategies

Among different types of dyslipidemia, familial combined hyperlipidemia (FCHL) is the most common genetic disorder, which is characterized by at least two different forms of lipid abnormalities: hypercholesterolemia and hypertriglyceridemia. FCHL is an important cause of cardiovascular diseases. FCHL is a heterogeneous condition linked with some metabolic defects that are closely associated with FCHL. These metabolic features include dysfunctional adipose tissue, delayed clearance of triglyceride-rich lipoproteins, overproduction of very low-density lipoprotein and hepatic lipids, and defect in the clearance of low-density lipoprotein particles. There are also some genes associated with FCHL such as those affecting the metabolism and clearance of plasma lipoprotein particles. Due to the high prevalence of FCHL especially in cardiovascular patients, targeted treatment is ideal but this necessitates identification of the genetic background of patients. This review describes the metabolic pathways and associated genes that are implicated in FCHL pathogenesis. We also review existing and novel treatment options for FCHL. © 2019 IUBMB Life, 71(9):1221-1229, 2019.

Methylenetetrahydrofolate Reductase Polymorphism and Premature Coronary Artery Disease

Methylenetetrahydrofolate reductase (MTHFR) catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a co-substrate for homocysteine re-methylation to methionine. Its deficiency leads to an increased serum level of homocysteine, which is well-known to be associated with premature coronary artery disease (CAD). Our case demonstrates the association of MTHFR polymorphism with premature CAD and myocardial infarction (MI) despite normal homocysteine levels. Screening for MTHFR polymorphisms in addition to homocysteine levels may be considered for patients presenting with premature CAD and a normal lipid profile. Aggressive risk reduction with lifestyle modifications and guideline-driven medical therapy supplementation might be necessary for secondary cardiovascular disease prevention until more specific therapeutic options are available for this subgroup of patients.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY GUIDELINES FOR MANAGEMENT OF DYSLIPIDEMIA AND PREVENTION OF CARDIOVASCULAR DISEASE

OBJECTIVE

The development of these guidelines is mandated by the American Association of Clinical Endocrinologists (AACE) Board of Directors and American College of Endocrinology (ACE) Board of Trustees and adheres with published AACE protocols for the standardized production of clinical practice guidelines (CPGs).

METHODS

Recommendations are based on diligent reviews of the clinical evidence with transparent incorporation of subjective factors, according to established AACE/ACE guidelines for guidelines protocols.

RESULTS

The Executive Summary of this document contains 87 recommendations of which 45 are Grade A (51.7%), 18 are Grade B (20.7%), 15 are Grade C (17.2%), and 9 (10.3%) are Grade D. These detailed, evidence-based recommendations allow for nuance-based clinical decision-making that addresses multiple aspects of real-world medical care. The evidence base presented in the subsequent Appendix provides relevant supporting information for Executive Summary Recommendations. This update contains 695 citations of which 203 (29.2 %) are EL 1 (strong), 137 (19.7%) are EL 2 (intermediate), 119 (17.1%) are EL 3 (weak), and 236 (34.0%) are EL 4 (no clinical evidence).

CONCLUSION

This CPG is a practical tool that endocrinologists, other health care professionals, health-related organizations, and regulatory bodies can use to reduce the risks and consequences of dyslipidemia. It provides guidance on screening, risk assessment, and treatment recommendations for a range of individuals with various lipid disorders. The recommendations emphasize the importance of treating low-density lipoprotein cholesterol (LDL-C) in some individuals to lower goals than previously endorsed and support the measurement of coronary artery calcium scores and inflammatory markers to help stratify risk. Special consideration is given to individuals with diabetes, familial hypercholesterolemia, women, and youth with dyslipidemia. Both clinical and cost-effectiveness data are provided to support treatment decisions.

