Low-density lipoprotein particle number and risk for cardiovascular disease

High-fat meal effect on LDL, HDL, and VLDL particle size and number in the Genetics of Lipid-Lowering Drugs and Diet Network (GOLDN): an interventional study

Background

Postprandial lipemia (PPL) is likely a risk factor for cardiovascular disease but these changes have not been well described and characterized in a large cohort. We assessed acute changes in the size and concentration of total and subclasses of LDL, HDL, and VLDL particles in response to a high-fat meal. Participants (n = 1048) from the Genetics of Lipid-Lowering Drugs and Diet Network (GOLDN) Study who ingested a high-fat meal were included in this analysis. Lipids were measured at 0 hr (fasting), 3.5 hr, and 6 hr after a standardized fat meal. Particle size distributions were determined using nuclear magnetic resonance spectroscopy. Analyses were stratified by baseline triglycerides (normal vs. elevated) and gender. The effect of PPL on changes in lipoprotein subclasses was assessed using repeated measures ANOVA.

Results

Postprandially, LDL-C, HDL-C, VLDL-C, and triglycerides increased regardless of baseline triglyceride status, with the largest increases in VLDL-C and TG; however, those with elevated triglycerides demonstrated larger magnitude of response. Total LDL particle number decreased over the 6-hour time interval, mostly from a decrease in the number of small LDL particles. Similarly, total VLDL particle number decreased due to reductions in medium and small VLDL particles. Large VLDL particles and chylomicrons demonstrated the largest increase in concentration. HDL particles demonstrated minimal overall changes in total particle number.

Conclusions

We have characterized the changes in LDL and VLDL particle number, and their subclass patterns following a high-fat meal.

Changes in emerging cardiac biomarkers after an intensive lifestyle intervention

The present study evaluated the changes in emerging cardiac biomarkers, cognitive function, and social support measures after a comprehensive lifestyle intervention that included a low-fat, whole-foods, plant-based diet, exercise, stress management, and group support meetings. We conducted a prospective cohort study of 131 participants (59.2% women and 43.1% with diabetes mellitus), 56 with coronary heart disease (CHD) (37.5% women and 27.3% diabetes mellitus), and 75 at high risk with ≥3 CHD risk factors and/or diabetes mellitus (76% women and 54.7% diabetes mellitus). The measurements were taken at baseline and 3 months after the intervention. Improvement in all targeted health behaviors was seen in both high-risk and CHD groups (all p <0.001) at 3 months, with reductions in body mass index, systolic and diastolic blood pressure, waist/hip ratio, C-reactive protein, insulin, low-density lipoprotein, high-density and total cholesterol, apolipoproteins A1 and B (all p <0.009) were observed. Nuclear magnetic resonance spectroscopy analysis of lipoprotein subclass particle concentrations and diameters showed a reduction in large very-low-density lipoprotein particles, size of the very-low-density lipoprotein particles, total low-density lipoprotein particles; total, large, and small high-density lipoprotein particles (all p <0.009) and small very-low-density lipoprotein particles (p <0.02). Increases in fibrinogen (p <0.03) and B-type natriuretic peptide (p <0.001) were seen, and these changes correlated inversely with the changes in the body mass index. The observed increase in B-type natriuretic peptide can be explained by the metabolic changes related to adipose tissue lipolysis. The quality of life, cognitive functioning, and social support measures significantly improved. In conclusion, lifestyle changes can be followed by favorable changes in traditional and emerging coronary heart disease biomarkers, quality of life, social support, and cognitive function among those with, or at high risk, of CHD.

Low-density lipoprotein cholesterol to apolipoprotein B ratio is independently associated with metabolic syndrome in Korean men

The low-density lipoprotein cholesterol to apolipoprotein B (LDL-C/apo B) ratio is associated with cardiovascular risk factors and the prevalence of metabolic syndrome. The aim of this study was to assess the relationship between LDL-C/apo B ratio and metabolic syndrome in Korean men. This study included 499 men (mean age, 49.1 years) without metabolic syndrome at baseline who were followed for an average of 2.9 years. Subjects were divided into 4 groups according to baseline LDL-C/apo B ratio quartiles: greater than 1.243 in group I, 1.164 to 1.243 in group II, 1.070 to 1.163 in group III, and less than 1.070 in group IV. The incidence of metabolic syndrome at follow-up was compared according to LDL-C/apo B ratio group. Metabolic syndrome was defined using the National Cholesterol Education Program Adult Treatment Panel III criteria. The overall incidence of metabolic syndrome was 9.6%: 1.6% in the highest quartile (group I), 9.7% in group II, 11.2% in group III, and 16.0% in the lowest quartile (group IV) (P = .001). In multivariable regression analysis model adjusting for age, lifestyle status, homeostasis model assessment of insulin resistance, LDL-C, and high-sensitivity C-reactive protein, groups II, III, and IV had significantly increased odds ratio for the incidence of metabolic syndrome compared with the highest LDL-C/apo B quartile (group I). The LDL-C/apo B ratio is independently associated with metabolic syndrome in Korean men, indicating that this ratio may provide additional information when assessing cardiometabolic risks and predicting future development of metabolic syndrome.

Honey promotes lower weight gain, adiposity, and triglycerides than sucrose in rats

Various dietary carbohydrates have been linked to obesity and altered adipose metabolism; however, the influences of honey vs common sweeteners have not been fully explored. We hypothesized that in comparison with sucrose, a honey-based diet would promote lower weight gain, adiposity, and related biomarkers (leptin, insulin, and adiponectin) as well as a better blood lipid profile. Thirty-six male Sprague-Dawley rats (228.1 ± 12.5 g) were equally divided by weight into 2 groups (n = 18) and provided free access to 1 of 2 diets of equal energy densities differing only in a portion of the carbohydrate. Diets contained 20% carbohydrate (by weight of total diet) from either clover honey or sucrose. After 33 days, epididymal fat pads were excised and weighed, and blood was collected for analyses of serum concentrations of lipids, glucose, and markers of adiposity and inflammation. Body weight gain was 14.7% lower (P ≤ .05) for rats fed honey, corresponding to a 13.3% lower (P ≤ .05) consumption of food/energy, whereas food efficiency ratios were nearly identical. Epididymal fat weight was 20.1% lower (P ≤ .05) for rats fed honey. Serum concentrations of triglycerides and leptin were lower (P ≤ .05) by 29.6% and 21.6%, respectively, and non-high-density lipoprotein cholesterol was higher (P ≤ .05) by 16.8% for honey-fed rats. No significant differences in serum total cholesterol, high-density lipoprotein cholesterol, adiponectin, C-reactive protein, monocyte chemoattractant protein-1, glucose, or insulin were detected. These results suggest that in comparison with sucrose, honey may reduce weight gain and adiposity, presumably due to lower food intake, and promote lower serum triglycerides but higher non-high-density lipoprotein cholesterol concentrations.

