A low high density lipoprotein (HDL) level is associated with carotid artery intima-media thickness in asymptomatic members of low HDL families

Interaction of genetic and environmental factors for body fat mass control: observational study for lifestyle modification and genotyping

Previous studies suggested that genetic, environmental factors and their interactions could affect body fat mass (BFM). However, studies describing these effects were performed at a single time point in a population. In this study, we investigated the interaction between genetic and environmental factors in affecting BFM and implicate the healthcare utilization of lifestyle modifications from a personalized and genomic perspective. We examined how nutritional intake or physical activity changes in the individuals affect BFM concerning the genetic composition. We conducted an observational study including 259 adult participants with single nucleotide polymorphism (SNP) genotyping and longitudinal lifestyle monitoring, including food consumption and physical activities, by following lifestyle modification guidance. The participants’ lifelog data on exercise and diet were collected through a wearable device for 3 months. Moreover, we measured anthropometric and serologic markers to monitor their potential changes through lifestyle modification. We examined the influence of genetic composition on body fat reduction induced by lifestyle changes using genetic risk scores (GRSs) of three phenotypes: GRS-carbohydrate (GRS-C), GRS-fat (GRS-F), and GRS-exercise (GRS-E). Our results showed that lifestyle modifications affected BFM more significantly in the high GRS class compared to the low GRS class, indicating the role of genetic factors affecting the efficiency of the lifestyle modification-induced BFM changes. Interestingly, the influence of exercise modification in the low GRS class with active lifestyle change was lower than that in the high GRS class with inactive lifestyle change (P = 0.022), suggesting the implication of genetic factors for efficient body fat control.

Large HDL2 combined with inflammatory factors as superior predictors for coronary artery disease than small HDL3

Background

This study investigated whether combinations of high-density lipoprotein (HDL) subfractions and inflammatory markers would add value to coronary artery disease (CAD) prediction.

Methods

Non-CAD subjects (n=245) were stratified into low/moderate/high-Framingham risk (L/M/H-FR) groups and 180 CAD patients were enrolled. Levels of HDL-C, HDL₂, HDL₃, monocyte chemoattractant protein-1 (MCP-1), and high-sensitivity C-reactive protein (hsCRP) were measured. Multivariable logistic models for CAD were estimated with a single parameter or all parameters together after adjustment for conventional risk factors (CRFs), and Z statistics, net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were used to compare discrimination among different models.

Results

The results show that HDL-C, HDL_2, and HDL₃ gradually decreased, while MCP-1 and hsCRP gradually increased from L/M/H-FR to the CAD group. When applying a single factor in the CRFs-adjusted models, HDL-C (OR 0.011, 95% CI, 0.002–0.071, P<0.05) and HDL₂ (OR 0.000072, 95% CI, 0.000001–0.004, P<0.05), but not HDL₃, were significantly related to CAD risk. Only HDL₂ (OR 0.000072, 95% CI, 0.000001–0.004, P<0.001) remained significant when applying all HDL parameters. In the model including all HDL and inflammatory parameters, HDL₂ (OR 0.001, 95% CI, 0.000027–0.051), MCP-1 (OR 1.066, 95% CI, 1.039–1.094), and hsCRP (OR 1.130, 95% CI, 1.041–1.227) showed significant differences (all P<0.05). This combined model showed improved discrimination over the models with a single factor (P<0.05) or all HDL parameters (Z=3.299, NRI =0.179, IDI =0.081, P<0.001).

Conclusions

Large HDL₂ is superior to small HDL₃ in the inverse association with CAD. The combination of HDL₂, MCP-1, and hsCRP with CRFs provides an optimal prediction for CAD.

The impact of monocyte to high-density lipoprotein ratio on reduced renal function: insights from a large population

Aim: To investigate whether monocyte to HDL cholesterol ratio (MHR) can improve the risk stratification of reduced renal function by estimating atherosclerosis. Patients & methods: The cross-sectional study included 8159 subjects (males: 45.73%, mean age: 54.12 years) from Northeast China in 2013. Results: Each standard deviation increase of MHR brought 42.9% additional risk of reduced renal function in males. In females, MHR strongly correlated with reduced renal function before it reached a breakpoint (MHR = 0.25). Additionally, net reclassification improvement identified the value of MHR (0.199; 95% CI: 0.030–0.369; p = 0.021) to improve the risk classification of renal function reduction. Conclusion: This study implicates that MHR is independently associated with reduced renal function and can refine the risk stratification of renal function reduction.