ABBREVIATIONS

4S = Scandinavian Simvastatin Survival Study A1C = glycated hemoglobin AACE = American Association of Clinical Endocrinologists AAP = American Academy of Pediatrics ACC = American College of Cardiology ACE = American College of Endocrinology ACS = acute coronary syndrome ADMIT = Arterial Disease Multiple Intervention Trial ADVENT = Assessment of Diabetes Control and Evaluation of the Efficacy of Niaspan Trial AFCAPS/TexCAPS = Air Force/Texas Coronary Atherosclerosis Prevention Study AHA = American Heart Association AHRQ = Agency for Healthcare Research and Quality AIM-HIGH = Atherothrombosis Intervention in Metabolic Syndrome With Low HDL/High Triglycerides trial ASCVD = atherosclerotic cardiovascular disease ATP = Adult Treatment Panel apo = apolipoprotein BEL = best evidence level BIP = Bezafibrate Infarction Prevention trial BMI = body mass index CABG = coronary artery bypass graft CAC = coronary artery calcification CARDS = Collaborative Atorvastatin Diabetes Study CDP = Coronary Drug Project trial CI = confidence interval CIMT = carotid intimal media thickness CKD = chronic kidney disease CPG(s) = clinical practice guideline(s) CRP = C-reactive protein CTT = Cholesterol Treatment Trialists CV = cerebrovascular CVA = cerebrovascular accident EL = evidence level FH = familial hypercholesterolemia FIELD = Secondary Endpoints from the Fenofibrate Intervention and Event Lowering in Diabetes trial FOURIER = Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects With Elevated Risk trial HATS = HDL-Atherosclerosis Treatment Study HDL-C = high-density lipoprotein cholesterol HeFH = heterozygous familial hypercholesterolemia HHS = Helsinki Heart Study HIV = human immunodeficiency virus HoFH = homozygous familial hypercholesterolemia HPS = Heart Protection Study HPS2-THRIVE = Treatment of HDL to Reduce the Incidence of Vascular Events trial HR = hazard ratio HRT = hormone replacement therapy hsCRP = high-sensitivity CRP IMPROVE-IT = Improved Reduction of Outcomes: Vytorin Efficacy International Trial IRAS = Insulin Resistance Atherosclerosis Study JUPITER = Justification for the Use of Statins in Primary Prevention: An Intervention Trial Evaluating Rosuvastatin LDL-C = low-density lipoprotein cholesterol Lp-PLA2 = lipoprotein-associated phospholipase A2 MACE = major cardiovascular events MESA = Multi-Ethnic Study of Atherosclerosis MetS = metabolic syndrome MI = myocardial infarction MRFIT = Multiple Risk Factor Intervention Trial NCEP = National Cholesterol Education Program NHLBI = National Heart, Lung, and Blood Institute PCOS = polycystic ovary syndrome PCSK9 = proprotein convertase subtilisin/kexin type 9 Post CABG = Post Coronary Artery Bypass Graft trial PROSPER = Prospective Study of Pravastatin in the Elderly at Risk trial QALY = quality-adjusted life-year ROC = receiver-operator characteristic SOC = standard of care SHARP = Study of Heart and Renal Protection T1DM = type 1 diabetes mellitus T2DM = type 2 diabetes mellitus TG = triglycerides TNT = Treating to New Targets trial VA-HIT = Veterans Affairs High-Density Lipoprotein Cholesterol Intervention Trial VLDL-C = very low-density lipoprotein cholesterol WHI = Women's Health Initiative.

Prevalence of heterozygous familial hypercholesterolemia and combined hyperlipidemia phenotype in very young survivors of myocardial infarction and their association with the severity of atheromatous burden

BACKGROUND

Heterozygous familial hypercholesterolemia (HeFH) and combined hyperlipidemia (CHL) phenotype are associated with premature myocardial infarction (MI).

OBJECTIVE

To assess the prevalence of HeFH and CHL phenotype among young survivors of MI and compare patients' characteristics with these 2 lipid disorders.

METHODS

We recruited 382 young survivors of MI (≤40 years). Fasting lipids, lipoprotein(a) [Lp(a)], apolipoprotein A-1, and apolipoprotein B (apoB) levels were determined. Using the Dutch Lipid Clinic Network (DLCN) algorithm, patients having definite or probable HeFH were identified. Patients with apoB levels >120 mg/dL and triglyceride levels >170 mg/dL (1.92 mmol/L) [>90th percentile of 326 age and sex-matched healthy controls] were classified as having CHL phenotype. Common carotid artery intima-media thickness (CCA-IMT) was measured by B-mode ultrasonography.

RESULTS

Eighty-one patients (21.2%) had definite/probable HeFH and 62 (16.2%) had CHL phenotype. Twenty-three patients fulfilled the criteria for both HeFH and CHL phenotype and were removed from further comparisons. Patients with HeFH (n = 58) had higher levels of total cholesterol, low-density lipoprotein (LDL)-cholesterol, Lp(a), and apoB, whereas patients with CHL phenotype (n = 39) had higher levels of triglycerides and lower high-density lipoprotein (HDL)-cholesterol levels. The prevalence of metabolic syndrome was higher in patients with CHL phenotype compared to those with HeFH (67.0% vs 16.4%, P < .001). Patients with HeFH had more extensive coronary artery disease (3-vessel disease: 36.2% vs 12.8%, P = .011) and greater right CCA-IMT (0.67 ± 0.11 mm vs 0.56 ± 0.09 mm, P < .001) and left CCA-IMT (0.68 ± 0.10 mm vs 0.56 ± 0.08 mm, P < .001) compared to CHL phenotype patients.

CONCLUSIONS

Both HeFH and CHL phenotype are common among patients with premature MI. CHL phenotype compared to HeFH is associated with less atheromatous burden in coronary and carotid arteries at the time of first MI.

Single Nucleotide Variants Associated With Polygenic Hypercholesterolemia in Families Diagnosed Clinically With Familial Hypercholesterolemia

INTRODUCTION AND OBJECTIVES

Approximately 20% to 40% of clinically defined familial hypercholesterolemia cases do not show a causative mutation in candidate genes, and some of them may have a polygenic origin. A cholesterol gene risk score for the diagnosis of polygenic hypercholesterolemia has been demonstrated to be valuable to differentiate polygenic and monogenic hypercholesterolemia. The aim of this study was to determine the contribution to low-density lipoprotein cholesterol (LDL-C) of the single nucleotide variants associated with polygenic hypercholesterolemia in probands with genetic hypercholesterolemia without mutations in candidate genes (nonfamilial hypercholesterolemia genetic hypercholesterolemia) and the genetic score in cascade screening in their family members.

