A prospective study of triglyceride level, low-density lipoprotein particle diameter, and risk of myocardial infarction

Anti-arthritogenic and cardioprotective action of hesperidin and daidzein in collagen-induced rheumatoid arthritis

Atherosclerosis has been linked to chronic inflammatory processes. Changes in the levels of lipoproteins, especially low-density lipoprotein or its variants, as well as inflammatory markers are risk factors for the atherosclerosis. In the present study, an experimental model of rheumatoid arthritis was developed by administrating collagen suspension intradermally in the tail region of Wistar albino rats. At the same time, a suspension of hesperidin (50 mg/kg body weight) and daidzein (20 mg/kg body weight) was orally administrated. The compounds were given in the morning and evening for 21 days. Levels of inflammatory markers in the homogenate of knee joints of experimental rats as well as plasma lipoproteins were investigated. The administration of hesperidin and daidzein caused significant (p < 0.001) decrease in articular elastase activity, TNF-α, and malondialdehyde levels. Further, arthritis scoring and histological findings supported the anti-inflammatory actions of the test compounds. Interestingly, the test compounds also lowered the plasma low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, and triglyceride but increased the level of high-density lipoprotein cholesterol. The test compounds thus ameliorated the risk factors of atherosclerosis. Furthermore, antioxidant roles of hesperidin as well as daidzein were evident from decrease in free radical load demonstrated as increase in total antioxidant level in plasma of arthritic animals treated with hesperidin and daidzein. In a separate in vitro experiment, enhanced free radical scavenging activity of hesperidin was demonstrated against 2,2-diphenyl-1-picrylhydrazyl and 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid. The anti-inflammatory, hypolipidemic, and antioxidant actions of the naturally occurring test compounds, particularly hesperidin, seem to be quite effective against rheumatoid arthritis and atherosclerosis. Thus, their consumption may be helpful in prevention or at least delaying the onset of these diseases in susceptible individuals.

Pioglitazone reduces atherogenic dense low density lipoprotein (LDL) particles in patients with type 2 diabetes mellitus

Aim The new oral antidiabetic agent pioglitazone improves insulin sensitivity and glycaemic control, lowers triglycerides and increases high density lipoprotein (HDL) cholesterol in type 2 diabetes. The effect of pioglitazone on low density lipoprotein (LDL) subfractions is investigated, herein.

Methods The effect of pioglitazone monotherapy (45 mg o.d. for six months) on LDL subfractions was observed in 30 patients with poorly controlled type 2 diabetes (HbA1C ≥ 7.5% and < 11.5% and triglycerides ≥ 150 mg/dL). The distribution of LDL subfractions was determined by equilibrium density gradient ultracentrifugation before and during treatment.

Results HbA1C (9.5% before and 7.4% on treatment, p<0.001), triglycerides (-135 mg/dL [-32.2%], p=0.002) and apo B in LDL-6 (the most dense LDL subfraction) decreased significantly. The mean diameter of LDL particles increased (19.5 nm before and 19.8 nm on treatment, p=0.005), while the mean LDL density decreased significantly (from 1.0394 kg/L to 1.0381 kg/L on treatment; p=0.033). HDL increased from 36.3 mg/dL to 44.2 mg/dL (+ 21.6%, p<0.001). Total cholesterol and LDL-cholesterol did not change significantly.

Conclusions The results confirm that pioglitazone improves glycaemic control in patients with type 2 diabetes. In addition, pioglitazone reduced the proportion of atherogenic dense LDL. The effects of pioglitazone on lipoprotein metabolism may translate into a reduced risk for atherosclerotic complications in type 2 diabetes.

Switching from EPA + DHA (Omega-3-acid Ethyl Esters) to High-Purity EPA (Icosapent Ethyl) in a Statin-Treated Patient with Persistent Dyslipidemia and High Cardiovascular Risk: A Case Study

Cardiovascular (CV) risk may remain despite statin treatment, and there is a need to address this risk with add-on therapy. The lipid effects of two different prescription omega-3 fatty acid therapies are described in a 55-year-old statin- and niacin-treated female with severe dyslipidemia and high CV risk. The patient was initially treated with omega-3-acid ethyl esters (eicosapentaenoic acid [EPA] and docosahexaenoic acid) 4 g/day. Due to persistently elevated low-density lipoprotein cholesterol (LDL-C), she was switched to icosapent ethyl (high-purity EPA ethyl ester) 4 g/day. Approximately 28 months after switching to icosapent ethyl, her LDL-C decreased by 69% to 52 mg/dL, triglycerides decreased by 35% to 119 mg/dL, non-high-density lipoprotein cholesterol (non-HDL-C) decreased by 63% to 76 mg/dL, total cholesterol decreased by 44% to 137 mg/dL, and HDL-C increased by 45% to 61 mg/dL. Total and small dense LDL particle concentrations decreased by 60 and 59%, respectively. Treatment was well tolerated, with improvements maintained over two years.

Association between small dense LDL and sub-clinical atherosclerosis in patients with psoriatic arthritis

Psoriatic arthritis (PsA) is an inflammatory rheumatic disorder occurring in patients with psoriasis. Several studies have shown an association between Psa and traditional atherosclerotic risk factors. We evaluated the relationship between small dense low-density lipoproteins particles (sd-LDL) a risk marker for atherosclerosis, sub-clinical atherosclerosis and PsA in a group of 50 patients with PsA and in 100 controls. Cholesterol, high-density lipoproteins (HDL), low-density lipoproteins (LDL), triglycerides, insulin, homeostasis model assessment (HOMA), Apo B, and sd-LDL have been measured. LDL particle separation was performed and seven LDL subfractions were obtained, LDL score (percentage of sd-LDL) and mean LDL particle size were calculated. PsA patients and control group differ significantly (p < 0.001) in triglycerides values (119.3 ± 52.0 vs 90.7 ± 40.7 mg/dL), Apo B (1.1 ± 0.2 vs 0.9 ± 0.1 g/L), insulin (8.9 ± 4.9 vs 5.8 ± 3.2 mU/L), HOMA (2.2 ± 1.7 vs 1.3 ± 0.8), BMI (27.7 ± 3.3 vs 25.8 ± 3.8). LDL score is significantly higher in PsA as compared to control (9.0 ± 10.7 vs 2.9 ± 4.7 mg/dL); and mean LDL size is significantly lower in PsA than control (268.1 ± 4.6 vs 271.2 ± 2.7 Å). These differences were confirmed when stratifying PsA patients for treatment and for disease activity. LDL score and LDL diameter significantly were correlated with the carotid IMT in patients with PsA. These findings show a novel relationship between LDL score and mean LDL size with PsA diagnosis and with sub-clinical atherosclerosis. Sd-LDL gives potentially useful information in the risk assessment for atherosclerotic disease in PsA patients.

Randomized double blind clinical trial on the effect of oral α-cyclodextrin on serum lipids

Background

This single center, double-blinded, cross-over, placebo controlled clinical trial investigated the effect of oral α-cyclodextrin (α-CD), a soluble dietary fiber, on blood lipid and lipoprotein levels in healthy human subjects. α-CD, a cyclical polymer containing 6 glucose subunits, is currently sold as an over the counter food supplement and is also a common additive in many foods. α-CD forms a hydrophobic central cavity that binds lipids and has been shown in animal studies and in previous clinical trials to alter plasma lipid levels.