Effect of combination of dietary fish protein and fish oil on lipid metabolism in rats

This study examined the effects of fish protein in combination with fish oil on rat lipid metabolism. Male Wistar rats were divided into four groups and fed an AIN93G-based diet with casein (20%) + soybean oil (7%), casein (10%) + fish protein (10%) + soybean oil (7%), casein (20%) + soybean oil (5%) + fish oil (2%), and casein (10%) + fish protein (10%) + soybean oil (5%) + fish oil (2%) for 4 weeks. The dietary combination of fish protein and fish oil decreased the contents of serum triacylglycerol, serum cholesterol, liver triacylglycerol and liver cholesterol in addition to altering liver lipid fatty acid composition. These effects are partly due to the increase in fecal cholesterol, bile acid excretion, and increased enzyme activities of fatty acid β-oxidation in the liver. These data suggest that combined intake of fish protein and fish oil lead to both hypocholesterolemic and hypotriglyceridemic in serum and the liver, while sole intake of fish protein or fish oil decrease only cholesterol and triglyceride levels, respectively. These results suggest that combined intake of fish protein and fish oil may play beneficial roles in the prevention of lifestyle-related diseases as compared with sole fish protein intake.

A pilot study of abacavir/lamivudine and raltegravir in antiretroviral-naïve HIV-1-infected patients: 48-week results of the SHIELD trial

PURPOSE

to evaluate raltegravir plus abacavir/lamivudine in antiretroviral-naïve, HIV-1-infected patients.

METHODS

SHIELD is an ongoing 96-week pilot study of abacavir/lamivudine 600 mg/300 mg once daily with raltegravir 400 mg twice daily among HLA-B*5701-negative adults with screening viral load (VL) > 1,000 copies/mL. HBsAg+ patients were excluded, as were patients with key mutation(s) to any study drug. Virologic failure (VF) was defined as either VL > 400 copies/mL at week 24 or confirmed virologic rebound.

RESULTS

thirty-five patients enrolled (mean age 38.7 years). Most were white males, but 26% self-identified as Hispanic/Latino. At baseline, 34% had VL ≥ 100,000 copies/mL (median, 4.8 log10 copies/mL) and 20% had CD4 cell counts <200 cells/mm3 (median, 301). One patient discontinued due to adverse events (AEs); one patient experienced VF. At week 48, 91% (32/35) had VL <50 and <400 copies/mL by missing/discontinuation equals failure analysis. Median CD4 cell count change from baseline was +247 cells/mm3. Five patients (14%) had treatment-related grade 2-4 AEs; no treatment-related serious AEs were reported. Over 48 weeks, median fasting lipids increased for total (+17%), LDL (+9%), and HDL (+6%) cholesterol but remained stable for triglycerides (-1%) and total:HDL cholesterol ratio (0%).

CONCLUSIONS

in this pilot study, abacavir/lamivudine plus raltegravir was effective and generally well-tolerated over 48 weeks with modest changes in fasting lipids.

Treatment of dyslipidemia in patients with type 2 diabetes

Type 2 diabetes is associated with significant cardiovascular morbidity and mortality. Although low-density lipoprotein cholesterol levels may be normal in patients with type 2 diabetes, insulin resistance drives a number of changes in lipid metabolism and lipoprotein composition that render low-density lipoprotein cholesterol and other lipoproteins more pathogenic than species found in patients without type 2 diabetes. Dyslipidemia, which affects almost 50% of patients with type 2 diabetes, is a cardiovascular risk factor characterized by elevated triglyceride levels, low high-density lipoprotein cholesterol levels, and a preponderance of small, dense, low-density lipoprotein particles. Early, aggressive pharmacological management is advocated to reduce low-density lipoprotein cholesterol levels, regardless of baseline levels. A number of lipid-lowering agents, including statins, fibrates, niacin, and bile acid sequestrants, are available to target normalization of the entire lipid profile. Despite use of combination and high-dose lipid-lowering agents, many patients with type 2 diabetes do not achieve lipid targets. This review outlines the characteristics and prevalence of dyslipidemia in patients with type 2 diabetes and discusses strategies that may reduce the risk of cardiovascular disease in this population.

Differences in lipoprotein particle subclass distribution for Japanese Americans in Hawaii and Japanese in Japan: the INTERLIPID study

BACKGROUND

Current data suggest that low density lipoprotein (LDL) and high density lipoprotein (HDL) subclass concentrations relate directly to the risk of coronary heart disease (CHD). Earlier Studies indicated that Japanese in Japan had lower rates of CHD than Japanese Americans in Hawaii. Rates of CHD appear to continue to be lower in Japan despite increasing cholesterol levels in Japan and decreasing CHD rates in the United States.

OBJECTIVE

To provide insight into CHD rate differences.

METHODS

Nuclear Magnetic Resonance (NMR) measurements of lipoprotein subclasses were used to assess lipoprotein particle concentration and size in samples from these two genetically similar populations in Japan and Hawaii.

RESULTS

Japanese Americans had significantly higher age- and risk factor- adjusted concentrations of lipoprotein particles implicated in atherogenesis, including large very low density lipoprotein (VLDL; P < 0.001), small LDL (P < 0.001), and small HDL (women, P < 0.001; men, P < 0.01), and significantly lower concentrations of large LDL (P < 0.001) and the putative cardio-protective large HDL (P < 0.05) than Japanese in Japan. Average age- and risk factor- adjusted LDL and HDL particle sizes were also significantly (P < 0.001) smaller in Japanese Americans. Adjustment for body mass index markedly reduced the differences in some lipoprotein measures, including total LDL and large HDL particle concentrations for both genders, total VLDL particle concentration for women, and large VLDL concentration and average HDL particle size for men.

CONCLUSIONS

Differences in lipoprotein subclass distributions and lifestyle factors such as body weight may contribute to differences in CHD incidence for Japanese in Japan and Japanese Americans.

HIV, HAART, and lipoprotein particle concentrations in the Women's Interagency HIV Study

BACKGROUND

Changes in lipoprotein particle concentrations, especially greater small low-density lipoprotein particle (LDL-p) and lower small high-density lipoprotein particle (HDL-p) may provide information regarding cardiovascular disease (CVD) risk above and beyond that which is provided by standard lipids. We quantified the association HIV and HAART use had with LDL-p and HDL-p.

METHODS

Cross-sectional study of 1077 individuals classified by HIV/HAART status (361 HIV-uninfected, 128 HIV-infected/HAART naive, 588 HIV-infected/on HAART) enrolled in the Women's Interagency HIV Study. Nuclear magnetic resonance spectroscopy estimated total and subclass lipoprotein particle concentrations. Quantile regression models were used to estimate differences in the 10th, 25th, 50th, 75th, and 90th percentiles of the distributions of lipoprotein particle concentrations between the two HIV-infected exposure groups and HIV-uninfected controls after adjustment for demographic, nonlipid metabolic factors, and standard lipids.

