Significance of high density lipoprotein-cholesterol in cardiovascular risk prevention: recommendations of the HDL Forum

Truncated variant rs373056577 confers increased risk of type 2 diabetes and missense variant rs121912717 is associated with hypertriglyceridemia in Bangladeshi population

This study investigates the association of allelic and genotypic variations of rs121912717 and rs373056577 within APOA1 and APOA2 genes, respectively with the risk of type 2 diabetes (T2D). In this cross-sectional study, real-time quantitative PCR with specific Taqman probes was used to determine the genotypic and allelic frequencies of rs121912717 and rs373056577 in 300 unrelated Bangladeshi individuals (Healthy = 144, T2D patients = 156). Logistic regression analysis was performed to investigate the association of genotypic and allelic frequencies of these SNPs with respect to T2D under different inheritance models. Neither allelic nor genotypic frequencies of rs121912717 within APOA1 showed any significant association with T2D. Genotypes with respect to rs373056577 within APOA2 showed significant association with the risk of T2D under co-dominant heterozygous model (GG vs GA) [OR (95 %CI): 2.64 (1.32-5.59), p = 0.008], dominant [OR (95 %CI): 2.31 (1.24-4.49), p = 0.01] and over-dominant [OR (95 %CI): 2.62 (1.31-5.53), p = 0.008] models without adjusting for age, gender and BMI. After adjusting for age, gender and BMI, the A allele of rs373056577 showed significant association with T2D only in the dominant model [OR (95 %CI): 3.20 (1.12-10.51), p = 0.04]. Also, A allele of rs373056577 demonstrated significant association with the risk of T2D compared to allele G with [OR (95 %CI): 2.90 (1.15-8.14), p = 0.03] and without adjusting for confounders [OR (95 %CI): 1.97 (1.14-3.52), p = 0.02]. The genotypic frequency was significantly associated with T2D in codominant, dominant, and overdominant models in male participants when a gender-stratified analysis was conducted for rs373056577. However, when the logistic regression analysis was adjusted for age and BMI, the association was not significant in any of the models with respect to rs373056577 for male participants. On the other hand, gender-stratified regression analyses revealed no significant association with T2D before and after adjusting for age and BMI with respect to both allelic and genotypic frequencies of rs121912717. Individuals with CT genotype of rs121912717 had significantly higher triglyceride levels (322.2 mg/dL) compared to those harboring CC genotype (202.8 mg/dL) with or without adjusting for age, gender, BMI and disease status of the study participants. In conclusion, this study revealed that individuals harboring the allele A of rs373056577 possessed an increased risk of developing T2D and individuals having CT genotype of rs121912717 had increased triglyceride levels. The result of this study needs to be validated in a larger cohort for a more robust assessment.

Anti-inflammatory and anti-apoptotic effect of zingiberene on isoproterenol-induced myocardial infarction in experimental animals

This study aimed to investigate the antihyperlipidemic and anti-inflammatory effect of zingiberene (ZBN) on isoproterenol-(ISO) induced myocardial infarction in rats. ZBN (10 mg/kg b.wt.) was orally administered to rats for 21 days and ISO (85 mg/kg b.wt.) was subcutaneously injected into the rats at 24 h intervals for the last 2 consecutive days. We observed increased serum creatine kinase, creatine kinase-MB, cardiac troponin T, and I levels in ISO-treated MI rats. Conversely, ZBN oral administration significantly prevented in cardiac marker enzyme activities in ISO-mediated rats. We also noticed that ZBN oral administration prevented ISO-induced expression of lipid peroxidative markers, total cholesterol, triglycerides, phospholipids, free fatty acids, very-low-density lipoprotein cholesterol (VLDL-C), low-density lipoprotein cholesterol (LDL-C) to the normal basal level. Furthermore, ZBN restored ISO-mediated antioxidant status, increased level of high-density lipoprotein cholesterol (HDL-C), and tissue phospholipids to the near-normal levels. Besides, ZBN pre-treatment significantly reduced the level of inflammatory markers (TNF-α, IL-6, NF-κB, and IL-1β) in ISO-induced MI in rats. We noticed that ZBN pretreatment inhibited the pro-apoptotic proteins Bax and cytochrome c and increased the Bcl-2 expression in ISO induced rats. The gene expression profiling by qRT-PCR array illustrates that ZBN treatment prevents the ISO mediated activation of cardiac markers, inflammatory, and fibrosis-related genes in the heart tissue. Taken together, pre-treatment with ZBN attenuated ISO-induced MI resolved exhibits the anti-inflammatory and antiapoptotic effect.