Methods

We screened for healthy subjects, males and females, between ages 18 to 75. Out of total 103 subjects interviewed, 75 subjects completed the study. Qualified individuals in each gender group were randomized into two groups in terms of which treatment arm they received first (placebo vs. α-CD, receiving 6 grams P.O. a day, for 12–14 weeks with a 7 day wash out between arms). The primary outcome variable, plasma total cholesterol, as well as other tests related to lipids and lipoprotein and glucose metabolism, were measured at baseline and at the end of each arm of the study.

Results

α-CD was well tolerated; no serious adverse events related to α-CD were observed. Approximately 8 % of the subjects on α-CD complained of minor gastrointestinal symptoms versus 3 % on placebo (p = 0.2). Small-LDL particle number decreased 10 % (p < 0.045) for subjects on α-CD versus placebo. Fasting plasma glucose (1.6 %, p < 0.05) and Insulin resistance index (11 %, p < 0.04) were also decreased when on α-CD versus placebo.

Conclusion

α-CD treatment appears to be safe and well tolerated in healthy individuals and showed a modest reduction in small LDL particles, and an improvement in glucose related parameters.

Trial registration

NCT01131299

Dyslipidemia in patients with systemic lupus erythematosus: Association with disease activity and B-type natriuretic peptide levels

The aim of the present study was to evaluate the association between the levels of lipids and B-type natriuretic peptide (BNP) in systemic lupus erythematosus (SLE) patients with heart failure (HF). A total of 46 patients with active SLE and 40 healthy, age-matched control subjects were studied. BNP was measured by an immunofluorescence assay in fresh plasma. Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, apolipoprotein (Apo) B, ApoA-I and lipoprotein(a) were assessed. Compared with the control subjects, HDL-C and ApoA-I levels were considerably decreased and TG level increased markedly from SLE patients. The average concentration of HDL-C and ApoA-I in the SLE group with HF was significantly reduced compared to those patients without HF. The results showed that the levels of HDL-C and ApoA-I in SLE patients were negatively correlated with BNP. Disease activity was associated with the TC and TG levels. The present data indicated the presence of a cardiovascular (CV) risk in active SLE with high disease activity, which was demonstrated by the high frequency of dyslipidemia and higher BNP concentrations. Therefore, dyslipoproteinemia may underlie some of the increased risk for CV disease and HF in patients with SLE.

Salsalate-induced changes in lipid, lipoprotein, and apoprotein concentrations in overweight or obese, insulin-resistant, nondiabetic individuals

BACKGROUND AND OBJECTIVE

Although salsalate administration consistently lowers plasma triglyceride concentrations in patients with type II diabetes, prediabetes, and/or insulin resistance, changes in low-density lipoprotein cholesterol (LDL-C) concentrations have been inconsistent; varying from no change to a significant increase. To evaluate the clinical relevance of this discordance in more detail, we directly measured LDL-C and obtained a comprehensive assessment of changes in lipid, lipoprotein, and apoprotein concentrations associated with salsalate use in insulin-resistant individuals, overweight or obese, but without diabetes, using vertical auto profile method.

METHODS

A single-blind, randomized, placebo-controlled study was performed in volunteers who were overweight or obese, without diabetes, and insulin resistant on the basis of their steady-state plasma glucose concentration during an insulin suppression test. Participants were randomized 2:1 to receive salsalate 3.5 g/d (n = 27) or placebo (n = 14) for 4 weeks. Comprehensive lipid, lipoprotein, and apoprotein analysis by vertical auto profile was obtained after an overnight fast, before and after study intervention.

RESULTS

There was no change in directly measured LDL-C concentration in salsalate-treated individuals. However, salsalate administration was associated with various changes considered to decrease atherogenicity; including decreases in triglyceride and total very low-density lipoprotein cholesterol (VLDL-C) concentrations, a shift from small denser LDL lipoproteins toward larger, more buoyant LDL particles, decreases in VLDL(1+2)-C and LDL(4)-C, and nonsignificant decreases in non-high-density lipoprotein cholesterol and apolipoprotein B. No significant changes occurred in the placebo-treated group.

CONCLUSIONS

Atherogenicity of the lipid, lipoprotein, and apoprotein profile of insulin-resistant individuals who were overweight or obese improved significantly in association with salsalate treatment. The clinical importance of this finding awaits further study.

Propionibacterium acnes Recovered from Atherosclerotic Human Carotid Arteries Undergoes Biofilm Dispersion and Releases Lipolytic and Proteolytic Enzymes in Response to Norepinephrine Challenge In Vitro

In the present study, human atherosclerotic carotid arteries were examined following endarterectomy for the presence of the Gram-positive bacterium Propionibacterium acnes and its potential association with biofilm structures within the arterial wall. The P. acnes 16S rRNA gene was detectable in 4 of 15 carotid artery samples, and viable P. acnes was one among 10 different bacterial species recoverable in culture. Fluorescence in situ hybridization analysis of 5 additional atherosclerotic carotid arteries demonstrated biofilm bacteria within all samples, with P. acnes detectable in 4 samples. We also demonstrated that laboratory-grown cultures of P. acnes biofilms were susceptible to induction of a biofilm dispersion response when challenged with physiologically relevant levels of norepinephrine in the presence of iron-bound transferrin or with free iron. The production and release of lipolytic and proteolytic extracellular enzymes by P. acnes were shown to increase in iron-induced dispersed biofilms, and these dispersion-induced P. acnes VP1 biofilms showed increased expression of mRNAs for the triacylglycerol lipases PPA2105 and PPA1796 and the hyaluronate lyase PPA380 compared to that in untreated biofilms. These results demonstrate that P. acnes can infect the carotid arteries of humans with atherosclerosis as a component of multispecies biofilms and that dispersion is inducible for this organism, at least in vitro, with physiologically relevant levels of norepinephrine resulting in the production and release of degradative enzymes.

Relationship of the triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio to the remainder of the lipid profile: The Very Large Database of Lipids-4 (VLDL-4) study

BACKGROUND

High levels of the triglycerides to high-density lipoprotein cholesterol (TG/HDL-C) ratio are associated with obesity, metabolic syndrome, and insulin resistance.

OBJECTIVES

We evaluated variability in the remaining lipid profile, especially remnant lipoprotein particle cholesterol (RLP-C) and its components (very low-density lipoprotein cholesterol subfraction 3 and intermediate-density lipoprotein cholesterol), with variability in the TG/HDL-C ratio in a very large study cohort representative of the general U.S.

METHODS

We examined data from 1,350,908 US individuals who were clinically referred for lipoprotein cholesterol ultracentrifugation (Atherotech, Birmingham, AL) from 2009 to 2011. Demographic information other than age and sex was not available. Changes to the remaining lipid profile across percentiles of the TG/HDL-C ratio were quantified, as well as by three TG/HDL-C cut-off points previously proposed in the literature: 2.5 (male) and 2 (female), 3.75 (male) and 3 (female), and 3.5 (male and female).

RESULTS

The mean age of our study population was 58.7 years, and 48% were men. The median TG/HDL-C ratio was 2.2. Across increasing TG/HDL-C ratios, we found steadily increasing levels of RLP-C, non-HDL-C and LDL density. Among the lipid parameters studied, RLP-C and LDL density had the highest relative increase when comparing individuals with elevated TG/HDL-C levels to those with lower TG/HDL-C levels using established cut-off points. Approximately 47% of TG/HDL-C ratio variance was attributable to RLP-C.

CONCLUSIONS

In the present analysis, a higher TG/HDL-C ratio was associated with an increasingly atherogenic lipid phenotype, characterized by higher RLP-C along with higher non-HDL-C and LDL density.

[Atherogenic indices in workers of different occupational sectors of the Spanish Mediterranean area]

INTRODUCTION

Atherogenic indices predict cardiovascular disease, as they provide a good reflection of the clinical and metabolic interactions of lipid fractions.