RESULTS

Compared with HIV-uninfected women, those on HAART had greater 75th and 90th percentiles of small LDL-p; there was little difference between HIV-infected/HAART naive and HIV-uninfected women. After adjustment for triglycerides, the association of HAART with greater 75th and 90th percentiles of small LDL-p was attenuated and no longer significant. In contrast, after adjustment for triglycerides, HIV infection irrespective of HAART status remained associated with significantly lower 10th, 25th, 50th, 75th, and 90th percentiles of small HDL-p.

CONCLUSION

Our findings suggest that testing for LDL-p confers little additional information beyond triglycerides levels when assessing CVD risk. Further investigation is needed to examine the role of HDL-p in the link between HIV and CVD in women.

Colesevelam: an improved bile acid sequestrant for treating hypercholesterolemia and improving diabetes

There is a well-established association between serum cholesterol and coronary heart disease. Statins are the first-line agents for the treatment of hypercholesterolemia, yet combination therapy is required to achieve the desired reduction in low-density lipoprotein cholesterol (LDL-C). Niacin and bile acid sequestrants were among the first lipid-lowering drugs developed to lower LDL-C and have been established to be effective both in monotherapy and in combination therapy. However, tolerability and compliance issues have limited their use. Colesevelam HCl is the newest bile acid sequestrant and reduces LDL-C by 16-22% in monotherapy and adds 12-14% in combination dual therapy with statins, fibrates and ezetimibe or in triple therapy with statin and ezetimibe. It reduces C-reactive protein levels by 16-19% in monotherapy or by 23% in combination with statins and other lipid-lowering therapies. In addition, it consistently reduces hemoglobin A_1c by 0.5% in addition to other hypoglycemic drugs in studies of patients with diabetes. Compared with other bile acid sequestrants it has a higher bile acid-binding capacity, reduced adverse effects and, therefore, has better compliance. Colesevelam HCl is thus a useful addition to the lipid-lowering formulary as a second-line agent, particularly for patients with metabolic syndrome requiring extra reduction in LDL-C.

Should we measure routinely oxidised and atherogenic dense low-density lipoproteins in subjects with type 2 diabetes?

Beyond low-density lipoprotein (LDL)-cholesterol concentrations, in recent years, several clinical studies have shown that both oxidised and small, dense LDL have a strong predictive role for the presence of vascular atherosclerosis. These two lipid parameters seem to have a synergistic impact on cardiovascular risk, with a greater importance in patients at higher-risk, such as those with type-2 diabetes. Increased levels of oxidised and small, dense LDL levels are a feature of diabetic dyslipidaemia, and small, dense LDL have been shown to be a good predictor of future cardiovascular events, at both univariate and multivariate analyses. On the other hand, although the association of oxidised LDL with surrogate markers of atherosclerosis is consistent, the correlation with hard clinical end points seems to be smaller. Yet, measurement of these two lipid parameters has not been widely used in daily practice because of the limited availability of clinical data and methodological problems: lack of availability of easy, cheap and reproducible essays for measurement of oxidised and, particularly, small, dense LDL has reduced their assessment in large clinical end-points trials. However, on the basis of available data, the therapeutic modulation of small, dense LDL is significantly associated with reduced cardiovascular risk, even after adjustment for confounding factors. In conclusion, the routine measurement of oxidised and small, dense LDL in patients with type-2 diabetes cannot be recommended in daily clinical practice so far; yet, their measurement is strongly encouraged to better understand their role on the cardiovascular risk of patients with type-2 diabetes.

Nuclear Magnetic Resonance Lipoprotein Subclasses and the APOE Genotype Influence Carotid Atherosclerosis in Patients with Systemic Lupus Erythematosus

Objective.

Patients with systemic lupus erythematosus (SLE) have accelerated atherosclerosis. Since the conventional lipid profile (total plasma cholesterol, triglycerides, low and high density lipoprotein cholesterol) is not consistently altered in SLE, we hypothesized that investigation of lipoprotein subclasses would improve prediction of risk of atherosclerosis in these patients.

Methods.

As a quantitative index of atherosclerosis, we measured the carotid intima-media thickness (IMT) in 68 patients with SLE and related the atherosclerosis to a detailed lipoprotein profile generated using nuclear magnetic resonance (NMR). We measured the cholesterol transported by the pool of remnant lipoproteins (RLPc) and evaluated the modulatory effect of the APOE genotype on the lipoprotein subclass profile and atherosclerosis associated with SLE.

Results.

Circulating lipoprotein remnant particles [RLPc and intermediate density lipoprotein (IDL)] were positively correlated with IMT, and among them, the indicator that explained 20.2% of the variability in carotid atherosclerosis measured in these patients was IDL, as assessed by NMR. Carriers of the APOE2 allele were at increased risk due to a significant accumulation of IDL particles.

Conclusion.

Lipoprotein subclasses are more associated with subclinical atherosclerosis in patients with SLE than the lipid variables that are routinely measured. The IDL fraction, which is significantly modulated by the APOE genotype, is the most strongly, significantly, and positively correlated with IMT.

Malnutrition, inflammation, and lipids in a cohort of dialysis patients

BACKGROUND

This study aimed to determine if there is an association between lipid levels, serum albumin, and C-reactive protein (CRP) levels in patients on dialysis.

METHODS

Lipid profiles, albumin, and CRP levels were collected after a 12-hour fast from patients with end-stage renal disease (N = 105) who were on chronic hemodialysis. Patients were placed in an albumin group (>or= 3.8 g/dL) or a hypoalbumin group (< 3.8 g/dL), a high-risk CRP group (> 3 mg/dL) or a low-risk CRP group (<or= 3 mg/dL), and a low-risk group (low CRP and normal albumin) and high-risk group (high CRP and hypoalbumin). Lipid values included low-density lipoprotein (LDL), LDL particle number, LDL particle size, very-low-density lipoprotein (VLDL), large VLDL, high-density lipoprotein (HDL), large HDL, total cholesterol, lipoprotein A (Lp[a]), and triglycerides. All variables were measured using nuclear magnetic resonance spectroscopy.

RESULTS

Analysis of variance revealed significant differences in the hypoalbumin group, with LDL particle number being lower in this group. Analysis of variance revealed significant differences in LDL, VLDL, and LDL particle number, with lower levels in the high-risk CRP group. Analysis of variance also revealed significant differences in total cholesterol, VLDL, large VLDL, triglycerides, Lp(a), LDL, and LDL particle number when risk was combined with hypoalbumin and high CRP.

CONCLUSIONS

Our study found a counterintuitive effect in LDL and VLDL in patients with high CRP levels, in LDL particle number in patients with low albumin levels, and most variables when patients had both high CRP levels and low levels of albumin.