HDL and associated factors stratified by sex and menopausal status: results from a community-based survey in Taiwan

AIM

To investigate factors, especially modifiable factors associated with high-density lipoprotein (HDL) in Taiwanese based on sex and menopausal status.

MATERIALS AND METHODS

Participants comprised 2022 men and 2392 women (1267 menopausal and 1125 non-menopausal) aged ≥30 years who resided in Pingzhen district, Taoyuan from 2006-2011. Their data, obtained through questionnaires and measurements were retrieved from the Li-Shin Hospital.

RESULTS

Higher HDL was associated with total cholesterol, underweight, and alcohol drinking in both men and women. It was also associated with education, blood group B, and marital status in men as well as with age in women. Moreover, it was associated with total cholesterol, underweight, and age in both menopausal and non-menopausal women. Furthermore, it was associated with marital status in non-menopausal women and alcohol drinking in menopausal women. Lower HDL was associated with triglycerides, low-density lipoprotein (LDL), overweight, obesity, waist-hip ratio (WHR), uric acid, and smoking in both men and women and with coffee drinking in only women. It was also associated with uric acid, triglycerides, LDL, overweight, obesity, WHR, and body fat in both menopausal and non-menopausal women. Moreover, it was associated with coffee drinking in menopausal women.

CONCLUSION

Modifiable factors associated with HDL differ according to sex and menopausal status. Sex and menopausal status should be considered when implementing lifestyle changes to raise HDL. For example, both men and women should maintain a normal weight as well as quit smoking.

Association of serum lipids and coronary artery disease with polymorphisms in the apolipoprotein AI-CIII-AIV gene cluster

Genetic variants are considered as one of the main determinants of the concentration of serum lipids and coronary artery disease (CAD). Polymorphisms in the Apolipoprotein (Apo) AI-CIII-AIV gene cluster has been known to affect the concentrations of various lipid sub-fractions and the risk of CAD. The present study assessed associations between polymorphisms of the Apo AI-CIII-AIV gene cluster, [ApoA-I,-75G > A, (rs1799837); ApoC-III 3238C > G, (SstI), (rs5128) and ApoA-IV, Thr347Ser(347A > T), (rs675)] with serum lipids and their contributions to CAD in North Indian population. We recruited age, sex matched, 200 CAD patients and 200 healthy controls and tested them for fasting levels of serum lipids. We genotyped selected polymorphisms using polymerase chain reaction-restriction fragment length polymorphism. There were no statistically significant association of selected polymorphisms (or their combinations) with CAD even after employing additive, dominant and recessive models. However there was significant association of selected polymorphisms with various lipid traits amongst the control cohort (p < 0.05). Mean levels of high density lipoprotein cholesterol and triglycerides were found to be significantly higher among controls carrying at least one mutant allele at ApoA1-75G > A (p = 0.019) and ApoCIII SstI (p < 0.001) polymorphism respectively. Our study observed that the selected polymorphisms in the ApoAI-CIII-AIV gene cluster although significantly affect various lipid traits but this affect does not seem to translate into association with CAD, at least among North Indian population.

The High Prevalence of Low HDL-Cholesterol Levels and Dyslipidemia in Rural Populations in Northwestern China

BACKGROUND

Dyslipidemia is a major health problem in China and an important modifiable cardiovascular disease (CVD) risk factor. This study aimed to describe the prevalence of dyslipidemia and low high density lipoprotein cholesterol (HDL-cholesterol) and associated risk factors among adults in rural northwest China.

