Beyond low-density lipoprotein cholesterol: defining the role of low-density lipoprotein heterogeneity in coronary artery disease.

Recent clinical trials in patients with coronary artery disease (CAD) provide evidence that low-density lipoprotein cholesterol (LDL-C) levels should be lowered even further to prevent recurrent CAD. However, despite more aggressive interventions for lowering LDL-C levels, the majority of CAD events go undeterred, perhaps related to the fact that intervention was not started earlier in life or that LDL-C levels represent an incomplete picture of atherogenic potential. Nevertheless, LDL-C remains the contemporary standard as the primary goal for aggressive LDL reduction. If triglycerides are >200 mg/dl, the measurement of non-high-density lipoprotein cholesterol (HDL-C) is recommended. Measurement of apolipoprotein (apo)B has been shown in nearly all studies to outperform LDL-C and non-HDL-C as a predictor of CAD events and as an index of residual CAD risk. This is because apoB reflects the total number of atherogenic apoB-containing lipoproteins and is a superior predictor of the number of low-density lipoprotein particles (LDL-P). Estimates of LDL-P and size can also be made by nuclear magnetic resonance spectroscopy, density gradient ultracentrifugation, and gradient gel electrophoresis. Although a number of studies show that such estimates predict CAD, LDL-P, and size often accompany low HDL-C and high triglyceride levels, and therefore such additional lipoprotein testing has not been recommended for routine screening and follow-up. Because apoB is a superior predictor of LDL-P, we recommend that apoB and the apoB/apoA-I ratio be determined after measurement of LDL-C, non-HDL-C, and the ratio of total cholesterol/HDL-C to better predict CAD and assess efficacy of treatment.     

Value of low-density lipoprotein particle number and size as predictors of coronary artery disease in apparently healthy men and women: the EPIC-Norfolk Prospective Population Study.

OBJECTIVES: We assessed relations of low-density lipoprotein (LDL) particle number (LDL-P) and LDL particle size as measured by nuclear magnetic resonance spectroscopy with LDL cholesterol (LDL-C) and the risk of future coronary artery disease (CAD). BACKGROUND: Whereas LDL-C is an established risk factor for CAD, its discriminative power is limited. Measuring LDL-P and size may have stronger associations with CAD than LDL-C. METHODS: A nested case-control study was performed in the prospective EPIC (European Prospective Investigation into Cancer and Nutrition)-Norfolk study, which comprises 25,663 subjects. Cases (n = 1,003) were individuals who developed CAD during 6 year follow-up. Control subjects (n = 1,885) were matched for age, gender, and enrollment time. Odds ratios (ORs) for future CAD were calculated, and we also evaluated whether LDL-P could improve the Framingham risk score (FRS) to predict CAD. RESULTS: In univariate analyses, LDL-P (OR 2.00, 95% confidence interval [CI] 1.58 to 2.59) and non-high-density lipoprotein cholesterol (non-HDL-C) (OR 2.14, 95% CI 1.69 to 2.69) were more closely associated with CAD than LDL-C (OR 1.73, 95% CI 1.37 to 2.18). The additional value of LDL-P was lost after adjustment for HDL-C and triglyceride levels. Whereas LDL size was inversely related to CAD (OR 0.60, 95% CI 0.47 to 0.76), this relation was abolished upon adjustment for LDL-P. In a model adjusted for the FRS, LDL-P retained its association with CAD (p for trend 0.02). CONCLUSIONS: In this large study of individuals with moderately elevated LDL-C, LDL-P was related to CAD on top of FRS as well as after adjusting for LDL-C. The additional value of LDL-P was comparable to non-HDL-C, and it was abolished after adjusting for triglycerides and HDL-C.     

非高密度脂蛋白胆固醇可以替代低密度脂蛋白胆固醇吗?

非高密度脂蛋白胆固醇(non-HDL-C)等于总胆固醇减去高密度脂蛋白胆固醇.流行病学研究认为,在糖尿病、甘油三酯过高和低密度脂蛋白胆固醇(LDL-C)过低的人群中,non-HDL-C比LDL-C更能反映动脉粥样硬化性心血管疾病的发病风险,预测能力更强.对于动脉粥样硬化性心血管疾病患者,non-HDL-C的目标值已被写...     