Lipoproteins and lipoprotein metabolism in periodontal disease

A growing body of evidence indicates that the incidence of atherosclerosis is increased in subjects with periodontitis - a chronic infection of the oral cavity. This article summarizes the evidence that suggests periodontitis shifts the lipoprotein profile to be more proatherogenic. LDL-C is elevated in periodontitis and most studies indicate that triglyceride levels are also increased. By contrast, antiatherogenic HDL tends to be low in periodontitis. Periodontal therapy tends to shift lipoprotein levels to a healthier profile and also reduces subclinical indices of atherosclerosis. In summary, periodontal disease alters lipoprotein metabolism in ways that could promote atherosclerosis and cardiovascular disease.

A case-control study on the relationship between HDL2b and non-alcoholic fatty liver disease in Chinese type 2 diabetic patients

BACKGROUND

It has been shown that low concentrations of high-density lipoprotein cholesterol (HDL-C) are associated with non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM). HDL2b, a major subfraction of high-density lipoprotein (HDL), is more significantly correlated with coronary heart disease (CHD) compared with total HDL. In this study, we analysed HDL2b in a cohort of Chinese T2DM subjects with or without NAFLD.

METHODS

A highly sensitive and reliable microfluidic chip method was adopted to measure HDL2b. In total, 48 T2DM patients with NAFLD diagnosed by a B-ultrasound were enrolled from our Beijing Community Pre-Diabetes (BCPD) study cohort. A total of 48 age and gender matched diabetic controls without NAFLD were selected from the same population.

RESULTS

Clinical characteristics and serum biochemical analyses demonstrated a significantly increased body mass index (BMI), waist circumference, homeostasis model assessment-insulin resistant index (HOMA-IR), total cholesterol (TC), and triglyceride (TG) concentrations in the NAFLD group. However, the concentrations of HDL2b and its ratio to total HDL in NAFLD patients was decreased, compared with controls (p<0.01). Significantly increased concentrations of high sensitive C-reactive protein (hs-CRP) (p<0.01) were also found. Multifactor logistic regression analysis showed that BMI and TG were the predominant risk factors for fatty liver, while HDL2b was a protective factor.

CONCLUSIONS

T2DM patients with NAFLD have characteristics including obesity, marked insulin resistance, high TG, high hs-CRP, low HDL2b and a low HDL2b ratio to total HDL. These factors may increase the incidence of atherosclerosis as well as the risk of CHD.

Characterization of metabolic interrelationships and in silico phenotyping of lipoprotein particles using self-organizing maps

Plasma lipid concentrations cannot properly account for the complex interactions prevailing in lipoprotein (patho)physiology. Sequential ultracentrifugation (UCF) is the gold standard for physical lipoprotein isolations allowing for subsequent analyses of the molecular composition of the particles. Due to labor and cost issues, however, the UCF-based isolations are usually done only for VLDL, LDL, and HDL fractions; sometimes with the addition of intermediate density lipoprotein (IDL) particles and the fractionation of HDL into HDL(2) and HDL(3) (as done here; n = 302). We demonstrate via these data, with the lipoprotein lipid concentration and composition information combined, that the self-organizing map (SOM) analysis reveals a novel data-driven in silico phenotyping of lipoprotein metabolism beyond the experimentally available classifications. The SOM-based findings are biologically consistent with several well-known metabolic characteristics and also explain some apparent contradictions. The novelty is the inherent emergence of complex lipoprotein associations; e.g., the metabolic subgrouping of the associations between plasma LDL cholesterol concentrations and the structural subtypes of LDL particles. Importantly, lipoprotein concentrations cannot pinpoint lipoprotein phenotypes. It would generally be beneficial to computationally enhance the UCF-based lipoprotein data as illustrated here. Particularly, the compositional variations within the lipoprotein particles appear to be a fundamental issue with metabolic and clinical corollaries.

Effects of cardiovascular lifestyle change on lipoprotein subclass profiles defined by nuclear magnetic resonance spectroscopy

Background

Low-density lipoprotein (LDL) cholesterol lowering is a primary goal in clinical management of patients with cardiovascular disease, but traditional cholesterol levels may not accurately reflect the true atherogenicity of plasma lipid profiles. The size and concentration of lipoprotein particles, which transport cholesterol and triglycerides, may provide additional information for accurately assessing cardiovascular risk. This study evaluated changes in plasma lipoprotein profiles determined by nuclear magnetic resonance (NMR) spectroscopy in patients participating in a prospective, nonrandomized lifestyle modification program designed to reverse or stabilize progression of coronary artery disease (CAD) to improve our understanding of lipoprotein management in cardiac patients.

Results

The lifestyle intervention was effective in producing significant changes in lipoprotein subclasses that contribute to CAD risk. There was a clear beneficial effect on the total number of LDL particles (-8.3%, p < 0.05 compared to matched controls), small dense LDL particles (-9.5%, p < 0.05), and LDL particle size (+0.8%; p < 0.05). Likewise, participants showed significant improvement in traditional CAD risk factors such as body mass index (-9.9%, p < 0.01 compared to controls), total cholesterol (-5.5%, p < 0.05), physical fitness (+37.2%, p < 0.01), and future risk for CAD (-7.9%, p < 0.01). Men and women responded differently to the program for all clinically-relevant variables, with men deriving greater benefit in terms of lipoprotein atherogenicity. Plasma lipid and lipoprotein responses to the lifestyle change program were not confounded by lipid-lowering medications.

Conclusion

In at risk patients motivated to participate, an intensive lifestyle change program can effectively alter traditional CAD risk factors and plasma lipoprotein subclasses and may reduce risk for cardiovascular events. Improvements in lipoprotein subclasses are more evident in men compared to women.

Effects of exercise on lipoprotein particles in women with polycystic ovary syndrome

PURPOSE

Women with polycystic ovary syndrome (PCOS) commonly have insulin resistance. Insulin resistance is associated with marked abnormalities of lipoprotein size and subclass particle concentration. The purpose of this study was to examine the effects of a moderate-intensity exercise program without weight loss on lipoprotein profiles in women with PCOS.

METHODS

Thirty-seven sedentary PCOS women were randomized to either an 8- to 12-wk ramp-up followed by a 12-wk moderate-intensity exercise program (16-24 wk total, approximately 228 min x wk at 40-60% peak V x O2, n = 21) or control (no change in lifestyle, n = 16). PCOS was defined as <or=8 menses per year and hyperandrogenism (biochemical or clinical with Ferriman-Gallwey score >or=8). Fasting lipoprotein profiles were obtained before and after the intervention. Nuclear magnetic resonance spectroscopy was used to quantify the following: average particle size, total and subclass concentrations of HDL, LDL, and VLDL particles, and calculated HDL cholesterol, triglycerides, and VLDL triglycerides. Wilcoxon exact rank sums tests were used to compare changes in these parameters in the exercise group relative to controls.

RESULTS

Twenty women (8 exercisers, 12 controls) completed the study. Comparing exercisers to controls, significant changes were seen in concentrations of the following lipoprotein parameters that are associated with decreased insulin resistance: decreased large VLDL (P = 0.007), calculated triglycerides (P = 0.003), VLDL triglycerides (P = 0.003), and medium/small HDL (P = 0.031) and increased large HDL (P = 0.002) and average HDL size (P = 0.001).