MATERIAL AND METHOD

A descriptive cross-sectional study was conducted on 60,798 workers in the Spanish Mediterranean area on whom different atherogenic indices (cholesterol/HDL, LDL/HDL, triglycerides/HDL) were determined, and the influence they have in the different productive work sectors.

RESULTS

In women, the mean values of the different atherogenic indices are better in the health sector, while they are better in men in the primary sector. The percentage of working women with low values is also greater in the healthcare sector, while in men there is no clear predominant sector, with the best values being shown in the hospitality and primary sector.

CONCLUSION

The distribution of cardiovascular risk factors and the values of the different atherogenic indices analyzed vary in different industrial sectors.

Flaxseed oil intake reduces serum small dense low-density lipoprotein concentrations in Japanese men: a randomized, double blind, crossover study

BACKGROUND

The effects of alpha-linolenic acid (ALA) on cardiovascular risk factors considerably vary between published reports. Therefore, we investigated the effects of 12-week supplementation with flaxseed oil (FO), which is a rich source of ALA, on cardiovascular risk factors such as serum small dense low-density lipoprotein (sd-LDL) concentrations.

METHODS

In a randomized, double blind, crossover study, 15 subjects ingested 10 g of FO or corn oil (CO), containing 5.49 g and 0.09 g of ALA, respectively, once daily with dinner. Blood samples were collected at 0, 4 and 12 weeks, and were used for analysis of serum lipid, lipid-related proteins, serum fatty acids and serum sd-LDL cholesterol. Differences during the test period were identified using a repeated-measures analysis of variance (ANOVA) for within-group effects. Group differences were identified using paired t-test at each blood sampling time point.

RESULTS

ALA and eicosapentaenoic acid concentrations were significantly higher in the FO period at 4 and 12 weeks than in the CO period. No significant differences in docosahexaenoic acid concentrations were observed between two periods, and cholesteryl ester transfer protein and apolipoprotein B concentrations were significantly lower in the FO period than in the CO period at 12 weeks. FO supplementation was associated with a significant decrease in sd-LDL concentrations at 4 and 12 weeks, and CO supplementation had no effect. Moreover, sd-LDL concentrations were significantly lower in the FO period than in the CO period at 4 weeks. Among subjects with triglyceride (TG) concentrations of >100 mg/dl, FO supplementation markedly reduced sd-LDL concentrations at 4 and 12 weeks compared with baseline. Sd-LDL concentrations significantly differed between the periods at both 4 and 12 weeks.

CONCLUSION

This study indicates that the FO, which is a rich source of ALA, leads to lower sd-LDL cholesterol concentrations.

Lipidomic analysis of plasma, erythrocytes and lipoprotein fractions of cardiovascular disease patients using UHPLC/MS, MALDI-MS and multivariate data analysis

Differences among lipidomic profiles of healthy volunteers, obese people and three groups of cardiovascular disease (CVD) patients are investigated with the goal to differentiate individual groups based on the multivariate data analysis (MDA) of lipidomic data from plasma, erythrocytes and lipoprotein fractions of more than 50 subjects. Hydrophilic interaction liquid chromatography on ultrahigh-performance liquid chromatography (HILIC-UHPLC) column coupled with electrospray ionization mass spectrometry (ESI-MS) is used for the quantitation of four classes of polar lipids (phosphatidylethanolamines, phosphatidylcholines, sphingomyelins and lysophosphatidylcholines), normal-phase UHPLC-atmospheric pressure chemical ionization MS (NP-UHPLC/APCI-MS) is applied for the quantitation of five classes of nonpolar lipids (cholesteryl esters, triacylglycerols, sterols, 1,3-diacylglycerols and 1,2-diacylglycerols) and the potential of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is tested for the fast screening of all lipids without a chromatographic separation. Obtained results are processed by unsupervised (principal component analysis) and supervised (orthogonal partial least squares) MDA approaches to highlight the largest differences among individual groups and to identify lipid molecules with the highest impact on the group differentiation.

Involvement of RBP4 in hyperinsulinism-induced vascular smooth muscle cell proliferation

Retinol-binding protein 4 (RBP4) is a newly discovered adipocytokine related to insulin resistance (IR). Hyperinsulinemia and IR are the major risk factors for cardiovascular diseases (CVD). The role of RBP4 in CVD has not yet been determined. The present study was designed to analyze the correlation of RBP4 and CVD risk factors and to evaluate the role of RBP4 in proliferation of vascular smooth muscle cells during hyperinsulinemia and the underlying mechanisms. Plasma RBP4 concentration, IR-related indexes, and cardiovascular risk factors were measured from blood samples of hyperinsulinemic rats (HIns) and control SD rats (Cons). The vascular morphology and the expression of ERK1/2, p-ERK1/2 in arterial tissues of rats were assessed. Different concentrations of RBP4 (1, 4 μg/ml) were used as intervention factor during insulin-induced aortic smooth muscle cells (RASMCs) proliferation. The expression of cell growth signaling pathways was assessed to identify the active pathway during this proliferation. Specifically, ERK1/2 inhibitor PD98059 and JAK2 inhibitor AG490 were used to detect it. RBP4 expression was higher in HIns compared with Cons (p < 0.01). Plasma RBP4 concentrations were positively correlated with TG (r = 0.490), hsCRP (r = 0.565), media thickness (r = 0.890), and p-ERK1/2 protein (r = 0.746) (p < 0.05 each). In cultured RASMCs, RBP4 enhanced insulin-induced proliferation of cells and expression of p-ERK1/2 and p-JAK2. Blockade of ERK1/2 signaling pathway inhibited RBP4-induced proliferation of RASMCs, while suppressing JAK2 remains unchanged. These results suggest that plasma RBP4 concentrations were associated with CVD. In addition, RBP4 increases the proliferation of VSMCs induced by hyperinsulinism via activation of MAPK signaling pathway.

High Postprandial Triglycerides Serum Levels: Is Obesity a Good Predictor?

The aim of this study was to analyze the correlation between triglyceride (TG) serum levels in obese and non-obese patients in a simulated postprandial state. Both groups showed TG levels < 150 mg/dL when fasting. After 12 h fasting, the subjects ingested a lipid overload diet and blood samples were collected. The variation between fasting and the postprandial TG peak levels were analyzed. The peak of postprandial TG levels occurred 4 h after the lipid overload in both groups. When the subjects were not fasting, the majority of non-obese subjects remained within the range of normal TG values, but the values for the obese group remained elevated. There was a significant correlation between Body Mass Index (BMI) and TG at each time point until 2 h after the meal, but the data did not show a correlation after 3 h. According to the receiver-operating characteristics (ROC) curve, postprandial TG values were not a good predictor of obesity (based on BMI), but they were a predictor of non-obesity. This study reinforces the importance of measuring non-fasting TG levels in obese and non-obese subjects, because some non-obese patients probably had altered fat metabolism, indicating that this examination could be an indicator of metabolic risk.

A 16-week study to compare the effect of vildagliptin versus gliclazide on postprandial lipoprotein concentrations and oxidative stress in patients with type 2 diabetes inadequately controlled with metformin monotherapy

BACKGROUND

Diabetes is closely linked with coronary artery disease, either by means of direct effects of hyperglycemia, or indirectly by its frequent association with dyslipidemia. Any treatment for diabetes that has beyond the capacity of reduce glycated hemoglobin, the propensity to improve lipid profile and reduce weight will bring many benefits to patients.