Diabetes alters the association between high-density lipoprotein subfractions and carotid intima-media thickness: The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

INTRODUCTION

High-density lipoprotein cholesterol comprises a group of heterogeneous subfractions that might have differential effects on atherosclerosis. Moreover, prior investigations suggest that the presence of diabetes (T2D) modifies the impact of some subfractions on atherosclerosis. In this study, we aimed to evaluate the association between high-density lipoprotein cholesterol subfractions and carotid intima-media thickness in the baseline assessment of the Brazilian Longitudinal Study of Adult Health participants from the São Paulo investigation centre.

METHODS

We evaluated 3930 individuals between 35 and 74 years without previous cardiovascular disease not using lipid-lowering drugs. High-density lipoprotein cholesterol subfractions (HDL₂-C and HDL₃-C) were measured by vertical ultracentrifugation (vertical auto profile). The relationship between each high-density lipoprotein cholesterol subfraction and carotid intima-media thickness was analysed by multiple linear regression models.

RESULTS

Total high-density lipoprotein cholesterol, as well as HDL₂-C and HDL₃-C, was negatively associated with carotid intima-media thickness after adjustment for demographic data (all p < 0.001) and traditional risk factors (all p < 0.05). When stratified by T2D status, the HDL₂-C/HDL₃-C ratio showed a negative association with carotid intima-media thickness in participants with T2D ( p = 0.032), even after fully controlling for confounding variables, including total high-density lipoprotein cholesterol.

CONCLUSION

HDL₂-C, HDL₃-C and HDL₂/HDL₃-C ratio are inversely associated with carotid intima-media thickness after adjustment for traditional risk factors. Association of the HDL₂-C/HDL₃-C ratio is modified by the presence of diabetes, being more pronounced in diabetic individuals.

High-density lipoprotein subclass profile and mortality in patients with coronary artery disease: Results from the GENES study

BACKGROUND

High-density lipoproteins (HDLs) are highly heterogeneous particles, and the specific contribution of each subclass to the prediction of clinical outcome in coronary artery disease (CAD) remains controversial.

OBJECTIVE

To examine the relationship between HDL subclass profile and mortality in patients with CAD, using a new and rapid electrophoretic quantitative method for the assessment of HDL particle size phenotype.

METHODS

We investigated 403 patients with CAD admitted for cardiovascular examination in the context of evaluation and management of CAD. HDL subclass distribution was analysed using the Quantimetrix Lipoprint^® HDL system. Cumulative survival of patients according to lipid variables was determined by the Kaplan-Meier method. The relationship between baseline variables and outcome criteria was assessed using Cox proportional hazards regression analysis.

RESULTS

During follow-up (9.8±3.1 years) the mortality rate was 31.0%; 60.8% of deaths were related to CAD. The concentration of total HDL cholesterol was similar in deceased patients (42±13mg/dL) and alive patients (43±12mg/dL); the concentrations of small, intermediate and large HDL cholesterol subclasses were not significantly different in alive and deceased patients (P=0.17, P=0.34 and P=0.81, respectively). We did not observe any independent associations between overall or cardiovascular mortality and total HDL cholesterol or any HDL subclass. However, heart rate, left ventricular ejection fraction and severity score for coronary atherosclerosis were more associated with mortality than classical cardiovascular risk factors.

CONCLUSIONS

HDL subclass profile is not associated with mortality in patients with CAD. Further investigations linking HDL subclass repartition with prediction of residual cardiovascular risk are required.

Atherogenesis in human - clinical aspects of circulating immune complexes

It has been suggested that circulating immune complexes containing low density lipoproteins (LDL-CIC) play a role in atherogenesis and are involved in the formation of early atherosclerotic lesions. The complexes, as well as anti-LDL antibody were found in the blood of patients with atherosclerotic process in various cardiovascular diseases, well as in the blood of animals with experimentally modulated atherosclerosis. One can assume that the presence anti-LDL antibodies in blood is a result of an immune response that is induced by modification of lipoproteins. LDL-CIC differ from native LDL in many aspects. They have much lower levels of sialic acid, a smaller diameter and a higher density electronegativity than native LDL. The fraction of the LDL-CIC in serum is an important manifestation of the atherosclerotic process. LDL-CIC, unlike the native LDL is able to induce intracellular accumulation of neutral lipids, especially esterified cholesterol in cell cultures obtained from healthy human aortic intima and macrophages in culture. After removal of the LDL-CIC, the serum of CHD-patients loses its atherogenic properties. The titer of the LDL-CIC in the blood serum significantly correlate with the progression of atherosclerosis and in vivo has the highest diagnostic yield of measured among other lipid parameters. Increasing CIC- cholesterol could also increase the risk of coronary artery atherosclerosis.