CONCLUSIONS

In this trial, moderate-intensity exercise without significant weight loss improved several components of the lipoprotein profiles of women with PCOS. These findings support the beneficial role of moderate exercise in this high-risk population.

Physical Activity, Blood Lipids, and Lipoproteins

Dyslipidemia is a major modifiable cardiovascular disease (CVD) risk factor. While pharmacological treatment has been a focal point of dyslipidemia management for several years, increasing physical activity is a safe, cost-effective treatment option that should also be recommended by health care practitioners. Moderate aerobic exercise consistently increases high-density lipoprotein cholesterol (HDL-C) and reduces triglycerides (TG), independent of changes in body weight. However, reductions in total and low-density lipoprotein cholesterol are reported less often following aerobic exercise. Therefore, clinicians should understand that aerobic exercise is not likely to be an effective treatment option for their management. Recent empirical evidence also indicates that aerobic exercise may be of benefit for treating emerging lipid and lipoprotein risk factors such as lipoprotein particle size and number and triglyceride-rich lipoproteins. Further work is needed to clarify the impact of aerobic exercise on apolipoproteins. Based on current evidence, prescribing aerobic exercise as a means of increasing HDL-C and lowering TG is usually an efficacious strategy for treating these aspects of dyslipidemia. These effects are likely to be accompanied by changes in emerging lipid and lipoprotein risk factors.

Macrovascular Complications of Diabetes Mellitus

Adults with diabetes mellitus frequently develop macrovascular complications. Vascular disease is a frequent cause of morbidity and mortality among patients with diabetes. Diabetes and vascular diseases remain among the most common causes of death in the United States. A number of clinical trials and practice guidelines have been published addressing the management of macrovascular complications. The cornerstone of preventing or delaying the progression of macrovascular complications of diabetes is aggressive management of hypertension and cholesterol. Angiotensin-converting enzyme inhibitors have proven effective in managing hypertension and avoiding other complications of diabetes. The body of evidence for angiotensin receptor blockers is growing in this area as well. Statins have been repeatedly proven to be the first-line agents in the management of dyslipidemia. Lifestyle modification strategies and antiplatelet therapy also remain essential. This review will focus on the role of newer diagnostic techniques, clinical trial evidence, and appropriate pharmacotherapy for macrovascular complications of diabetes.

Quantitative and qualitative effects of rosuvastatin on LDL-cholesterol: what is the clinical significance?

BACKGROUND

Statins have emerged as the global leader in pharmacologic therapy for dyslipidaemia, and rosuvastatin has demonstrated clinical efficacy as well as safety in several clinical trials and postmarketing analyses.

AIM

The present article reviewed the effects of rosuvastatin on the quantity and the quality of low-density lipoproteins (LDL).

METHODS

We searched for and reviewed all the available evidence in a systematic way. A literature search (by Medline and Scopus) was performed using the following headings: 'LDL-cholesterol', 'LDL size', 'LDL subclasses', 'small dense LDL', 'apolipoprotein B, apo B' and 'rosuvastatin' up to 11 November 2008. The authors also manually reviewed the references of selected articles for any pertinent material.

RESULTS

Rosuvastatin reduces LDL-cholesterol levels to a greater extent than other statins and is able to modulate significantly LDL size and subclasses towards less atherogenic particles as well as the LDL particle number, as indirectly measured by the levels of apo B.

DISCUSSION AND CONCLUSIONS

The recent Justification for the Use of statins in Primary prevention: an Intervention Trial Evaluating Rosuvastatin study provides more evidence about the effectiveness of rosuvastatin therapy in reducing cardiovascular risk, even among persons who would not currently be considered for pharmacotherapy. Further insights on cardiovascular outcomes will be available by the on-going trials included in the GALAXY program that includes subjects with type-2 diabetes, haemodialysis recipients, patients with congestive heart failure and specific ethnic groups, such as African American, Hispanic and South Asian populations.

Advanced lipoprotein testing: recommendations based on current evidence

Low-density lipoprotein cholesterol (LDL-C) level currently is used as the major determinant of lipid- and lipoprotein-associated risk for ischemic cardiovascular disease, and varying levels have become the standard goals of lipid-altering treatment. The predictive value of the LDL-C cholesterol level, however, often is less than that provided by other variables such as non-high-density lipoprotein cholesterol (non-HDL-C), apolipoprotein B (apoB), and the number of LDL particles measured by nuclear magnetic resonance spectroscopy. This article reviews studies that compare these different lipoprotein variables, describes advanced methodologies of lipoprotein testing, and suggests goals of treatment and clinical situations in which these tests might be ordered.

Lipoprotein Changes in HIV-Infected Antiretroviral-Naïve Individuals after Starting Antiretroviral Therapy: ACTG Study A5152s Stein: Lipoprotein Changes on Antiretroviral Therapy

BACKGROUND: Dyslipidemia is a frequent complication of antiretroviral therapy (ART) for patients with human immunodeficiency virus infection (HIV). The effects of ART on lipoproteins are less well-understood, and have not been investigated in a prospective study where assignment to ART is randomized. OBJECTIVE: To evaluate the effects of three class-sparing ART regimens on lipids and lipoproteins. METHODS: This was a substudy of a prospective, multicenter study treatment-naïve HIV-infected individuals randomly assigned to receive a regimen of nucleoside reverse transcriptase inhibitors (NRTIs) + the non-nucleoside reverse transcriptase inhibitor efavirenz, NRTIs + the protease inhibitor lopinavir/ritonavir, or a NRTI-sparing regimen of efavirenz + lopinavir/ritonavir. Lipoproteins were measured by nuclear magnetic resonance spectroscopy. RESULTS: Among the 82 participants, total and small low-density lipoprotein concentrations increased (median, interquartile range) by 152 (-49 - +407, p<0.01) and 130 (-98 - +417, p<0.01) nmol/L, respectively, especially in the arms containing lopinavir/ritonavir (p(KW)<0.04). Very low-density lipoproteins also increased (p<0.01), with a larger increase in the arms that contained lopinavir/ritonavir (p=0.022). High-density lipoproteins increased by 6.0 nmol/L (2.8 - 10.4, p<0.01), but differences between arms were not significant (p(KW)=0.069). Changes were not related to changes in markers of insulin/glucose metabolism. CONCLUSIONS: Total and small low-density lipoprotein concentrations increased, especially in the arms containing lopinavir/ritonavir, as did increases in total very low-density lipoproteins. Adverse changes were especially prominent in the arm with efavirenz + lopinavir/ritonavir.

Is it LDL particle size or number that correlates with risk for cardiovascular disease?