METHOD

We compare the effects of vildagliptin with the gliclazide on lipid profile before and after a standardized meal test, on glycemic control and oxidative stress in diabetic patients using metformin without adequate glycemic control. This is a prospective study of 16 weeks with diabetic patients using metformin without adequate glycemic control. Patients were randomized to receive gliclazide 30-120 mg/day or vildagliptin 100 mg/day.

RESULTS

36 patients were randomized, with no loss of follow up. Regarding the lipid profile the difference observed at the end of the study was a higher HDL level in the vildagliptin group compared with gliclazide fasting (62.3 vs. 51.3 mg/dL, p = 0.021) and postprandial (62.9 vs. 51.1 mg/dL, p = 0.015). We also observed a variation of negative weight (decrease the end compared to the beginning) of the vildagliptin and a positive (increase) in the gliclazide (-0.3 vs. +1.4 Kg, p = 0.048). The decrease in A1c was lower in the vildagliptin group compared to gliclazide (-1.7 vs.-2.3 %, P = 0.031), however there was no difference in the number of patients reaching target glycated hemoglobin <7 % (50 vs. 61.1 %, p = 0.738). Only the group of vildagliptin presented at the end of the study compared to the beginning, decreased insulin values (599.6 vs.705, 59 pg/ml, p = 0.021), glucagon (46.6 vs.65, 2 pg/ml, p = 0.004) and the marker of oxidative stress TBARS (8.0 vs. 9.0 nmol MDA/ml, p = 0.035).

CONCLUSION

Vildagliptin showed some advantages in addition to metformin in relation to addition of gliclazide. Patients treated with vildagliptin had a higher HDL at the end of the study, less variance in weight, reduced insulin and glucagon as well as reduction of oxidative stress.

Effects of icosapent ethyl on lipoprotein particle concentration and size in statin-treated patients with persistent high triglycerides (the ANCHOR Study)

BACKGROUND

Icosapent ethyl (IPE) is a high-purity prescription form of eicosapentaenoic acid ethyl ester approved at a dose of 4 g/day as an adjunct to diet to reduce triglyceride (TG) levels in adult patients with severe hypertriglyceridemia (TG ≥ 500 mg/dL).

OBJECTIVE

In this prespecified exploratory analysis from the ANCHOR study of patients at high cardiovascular risk with TG ≥ 200 and <500 mg/dL despite statin control of low-density lipoprotein cholesterol, we assessed the effects of IPE on lipoprotein particle concentration and size and examined correlations of atherogenic particles with apolipoprotein B (ApoB).

METHODS

Nuclear magnetic resonance spectroscopy was used to measure lipoprotein particle concentration and size.

RESULTS

Compared with placebo (n = 211), IPE 4 g/day (n = 216) significantly reduced concentrations of: total (12.2%, P = .0002), large (46.4%, P < .0001), and medium (12.1%, P = .0068) very-low-density lipoprotein (VLDL) particles; total (7.7%, P = .0017) and small (13.5%, P < .0001) LDL particles; and total (7.4%, P < .0001) and large (31.0%, P < .0001) high-density lipoprotein particles. Atherogenic lipoprotein particles (total VLDL and total LDL) correlated with ApoB at baseline (R(2) = 0.57) and week 12 (R(2) = 0.65) as did total LDL particle concentration at baseline (R(2) = 0.53) and week 12 (R(2) = 0.59). Compared with placebo, IPE 4 g/day significantly reduced VLDL (7.7%, P < .0001) and high-density lipoprotein (1.2%, P = .0014) particle sizes with a modest but significant increase in LDL particle size (0.5%, P = .0031).

CONCLUSIONS

Compared with placebo, treatment with IPE 4 g/day for 12 weeks reduced key atherogenic lipoprotein particle concentrations. At both baseline and end of study, atherogenic lipoprotein concentrations correlated with ApoB.

The traditions and risks of fasting for lipid profiles in patients with diabetes

Fasting overnight has been traditionally recommended by clinicians when ordering laboratory tests for lipid profiles for the purposes of health screening or monitoring of the effects of lipid-lowering medications. Patients with diabetes are tested for lipid profiles at least annually. This deeply rooted tradition of fasting for lipid testing has recently been challenged. Several studies have shown little benefit obtained by testing lipids in fasting compared with postprandial states. Furthermore, recent studies have shown the importance of postprandial lipid spikes in the pathogenesis of cardiovascular disease. At the same time, recent reports have alerted the medical community to the risk of hypoglycemia in patients with diabetes on antidiabetic medications (particularly insulin and sulfonylureas) who are asked to fast for lab tests. This article reviews the literature on these emerging issues in lipid testing in patients with diabetes, and offers recommendations for lipid testing in these patients in view of these emerging discussions.

Peripheral arterial disease, type 2 diabetes and postprandial lipidaemia: Is there a link?

Peripheral arterial disease, manifested as intermittent claudication or critical ischaemia, or identified by an ankle/brachial index < 0.9, is present in at least one in every four patients with type 2 diabetes mellitus. Several reasons exist for peripheral arterial disease in diabetes. In addition to hyperglycaemia, smoking and hypertension, the dyslipidaemia that accompanies type 2 diabetes and is characterised by increased triglyceride levels and reduced high-density lipoprotein cholesterol concentrations also seems to contribute to this association. Recent years have witnessed an increased interest in postprandial lipidaemia, as a result of various prospective studies showing that non-fasting triglycerides predict the onset of arteriosclerotic cardiovascular disease better than fasting measurements do. Additionally, the use of certain specific postprandial particle markers, such as apolipoprotein B-48, makes it easier and more simple to approach the postprandial phenomenon. Despite this, only a few studies have evaluated the role of postprandial triglycerides in the development of peripheral arterial disease and type 2 diabetes. The purpose of this review is to examine the epidemiology and risk factors of peripheral arterial disease in type 2 diabetes, focusing on the role of postprandial triglycerides and particles.

Genomics of post-prandial lipidomic phenotypes in the Genetics of Lipid lowering Drugs and Diet Network (GOLDN) study

BACKGROUND

Increased postprandial lipid (PPL) response to dietary fat intake is a heritable risk factor for cardiovascular disease (CVD). Variability in postprandial lipids results from the complex interplay of dietary and genetic factors. We hypothesized that detailed lipid profiles (eg, sterols and fatty acids) may help elucidate specific genetic and dietary pathways contributing to the PPL response.

METHODS AND RESULTS

We used gas chromatography mass spectrometry to quantify the change in plasma concentration of 35 fatty acids and 11 sterols between fasting and 3.5 hours after the consumption of a high-fat meal (PPL challenge) among 40 participants from the GOLDN study. Correlations between sterols, fatty acids and clinical measures were calculated. Mixed linear regression was used to evaluate associations between lipidomic profiles and genomic markers including single nucleotide polymorphisms (SNPs) and methylation markers derived from the Affymetrix 6.0 array and the Illumina Methyl450 array, respectively. After the PPL challenge, fatty acids increased as well as sterols associated with cholesterol absorption, while sterols associated with cholesterol synthesis decreased. PPL saturated fatty acids strongly correlated with triglycerides, very low-density lipoprotein, and chylomicrons. Two SNPs (rs12247017 and rs12240292) in the sorbin and SH3 domain containing 1 (SORBS1) gene were associated with b-Sitosterol after correction for multiple testing (P≤4.5*10(-10)). SORBS1 has been linked to obesity and insulin signaling. No other markers reached the genome-wide significance threshold, yet several other biologically relevant loci are highlighted (eg, PRIC285, a co-activator of PPARa).

CONCLUSIONS

Integration of lipidomic and genomic data has the potential to identify new biomarkers of CVD risk.