METHODS

In a cross-sectional analyses involving 2,980 adults aged >18 years, information on the demographics, cigarette smoking, alcohol consumption, education, and medical history was collected via face-to-face interviews. Blood samples were collected to determine total cholesterol (TC), low-density lipoprotein cholesterol (LDL-cholesterol), and HDL-cholesterol, and triglycerides (TG) levels.

RESULTS

The prevalence of high TC, high LDL-cholesterol, low HDL-cholesterol, and high TG were 1.0%, 0.6%, 60.9%, and 13.7%, respectively. TC, LDL-cholesterol, and TG increased with age in females. Elevated TC was more common in females than in males. The prevalence of low HDL-cholesterol was 67.6% in males and 55.4% in females. Current smokers, those with less education, those who were overweight or obese, and those with large waist circumference were more likely to have low HDL-cholesterol (p<0.05). Multivariable regression showed that male gender showed an association with low HDL-cholesterol (OR 2.10, 95%CI 1.68-2.61), age ≥60 years (OR 0.80, 95% CI 0.64-0.99), BMI (BMI = 24-27.9, OR 1.27, 95%CI 1.04-1.54, p = 0.02 and BMI≥28, OR 1.56, 95%CI 1.10-2.20, p = 0.01) and enlarged waist circumference (OR 2.10, 95%CI 1.51-2.92). Non-alcohol drinker was associated with low HDL-cholesterol levels (OR 0.72, 95%CI 0.53-0.99, p = 0.04).

CONCLUSIONS

This study found that the prevalence of low HDL-cholesterol was 67.6% and 55.4% for males and females. Male gender, non-alcohol drinker, BMI and central obesity were important risk factors for low HDL-cholesterol in Chinese adults.

Coenzyme Q10 supplementation improves metabolic parameters, liver function and mitochondrial respiration in rats with high doses of atorvastatin and a cholesterol-rich diet

Background

The aim of this study was to evaluate the actions of coenzyme Q₁₀ (CoQ₁₀) on rats with a cholesterol-rich diet (HD) and high doses of atorvastatin (ATV, 0.2, 0.56 or 1.42 mg/day).

Methods

Two experiments were done, the first one without coenzyme Q₁₀ supplementation. On the second experiment all groups received coenzyme Q₁₀ 0.57 mg/day as supplement. After a 6-week treatment animals were sacrificed, blood and liver were analyzed and liver mitochondria were isolated and its oxygen consumption was evaluated in state 3 (phosphorylating state) and state 4 (resting state) in order to calculate the respiratory control (RC).

Results

HD increased serum and hepatic cholesterol levels in rats with or without CoQ₁₀. ATV reduced these values but CoQ₁₀ improved even more serum and liver cholesterol. Triacylglycerols (TAG) were also lower in blood and liver of rats with ATV + CoQ₁₀. HDL-C decreased in HD rats. Treatment with ATV maintained HDL-C levels. However, these values were lower in HD + CoQ₁₀ compared to control diet (CD) + CoQ₁₀. RC was lessened in liver mitochondria of HD. The administration of ATV increased RC. All groups supplemented with CoQ₁₀ showed an increment in RC. In conclusion, the combined administration of ATV and CoQ₁₀ improved biochemical parameters, liver function and mitochondrial respiration in hypercholesterolemic rats.

Conclusions

Our results suggest a potential beneficial effect of CoQ₁₀ supplementation in hypercholesterolemic rats that also receive atorvastatin. This beneficial effect of CoQ₁₀ must be combined with statin treatment in patient with high levels of cholesterol.

HDL inflammation and atherosclerosis: current and future perspectives

The role of high-density lipoprotein (HDL) in the genesis and evolution of cardiovascular disease is a topical and interesting issue. Reduced HDL concentrations appear to be unable to efficiently eliminate the cholesterol excess at the vascular wall level, contributing to the onset of the inflammatory response that typically occurs in the pathogenesis of atherosclerosis from its earliest stages. In the last decade, many studies have explored the possibility of reducing cardiovascular risk through modulation of HDL levels, glimpsing new fascinating therapeutic horizons. This review summarizes recent findings on HDL and cardiovascular disease, mainly with an educational objective, considering the biochemical, cellular and molecular aspects of these particles.