Subfractions of High-Density Lipoprotein-Cholesterol and Carotid Intima-Media Thickness: The Northern Manhattan Study

BACKGROUND AND PURPOSE

Recent drug trials have challenged the high-density lipoprotein-cholesterol (HDL-C) antiatherosclerotic hypothesis, suggesting that total level of HDL-C may not be the best target for intervention. HDL-C subfractions may be better markers of vascular risk than total levels of HDL-C. The objective of this cross-sectional study was to investigate the relationship between HDL2-C and HDL3-C fractions and carotid intima-media thickness (cIMT) in the population-based Northern Manhattan Study.

METHODS

We evaluated 988 stroke-free participants (mean age, 66±8 years; 60% women; 66% Hispanic, and 34% non-Hispanic) with available data on HDL-C subfractions using precipitation method and cIMT assessed by a high-resolution carotid ultrasound. The associations between HDL-C subfractions and cIMT were analyzed by multiple linear regression models.

RESULTS

The mean HDL2-C was 14±8 mg/dL, HDL3-C 32±8 mg/dL, and the mean total HDL-C was 46±14 mg/dL. The mean cIMT was 0.90±0.08 mm. After controlling for demographics and vascular risk factors, HDL2-C and total HDL-C were inversely associated with cIMT (per 2 SDs, β=-0.017, P=0.001 and β=-0.012, P=0.03, respectively). The same inverse association was more pronounced among those with diabetes mellitus (per 2SDs, HDL2-C: β=-0.043, P=0.003 and HDL-C: β=-0.029, P=0.02). HDL3-C was not associated with cIMT.

CONCLUSIONS

HDL2-C had greater effect on cIMT than HDL3-C in this large urban population. The effect of HDL2-C was especially pronounced among individuals with diabetes mellitus. More research is needed to determine antiatherosclerotic effects of HDL-C subfractions and their clinical relevance.

HDL as a prognostic biomarker for coronary atherosclerosis: the role of inflammation

INTRODUCTION

Emerging evidence suggests that the role of high density lipoprotein (HDL) in the atherosclerotic process is not as clear as previously thought, since atheroprotective HDL becomes atherogenic in states of increased inflammatory processes.

AREAS COVERED

In this review we aim to elucidate the role of HDL as a prognostic biomarker and we discuss therapeutic approaches that aim to increase HDL and their possible clinical benefit.

EXPERT OPINION

Given the structural variability and biological complexity of the HDL particle, its role in the atherosclerotic process is far from clear. According to current evidence, the atheroprotective role of HDL turns atherogenic in states of increased inflammatory processes, while even minor alterations in systemic inflammation are likely to hinder the endothelial protective effects of HDL. In accordance, significant data have revealed that HDL-related drugs may be effective in reducing cardiovascular mortality; however they are not as encouraging or unanimous as expected. Possible future goals could be to quantify either HDL subclasses or functions in an attempt to reach safer conclusions as to the prognostic importance of HDL in coronary atherosclerosis. Having achieved that, a more targeted therapy that would aim to raise either HDL functionality or to remodel HDL structure would be more easily designed.

Triglyceride to HDL-C ratio and increased arterial stiffness in children, adolescents, and young adults

BACKGROUND AND OBJECTIVE

Lipid levels are linked to early atherosclerosis. Risk stratification may be improved by using triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C), which relates to arterial stiffness in adults. We tested whether TG/HDL-C was an independent predictor of arterial stiffness in youth.

METHODS

Subjects 10 to 26 years old (mean 18.9 years, 39% male, 56% non-Caucasian, n = 893) had laboratory, anthropometric, blood pressure, and arterial stiffness data collected (brachial distensibility, augmentation index, carotid-femoral pulse-wave velocity). Subjects were stratified into tertiles of TG/HDL-C (low, n = 227; mid, n = 288; high, n = 379).

RESULTS

There was a progressive rise in cardiovascular (CV) risk factors and arterial stiffness across TG/HDL-C ratio. The high TG/HDL-C ratio group had the stiffest vessels (all P < .03 by analysis of variance). TG/HDL-C as a continuous variable was an independent determinant of brachial distensibility in CV risk factor adjusted model and for carotid-femoral pulse-wave velocity in obese subjects, with trend for higher augmentation index.

CONCLUSIONS

TG/HDL-C, an estimate of small, dense low-density lipoprotein cholesterol, is an independent determinant of arterial stiffness in adolescents and young adults, especially in obese youth. These data suggest that use of TG/HDL-C may be helpful in identifying young adults requiring aggressive intervention to prevent atherosclerotic CV diseases.