METHODS

We recruited 49 nonfamilial hypercholesterolemia genetic hypercholesterolemia families (294 participants) and calculated cholesterol gene scores, derived from single nucleotide variants in SORT1, APOB, ABCG8, APOE and LDLR and lipoprotein(a) plasma concentration.

RESULTS

Risk alleles in SORT1, ABCG8, APOE, and LDLR showed a statistically significantly higher frequency in blood relatives than in the 1000 Genomes Project. However, there were no differences between affected and nonaffected members. The contribution of the cholesterol gene score to LDL-C was significantly higher in affected than in nonaffected participants (P = .048). The percentage of the LDL-C variation explained by the score was 3.1%, and this percentage increased to 6.9% in those families with the highest genetic score in the proband.

CONCLUSIONS

Nonfamilial hypercholesterolemia genetic hypercholesterolemia families concentrate risk alleles for high LDL-C. Their contribution varies greatly among families, indicating the complexity and heterogeneity of these forms of hypercholesterolemias. The gene score explains a small percentage of LDL-C, which limits its use in diagnosis.

Dysfunctional HDL in diabetes mellitus and its role in the pathogenesis of cardiovascular disease

Coronary artery disease, the leading cause of death in the developed and developing countries, is prevalent in diabetes mellitus with 68% cardiovascular disease (CVD)-related mortality. Epidemiological studies suggested inverse correlation between HDL and CVD occurrence. Therefore, low HDL concentration observed in diabetic patients compared to non-diabetic individuals was thought to be one of the primary causes of increased risks of CVD. Efforts to raise HDL level via CETP inhibitors, Torcetrapib and Dalcetrapib, turned out to be disappointing in outcome studies despite substantial increases in HDL-C, suggesting that factors beyond HDL concentration may be responsible for the increased risks of CVD. Therefore, recent studies have focused more on HDL function than on HDL levels. The metabolic environment in diabetes mellitus condition such as hyperglycemia-induced advanced glycation end products, oxidative stress, and inflammation promote HDL dysfunction leading to greater risks of CVD. This review discusses dysfunctional HDL as one of the mechanisms of increased CVD risks in diabetes mellitus through adversely affecting components that support HDL function in cholesterol efflux and LDL oxidation. The dampening of reverse cholesterol transport, a key process that removes cholesterol from lipid-laden macrophages in the arterial wall, leads to increased risks of CVD in diabetic patients. Therapeutic approaches to keep diabetes under control may benefit patients from developing CVD.

Genotype-guided diagnosis in familial hypercholesterolemia: clinical management and concerns

PURPOSE OF REVIEW

In this review, we examine benefits and concerns associated with genetic testing in the clinical management of familial hypercholesterolemia (FH).

RECENT FINDINGS

Application of next-generation sequencing and other advances provide improved yield of causal mutations compared with older methods and help disclose underlying pathophysiology in many instances. Concerns regarding clinical application of genetic testing remain.

SUMMARY

More widespread application of genetic testing for FH in the USA may be forthcoming. When a genetic cause of FH can be identified or is known for the family, test results can provide more accurate individual diagnosis of FH, clarification of underlying pathophysiology, and greater clinical insight. However, several concerns persist, particularly cost to FH patients, potential discrimination, and inappropriate denial of clinically indicated therapies for patients without definitive genetic testing results.

The effect of preoperative serum triglycerides and high-density lipoprotein-cholesterol levels on the prognosis of breast cancer

OBJECTIVES

Although dyslipidemia has been documented to be associated with several types of cancer including breast cancer, it remains uncertainty the prognostic value of serum lipid in breast cancer. The purpose of this study is to evaluate the association between the preoperative plasma lipid profile and the prognostic of breast cancer patients.

METHODS

The levels of preoperative serum lipid profile (including cholesterol [CHO], Triglycerides [TG], high-density lipoprotein-cholesterol [HDL-C], low-density lipoprotein-cholesterol [LDL-C], apolipoprotein A-I [ApoAI], and apolipoprotein B [ApoB]) and the clinical data were retrospectively collected and reviewed in 1044 breast cancer patients undergoing operation. Kaplan-Meier method and the Cox proportional hazards regression model were used in analyzing the overall survival [OS] and disease-free survival [DFS].

RESULTS

Combining the receiver-operating characteristic and Kaplan-Meier analysis, we found that preoperative lower TG and HDL-C level were risk factors of breast cancer patients. In multivariate analyses, a decreased HDL-C level showed significant association with worse OS (HR: 0.528; 95% CI: 0.302-0.923; P = 0.025), whereas a decreased TG level showed significant association with worse DFS (HR: 0.569; 95% CI: 0.370-0.873; P = 0.010).

CONCLUSIONS

Preoperative serum levels of TG and HDL-C may be independent factor to predict outcome in breast cancer patient.

c.*84G>A Mutation in CETP Is Associated with Coronary Artery Disease in South Indians

BACKGROUND

Coronary artery disease (CAD) is one of the leading causes of mortality worldwide. It is a multi-factorial disease and several studies have demonstrated that the genetic factors play a major role in CAD. Although variations in cholesteryl ester transfer protein (CETP) gene are reported to be associated with CAD, this gene has not been studied in South Indian populations. Hence we evaluated the CETP gene variations in CAD patients of South Indian origin.