The role of low-density lipoprotein cholesterol (LDL-C) in the pathogenesis of cardiovascular disease (CVD) and the clinical benefit of lowering LDL-C in high-risk patients is well established. What remains controversial is whether we are using the best measure(s) of LDL characteristics to identify all individuals who are at CVD risk or if they would benefit from specific therapies. Despite the successful LDL-C reduction trials, substantial numbers of patients continue to have clinical events in the treatment groups. The size of LDL particles and assessment of the number of LDL particles (LDL-Num) have been suggested as a more reliable method of atherogenicity. Each LDL particle has one apoprotein B-100 measure attached; therefore, determination of whole plasma apoprotein B can be considered the best measure of LDL-Num. Because the cholesterol content per LDL particle exhibits large interindividual variation, the information provided by LDL-C and LDL-Num is not equivalent. Individuals with the same level of LDL-C may have higher or lower numbers of LDL particles and, as a result, may differ in terms of absolute CVD risk. LDL particle size and number provide independent measures of atherogenicity and are strong predictors of CVD.

The effects of ezetimibe on LDL-cholesterol: quantitative or qualitative changes?

Ezetimibe represents the first of a new class of agents, the cholesterol absorption inhibitors, able to reduce low-density lipoproteins (LDL)-cholesterol by 15-25% from baseline in monotherapy and on top of statins and fibrates. To-date all the data regarding the efficacy of ezetimibe comes from the studies of its lipid-lowering power. Yet, recent findings from the ENHANCE study on atherosclerosis progression showed that the addition of ezetimibe to simvastatin in patients with heterozygous familial hypercholesterolemia did not affect the mean change in carotid intima-media thickness, although a significant reduction in LDL-cholesterol levels was present. Therefore, we cannot exclude that ezetimibe is treating mainly LDL-cholesterol and not the underlying dyslipidemia. Reviewing all available evidences on the effects on atherogenic small, dense LDL, it seems that ezetimibe produce quantitative rather than qualitative changes in LDL, with small net effects on LDL subclass distribution. Yet, we cannot exclude that clinical and laboratory factors influenced this result. We found important differences in the methodology used to measure LDL size and subfractions and this represents a crucial point, since these methods cannot be fully used interchangeably. In addition, it is reasonable to imagine that ezetimibe may be more effective on small, dense LDL in subjects with hypertriglyceridemia. Further formal cardiovascular event outcome trials are underway and this will provide additional insights into the long-term effects of ezetimibe. Future prospective studies are also needed to clarify to which extent ezetimibe is able to reduce atherogenic dyslipidemia, beyond LDL-cholesterol levels.

Effects of adding prescription omega-3 acid ethyl esters to simvastatin (20 mg/day) on lipids and lipoprotein particles in men and women with mixed dyslipidemia

Prescription omega-3 acid ethyl esters (P-OM3) are commonly used for treatment of very high triglyceride levels, often in combination with a statin, to lower persistent hypertriglyceridemia. This randomized, crossover trial evaluated 6 weeks of combination therapy with simvastatin 20 mg/day plus P-OM3 4 g/day or placebo in 39 men and women (average age 58 years) with a triglyceride concentration 200 to 600 mg/dl and non-high-density lipoprotein (non-HDL) cholesterol greater than their National Cholesterol Education Program treatment goals after a 5-week diet lead-in. Non-HDL cholesterol decreased from baseline (209 mg/dl) by 40% for P-OM3 + simvastatin compared with 34% for placebo + simvastatin (p <0.001). Favorable changes for P-OM3 + simvastatin versus placebo + simvastatin were also observed for very low-density lipoprotein (VLDL) cholesterol (-42% vs -22%), triglyceride (-44% vs -29%), total cholesterol (-31% vs -26%), HDL cholesterol (+16% vs +11%), apolipoprotein B (-32% vs -28%), total cholesterol:HDL cholesterol ratio (-39% vs -33%), triglyceride:HDL cholesterol ratio (-51% vs -37%), and systolic (-5.0 vs 0.3 mm Hg) and diastolic (-3.3 vs -1.8 mm Hg) blood pressures (p <0.05 for all). VLDL particle concentration and size decreased and LDL particle size increased significantly more with P-OM3 + simvastatin than with placebo + simvastatin (all p <0.05). Changes in LDL cholesterol, LDL particle concentration, HDL particle size and concentration, and apolipoprotein A-I did not differ significantly between treatments. In conclusion, P-OM3 + simvastatin appears to be a useful therapeutic option for the management of mixed dyslipidemia.

The importance of non-HDL cholesterol reporting in lipid management

Plasma levels of lipids and lipoproteins are essential to the management of lipid disorders by generalists and by practitioners of the emerging specialty of clinical lipidology. The routine lipid panel consists of total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides. Several additional lipid parameters are emerging as potentially valuable adjuncts to the standard panel, including measurements of apolipoproteins and LDL particle size and concentration, but most of these serve mainly as research tools at present. One major exception is non-HDL-C, which is readily available for routine clinical use. This review outlines some of the numerous research studies that clearly establish the clinical utility and even preeminence of non-HDL-C as a comprehensive measure of atherogenic lipoproteins. Non-HDL-C was highlighted as a key secondary goal of therapy several years ago in the National Cholesterol Education Program Adult Treatment Panel III national lipid treatment guidelines and recently was further emphasized as a major goal of therapy in the consensus guidelines for lipoprotein management in patients with cardiometabolic risk from the American Diabetes Association and the American College of Cardiology. Non-HDL-C is superior to LDL-C for the prediction of cardiovascular events and has many other compelling advantages over LDL-C and other traditional lipid parameters. Importantly, it can be calculated directly from values in routine lipid panels, at no added expense. It is our opinion that non-HDL-C should be reported on all routine lipid profiles and used regularly in the management of dyslipidemia for optimal prevention of atherosclerosis and cardiovascular disease.

Critical evaluation of 1H NMR metabonomics of serum as a methodology for disease risk assessment and diagnostics

This review focuses on (i) the current status of 1H NMR spectroscopy to quantify lipoprotein subclasses directly from serum or plasma, and (ii) the applications of 1H NMR metabonomics of serum in biomedicine. Related to both themes, experimental and data analysis methodologies are discussed together with the biochemical rationales. Particular emphasis is placed on the concepts of risk assessment and diagnostics in relation to the potential clinical role of 1H NMR metabonomics; recent applications in the area of coronary heart disease and diabetes are addressed in more detail.