High-density lipoprotein subclasses and their relationship to cardiovascular disease

OBJECTIVE

To assess the clinical utility of measuring high-density lipoprotein (HDL) subfractions to assess coronary heart disease (CHD) risk.

METHODS

Literature review of 80 published investigations.

RESULTS

Measurements of HDL2b by gradient gel electrophoresis provided more consistent evidence of CHD risk than measurement of HDL2 cholesterol. Five of the seven studies that compared the extent or progression of atherosclerosis with gradient gel electrophoresis estimates of HDL subclasses (71%) assigned statistical significance to HDL2b. Ten of the 11 case-control comparisons (91%) reported lower HDL2b in cases. In contrast, of the 16 association studies relating HDL2 cholesterol and HDL3 cholesterol to extent of disease, five reported no significant relationships with either subfraction, two reported significant relationships with both HDL2 and HDL3 cholesterol, four reported significant relationships with HDL2 but not HDL3 cholesterol, and five reported relationships with HDL3 but not HDL2 cholesterol. Forty-five percent of the case-control comparisons reported that both HDL2 cholesterol and HDL3 cholesterol were significantly lower in cases than controls, 17% failed to find significance for either subfraction, and the remainder reported significantly lower values in cases for HDL2 cholesterol only (26%) or HDL3 cholesterol only (11%). On average, the case-control differences were similar for HDL2 (-0.12 ± 0.01 mmol/L) and HDL3 cholesterol (-0.10 ± 0.02 mmol/L), although relative to controls, the percent reduction was twice as great for HDL2 (-25.7 ± 2.9%) than HDL3 cholesterol (-12.1 ± 1.5%). Eight prospective studies were identified and four reported that both HDL2 and HDL3 predicted lower risk for CHD, one reported reductions in risk for HDL2 but not HDL3 cholesterol, and three reported reductions in risk for HDL3 but not HDL2 cholesterol. None of the prospective studies show that measurements of HDL cholesterol subfractions improve the identification of persons at risk.

CONCLUSIONS

HDL2 and HDL3 cholesterol do not distinguish cardioprotective differences between HDL subclasses. More extensive characterization of HDL particles by one or two dimensional gel electrophoresis, ion mobility, or ultracentrifugation may provide more specific information about CHD risk than the measurement of HDL cholesterol, HDL3 cholesterol, or HDL2 cholesterol.

The fat-1 transgene in mice increases antioxidant potential, reduces pro-inflammatory cytokine levels, and enhances PPAR-gamma and SIRT-1 expression on a calorie restricted diet

Both n-3 fatty acids (FA) and calorie-restriction (CR) are known to exert anti-inflammatory and anti-oxidative effects in animals and humans. In this study, we investigated the synergistic anti-inflammatory and anti-oxidative capacity of n-3 FA and CR using Fat-1 transgenic mice (Fat-1) that are capable of converting n-6 FA to n-3 FA endogenously. Wild type (WT) and Fat-1 mice were maintained on ad libitum (AL) or CR (40% less than AL) AIN-93 diet supplemented with 10% corn oil (rich in n-6 FA) for 5 months. Significantly lower levels of n-6/n-3 FA ratio were observed in serum, muscle and liver of Fat-1 mice fed AL or CR as compared to that of WT mice fed AL or CR. Muscle catalase (CAT), super oxide dismutase (SOD), glutathione peroxidase (GPX) activities, and liver CAT and SOD activities were found higher in Fat-1 mice as compared to that of WT mice. These activities were more pronounced in Fat-1/CR group as compared to other groups. Serum pro-inflammatory markers, such as tumor necrosis factor (TNF)α, interleukin (IL)-1β and IL-6 were found lower in Fat-1 mice, as compared to that of WT mice. This anti-inflammatory effect was also more pronounced in Fat-1/CR group as compared to that of other groups. Furthermore, significantly higher levels of peroxisome proliferator-activated receptor (PPA R)gamma and life prolonging gene, sirtuin (SIRT)-1 expression were found in liver of Fat-1/CR mice, as compared to that of WT/CR mice. These data suggest that n-3 FA along with moderate CR may prolong lifespan by attenuating inflammation and oxidative stress.