METHODS

We sequenced all the exons, exon-intron boundaries and UTRs of CETP in 323 CAD patients along with 300 ethnically and age matched controls. Variations observed in CETP were subjected to various statistical analyses.

RESULTS AND DISCUSSION

Our analysis revealed a total of 13 variations. Of these, one3'UTRvariant rs1801706 (c.*84G>A) was significantly associated with CAD (genotype association test: OR = 2.16, 95% CI: 1.50-3.10, p = 1.88x10-5 and allelic association test: OR = 1.92, 95% CI: 1.40-2.63, p = 2.57x10-5). Mutant allele "A" was observed to influence the higher concentration of mRNA (p = 7.09×10-3, R2 = 0.029 and β = 0.2163). Since expression of CETP has been shown to be positively correlated with the risk of CAD, higher frequency of "A" allele (patients: 22.69% vs.controls: 13%) reveals that c.*84G>A is a risk factor for CAD in South Indians.

CONCLUSIONS

This is the first report of the CETP gene among South Indians CAD patients. Our results suggest that rs1801706 (c.*84G>A) is a risk factor for CAD in South Indian population.

Progress in the care of common inherited atherogenic disorders of apolipoprotein B metabolism

Familial hypercholesterolaemia, familial combined hyperlipidaemia (FCH) and elevated lipoprotein(a) are common, inherited disorders of apolipoprotein B metabolism that markedly accelerate the onset of atherosclerotic cardiovascular disease (ASCVD). These disorders are frequently encountered in clinical lipidology and need to be accurately identified and treated in both index patients and their family members, to prevent the development of premature ASCVD. The optimal screening strategies depend on the patterns of heritability for each condition. Established therapies are widely used along with lifestyle interventions to regulate levels of circulating lipoproteins. New therapeutic strategies are becoming available, and could supplement traditional approaches in the most severe cases, but their long-term cost-effectiveness and safety have yet to be confirmed. We review contemporary developments in the understanding, detection and care of these highly atherogenic disorders of apolipoprotein B metabolism.

Effect of Hypertriglyceridemia on Beta Cell Mass and Function in ApoC3 Transgenic Mice

Hypertriglyceridemia results from increased production and decreased clearance of triglyceride-rich very low-density lipoproteins, a pathological condition that accounts for heightened risk of ischemic vascular diseases in obesity and type 2 diabetes. Despite its intimate association with insulin resistance, whether hypertriglyceridemia constitutes an independent risk for beta cell dysfunction in diabetes is unknown. Answering this fundamental question is stymied by the fact that hypertriglyceridemia is intertwined with hyperglycemia and insulin resistance in obese and diabetic subjects. To circumvent this limitation, we took advantage of apolipoprotein C3 (ApoC3)-transgenic mice, a model with genetic predisposition to hypertriglyceridemia. We showed that ApoC3-transgenic mice, as opposed to age/sex-matched wild-type littermates, develop hypertriglyceridemia with concomitant elevations in plasma cholesterol and non-esterified fatty acid levels. Anti-insulin and anti-glucagon dual immunohistochemistry in combination with morphometric analysis revealed that ApoC3-transgenic and wild-type littermates had similar beta cell and alpha cell masses as well as islet size and architecture. These effects correlated with similar amplitudes of glucose-stimulated insulin secretion and similar degrees of postprandial glucose excursion in ApoC3-transgenic versus wild-type littermates. Oil Red O histology did not visualize lipid infiltration into islets, correlating with the lack of ectopic triglyceride and cholesterol depositions in the pancreata of ApoC3-transgenic versus wild-type littermates. ApoC3-transgenic mice, despite persistent hypertriglyceridemia, maintained euglycemia under both fed and fasting conditions without manifestation of insulin resistance and fasting hyperinsulinemia. Thus, hypertriglyceridemia per se is not an independent risk factor for beta cell dysfunction in ApoC3 transgenic mice.

Rare genetic variants with large effect on triglycerides in subjects with a clinical diagnosis of familial vs nonfamilial hypertriglyceridemia

BACKGROUND

Most primary severe hypertriglyceridemias (HTGs) are diagnosed in adults, but their molecular foundations have not been completely elucidated.

OBJECTIVE

We aimed to identify rare dysfunctional mutations in genes encoding regulators of lipoprotein lipase (LPL) function in patients with familial and non-familial primary HTG.

METHODS

We sequenced promoters, exons, and exon-intron boundaries of LPL, APOA5, LMF1, and GPIHBP1 in 118 patients with severe primary HTG (triglycerides >500 mg/dL) and 53 normolipidemic controls. Variant functionality was analyzed using predictive software and functional assays for mutations in regulatory regions.