Association of lifestyle-related factors with circadian onset patterns of acute myocardial infarction: a prospective observational study in Japan

OBJECTIVE

The onset of acute myocardial infarction (AMI) shows characteristic circadian variations involving a definite morning peak and a less-defined night-time peak. However, the factors influencing the circadian patterns of AMI onset and their influence on morning and night-time peaks have not been fully elucidated.

DESIGN, SETTING AND PARTICIPANTS

An analysis of patients registered between 1998 and 2008 in the Osaka Acute Coronary Insufficiency Study, which is a prospective, multicentre observational study of patients with AMI in the Osaka region of Japan. The present study included 7755 consecutive patients with a known time of AMI onset.

MAIN OUTCOMES AND MEASURES

A mixture of two von Mises distributions was used to examine whether a circadian pattern of AMI had uniform, unimodal or bimodal distribution, and the likelihood ratio test was then used to select the best circadian pattern among them. The hierarchical likelihood ratio test was used to identify factors affecting the circadian patterns of AMI onset. The Kaplan-Meier method was used to estimate survival curves of 1-year mortality according to AMI onset time.

RESULTS

The overall population had a bimodal circadian pattern of AMI onset characterised by a high and sharp morning peak and a lower and less-defined night-time peak (bimodal p<0.001). Although several lifestyle-related factors had a statistically significant association with the circadian patterns of AMI onset, serum triglyceride levels had the most prominent association with the circadian patterns of AMI onset. Patients with triglyceride ≥150 mg/dL on admission had only one morning peak in the circadian pattern of AMI onset during weekdays, with no peaks detected on weekends, whereas all other subgroups had two peaks throughout the week.

CONCLUSIONS

The circadian pattern of AMI onset was characterised by bimodality. Notably, several lifestyle-related factors, particularly serum triglyceride levels, had a strong relation with the circadian pattern of AMI onset.

TRIAL REGISTRATION NUMBER

UMIN000004575.

Small dense low-density lipoprotein-cholesterol concentrations predict risk for coronary heart disease: the Atherosclerosis Risk In Communities (ARIC) study

OBJECTIVE

To investigate the relationship between plasma levels of small dense low-density lipoprotein-cholesterol (sdLDL-C) and risk for incident coronary heart disease (CHD) in a prospective study among Atherosclerosis Risk in Communities (ARIC) study participants.

APPROACH AND RESULTS

Plasma sdLDL-C was measured in 11 419 men and women of the biracial ARIC study using a newly developed homogeneous assay. A proportional hazards model was used to examine the relationship among sdLDL-C, vascular risk factors, and risk for CHD events (n=1158) for a period of ≈11 years. Plasma sdLDL-C levels were strongly correlated with an atherogenic lipid profile and were higher in patients with diabetes mellitus than non-diabetes mellitus (49.6 versus 42.3 mg/dL; P<0.0001). In a model that included established risk factors, sdLDL-C was associated with incident CHD with a hazard ratio of 1.51 (95% confidence interval, 1.21-1.88) for the highest versus the lowest quartile, respectively. Even in individuals considered to be at low cardiovascular risk based on their LDL-C levels, sdLDL-C predicted risk for incident CHD (hazard ratio, 1.61; 95% confidence interval, 1.04-2.49). Genome-wide association analyses identified genetic variants in 8 loci associated with sdLDL-C levels. These loci were in or close to genes previously associated with risk for CHD. We discovered 1 novel locus, PCSK7, for which genetic variation was significantly associated with sdLDL-C and other lipid factors.

CONCLUSIONS

sdLDL-C was associated with incident CHD in ARIC study participants. The novel association of genetic variants in PCSK7 with sdLDL-C and other lipid traits may provide new insights into the role of this gene in lipid metabolism.

Narrowing sex differences in lipoprotein cholesterol subclasses following mid-life: the very large database of lipids (VLDL-10B)

Background

Women have less risk of atherosclerotic cardiovascular disease compared with men up until midlife (ages 50 to 60), after which the gap begins to narrow post menopause. We hypothesized that the average lipid profile of women undergoes unfavorable changes compared with men after midlife.

Methods and Results

We examined lipids by sex and age in the Very Large Database of Lipids 10B (VLDL 10B) study. The analysis included 1 350 908 unique consecutive patients clinically referred for lipoprotein testing by density gradient ultracentrifugation from 2009 to 2011. Ratio variables were created for density subclasses of LDL‐C, HDL‐C, and VLDL‐C (LLDR, LHDR, LVDR, respectively). Men showed higher median LDL‐C values than women for ages 20 to 59, with the greatest difference in their 30s: 146 mg/dL in men versus 130 mg/dL in women. In contrast, women consistently had higher values after midlife (age 60), for example ages 70 to 79: 129 mg/dL in women versus 112 mg/dL in men. After age 50, women had higher LDL‐C each decade, for example 14% higher from their 30s to 50s, while HDL‐C concentrations did not differ. Women had more buoyant LDL‐C and HDL‐C (lower LLDR and LHDR) than men at all ages but the gap closed in higher age groups. In contrast, women had a generally denser VLDL‐C (higher LVDR) leading into midlife, with the gap progressively closing in higher age groups, approximating that of men in their 60s and 70s.

Conclusion

The narrowing sex differential in cardiovascular disease risk after midlife is mirrored by a higher total atherogenic lipoprotein cholesterol burden in women and a closer approximation of the less favorable density phenotype characteristic of men.

Effects of atorvastatin 10 mg and fenofibrate 200 mg on the low-density lipoprotein profile in dyslipidemic patients: A 12-week, multicenter, randomized, open-label, parallel-group study

BACKGROUND

Elevated plasma low-density lipoprotein cholesterol (LDL-C) concentrations are highly atherogenic, especially the small, dense LDL (sdLDL) species. Fenofibrate has been reported to shift the LDL profile by decreasing the sdLDL subfraction and increasing larger LDL subclasses. Atorvastatin, anantihyperlipidemic agent, has been reported to reduce plasma total cholesterol (TC) and triglyceride (TG) concentrations and thus could modify the LDL profile.

OBJECTIVE

The aim of this study was to compare the effects of fenofi brate and atorvastatin on standard lipid concentrations and the LDL profile.

METHODS

In this randomized, open-label, parallel-group study, men and women aged 18 to 79 years with type II primary dyslipidemia, defined as LDL-C ≥160 and TG 150 to 400 mg/dL, after a 4- to 6-week washout period while eating an appropriate diet, were randomized to receive either atorvastatin 10 mg once daily or fenofi-brate 200 mg once daily. Plasma lipid concentrations and cholesterol and apolipoprotein (apo) B (reflecting the LDL particle number) in each LDL subfraction prepared by ultracentrifiigation were determined at baseline and after 12 weeks of treatment. Tolerability was assessed using adverse events (AEs) obtained on laboratory analysis and vital sign measurement. Adherence was assessed by counting unused drug supplies.