Inclusion of Atlantic salmon in the Chinese diet reduces cardiovascular disease risk markers in dyslipidemic adult men

Although the beneficial effects of n-3 fatty acids on several physiologic functions have been widely reported, information about the effects of oily fish in the Asian diet on cardiovascular disease (CVD) risk is diminutive. We hypothesize that daily inclusion of oily fish for 8 weeks in the Chinese diet will elevate serum eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels and reduce CVD risk markers in dyslipidemic adult men, comparable with the effects generally observed by inclusion of oily fish in the Western diet. In this 8-week randomized, parallel-arm, food-based intervention study, lunches were prepared with 500 g pork/chicken/beef, typically consumed fish (hairtail and freshwater carp), or oily fish (salmon). Male subjects aged between 35 and 70 years with hyperlipidemia were randomly assigned to eat lunches with pork/chicken/beef (n = 30 subjects at 8 weeks), freshwater fish (n = 30), or oily fish (n = 32). Circulating markers were measured at baseline and at 8 weeks. In the oily fish diet, dietary EPA and DHA levels were significantly increased as compared with other diets; and the n-6:n-3 polyunsaturated fatty acid ratio was decreased (P < .05). Thus, the oily fish diet significantly elevated serum EPA and DHA concentrations (P < .01) and lowered serum n-6:n-3 ratio at 8 weeks (P < .05). Furthermore, oily fish intake significantly reduced serum levels of triglycerides (P < .05) and interleukin-6 (P < .01) and increased levels of high-density lipoprotein cholesterol (P < .01). In conclusion, daily inclusion of oily fish as part of the Chinese diet for 8 weeks is sufficient to significantly increase the serum content of long-chain n-3 polyunsaturated fatty acids and reduce levels of CVD risk markers in dyslipidemic adult men.

Intervention with fish oil, but not with docosahexaenoic acid, results in lower levels of hepatic soluble epoxide hydrolase with time in apoE knockout mice

Long-chain n-3 PUFA from fish oil protect against death from CHD but mechanisms are not well understood. Preliminary results indicate that fish oil may affect the enzyme soluble epoxide hydrolase (sEH) and influence inflammatory pathways in a time-dependent manner. In the present study male apoE knockout (Apoe-/-) mice were randomised to three dietary groups receiving a high-fat high-cholesterol diet supplemented with 2 % (w/w) high-oleic acid sunflower-seed (HOSF) oil, DHA oil or fish oil. Livers and proximal aortas were collected on day 2 and on weeks 1, 2, 4 and 10 to determine hepatic sEH levels, hepatic fatty acid composition, hepatic proteome and atherosclerotic plaque size in the aortic root. Intervention with fish oil, but not with DHA, resulted in significantly lower levels of hepatic sEH levels with time compared with HOSF oil. DHA and fish oil caused differential regulation of thirty-five hepatic proteins which were mainly involved in lipoprotein metabolism and oxidative stress. All mice developed atherosclerosis without differences in plaque size between the three groups. Thus EPA may be responsible for lowering levels of hepatic sEH and both fish oil and DHA could beneficially affect lipoprotein metabolism and oxidative stress.

Intima-media thickness measurements in children with cardiovascular risk factors

Measuring intima-media thickness (IMT) is now a standard diagnostic procedure in assessing cardiovascular risk and hypertensive target-organ damage (TOD) in adults. There is also an increasing number of pediatric publications evaluating IMT in children from high-risk groups, such as those with arterial hypertension, diabetes, chronic kidney disease, obesity, dyslipidemia, and homocystinurias. It has been shown that carotid IMT is strongly related with other markers of TOD in children with arterial hypertension and with metabolic cardiovascular risk factors. In children with coarctation of the aorta, carotid IMT correlated both with blood pressure and even with mild residual aortic gradient. On the other hand, studies in children with high cardiovascular risk have shown that normalization of blood pressure and metabolic abnormalities led to regression of arterial changes and decrease of IMT. Although not yet accepted as standard pediatric procedure, IMT measurement is emerging as a promising method of assessing TOD and cardiovascular risk and monitoring treatment efficacy. From a practical point of view, clinical utility of IMT measurements seems to be similar to use of echocardiography in assessing left ventricular mass. However, IMT measurements in children and adolescents should be standardized to avoid bias caused by the use of different measurement methods.