RESULTS

We identified 29 rare variants, 10 of which had not been previously described: c.(-16A>G), c.(1018+2G>A), and p.(His80Arg) in LPL; p.(Arg143Alafs*57) in APOA5; p.(Val140Ile), p.(Leu235Ile), p.(Lys520*), and p.(Leu552Arg) in LMF1; and c.(-83G>A) and c.(-192A>G) in GPIHBP1. The c.(1018+2G>A) variant led to deletion of exon 6 in LPL cDNA, whereas the c.(-16A>G) analysis showed differences in the affinity for nuclear proteins. Overall, 20 (17.0%) of the patients carried at least one allele with a rare pathogenic variant in LPL, APOA5, LMF1, or GPIHBP1. The presence of a rare pathogenic variant was not associated with lipid values, family history of HTG, clinical diagnosis, or previous pancreatitis.

CONCLUSIONS

Less than one in five subjects with triglycerides >500 mg/dL and no major secondary cause for HTG may carry a rare pathogenic mutation in LPL, APOA5, LMF1, or GPIHBP1. The presence of a rare pathogenic variant is not associated with a differential phenotype.

Hypercoagulation and elevation of blood triglycerides are characteristics of Kawasaki disease

Background

Cardiovascular damages poses risks to children with Kawasaki disease (KD). Although hypertriglyceridemia and hypercholesteremia are risk factors of cardiovascular damages, studies on the blood lipid metabolism in KD are still limited. This study aims to analyze the blood lipids and coagulation in KD.

Methods

Triglyceride (TG) and cholesterol levels in the plasma and serum from 20 children with KD were examined in comparison with 10 healthy children (HC) as well as 10 children with high fever from identified bacterial infections (BT). Using electrospray ionization mass spectrometry, we profiled the lipid species. Blood coagulation was analyzed. Statistics was analyzed by one-way ANOVA using SigmaStat.

Results

We found that in KD, plasma TG level was significantly increased, but not serum TG. A total of 19 molecular species of TG were identified, and they were all increased in KD and BT patients, and more pronounced in KD. On the other hand, major molecular species of plasma phosphotidylcholine and lyso-phosphotidylcholine were decreased in KD and BT. Pronounced hypercoagulation was found in KD blood.

Conclusion

Our data indicate hyperlipidemia in KD, especially for TG, which contributes to the hypercoagulation and the potential risk of cardiovascular damages. Evaluation of blood lipid levels in severe KD patients could provide valuable information for treatment and prognosis, thus would be worthy of consideration.

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-015-0167-2) contains supplementary material, which is available to authorized users.

Effects of Armolipid Plus on small dense LDL particles in a sample of patients affected by familial combined hyperlipidemia

AIM

The aim of this study was to test small dense LDL changes with Armolipid Plus treatment in patients with familial combined hyperlipidemia (FCHL).

METHODS

After 4 weeks, 30 patients with FCHL were included in an 8-week, randomized, double-blind study and were taking, in addition to the standard diet, either placebo or Armolipid Plus.

RESULTS

The placebo group showed no statistically significant differences in the studied parameters; instead, in the Armolipid Plus group, statistically significant reduction differences were detected in BMI (p = 0.010), LDL score (p = 0.035) and an increase in mean LDL particle diameter (p = 0.040).

CONCLUSION

The combination of a standard diet with Armolipid Plus is able to reduce LDL score and increase LDL particle diameter in a group of FCHL after 8 weeks of treatment.

Study of Five Pubertal Transition-Related Gene Polymorphisms as Risk Factors for Premature Coronary Artery Disease in a Chinese Han Population

Background

Recently, single nucleotide polymorphisms (SNPs) (DLK-rs10144321, SIX6-rs1254337, MKRN3-rs12148769, LIN28B-rs7759938, and KCNK9-rs1469039) were found to be strongly associated with age at menarche. Recent studies also suggested that age at menarche is a heritable trait and is associated with risks for obesity, type 2 diabetes mellitus (T2DM), cardiovascular disease, and all-cause mortality. Since an association between these five SNPs and premature coronary artery disease (CAD) has never been reported, we investigated whether these SNPs are associated with premature CAD and its severity in a Chinese Han population.

Methods

We enrolled 432 consecutive patients including 198 with premature CAD (<55 years in men and <65 years in women) and 234 controls. All subjects were genotyped for the five SNPs by the PCR-ligase detection reaction method. The associations between these SNPs and premature CAD and its severity were analyzed.

Results

The following genotypes were identified: GG, AG, and AA at rs10144321 and rs12148769; TT, AT, and AA at rs1254337; CC, CT, and TT at rs1469039; and TT and CT at rs7759938. Significant differences in genotype distribution frequencies at rs1254337 were found between controls and patients with premature CAD (P<0.05). No associations were found between the five SNPs and the severity of coronary lesions (all P>0.05). Compared with controls, patients with premature CAD had a higher prevalence of T2DM and dyslipidemia, and the proportion of patients with T2DM rose significantly with an increase in the number of stenosed coronary vessels (all P<0.05). After adjustment for the clinical parameters in multivariable analysis, three factors were identified that significantly increased the risk of premature CAD: the AA genotype at rs1254337 (OR: 2.388, 95% CI: 1.190–4.792, P = 0.014), male gender (OR: 1.565, 95% CI: 1.012–2.420, P = 0.044), and T2DM (OR 2.252, 95% CI: 1.233–4.348, P = 0.015).

Conclusions

Among the five pubertal transition-related gene polymorphisms, we identified an association between rs1254337 and premature CAD in a Chinese Han population.