RESULTS

A total of 165 patients (117 men, 48 women; mean [SD] age, 50.1 [10.7] years; mean TC concentration, 289 mg/dL) were randomized to receive atorvastatin (n = 81) or fenofibrate (n = 84). Compared with fenofibrate, atorvastatin was associated with a significantly greater mean (SD) percentage decrease in TC (27.0% [12.3%] vs 16.5% [12.9%]; P < 0.001), calculated LDL-C (35.4% [15.8%] vs 17.3% [17.2%]; P < 0.001), TC/high-density lipoprotein cholesterol (HDL-C) ratio (29.1% [16.3%] vs 22.9% [15.9%]; P = 0.001), and apoB (30.3% [12.7%] vs 19.6% [15.5%]; P < 0.001). Compared with atorvastatin, fenofibrate was associated with a significantly greater decrease in TG (37.2% [25.9%] vs 20.2% [27.3%]; P < 0.001) and a significantly greater increase in HDL-C concentration (10.4% [15.7%] vs 4.6% [12.1%]; P = 0.017). Fibrinogen concentration was significantly different between the 2 groups (P = 0.002); it was decreased with fenofibrate use (4.6% [23.7%]) and was increased with atorvastatin use (5.7% [23.5%]). Atorvastatin did not markedly affect the LDL distribution; it was associated with a homogeneous decrease in cholesterol and apoB concentrations in all subfractions, whereas fenofibrate was associated with a marked movement toward a normalized LDL profile, shifting the sdLDL subfractions toward larger and less atherogenic particles, particularly in those patients with baseline TG ≥200 mg/dL. No serious AEs related to the study treatments were reported. A total of 5 AEs were observed in 8 patients, including: abdominal pain, 3 patients (2 in the atorvastatin group and 1 in the fenofibrate group); abnormal liver function test results, 1 (fenofibrate); increased creatine Phosphokinase activity, 2 (atorvastatin); gastrointestinal disorders, 1 (fenofibrate); and vertigo, 1 (fenofibrate).

CONCLUSION

In these dyslipidemic patients, fenofibrate treatment was associated with an improved LDL subfraction profile beyond reduction in LDL-C, particularly in patients with elevated TG concentration, whereas atorvastatin was associated with equally reduced concentrations of cholesterol and apoB in all LDL subfractions independent of TG concentrations.

Beneficial effects of rosuvastatin treatment in patients with metabolic syndrome

We determined the effect of 6-month rosuvastatin treatment on blood lipids, oxidative parameters, apolipoproteins, high-sensitivity C-reactive protein, lipoprotein(a), homocysteine, and glycated hemoglobin (HbA1c) in patients with metabolic syndrome (MetS). Healthy individuals (men aged >40 years and postmenopausal women) with a body mass index ≥ 30 (n = 100) who fulfilled the National Cholesterol Education Program Adult Treatment Panel III diagnostic criteria for MetS were included. Total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels decreased (P < .0001). The change in LDL 1 to 3 subgroups was significant (P = .0007, P < .0001, and P = .006, respectively). Changes in LDL 4 to 7 subgroups were not significant. There was a beneficial effect on oxidized LDL, fibrinogen, homocysteine, and HbA1c. Rosuvastatin significantly increased high-density lipoprotein levels (P = .0003). The oxidant/antioxidant status and subclinical inflammatory state were also beneficially changed. Rosuvastatin had a significant beneficial effect on atherogenic dyslipidemia as well as on oxidative stress and inflammatory biomarkers in patients with MetS.

Sexual dimorphism in the effects of exercise on metabolism of lipids to support resting metabolism

Exercise training is generally a healthful activity and an effective intervention for reducing the risk of numerous chronic diseases including cardiovascular disease and diabetes. This is likely both a result of prevention of weight gain over time and direct effects of exercise on metabolism of lipids and the other macronutrient classes. Importantly, a single bout of exercise can alter lipid metabolism and metabolic rate for hours and even into the day following exercise, so individuals who regularly exercise, even if not performed every single day, overall could experience a substantial change in their resting metabolism that would reduce risk for metabolic diseases. However, resting metabolism does not respond similarly in all individuals to exercise participation, and indeed gender or sex is a major determinant of the response of resting lipid metabolism to prior exercise. In order to fully appreciate the metabolic effects and health benefits of exercise, the differences between men and women must be considered. In this article, the differences in the effects of exercise on resting metabolic rate, fuel selection after exercise, as well as the shuttling of triglyceride and fatty acids between tissues are discussed. Furthermore, concepts related to sex differences in the precision of homeostatic control and sex differences in the integration of metabolism between various organs are considered.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effect of green tea extract microencapsulation on hypertriglyceridemia and cardiovascular tissues in high fructose-fed rats

The application of polyphenols has attracted great interest in the field of functional foods and nutraceuticals due to their potential health benefits in humans. However, the effectiveness of polyphenols depends on their bioactivity and bioavailability. In the present study, the bioactive component from green tea extract (GTE) was administrated orally (50 mg/kg body weight/day) as free or in a microencapsulated form with maltodextrin in rats fed a high fructose diet. High fructose diet induced features of metabolic syndrome including hypertriglyceridemia, hyperuricemia, increased serum total cholesterol, and retroperitoneal obesity. In addition, myocardial fibrosis was increased. In rats receiving high fructose diet, the lowering of blood triglycerides, total cholesterol, non esterified fatty acid (NEFA) and uric acid, as well as the reduction in final body weight and retroperitoneal fat weight associated with the administration of GTE, led to a reversal of the features of metabolic syndrome (P < 0.05). In particular, the administration of microencapsulated GTE decreased myocardial fibrosis and increased liver catalase activity consistent with a further alleviation of serum NEFA, and hyperuricemia compared to administration of GTE. Taken together, our results suggest that microencapsulation of the bioactive components of GTE might have a protective effect on cardiovasucular system by attenuating the adverse features of myocardial fibrosis, decreasing uric acid levels and increasing hepatic catalase activity effectively by protecting their bioactivities.

The effect of intensive glucose lowering on lipoprotein particle profiles and inflammatory markers in the Veterans Affairs Diabetes Trial (VADT)

OBJECTIVE

Intensive glucose-lowering therapy (INT) did not reduce macrovascular events in the recent randomized trials, possibly because it did not improve or worsen other traditional or novel cardiovascular risk factors.

RESEARCH DESIGN AND METHODS

Standard plasma lipids, cholesterol content of lipoprotein subfractions, and plasma inflammatory and prothrombotic markers were determined in a subgroup of the Veterans Affairs Diabetes Trial (VADT) participants (n = 266) at baseline and after 9 months of INT or standard therapy.

RESULTS

INT lowered glycated hemoglobin (by a median of 2% vs. a median of 0.7% by standard treatment; P < 0.0001); increased BMI (4 vs. 1%; P < 0.001), total HDL (9 vs. 4%; P < 0.05), HDL2 (14 vs. 0%; P = 0.009), LDL2 (36 vs. 1%; P < 0.0001), and plasma adiponectin (130 vs. 80%; P < 0.01); and reduced triglycerides (-13 vs. -4%; P = 0.02) and small, dense LDL4 (-39 vs. -13%; P < 0.001), but had no effect on levels of plasma apolipoproteins B-100 and B-48, C-reactive protein, interleukin-6, lipoprotein-associated phospholipase A2, myeloperoxidase, fibrinogen, and plasminogen activator inhibitor 1. Incident macrovascular events were associated with baseline interleukin-6 (hazard ratio per each quartile increase 1.33 [95% CI 1.06-1.66]), total LDL (1.25 [1.01-1.55]), apolipoprotein B-100 (1.29 [1.01-1.65]), and fibrinogen (1.26 [1.01-1.57]) but not changes in any cardiovascular risk factors at 9 months.

CONCLUSIONS

INT was associated with improved adiponectin, lipid levels, and a favorable shift in LDL and HDL subfractions after 9 months. These data suggest that the failure of INT to lower cardiovascular outcomes occurred despite generally favorable changes in standard and novel risk factors early in the study.

Effect of hypolipidemic treatment on emerging risk factors in mixed dyslipidemia: a randomized pilot trial

BACKGROUND

The effects of different hypolipidemic treatment strategies on emerging atherosclerosis risk factors remain unknown.