Circulating triacylglycerol and apoE levels in response to EPA and docosahexaenoic acid supplementation in adult human subjects

High doses ofn–3 PUFA found in fish oils can reduce the circulating concentration of triacylglycerol (TG), which may contribute to the positive impact of these fatty acids on the risk of CVD. The present study aimed to establish the differential impact of EPA and docosahexaenoic (DHA) on plasma lipids and apo in adults. Forty-two normolipidaemic adult subjects completed a double-blind placebo controlled parallel study, receiving an EPA-rich oil (4·8 g EPA/d), DHA-rich oil (4·9 g DHA/d) or olive oil as control, for a period of 4 weeks. No effects of treatment on total cholesterol, LDL-cholesterol or HDL-cholesterol were evident. There was a significant 22 % reduction in TG level relative to the control value following the DHA treatment (P=0·032), with the 15 % decrease in the EPA group failing to reach significance (P=0·258). There were no significant inter-group differences in response to treatment for plasma apoA1, -C3 or -E levels, although a significant 15 % within-group increase in apoE was evident in the EPA (P=0·006) and DHA (P=0·003) groups. In addition, a within-group decrease in the apoA1:HDL-cholesterol ratio was observed in the DHA group, suggesting a positive impact of DHA on HDL particle size. The DHA intervention resulted in a significant increase in the proportion of EPAP=0·000 and DHAP=0·000 in plasma phospholipids, whilst significant increases in EPAP=0·000 and docosapentaenoic acidP=0·002, but not DHAP=0·193, were evident following EPA supplementation (P>0·05). Our present results indicate that DHA may be more efficacious than EPA in improving the plasma lipid profile.

Functionally defective high-density lipoprotein: a new therapeutic target at the crossroads of dyslipidemia, inflammation, and atherosclerosis

High-density lipoproteins (HDL) possess key atheroprotective biological properties, including cellular cholesterol efflux capacity, and anti-oxidative and anti-inflammatory activities. Plasma HDL particles are highly heterogeneous in physicochemical properties, metabolism, and biological activity. Within the circulating HDL particle population, small, dense HDL particles display elevated cellular cholesterol efflux capacity, afford potent protection of atherogenic low-density lipoprotein against oxidative stress and attenuate inflammation. The antiatherogenic properties of HDL can, however be compromised in metabolic diseases associated with accelerated atherosclerosis. Indeed, metabolic syndrome and type 2 diabetes are characterized not only by elevated cardiovascular risk and by low HDL-cholesterol (HDL-C) levels but also by defective HDL function. Functional HDL deficiency is intimately associated with alterations in intravascular HDL metabolism and structure. Indeed, formation of HDL particles with attenuated antiatherogenic activity is mechanistically related to core lipid enrichment in triglycerides and cholesteryl ester depletion, altered apolipoprotein A-I (apoA-I) conformation, replacement of apoA-I by serum amyloid A, and covalent modification of HDL protein components by oxidation and glycation. Deficient HDL function and subnormal HDL-C levels may act synergistically to accelerate atherosclerosis in metabolic disease. Therapeutic normalization of attenuated antiatherogenic HDL function in terms of both particle number and quality of HDL particles is the target of innovative pharmacological approaches to HDL raising, including inhibition of cholesteryl ester transfer protein, enhanced lipidation of apoA-I with nicotinic acid and infusion of reconstituted HDL or apoA-I mimetics. A preferential increase in circulating concentrations of HDL particles possessing normalized antiatherogenic activity is therefore a promising therapeutic strategy for the treatment of common metabolic diseases featuring dyslipidemia, inflammation, and premature atherosclerosis.

ApoE polymorphism is associated with C-reactive protein in low-HDL family members and in normolipidemic subjects

The study was aimed to compare inflammatory parameters between carriers of apoE4 isoforms (apoE4/3, apoE4/2, and apoE4/4 phenotypes) and those of carrying apoE3 isoform without apoE4 isoform (apoE3/3 phenotypes and apoE2/3 phenotypes). The concentrations of serum hsCRP, sVCAM-1, sICAM-1, and sE-selectin were measured in 211 subjects from Finnish low-HDL families and in 157 normolipidemic subjects. The subjects with apoE4 isoform had lower concentrations of serum hsCRP both in low-HDL family members (p < 0.05) and in normolipidemic subjects (p < 0.01). The differences in serum CRP values remained significant after adjustment for age, BMI, smoking status, hypertension, gender, lipoprotein variables, and family number. We conclude that apoE phenotype has a strong influence on serum CRP values.

Left ventricular hypertrophy and arterial wall thickening in children with essential hypertension

OBJECTIVE

Our aim was to determine the prevalence of left ventricular hypertrophy (LVH) and increased intima-media thickness (IMT) in Caucasian children with newly diagnosed, untreated essential hypertension (EH).

PARTICIPANTS

Our study cohort consisted of 72 children with EH (mean age: 14.5 years; range: 5-18 years). The control groups consisted of 103 age-matched, healthy children.

METHODS

We evaluated the left ventricular mass (LVM), intima-media thickness in the carotid (cIMT) and superficial femoral (fIMT) arteries, 24-h ambulatory blood pressure, and biochemical cardiovascular risk factors.