Decreased plasma endogenous soluble RAGE, and enhanced adipokine secretion, oxidative stress and platelet/coagulative activation identify non-alcoholic fatty liver disease among patients with familial combined hyperlipidemia and/or metabolic syndrome

OBJECTIVE

In patients with familial combined hyperlipidemia (FCHL), without metabolic syndrome (MS), occurrence of non-alcoholic fatty liver disease (NAFLD) is related to a specific pro-inflammatory profile, influenced by genetic traits, involved in oxidative stress and adipokine secretion. Among FCHL or MS patients, hyperactivity of the ligand-receptor for advanced glycation-end-products (RAGE) pathway, as reflected by inadequate protective response by the endogenous secretory (es)RAGE, in concert with genetic predisposition, may identify those with NAFLD even before and regardless of MS.

METHODS

We cross-sectionally compared 60 patients with vs. 50 without NAFLD. Each group included patients with FCHL alone, MS alone, and FCHL plus MS.

RESULTS

NAFLD patients had significantly lower plasma esRAGE, IL-10 and adiponectin, and higher CD40 ligand, endogenous thrombin potential and oxidized LDL. The effects of MS plus FCHL were additive. The genotypic cluster including LOX-1 IVS4-14A plus ADIPO 45GG and 256 GT/GG plus IL-10 10-1082G, together with higher esRAGE levels highly discriminate FCHL and MS patients not developing NAFLD.

CONCLUSIONS

Among FCHL or MS patients, noncarriers of the protective genotypic cluster, with lower esRAGE and higher degree of atherothrombotic abnormalities coincide with the diagnosis of NAFLD. This suggests an interplay between genotype, adipokine secretion, oxidative stress and platelet/coagulative activation, accelerating NAFLD occurrence as a proxy for cardiovascular disease.

α-Lipoic acid as a triglyceride-lowering nutraceutical

Considering the current obesity epidemic in the United States (>100 million adults are overweight or obese), the prevalence of hypertriglyceridemia is likely to grow beyond present statistics of ∼30% of the population. Conventional therapies for managing hypertriglyceridemia include lifestyle modifications such as diet and exercise, pharmacological approaches, and nutritional supplements. It is critically important to identify new strategies that would be safe and effective in lowering hypertriglyceridemia. α-Lipoic acid (LA) is a naturally occurring enzyme cofactor found in the human body in small quantities. A growing body of evidence indicates a role of LA in ameliorating metabolic dysfunction and lipid anomalies primarily in animals. Limited human studies suggest LA is most efficacious in situations where blood triglycerides are markedly elevated. LA is commercially available as dietary supplements and is clinically shown to be safe and effective against diabetic polyneuropathies. LA is described as a potent biological antioxidant, a detoxification agent, and a diabetes medicine. Given its strong safety record, LA may be a useful nutraceutical, either alone or in combination with other lipid-lowering strategies, when treating severe hypertriglyceridemia and diabetic dyslipidemia. This review examines the current evidence regarding the use of LA as a means of normalizing blood triglycerides. Also presented are the leading mechanisms of action of LA on triglyceride metabolism.

Hyperlipidemia in early adulthood increases long-term risk of coronary heart disease

BACKGROUND

Many young adults with moderate hyperlipidemia do not meet statin treatment criteria under the new American Heart Association/American College of Cardiology cholesterol guidelines because they focus on 10-year cardiovascular risk. We evaluated the association between years of exposure to hypercholesterolemia in early adulthood and future coronary heart disease (CHD) risk.

METHODS AND RESULTS

We examined Framingham Offspring Cohort data to identify adults without incident cardiovascular disease to 55 years of age (n=1478), and explored the association between duration of moderate hyperlipidemia (non-high-density lipoprotein cholesterol ≥ 160 mg/dL) in early adulthood and subsequent CHD. At median 15-year follow-up, CHD rates were significantly elevated among adults with prolonged hyperlipidemia exposure by 55 years of age: 4.4% for those with no exposure, 8.1% for those with 1 to 10 years of exposure, and 16.5% for those with 11 to 20 years of exposure (P<0.001); this association persisted after adjustment for other cardiac risk factors including non-high-density lipoprotein cholesterol at 55 years of age (hazard ratio, 1.39; 95% confidence interval, 1.05-1.85 per decade of hyperlipidemia). Overall, 85% of young adults with prolonged hyperlipidemia would not have been recommended for statin therapy at 40 years of age under current national guidelines. However, among those not considered statin therapy candidates at 55 years of age, there remained a significant association between cumulative exposure to hyperlipidemia in young adulthood and subsequent CHD risk (adjusted hazard ratio, 1.67; 95% confidence interval, 1.06-2.64).

CONCLUSIONS

Cumulative exposure to hyperlipidemia in young adulthood increases the subsequent risk of CHD in a dose-dependent fashion. Adults with prolonged exposure to even moderate elevations in non-high-density lipoprotein cholesterol have elevated risk for future CHD and may benefit from more aggressive primary prevention.

Lipidomic assessment of plasma and placenta of women with early-onset preeclampsia

Introduction

Adipose tissue is responsible for triggering chronic systemic inflammatory response and these changes may be involved in the pathophysiology of preeclampsia.