Lipid peroxidation and decomposition--conflicting roles in plaque vulnerability and stability

The low density lipoprotein (LDL) oxidation hypothesis has generated considerable interest in oxidative stress and how it might affect atherosclerosis. However, the failure of antioxidants, particularly vitamin E, to affect the progression of the disease in humans has convinced even staunch supporters of the hypothesis to take a step backwards and reconsider alternatives. Preponderant evidence for the hypothesis came from animal antioxidant intervention studies. In this review we point out basic differences between animal and human atherosclerosis development and suggest that human disease starts where animal studies end. While initial oxidative steps in the generation of early fatty streak lesions might be common, the differences might be in the steps involved in the decomposition of peroxidized lipids into aldehydes and their further oxidation into carboxylic acids. We suggest that these steps may not be amenable to attenuation by antioxidants and antioxidants might actually counter the stabilization of plaque by preventing the formation of carboxylic acids which are anti-inflammatory in nature. The formation of such dicarboxylic acids may also be conducive to plaque stabilization by trapping calcium. We suggest that agents that would prevent the decomposition of lipid peroxides and promote the formation and removal of lipid hydroxides, such as paraoxonase (PON 1) or apo A1/high density lipoprotein (HDL) might be more conducive to plaque regression.

Biomarkers related to aging in human populations

Biomarkers are increasingly employed in empirical studies of human populations to understand physiological processes that change with age, diseases whose onset appears linked to age, and the aging process itself. In this chapter, we describe some of the most commonly used biomarkers in population aging research, including their collection, associations with other markers, and relationships to health outcomes. We discuss biomarkers of the cardiovascular system, metabolic processes, inflammation, activity in the hypothalamic-pituitary axis (HPA) and sympathetic nervous system (SNS), and organ functioning (including kidney, lung, and heart). In addition, we note that markers of functioning of the central nervous system and genetic markers are now becoming part of population measurement. Where possible, we detail interrelationships between these markers by providing correlations between high risk levels of each marker from three population-based surveys: the National Health and Nutrition Examination Survey (NHANES) III, NHANES 1999-2002, and the MacArthur Study of Successful Aging. NHANES III is used instead of NHANES 1999-2002 when specific markers of interest are available only in NHANES III and when we examine the relationship of biomarkers to mortality which is only known for NHANES III. We also describe summary measures combining biomarkers across systems. Finally, we examine associations between individual markers and mortality and provide information about biomarkers of growing interest for future research in population aging and health.

LDL Particle Number and Risk of Future Cardiovascular Disease in the Framingham Offspring Study - Implications for LDL Management

BACKGROUND

The cholesterol content of LDL particles is variable, causing frequent discrepancies between concentrations of LDL cholesterol and LDL particle number. In managing patients at risk for cardiovascular disease (CVD) to LDL target levels, it is unclear whether LDL cholesterol provides the optimum measure of residual risk and adequacy of LDL lowering treatment.

OBJECTIVE

To compare the ability of alternative measures of LDL to provide CVD risk discrimination at relatively low levels consistent with current therapeutic targets.

METHODS

Concentrations of LDL cholesterol (LDL-C) and non-HDL cholesterol (non-HDL-C) were measured chemically and LDL particle number (LDL-P) and VLDL particle number (VLDL-P) were measured by nuclear magnetic resonance (NMR) in 3066 middle-aged white participants (53% women) without CVD in the Framingham Offspring cohort. The main outcome measure was incidence of first CVD event.

RESULTS

At baseline, the cholesterol content per LDL particle was negatively associated with triglycerides and positively associated with LDL-C. On follow-up (median 14.8 yrs), 265 men and 266 women experienced a CVD event. In multivariable models adjusting for non-lipid CVD risk factors, LDL-P was related more strongly to future CVD in both sexes than LDL-C or non-HDL-C. Subjects with a low level of LDL-P (<25(th) percentile) had a lower CVD event rate (59 events per 1000 person-years) than those with an equivalently low level of LDL-C or non-HDL-C (81 and 74 events per 1000 person-years, respectively).

CONCLUSIONS

In a large community-based sample, LDL-P was a more sensitive indicator of low CVD risk than either LDL-C or non-HDL-C, suggesting a potential clinical role for LDL-P as a goal of LDL management.

Pioglitazone and rosiglitazone have different effects on serum lipoprotein particle concentrations and sizes in patients with type 2 diabetes and dyslipidemia

OBJECTIVE

Associated with insulin resistance in type 2 diabetes are increased serum triglycerides, decreased HDL cholesterol, and a predominance of large VLDL, small LDL, and small HDL particles. The comparative effects of thiazolidinedione insulin sensitizers on serum lipoprotein particle concentrations and sizes in type 2 diabetes are not known. We studied the effects of pioglitazone (PIO) and rosiglitazone (ROSI) treatments on serum lipoprotein particle concentrations and sizes in type 2 diabetic patients with dyslipidemia.

RESEARCH DESIGN AND METHODS

This is a prospective, randomized, double-blind, multicenter, parallel-group study. After a 4-week placebo washout period, patients randomized to PIO (n = 369) were treated with 30 mg q.d. for 12 weeks followed by 45 mg q.d. for another 12 weeks, while patients randomized to ROSI (n = 366) were treated with 4 mg q.d. followed by 4 mg b.i.d. for the same intervals. Lipoprotein subclass particle concentrations and sizes were determined by proton nuclear magnetic resonance spectroscopy at baseline and end point (PIO [n = 333] and ROSI [n = 325] patients).

RESULTS

PIO treatment increased total VLDL particle concentration less than ROSI treatment and decreased VLDL particle size more than ROSI. PIO treatment reduced total LDL particle concentration, whereas ROSI treatment increased it. Both treatments increased LDL particle size, with PIO treatment having a greater effect. Whereas PIO treatment increased total HDL particle concentration and size, ROSI treatment decreased them; both increased HDL cholesterol levels.

CONCLUSIONS

PIO and ROSI treatments have different effects on serum lipoprotein subclass particle concentrations and sizes in patients with type 2 diabetes and dyslipidemia.

The effect of NeOpuntia on blood lipid parameters--risk factors for the metabolic syndrome (syndrome X)

Metabolic syndrome (syndrome X) causes millions of cardiovascular complications and premature deaths every year. The aim of this study was to evaluate the effects of NeOpuntia, patented, dehydrated, Opuntia ficus-indica leaves, on blood lipid parameters and metabolic syndrome. Opuntia ficus-indica leaves are traditionally consumed as a vegetable. Participants in this monocentric, randomized, placebocontrolled, double-blind, 6-wk study were 68 women, ages 20 to 55 y, with metabolic syndrome and a body mass index between 25 and 40. Fifty-nine subjects completed the study according to the study plan. All volunteers followed wellbalanced diets with controlled lipid input. NeOpuntia or placebo capsules were taken at a dosage of 1.6 g per meal. All 5 syndrome X criteria were measured on days 0, 14, and 42, including low-density lipoprotein cholesterol (LDL-C), highdensity lipoprotein cholesterol (HDL-C), and triglyceride levels. For the 42 females above 45 y of age, we show a significant increase in HDL-C levels with NeOpuntia and a tendency toward decreased triglyceride levels. At the same time, there was a decrease in HDL-C levels with placebo. Overall, for the entire study population, similar but less pronounced tendencies were demonstrated. Forty-two females taking NeOpuntia with no additional hypolipemic treatment, had a pronounced reduction in LDL cholesterol, especially after day 14. At the study end, 39% of the NeOpuntia group, but only 8% of the placebo group, were no longer diagnosed with metabolic syndrome. Our results indicate an advantage of using NeOpuntia in dietary supplements and functional foods because of improvement of blood lipid parameters associated with cardiovascular risks.