[Prevalence of metabolic syndrome and its components in patients with acute coronary syndrome]

INTRODUCTION AND OBJECTIVES

A large proportion of patients with coronary disease have metabolic syndrome, although the frequency and association of its different components are not well understood. The aim of this study was to determine the prevalence of metabolic syndrome and the combination of its components in a Spanish cohort of patients with acute coronary syndrome.

METHODS

Clinical histories of 574 inpatients with acute coronary syndrome in 6 tertiary hospitals were reviewed and the presence of metabolic syndrome and its components determined by applying Adult Treatment Panel III criteria. In a second step, the components of the metabolic syndrome were analyzed, excluding those patients with diabetes mellitus.

RESULTS

The metabolic syndrome was present in 50.9% of patients and was more frequent in women than in men (66.3% vs. 47.3%; P<.001). The most prevalent component was carbohydrate metabolism disorder (85.3%), followed by low high-density lipoprotein cholesterol (HDLc) levels (80.5%). In nondiabetic patients, 34.6% had metabolic syndrome and the most prevalent component was low HDLc levels (86%), followed by high blood pressure and hypertriglyceridemia and, in fourth place, impaired fasting serum glucose levels.

CONCLUSIONS

The metabolic syndrome has a high prevalence in patients with an acute coronary syndrome, especially in women. The most frequent components are hyperglycemia and low HDLc levels. After excluding diabetic patients, the most prevalent diagnostic criterion of metabolic syndrome was low HDLc levels. Full English text available from: www.revespcardiol.org.

[Residual lipid profile in recurrent ischemic cardiopathy]

BACKGROUND AND OBJECTIVES

In this paper we analyze the lipid profile of a cohort of patients attended in different tertiary hospitals with acute coronary syndrome (angor pectoris or acute myocardial infarction).

PATIENTS AND METHODS

We have analysed different variables of patients with acute coronary syndrome, related with the prevalence and grade of main cardiovascular risk factors, and related with different treatments. We have analysed the lipid profile, and stratified the results according with the status of the first acute coronary event or recurrent coronary event.

RESULTS

Patients with recurrent disease showed lower levels of total cholesterol and LDL-c, and similar levels of HDL-c and triglycerides in relation with patients with a first event.

CONCLUSIONS

We found similar HDL-c and triglycerides levels in both groups of patients meaning that, despite a standard statins treatment, patients with a first coronary event did not modify such a lipid profile. It is necessary to do a more intensive therapeutic effort over all the lipid fractions with the aim to reduce the recurrences of coronary events.

A very high prevalence of low HDL cholesterol in Spanish patients with acute coronary syndromes

BACKGROUND

Total and low-density lipoprotein cholesterol (LDL-C) concentrations in coronary artery disease have progressively declined, although high-density lipoprotein cholesterol (HDL-C) has not always been evaluated. The prevalence and related factors of low HDL-C in a cohort of Spanish patients with acute coronary syndromes (ACS) were assessed.

METHODS

Clinical and laboratory data registered at admission and at discharge of 648 patients admitted to coronary care units of 6 Spanish hospitals for ACS between January 2004 and September 2007 were analyzed.

RESULTS

Low HDL-C (HDL-C < 1.04 mmol/L) was observed in 367 (56.6%) patients. Male gender, smoking, hypertension, diabetes, high body mass index, and triglycerides were related to low HDL-C. Female gender was the strongest protective factor against low HDL-C (0.619; 95% confidence interval [CI]: 0.410-0.934; P = 0.022), whereas high triglycerides (1.653; 95% CI: 1.323-2.064; P < 0.001) followed by previous ischemic disease (1.504; 95% CI: 1.073-2.110; P = 0.018) were the strongest factors associated with low HDL-C. One-third of patients were taking statins at admission, but only 2% were on fibrate therapy. A large increase in statin therapy, but not in other hypolipemiant drug therapy, between admission and discharge was noted in the whole cohort and among patients with low HDL-C.