Objective

To characterize the lipid profile in the placenta and plasma of patients with preeclampsia.

Methodology

Samples were collected from placenta and plasma of 10 pregnant women with preeclampsia and 10 controls. Lipids were extracted using the Bligh–Dyer protocol and were analysed by MALDI TOF-TOF mass spectrometry.

Results

Approximately 200 lipid signals were quantified. The most prevalent lipid present in plasma of patients with preeclampsia was the main class Glycerophosphoserines-GP03 (PS) representing 52.30% of the total lipid composition, followed by the main classes Glycerophosphoethanolamines-GP02 (PEt), Glycerophosphocholines-GP01 (PC) and Flavanoids-PK12 (FLV), with 24.03%, 9.47% and 8.39% respectively. When compared to the control group, plasma samples of patients with preeclampsia showed an increase of PS (p<0.0001), PC (p<0.0001) and FLV (p<0.0001). Placental analysis of patients with preeclampsia, revealed the PS as the most prevalent lipid representing 56.28%, followed by the main class Macrolides/polyketides-PK04 with 32.77%, both with increased levels when compared with patients control group, PS (p<0.0001) and PK04 (p<0.0001).

Conclusion

Lipids found in placenta and plasma from patients with preeclampsia differ from those of pregnant women in the control group. Further studies are needed to clarify if these changes are specific and a cause or consequence of preeclampsia.

Common genetic variants contribute to primary hypertriglyceridemia without differences between familial combined hyperlipidemia and isolated hypertriglyceridemia

BACKGROUND

The majority of hypertriglyceridemias are diagnosed as familial combined hyperlipidemia (FCHL) and primary isolated hypertriglyceridemias. The contribution of common genetic variants in primary hypertriglyceridemias and the genetic difference between FCHL and isolated hypertriglyceridemias have not been thoroughly examined.

METHODS AND RESULTS

This study involved 580 patients with hypertriglyceridemias and 403 controls. Of the 37 single nucleotide polymorphisms examined, 12 located in 10 genes showed allelic and genotype frequency differences between hypertriglyceridemias and controls. The minor alleles of APOE, APOA5, GALNTN2, and GCKR variants were positively correlated with plasma triglycerides, whereas minor alleles of ADIPOR2, ANGPTL3, LPL, and TRIB1 polymorphisms were inversely associated. Body mass index, glucose, sex, rs328 and rs7007797 in LPL, rs662799 and rs3135506 in APOA5, and rs1260326 in GCKR explained 36% of the variability in plasma triglycerides, 7.3% of which was attributable to the genetic variables. LPL, GCKR, and APOA5 polymorphisms fit dominant, recessive, and additive inheritance models, respectively. Variants more frequently identified in isolated hypertriglyceridemias were rs7412 in APOE and rs1800795 in IL6; rs2808607 in CYP7A1 and rs3812316 and rs17145738 in MLXIPL were more frequent in FCHL. The other 32 single nucleotide polymorphisms presented similar frequencies between isolated hypertriglyceridemias and FCHL.

CONCLUSIONS

Common genetic variants found in LPL, APOA5, and GCKR are associated with triglycerides levels in patients with primary hypertriglyceridemias. FCHL and isolated hypertriglyceridemias are probably trace to an accumulation of genetic variants predisposing to familial and sporadic hypertriglyceridemias or to hypertriglyceridemias and hypercholesterolemia in case of FCHL.

Determinants of VLDL composition and apo B-containing particles in familial combined hyperlipidemia

BACKGROUND

In familial combined hyperlipidemia (FCHL) the severity of the dyslipidemia is determined by an overproduction of VLDL (very low density lipoprotein) particles and by its abnormal lipid composition. However, few are known regarding the metabolic factors that determine these abnormalities. We investigated the impact of metabolic factors on the number of atherogenic particles (apolipoprotein B level (apoB)) and the triglyceride content of very low-density lipoproteins (VLDLs-TG).

METHODS

A cross-sectional study done in FCHL subjects and gender and age-matched healthy subjects. A clinical assessment, lipid profile and plasma concentrations of insulin, apolipoprotein CIII (apo CIII), apolipoprotein AII (apo AII), high sensitive C-reactive protein (HS-CRP), adiponectin and leptin were documented in 147 FCHL patients and 147 age-matched healthy subjects. Multivariate regression models were performed to investigate the independent determinants of VLDL-TG and apo B levels adjusting for confounding factors.

RESULTS

The variables that determined the VLDL-triglyceride content as a surrogate of VLDL composition were apo CIII (β=0.365, p<0.001), insulin (β=0.281, p<0.001), Apo AII (β=0.145, p<0.035), and adiponectin levels (β=-0.255, p<0.001). This model explained 34% of VLDL composition (VLDL-TG) variability. However, none of these variables were independent contributors of apo B-containing particles.

CONCLUSIONS

In patients with FCHL apo CIII, apo AII and adiponectin are major novel factors determining the VLDL particle composition. However, such factors do not explain apo B-containing particles.