RESULTS

Of the hypertensive children examined, 41.6% had LVM above the 95th percentile, and 13.2% had LVM above 51 g/m2.7. Of the hypertensive subjects, the cIMT was above 2 SDS of normal values in 38.8%, and the flMT was above 2 SDS of normal values in 17.5%. Patients with LVM above 51 g/m2.7 had a higher birth weight than other patients. LVM, cIMT, and fIMT correlated with 24-h SBP and pulse pressure; LVM also correlated with homocysteine and serum uric acid concentrations. fIMT correlated with low Aprotein A1 (ApoA1), higher ApoB and C reactive protein, and daily sodium excretion. Step-wise regression analysis revealed that serum uric acid and higher birth weight were predictors for LVM, pulse pressure was a predictor for cIMT, and ApoB was a predictor for fIMT.

CONCLUSIONS

A significant number of adolescents with EH already had cardiovascular damage at diagnosis. LVM and markers of arterial injury correlate with SBP, biochemical, and perinatal cardiovascular risk factors. Serum uric acid and higher birth weight are predictors of LVM.

Decreased high-density lipoprotein (HDL) particle size, prebeta-, and large HDL subspecies concentration in Finnish low-HDL families: relationship with intima-media thickness

OBJECTIVE

High-density lipoprotein (HDL) cholesterol correlates inversely with the risk of coronary heart disease (CHD). The precise antiatherogenic mechanisms of HDL subspecies are not thoroughly elucidated. We studied the relationship between carotid intima-media thickness (IMT) and HDL subspecies distribution in Finnish families with low HDL cholesterol and premature CHD.

METHODS AND RESULTS

Altogether, 148 members of Finnish low-HDL families and 133 healthy control subjects participated in our study. HDL particle size was significantly smaller in affected family members (HDL < or =10th Finnish age-sex specific percentile) compared with unaffected family members and control subjects (9.1+/-0.04 nm versus 9.5+/-0.05 nm, P<0.0001, versus 9.8+/-0.03 nm, P<0.0001 [mean+/-SE]). Large HDL2b particles as well as prebeta-HDL concentration were significantly decreased among the affected family members. Mean IMT was significantly higher in the affected family members than in the control subjects (0.85+/-0.01 mm versus 0.79+/-0.01 mm; P<0.0001). Age, HDL2b, systolic blood pressure, and prebeta-HDL were significant independent determinants of mean IMT.

CONCLUSIONS

The decreased levels of HDL2b and prebeta-HDL reflect the potentially efflux-deficient HDL subspecies profile in the affected low-HDL family members. Decreased HDL particle size caused by the decrease of plasma concentration of HDL2b and decreased prebeta-HDL levels correlate with increased IMT.

Hypertriglyceridemia is associated with preβ-HDL concentrations in subjects with familial low HDL

Prebeta-HDL particles act as the primary acceptors of cellular cholesterol in reverse cholesterol transport (RCT). An impairment of RCT may be the reason for the increased risk of coronary heart disease (CHD) in subjects with familial low HDL. We studied the levels of serum prebeta-HDL and the major regulating factors of HDL metabolism in 67 subjects with familial low HDL and in 64 normolipidemic subjects. We report that the subjects with familial low HDL had markedly reduced prebeta-HDL concentrations compared with the normolipidemic subjects (17.4 +/- 7.2 vs. 23.4 +/- 7.8 mg apolipoprotein A-I/dl; P < 0.001). A positive correlation was observed between prebeta-HDL concentration and serum triglyceride (TG) level (r = 0.334, P = 0.006). In addition, serum TG level was found to be the strongest predictor of prebeta-HDL concentration in subjects with familial low HDL. The activities of cholesteryl ester transfer protein and hepatic lipase were markedly increased in subjects with familial low HDL without a significant correlation to prebeta-HDL concentration. Our results support the hypothesis that impaired RCT is one mechanism behind the increased risk for CHD in subjects with familial low HDL.