CONCLUSION

Spanish patients with ACS have a very high prevalence of low HDL-C. Male gender, high triglycerides, and previous ischemic disease are strong, independent factors associated with this disorder. As low HDL-C remains almost completely untreated in ACS, strategies to enhance the treatment of this lipoprotein abnormality are urgently required.

Management of dyslipidemias with fibrates, alone and in combination with statins: role of delayed-release fenofibric acid

Cardiovascular disease (CVD) represents the leading cause of mortality worldwide. Lifestyle modifications, along with low-density lipoprotein cholesterol (LDL-C) reduction, remain the highest priorities in CVD risk management. Among lipid-lowering agents, statins are most effective in LDL-C reduction and have demonstrated incremental benefits in CVD risk reduction. However, in light of the residual CVD risk, even after LDL-C targets are achieved, there is an unmet clinical need for additional measures. Fibrates are well known for their beneficial effects in triglycerides, high-density lipoprotein cholesterol (HDL-C), and LDL-C subspecies modulation. Fenofibrate is the most commonly used fibric acid derivative, exerts beneficial effects in several lipid and nonlipid parameters, and is considered the most suitable fibrate to combine with a statin. However, in clinical practice this combination raises concerns about safety. ABT-335 (fenofibric acid, Trilipix^®) is the newest formulation designed to overcome the drawbacks of older fibrates, particularly in terms of pharmacokinetic properties. It has been extensively evaluated both as monotherapy and in combination with atorvastatin, rosuvastatin, and simvastatin in a large number of patients with mixed dyslipidemia for up to 2 years and appears to be a safe and effective option in the management of dyslipidemia.

When high is low: raising low levels of high-density lipoprotein cholesterol

Low serum levels of high-density lipoprotein cholesterol (HDL-C) are highly prevalent and are recognized as an independent risk factor for cardiovascular morbidity (myocardial infarction, stroke, peripheral arterial disease, and restenosis after coronary stenting) and mortality. HDL plays an important role in modulating atherogenesis, although its functions are varied and complex and the mechanisms for its antiatherogenic effects have not been completely elucidated. The inverse relationship between HDL-C and cardiovascular risk is well established, and epidemiologic studies and clinical trials have provided ample evidence that higher levels of HDL-C are vasculoprotective. Although considerable interest exists in the development of novel approaches to raise serum HDL-C and to augment HDL functionality, this article discusses currently available therapies to raise suboptimal levels of this important lipoprotein.

Effects of short-term cinnamon ingestion on in vivo glucose tolerance

AIMS

Various spices display insulin-potentiating activity in vitro, and in particular, cinnamon spice and its phenolic extracts have been shown to exhibit these capabilities. In vivo study shows that cinnamon may have beneficial effects on glucose homeostasis; therefore the aim of this study was to further investigate this phenomenon in humans.

METHODS

Seven lean healthy male volunteers, aged 26 +/- 1 years, body mass index 24.5 +/- 0.3 kg/m(2) (mean +/- s.e.m.), underwent three oral glucose tolerance tests (OGTT) supplemented with either a 5 g placebo (OGTT(control)), 5 g of cinnamon (OGTT(cin)), or 5 g of cinnamon taken 12 h before (OGTT(cin12hpre)) in a randomized-crossover design.

RESULTS

Cinnamon ingestion reduced total plasma glucose responses (AUC) to oral glucose ingestion [-13% and -10% for OGTT(cin) (p < 0.05) and OGTT(cin12hpre) (p < 0.05), respectively], as well as improving insulin sensitivity as assessed by insulin sensitivity index measures based on Matsuda's model in both OGTT(cin) (p < 0.05) and OGTT(cin12hpre) (p < 0.05) trials compared with OGTT(control).

CONCLUSIONS

These data illustrate that cinnamon spice supplementation may be important to in vivo glycaemic control and insulin sensitivity in humans, and not only are its effects immediate, they also appear to be sustained for 12 h.