[Familial combined hyperlipidemia: consensus document]

Familial combined hyperlipidemia (FCH) is a frequent disorder associated with premature coronary artery disease. It is transmitted in an autosomal dominant manner, although there is not a unique gene involved. The diagnosis is performed using clinical criteria, and variability in lipid phenotype and family history of hyperlipidemia are necessaries. Frequently, the disorder is associated with type2 diabetes mellitus, arterial hypertension and central obesity. Patients with FCH are considered as high cardiovascular risk and the lipid target is an LDL-cholesterol <100mg/dL, and <70mg/dL if cardiovascular disease or type 2 diabetes are present. Patients with FCH require lipid lowering treatment using potent statins and sometimes, combined lipid-lowering treatment. Identification and management of other cardiovascular risk factors as type 2 diabetes and hypertension are fundamental to reduce cardiovascular disease burden. This document gives recommendations for the diagnosis and global treatment of patients with FCH directed to specialists and general practitioners.

Serum lipid responses to weight loss differ between overweight adults with familial hypercholesterolemia and those with familial combined hyperlipidemia

The effect of weight loss on lipids differs among individuals, although whether it can modify the management of hereditary hyperlipidemias has not yet been explored. The objective of this study was to examine the effect of weight loss on cholesterol metabolism, assessed by circulating noncholesterol sterols, in overweight adults with familial hypercholesterolemia (FH) and familial combined hyperlipidemia (FCHL). We conducted a 6-mo weight loss intervention in untreated individuals (FH: n = 28; FCHL: n = 50) with a body mass index of >25 kg/m(2) and mean age of 46.9 ± 11.3 y, of whom 53.8% were men. A hypocaloric diet was implemented and serum lipid analyses, including noncholesterol sterols, were assessed. Global significant mean weight losses of 5.7 kg (-6.6%) and 6.6 kg (-7.6%) were achieved after 3 and 6 mo, respectively. Mean non-HDL cholesterol and triglyceride (TG) changes at 3 and 6 mo compared with baseline were -5.8% (P = 0.004) and -7.1% (P = 0.014), and -30.1% (P < 0.001) and -31.4% (P < 0.001), respectively. Among participants who lost ≥5% body weight, only significant changes in TGs and non-HDL cholesterol were observed in FCHL participants. Sterol precursors of cholesterol synthesis decreased significantly by 10.4% at 6 mo in FCHL participants, mostly because of a 23.9% lathosterol reduction. Baseline synthesis precursors were associated with TG reduction in FCHL participants (P = 0.039; R(2) = 0.20), and intestinally derived sterols were inversely associated with non-HDL cholesterol changes in FH participants (P = 0.036; R(2) = 0.21). Thus, FCHL participants had a better lipid-lowering response to weight loss than did FH participants. This response was positively associated with baseline cholesterol synthesis, which was reduced by weight loss. Our results confirm the cholesterol overproduction mechanism of FCHL and its interaction with fat mass, while also supporting the differential management of familial hyperlipidemias if obesity coexists. This trial was registered at clinicaltrials.gov as NCT01995149.

[Familial combined hyperlipidemia: consensus document]

Familial combined hyperlipidemia (FCH) is a frequent disorder associated with premature coronary artery disease. It is transmitted in an autosomal dominant manner, although there is not a unique gene involved. The diagnosis is performed using clinical criteria, and variability in lipid phenotype and family history of hyperlipidemia are necessaries. Frequently, the disorder is associated with type2 diabetes mellitus, arterial hypertension and central obesity. Patients with FCH are considered as high cardiovascular risk and the lipid target is an LDL-cholesterol <100mg/dL, and <70mg/dL if cardiovascular disease or type 2 diabetes are present. Patients with FCH require lipid lowering treatment using potent statins and sometimes, combined lipid-lowering treatment. Identification and management of other cardiovascular risk factors as type 2 diabetes and hypertension are fundamental to reduce cardiovascular disease burden. This document gives recommendations for the diagnosis and global treatment of patients with FCH directed to specialists and general practitioners.

Familial combined hyperlipidemia: from molecular insights to tailored therapy

PURPOSE OF REVIEW

This review presents recent basic and clinical developments in familial combined hyperlipidemia (FCHL).

RECENT FINDINGS

A variety of experiments have contributed to the elucidation of this complex disease. They consist of dynamic and gene expression studies in adipocytes, confirming the role of dysfunctional adipose tissue in the pathogenesis of FCHL and identifying potential new pathways, such as complement activation. Whole exome sequencing and classical linkage studies in FCHL pedigrees, some conducted with new traits (e.g. plasma proprotein convertase subtilisin/kexin type 9 [PCSK9] and phospholipid transfer protein activity), have revealed new genes of interest, among which SLC25A40 and LASS4. Finally, gene expression studies in liver biopsies and liver cell culture experiments have gained further insight in the role of upstream stimulatory factor 1, one of the most replicated genes in FCHL, in its pathogenesis.On the basis of these observations and recent phase II clinical trials, PCSK9 antagonizing is the most promising lipid-lowering therapy to be added to our current arsenal of statins and fibrates in FCHL treatment.

SUMMARY

Ongoing basic research provides a steady growth in our knowledge on the genes that are involved in FCHL as well as their metabolic function(s). This field of research may be enhanced when data are expanded and integrated for systems biology approaches. Our growing insights in the cause of FCHL allow for better, targeted treatment of dyslipidemia and prevention of cardiovascular complications.