MATERIALS AND METHODS

This is a prespecified analysis of a prospective, randomized, open-label, blinded end point (PROBE) study (ClinicalTrials.gov identifier: NCT01010516). Patients (n = 100) with mixed dyslipidaemia on a standard statin dose who had not achieved lipid targets were randomized to switch to the highest dose of rosuvastatin (40 mg/day) or to add-on-statin extended release nicotinic acid (ER-NA)/laropiprant (LRPT) or to add-on-statin micronized fenofibrate for a total of 3 months.

RESULTS

Following 3 months of treatment, low-density lipoprotein (LDL) particle size increased equally in all groups. Similarly, all treatments were associated with comparable small dense LDL cholesterol reduction. Apolipoprotein B levels decreased by 15%, 7% and 4% in the rosuvastatin, add-on ER-NA/LRPT and add-on fenofibrate group, respectively (P < 0.01 for all compared with baseline, P < 0.01 for all comparisons between groups). Only add-on ER-NA/LRPT was associated with lipoprotein (a) reduction (26%, P < 0.01 compared with baseline). Rosuvastatin monotherapy and add-on ER-NA/LRPT groups were associated with 56% and 24% reduction in high-sensitivity C-reactive protein levels (hsCRP), respectively (P < 0.01 compared with baseline), while add-on fenofibrate was not associated with changes in hsCRP concentration. Lipoprotein-associated phospholipase A2 (Lp-PLA2) activity decreased similarly in both rosuvastatin and add-on fenofibrate groups, while add-on ER-NA/LRPT was associated with a more pronounced Lp-PLA2 activity reduction. ER-NA/LRPT was associated with more side effects compared with rosuvastatin and add-on fenofibrate.

CONCLUSIONS

Add-on ER-NA/LRPT followed by switch to the highest dose rosuvastatin were associated with more pronounced beneficial modifications in emerging cardiovascular risk factors compared with add-on fenofibrate in patients with mixed dyslipidaemia.

Two novel mutations in apolipoprotein C3 underlie atheroprotective lipid profiles in families

Apolipoprotein C3 (APOC3) mutations carriers typically display high plasma high-density lipoprotein cholesterol (HDL-C) and low triglycerides (TGs). We set out to investigate the prevalence and clinical consequences of APOC3 mutations in individuals with hyperalphalipoproteinemia. Two novel mutations (c.-13-2A>G and c.55+1G>A) and one known mutation (c.127G>A;p.Ala43Thr) were found. Lipid profiles and apoCIII isoform distributions were measured. c.55+1G>A mutation carriers displayed higher HDL-C percentiles (35.6 ± 35.8 vs 99.0 ± 0, p = 0.002) and lower TGs (0.51 (0.37-0.61) vs 1.42 (1.12-1.81) mmol/l, p = 0.007) and apoCIII levels (4.24 ± 1.57 vs 7.33 ± 3.61 mg/dl, p = 0.18). c.-13-2A>G mutation carriers did not display significantly different HDL-C levels (84.0 ± 30.0 vs 63.7 ± 45.7, p = 0.50), a trend towards lower TGs [0.71 (0.54 to 0.78) vs 0.85 (0.85 to -) mmol/l, p = 0.06] and significantly lower apoCIII levels (3.09 ± 1.08 vs 11.45 ± 1.06 mg/dl, p = 0.003). p.Ala43Thr mutation carriers displayed a trend towards higher HDL-C percentiles (91.2 ± 31.8 vs 41.0 ± 29.7 mmol/l, p = 0.06) and significantly lower TGs [0.58 (0.36-0.63) vs 0.95 (0.71-1.20) mmol/l, p = 0.02] and apoCIII levels (4.92 ± 2.33 vs 6.60 ± 1.60, p = 0.25). Heterozygosity for APOC3 mutations results in high HDL-C and low TGs and apoCIII levels. This favourable lipid profile in patients with genetically low apoCIII levels holds promise for current studies investigating the potential of apoCIII inhibition as a novel therapeutic in cardiovascular disease prevention.

Hypoadiponectinemia: a useful marker of dyslipidemia in women with polycystic ovary syndrome

OBJECTIVE

Adiponectin plays a role in obesity, lipid metabolism, and anti-inflammation. Women with polycystic ovary syndrome (PCOS) are also at risk for dyslipidemia. Therefore, we investigated the association between adiponectin levels and the lipid profile including high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TGs) in women with PCOS and contemplated what role adiponectin might play in dyslipidemia with PCOS.

MATERIALS AND METHODS

We recruited 118 young Taiwanese women with PCOS. The women enrolled were not taking any medication and those with other systemic diseases of nonovarian origin, which could have affected the hypothalamic-pituitary-ovarian axis, were excluded. The serum lipid profile, metabolic and hormonal parameters, and adiponectin were measured. The lipid profile and adiponectin were analyzed and adjusted for age, body mass index (BMI), homeostasis model assessment-insulin resistance (HOMA-IR), and sex hormone-binding globulin (SHBG).

RESULTS

In a simple linear regression, adiponectin was significantly inversely related to LDL-C and TGs, but positively related to HDL-C (all p < 0.001) after logarithmic transformation. In the multiple linear regression, adiponectin was significantly related to HDL-C (p < 0.001) independent of age, BMI, HOMA-IR, and SHBG after logarithmic transformation. Using a logistic regression, the odds ratio was 0.088 between the association of increased adiponectin and abnormal HDL-C (≤ 50 mg/dL).

CONCLUSIONS

We demonstrated that adiponectin is an independent biomarker that is positively and evidently related to HDL-C and TGs in women with PCOS. Hypoadiponectinemia may be a useful marker of dyslipidemia in women with PCOS.

Elucidation of mechanisms of actions of thymoquinone-enriched methanolic and volatile oil extracts from Nigella sativa against cardiovascular risk parameters in experimental hyperlipidemia

BACKGROUND

Nigella sativa belonging to the Ranunculaceae family has been reported to use for thousands of years as protective and curative traditional medicine against a number of diseases. GC-MS analysis of methanolic extract (ME) and volatile oil (VO) extracted from Nigella sativa seed oil was performed by two different mass spectrometry libraries, WIlEY8 and NIST05s. The cholesterol lowering and antioxidant actions of VO and ME fractions were investigated in atherogenic suspension fed rats.

METHODS

In this study, four groups of male Wistar rats were used: normolipidemic control (NLP-C), hyperlipidemic control (HLP-C), methanolic extract (HLP-ME) and volatile oil treated (HLP-VO) groups for 30 days of duration. P value < 0.05 was assumed as significant data in groups.

RESULTS

Administration of atherogenic suspension to male Wistar rats for 30 days resulted in a marked increase of plasma triglycerides and total cholesterol, and significant change in plasma lipoprotein levels along with a decrease in antioxidant arylesterase activity in hyperlipidemic control (HLP-C) group. The oral feeding of 100 mg ME or 20 mg VO per rat/day effectively reduced the plasma triglycerides to near normal level, while high density lipoprotein cholesterol and its subfraction along with arylesterase activity levels were significantly increased. The test fractions elicited a significant decrease in hepatic HMG-CoA reductase activity. The fractions significantly blocked the ex vivo basal and in vitro maximal formation of conjugated diene and malondialdehyde, and lengthened the lag times of low density lipoprotein, small dense low density lipoprotein and large buoyant low density lipoprotein. ME possessing ω-6 linoleic acid along with palmitic acid active compounds was more effective than VO extract containing thymol and isothymol phenolic antioxidant compounds, thymoquinone phenolic compound common to the both extracts, via reduction in hepatic HMG-CoA reductase activity as well as antioxidant mechanisms.