Intima-media thickness and arterial elasticity in hypertensive children: controlled study

The objective of this cross-sectional controlled study was to evaluate the intima-media thickness (IMT) of the common carotid artery (cIMT) and superficial femoral artery (fIMT), as well as the elastic properties of the common carotid artery, in children with essential arterial hypertension. The study included 49 children with newly detected essential hypertension [mean age 14.5 (range 6-20) years] and 61 healthy normotensive children [mean age 13.5 (range 6-20) years]. The cIMT and fIMT were evaluated by ultrasonography. The elastic properties of the carotid artery were calculated from actual blood pressure values, arterial dimensions, and carotid wall thickness. Hypertensive children had greater values of both cIMT (0.45+/-0.05 mm) ( P=0.0001) and fIMT (0.37+/-0.05 mm) ( P=0.005) than controls (0.41+/-0.04 and 0.33+/-0.06 mm, respectively). The internal systolic and diastolic diameters of the common carotid artery were also significantly greater in hypertensive patients. The distensibility and elasticity of the common carotid artery were significantly decreased in hypertensive patients, while arterial compliance was significantly greater than in controls. cIMT and fIMT correlated with systolic and pulse pressure values, body mass index (BMI), homocysteine, low high-density lipoprotein, and apolipoprotein AI. After subdividing the control group and patients according to BMI below or above the 95th percentile for age and sex, there were differences only between normal-weight normotensive children and the two groups of hypertensive children. The stepwise regression analysis showed that the predictive factor for cIMT was pulse pressure and for fIMT body mass and homocysteine. Hence, in newly diagnosed children with essential hypertension, functional and anatomical changes in elastic and muscular arteries are observed. Pulse pressure and biochemical risk factors for cardiovascular damage were predictors of vessel wall injury, even if it remained within the normal range. BMI is an important factor influencing IMT values.

Effect of atorvastatin on high density lipoprotein cholesterol and its relationship with coronary events: a subgroup analysis of the GREek Atorvastatin and Coronary-heart-disease Evaluation (GREACE) Study

OBJECTIVE

To investigate the relationship between changes in high density lipoprotein cholesterol(HDL-C) levels after statin treatment and the risk for coronary heart disease (CHD)-related events in the secondary CHD prevention GREek Atorvastatin and Coronary heart disease Evaluation (GREACE) Study. These findings suggested that dose titration with atorvastatin (10-80 mg/day, mean 24 mg/day)achieves the National Cholesterol Educational Program treatment goals and significantly reduces morbidity and mortality, in comparison to usual care.

METHODS

Analysis of variance was used to assess the effect of atorvastatin on HDL-C over time (up to 48 months) in 1600 CHD patients. The time-dependent multivariate Cox predictive model,involving backward stepwise logistic regression,was used to evaluate the relation between coronary events and HDL-C changes.

RESULTS

The mean increase in HDL-C levels during the study was 7%. All doses of atorvastatin significantly increased HDL-C levels. Increases were greater in men (7.8 vs 6.1%; p = 0.02), in combined hyperlipidaemia (7.9 vs 6.4% for hypercholesterolaemia; p = 0.04), and in the lower baseline HDL-C quartile (9.2 vs 5.3%, 1st vs 4th quartile; p = 0.001). After adjustment for 24 predictors of coronary events, multivariate analysis revealed a Hazards Ratio of 0.85 (95% confidence interval 0.76-0.94; p = 0.002) for every 4 mg/dL(0.1 mmol/L) increase in HDL-C.

CONCLUSIONS

There was a significant beneficial effect on HDL-C levels across the dose range of atorvastatin. Clinical outcomes in the structured care arm of GREACE were determined in part by the extent of atorvastatin-induced HDL-C increase. This effect was independent from benefit induced by low density lipoprotein cholesterol (LDL-C)reduction, suggesting that the CHD risk reduction associated with a rise in a low HDL-C at baseline remains significant under aggressive (-46%) LDL-C lowering conditions. However, the relationship between HDL-C and vascular risk may be weaker when LDL-C levels are aggressively lowered.

LDL-cholesterol, HDL-cholesterol or triglycerides--which is the culprit?

Dyslipidaemia in patients with type 2 diabetes commonly consists of elevated triglyceride levels; normal or slightly elevated low-density lipoprotein (LDL)-cholesterol levels with a preponderance of small, dense LDL particles; and low high-density lipoprotein (HDL)-cholesterol levels with a preponderance of small, dense HDL. These abnormalities are closely connected, with prolonged residence of high levels of triglyceride-rich particles in the circulation favoring abnormalities in LDL and HDL. Each of these factors has been associated with endothelial dysfunction; each contributes directly or indirectly to atheroma formation, with small, dense LDL and triglyceride-rich remnants increasing deposition of cholesteryl ester in vessel walls. This process is facilitated by reduced reverse cholesterol transport in association with low levels of HDL-cholesterol and abnormal HDL. Lipid-lowering therapy focused on LDL-cholesterol reduction is highly successful in preventing coronary disease in diabetic patients. Additional strategies for treating the cluster of risk factors in dyslipidaemia are necessary to further reduce atherosclerotic disease in this population.