LDL particle subclasses, LDL particle size, and carotid atherosclerosis in the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Previous studies showing that smaller low-density lipoprotein (LDL) size is associated with greater atherosclerotic risk did not adequately control for small and large LDL particle correlation.

METHODS AND RESULTS

We studied the association of lipoproteins measured by proton nuclear magnetic resonance spectroscopy with carotid intima-media thickness (IMT) in apparently healthy individuals (N = 5538, 38% White, 28% African American, 22% Hispanic, 12% Chinese). Small and large LDL particle concentrations (LDL-p) were inversely correlated (r = /-0.63, P < 0.0001). Controlling for risk factors but not for LDL subclass correlation, LDL size and small LDL-p separately were associated with IMT (-20.9 and 31.7 microm change in IMT per 1-S.D., respectively, both P < 0.001), but large LDL-p was not (4.9 microm, P = 0.27). When LDL subclasses were included in the same model, large and small LDL-p were both associated with IMT (36.6 and 52.2 microm higher IMT per 1-S.D., respectively, both P < 0.001; 17.7 and 11.6 microm per 100 nmol/L, respectively). LDL size was not significant after accounting for LDL subclasses and risk factors (P = 0.10).

CONCLUSION

Both LDL subclasses were significantly associated with subclinical atherosclerosis, with small LDL confounding the association of large LDL with atherosclerosis. Future studies of LDL size should account for the strong inverse correlation of LDL subclasses.

Alcohol consumption and lipoprotein subclasses in older adults

CONTEXT

Limited evidence suggests that alcohol intake may be associated with lipoprotein subclass distribution, which could mediate its relationship with coronary heart disease.

OBJECTIVES

The objective was to determine the relationship of alcohol intake with lipoprotein particle subclasses.

DESIGN, SETTING, AND PARTICIPANTS

The study included a cross-sectional analysis of 1850 participants of the Cardiovascular Health Study aged 65 yr and older and free of clinical cardiovascular disease.

MAIN OUTCOME MEASURE

Lipoprotein subclass distribution was measured with nuclear magnetic resonance spectroscopy, according to self-reported alcohol intake.

RESULTS

Alcohol intake was associated with total low-density lipoprotein (LDL) particles in a U-shaped manner. Consumers of one or more drinks per week had the highest number of large LDL particles, whereas consumers of 7-13 drinks per week had the lowest number of small LDL particles. Alcohol intake was strongly positively associated with large- and medium-sized high-density lipoprotein (HDL) particles but had an inverse relationship with concentrations of small HDL particles and small- and medium-sized very-low-density lipoprotein particles. Average particle sizes of all three lipoproteins were positively associated with alcohol intake. Associations were generally stronger among women than men but in similar directions. Beverage type did not consistently modify these findings.

CONCLUSIONS

Alcohol intake is associated with less total LDL particles, lower levels of small LDL, HDL, and very-low-density lipoprotein particles, and higher levels of large LDL and medium- and large-sized HDL particles in older adults free of prevalent clinical cardiovascular disease.

Endurance exercise training raises high-density lipoprotein cholesterol and lowers small low-density lipoprotein and very low-density lipoprotein independent of body fat phenotypes in older men and women

Endurance exercise training improves plasma lipoprotein and lipid profiles and reduces cardiovascular disease risk. However, the effect of endurance exercise training, independent of diet and body fat phenotypes, on plasma lipoprotein subfraction particle concentration, size, and composition as measured by nuclear magnetic resonance (NMR) spectroscopy is not known. We hypothesized that 24 weeks of endurance exercise training would independently improve plasma lipoprotein and lipid profiles as assessed by both conventional and novel NMR measurement techniques. One hundred sedentary, healthy 50- to 75-year-olds following a standardized diet were studied before and after 24 weeks of aerobic exercise training. Lipoprotein and lipid analyses, using both conventional and NMR measures, were performed at baseline and after 24 weeks of exercise training. Relative and absolute maximum oxygen consumption increased 15% with exercise training. Most lipoprotein and lipid measures improved with 24 weeks of endurance exercise training, and these changes were consistently independent of baseline body fat and body fat changes with training. For example, with exercise training, total cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-C) decreased significantly (2.1+/-1.8 mg/dL, P=.001; -17+/-3.5 mg/dL, P<.0001; and -0.7+/-1.7 mg/dL, P<.0001, respectively), and high-density lipoprotein cholesterol subfractions (HDL3-C and HDL2-C) increased significantly (1.9+/-0.5 mg/dL, P=.01, and 1.2+/-0.3 mg/dL, P=.02, respectively). Particle concentrations decreased significantly for large and small very low-density lipoprotein particles (-0.7+/-0.4 nmol/L, P<.0001, and -1.1+/-1.7 nmol/L, P<.0001, respectively), total, medium, and very small LDL particles (-100+/-26 nmol/L, P=.01; -26+/-7.0 nmol/L, P=.004; and -103+/-27 nmol/L, P=.02, respectively), and small HDL particles (-0.03+/-0.4 micromol/L, P=.007). Mean very low-density lipoprotein particle size also decreased significantly (-1.7+/-0.9 nm, P<.0001) and mean HDL particle size increased significantly with exercise training (0.1+/-0.0 nm, P=.04). These results show that 24 weeks of endurance exercise training induced favorable changes in plasma lipoprotein and lipid profiles independent of diet and baseline or change in body fat.

High-density lipoprotein associations with coronary heart disease: Does measurement of cholesterol content give the best result?

The protective role played by high-density lipoprotein (HDL) in atherogenesis is well-accepted, as is the significant inverse association of HDL cholesterol (HDL-C) with coronary heart disease (CHD) risk. What remains controversial is whether we are using the best measure(s) of HDL to identify and manage HDL-related cardiovascular risk. Measuring particle number has been postulated to offer additional and possibly more specific information regarding risk. Although HDL-C is thought to indicate the quantity of circulating HDL particles, it is underappreciated that the amount of cholesterol carried inside lipoprotein particles is highly variable among individuals with the same HDL-C. Numerous trials have investigated the relations of CHD with various measures of HDL other than those based on cholesterol content of the particles present. Studies regarding the association of alternate measures of HDL with CHD risk have been mixed, possibly due to diversity in clinical characteristics accompanying low HDL-C states, variability in cholesterol content of HDL particles, and substantial inter-correlations of HDL with other lipoprotein particles. Additional research is needed to assess the clinical settings in which individual HDL tests, after multivariate adjustment for confounding factors, provide superior independent prediction of CHD events beyond HDL-C. Such studies show promise in defining measures of particle number that will prove useful in future strategies to enhance management of CHD risk and assess response to therapy at an individual patient level.