CONCLUSION

The both extracts especially, ME significantly improve cardiovascular risk parameters in treated rats, and can be used in reactive oxygen species disorders such as cardiovascular diseases.

Dietary fats and health: dietary recommendations in the context of scientific evidence

Although early studies showed that saturated fat diets with very low levels of PUFAs increase serum cholesterol, whereas other studies showed high serum cholesterol increased the risk of coronary artery disease (CAD), the evidence of dietary saturated fats increasing CAD or causing premature death was weak. Over the years, data revealed that dietary saturated fatty acids (SFAs) are not associated with CAD and other adverse health effects or at worst are weakly associated in some analyses when other contributing factors may be overlooked. Several recent analyses indicate that SFAs, particularly in dairy products and coconut oil, can improve health. The evidence of ω6 polyunsaturated fatty acids (PUFAs) promoting inflammation and augmenting many diseases continues to grow, whereas ω3 PUFAs seem to counter these adverse effects. The replacement of saturated fats in the diet with carbohydrates, especially sugars, has resulted in increased obesity and its associated health complications. Well-established mechanisms have been proposed for the adverse health effects of some alternative or replacement nutrients, such as simple carbohydrates and PUFAs. The focus on dietary manipulation of serum cholesterol may be moot in view of numerous other factors that increase the risk of heart disease. The adverse health effects that have been associated with saturated fats in the past are most likely due to factors other than SFAs, which are discussed here. This review calls for a rational reevaluation of existing dietary recommendations that focus on minimizing dietary SFAs, for which mechanisms for adverse health effects are lacking.

Postprandial triglyceride and free fatty acid metabolism in obese women after either endurance or resistance exercise

We investigated the effects of two exercise modalities on postprandial triglyceride (TG) and free fatty acid (FFA) metabolism. Sedentary, obese women were studied on three occasions in randomized order: endurance exercise for 60 min at 60-65% aerobic capacity (E), ~60 min high-intensity resistance exercise (R), and a sedentary control trial (C). After exercise, a liquid-mixed meal containing [U-(13)C]palmitate was consumed, and subjects were studied over 7 h. Isotopic enrichment (IE) of plasma TG, plasma FFA, and breath carbon dioxide compared with meal IE indicated the contribution of dietary fat to each pool. Total and endogenously derived plasma TG content was reduced significantly in both E and R compared with C (P < 0.05), with no effect of exercise on circulating exogenous (meal-derived) TG content. Exogenous plasma FFA content was increased significantly following both E and R compared with C (P < 0.05), whereas total and endogenous FFA concentrations were elevated only in E (P < 0.05) compared with C. Fatty acid (FA) oxidation rates were increased significantly after E and R compared with C (P < 0.05), with no difference between exercise modalities. The present results indicate that E and R may be equally effective in reducing postprandial plasma TG concentration and enhancing lipid oxidation when the exercise sessions are matched for duration rather than for energy expenditure. Importantly, tracer results indicated that the reduction in postprandial lipemia after E and R exercise bouts is not achieved by enhanced clearance of dietary fat but rather, is achieved by reduced abundance of endogenous FA in plasma TG.

Effect of fish oil supplementation on serum triglycerides, LDL cholesterol and LDL subfractions in hypertriglyceridemic adults

BACKGROUND AND AIMS

The well-established triglyceride (TG) lowering effect of fish oil is accompanied by an increase in LDL-cholesterol (LDL-C) concentration. Less is known about the differential impact on LDL particle distribution - the smaller particles being associated with a greater risk for atherosclerosis. We aimed to examine the changes in serum concentrations of four subclasses of LDL particles as well as shifts in LDL phenotype patterns (A, B, AB) among hypertriglyceridemic adults.

METHODS AND RESULTS

This was a secondary analysis from a double-blind, parallel design, placebo controlled trial with 42 adults that experienced significant TG lowering and modest increases in total LDL-C concentrations after 12 weeks of 4 g/d EPA + DHA. Reduction in serum TG concentrations (mean ± SEM) was -26 ± 4% (-0.81 ± 10.12 mmol/L), p < 0.0001. Total LDL-C concentration increased by 13 ± 3% (+0.31 ± 0.08 mmol/L), p < 0.0001. The 12-week changes in concentrations of LDL1, LDL2, LDL3 and LDL4 were +0.06 ± 0.02 mmol/L [+2.2 ± 0.7 mg/dL], +0.07 ± 0.03 mmol/L [+2.6 ± 1.0 mg/dL], +0.16 ± 0.05 mmol/L [+6.3 ± 1.8 mg/dL], and +0.04 ± 0.04 mmol/L [+1.4 ± 1.7 mg/dL], respectively (+20 ± 5%, +64 ± 13%, +26 ± 6%, and +17 ± 9%), p < 0.05 for all but LDL4. Changes in LDL phenotype patterns A, B and A/B were negligible and not statistically significant.

CONCLUSION

In this population of hypertriglyceridemic adults, dietary supplementation with fish oil resulted in an increase in total LDL-C concentration which was distributed relatively evenly across the range of smaller and more atherogenic as well as larger and less atherogenic LDL particles.

Surrogate lipid markers for small dense low-density lipoprotein particles in overweight youth

OBJECTIVES

To determine if the ratio of triglycerides to high-density lipoprotein cholesterol (TG/HDL) and non-HDL cholesterol concentration could identify youth with small dense low-density lipoprotein (LDL).

STUDY DESIGN

One hundred forty-one (75 black and 66 white) overweight adolescents (9 to <18 years) had a fasting measurement of plasma lipids and LDL particle concentrations and size. Receiver operating characteristic curves were used to indicate the ability of different TG/HDL ratios and non-HDL cholesterol concentrations to identify overweight youth with atherogenic LDL concentration and size.

RESULTS

Youth with a TG/HDL ratio of ≥3 vs <3 had higher concentrations of small dense LDL (1279.5 ± 60.1 vs 841.8 ± 24.2 nmol/L, P < .001) and smaller LDL particle size (20.3 ± 0.1 vs 21.2 ± 0.1 nm, P < .001). In receiver operating characteristic analyses a TG/HDL cut-point of 3 best predicted LDL concentration in white youth, and 2.5 in black youth. Non-HDL cholesterol cut-point of 120 mg/dL and 145 mg/dL predicted LDL particle concentration in white and in black youth, respectively. TG/HDL ratio with body mass index or waist circumference explained 71% and 79% of the variance, respectively, in total small LDL.

CONCLUSIONS

TG/HDL ratio and non-HDL cholesterol can identify overweight youth with atherogenic LDL particles. These easily obtained clinical lipid markers, in combination with body mass index and waist circumference, could be cost effective, in observational or interventional studies, for screening and follow-up of youth at heightened risk for atherogenic LDL.

Current perspectives on laboratory markers for the assessment of cardiovascular disease and myocardial damage

The disruption of the endothelim is a prelude to the evolution of arteriosclerosis. Nitric oxide is critical to endothelial function. The oxidation of low density lipoprotein (LDL) mediated by small dense LDL particles contributes to the development of cardiovascular disease. The multiple effects of homocysteine including its potentiating the binding of lipoprotein(a) (LP(a)) to fibrin and its role in the formation of small dense LDL particles highlights its importance in the evolution of cardiovascular disease and justifies its measurement. Problems in measurement of homocysteine should be kept in perspective. The measurement of release of proteins from the cardiac contractile apparatus such as Troponin I has advantages over conventional measurement of cardiac enzymes and isozymes.