ApolipoproteinA1-75 G/A (M1-) polymorphism and lipoprotein(a); anti- vs. pro-Atherogenic properties

BACKGROUND

ApolipoproteinA1 (apoA1) is the major apoprotein constituent of high-density-lipoprotein(HDL). The relationship of apoA1 -75 bp(M1-) allele polymorphism with lipoprotein phenotype and cardiovascular disease (CVD) remain unclear. Overnight fasting blood samples were collected from a cohort of high-risk Omani population, 90 non-diabetic subjects and 149 type 2 diabetes mellitus (T2DM) subjects for genotype and phenotype studies.

RESULTS

The M1+ and M1- alleles frequencies were 0.808 and 0.192 for M1+ and M1-, respectively, comparable to the frequency of apoA1 (M1+ and M1-) amongst a healthy Omani population, 0.788 and 0.212, respectively. The frequencies of the hetero- and homozygous subjects for the MspI polymorphism at -75 (M1-) of the apoA1 gene were in Hardy-Weinberg equilibrium. The mean Lp(a) concentration was significantly higher(P = 0.02) in subjects carrying M1- allele compared to M1+ allele of the APOA1 gene with an odd ratio of 2.3(95% CI, 1.13-14.3), irrespective of gender and the diabetic status.

CONCLUSION

ApolipoproteinA1-75 G/A (M1-) polymorphism is relatively common and is positively associated with Lp(a) and therefore, may confer a potential risk for cardiovascular disease (CVD).

[Lipid profile of patients with increased risk for cardiovascular events in daily clinical practice]

Although there are specific guidelines regarding the treatment of dyslipidemia in highly risk patients, these recommendations are usually inadequately followed. The aim of this study is to investigate risk factors in patients with increased cardiovascular risk currently treated in Brazil and Venezuela. Medical charts of 412 patients were selected in 4 institutions. Patients were divided into groups according to the use of lipid-lowering drugs (LLD), particularly statins. Patients who did not use LLD showed higher levels of total cholesterol (p< 0.001), LDL cholesterol (p< 0,001) and HDL cholesterol (p< 0.001), besides lower levels of triglycerides (p< 0.001). The use of statins was associated with a decrease in levels of total cholesterol (from 251.0 +/- 40.0 to 196.0 +/- 46.0), LDL cholesterol (from 168.0 +/- 36.0 to 116.0 +/- 39.0), HDL cholesterol (from 51.0 +/- 46.0 to 46.0 +/- 12.0) and triglycerides (from 181.0 +/- 120.0 to 160.0 +/-79.0). Finally, only a small percentage of patients, even those under treatment with LLD, showed cholesterol levels according to currently available guidelines. Therefore, although the guidelines for the treatment of dyslipidemia are widely known, only a small percentage of patients achieve adequate levels of cholesterol. It is necessary to decrease lipid levels of these patients by increasing the dose of the statins or using a second drug.

Lipids for psychiatrists - an overview

Serum cholesterol is a major risk factor for cardiovascular disease. Total cholesterol, LDL cholesterol and triglycerides are positively related to cardiovascular disease, while HDL cholesterol has an inverse relationship. Measurement of lipids is essential in individuals with established cardiovascular disease or type 2 diabetes, and may also be carried out in healthy individuals as part of cardiovascular risk assessment. Lifestyle measures are important in cardiovascular disease prevention, but the mainstay of lipid lowering therapy is appropriate use of lipid lowering drugs. Total and LDL cholesterol are the primary targets for treatment, but consideration should also be given to raising HDL cholesterol and lowering triglycerides where appropriate. Statins are the most frequently used lipid lowering agents, but there is an important place for other drugs, including ezetimibe, fibrates and nicotinic acid.

ABCG1: how critical for cholesterol transport?

In the current issue of Cell Metabolism, Kennedy et al. (2005) have extended our understanding of the ABCG1 transporter. Their studies demonstrate that, at least in macrophages, ABCG1 is responsible for much of the cholesterol efflux that utilizes mature HDL as an acceptor.