Non-high-density lipoprotein cholesterol: why lower is better

Recent comparative trials of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) suggest that lower is better and that reducing low-density lipoprotein cholesterol (LDL-C) levels to below 100 mg/dL can provide additional clinical benefit. Non-high-density lipoprotein cholesterol (non-HDL-C) contains more atherogenic cholesterol than LDL-C and is considered a more accurate measurement of the total amount of atherogenic particles in the circulation. Therefore, the principle that "lower is better" may also apply to lowering levels of non-HDL-C. In persons with high triglycerides (200-499 mg/dL), LDL-C remains the primary target of therapy, but non-HDL-C is an important secondary therapeutic target. Non-HDL-C is strongly correlated with small dense LDL as well as apolipoprotein B, an established predictor of cardiovascular disease risk. Current evidence indicates that statins not only rapidly and dramatically reduce LDL-C, but also have a similar effect on non-HDL-C, and that the greater the reduction in LDL-C, the greater will be the reduction in non-HDL-C.     

脂蛋白(a)与其他脂蛋白和载脂蛋白相关性研究

目的探讨冠心病患者血浆脂蛋白(a)与HDL-C、LDL-C、载脂蛋白(apo)A-Ⅰ、apoB的相关性,评价血脂异常与冠心病的相关性。方法选择因胸痛入院的患者1011例,经冠状动脉造影确诊为冠心病患者613例作为冠心病组,非冠心病患者398例作为对照组。测定脂蛋白(a)、apoA-Ⅰ、apoB、HDL-C和LDL-C,进行相关性分析,并计算apoB/apoA-Ⅰ比值。结果冠心病组的脂蛋白(a)、LDL-C及apoB水平较对照组明显升高(P=0.000);冠心病组脂蛋白(a)水平与LDL-C、apoB呈显著正相关(r=0.135、r=0.168,P0.01),与HDL-C、apoA-Ⅰ无相关性。对照组脂蛋白(a)与LDL-C、apoB呈显著正相关(r=0.201、r=0.236,P0.01),与HDL-C、apoA-Ⅰ无相关性。apoB/apoA-Ⅰ是诊断冠心病最显著的独立危险因素(OR=31.577,95% CI:8.324～11 9.788,P=0.000),其次为脂蛋白(a)(OR=19.446,95% CI:3.831～98.716,P=0.000)。结论脂蛋白(a)与LDL-C、apoB呈正相关,提示三者均为动脉粥样硬化的危险因素;apoB/apoA-Ⅰ和脂蛋白(a)为冠心病的独立危险因素。     

Non-high-density lipoprotein cholesterol level as a predictor of cardiovascular disease mortality

BACKGROUND: Non-high-density lipoprotein cholesterol (non-HDL-C) contains all known and potential atherogenic lipid particles. Therefore, non-HDL-C level may be as good a potential predictor of risk for cardiovascular disease (CVD) as low-density lipoprotein cholesterol (LDL-C). OBJECTIVES: To determine whether non-HDL-C level could be useful in predicting CVD mortality and to compare the predictive value of non-HDL-C and LDL-C levels. METHODS: Data are from the Lipid Research Clinics Program Follow-up Study, a mortality study with baseline data gathered from 1972 through 1976, and mortality ascertained through 1995. A total of 2406 men and 2056 women aged 40 to 64 years at entry were observed for an average of 19 years, with CVD death as the main outcome measure. RESULTS: A total of 234 CVD deaths in men and 113 CVD deaths in women occurred during follow-up. Levels of HDL-C and non-HDL-C at baseline were significant and strong predictors of CVD death in both sexes. In contrast, LDL-C level was a somewhat weaker predictor of CVD death in both. Differences of 0.78 mmol/L (30 mg/dL) in non-HDL-C and LDL-C levels corresponded to increases in CVD risk of 19% and 15%, respectively, in men. In women, differences of 0.78 mmol/L (30 mg/dL) in non-HDL-C and LDL-C levels corresponded to increases in CVD risk of 11% and 8%, respectively. CONCLUSIONS: Non-HDL-C level is a somewhat better predictor of CVD mortality than LDL-C level. Screening for non-HDL-C level may be useful for CVD risk assessment.     

Effects of pravastatin on coronary events in 2073 patients with low levels of both low-density lipoprotein cholesterol and high-density lipoprotein cholesterol: results from the LIPID study.

AIMS: Fibrates or nicotinic acid are usually recommended for secondary prevention of coronary heart disease in patients with low plasma levels of both low-density lipoprotein cholesterol (LDL-C) < or =140 mg/dL (< or =3.6 mmol/L) and high-density lipoprotein cholesterol (HDL-C) < or =40 mg/dL (< or =1.03 mmol/L). The LIPID trial, a randomised, placebo-controlled trial in 9014 patients at 87 centres in Australia and New Zealand, provided an opportunity to investigate the effects of an HMG-CoA reductase inhibitor in patients with low LDL-C and low HDL-C. METHODS AND RESULTS: Participants in this post hoc substudy were 2073 patients aged 31-75 years with baseline LDL-C < or =140 mg/dL (< or =3.6 mmol/L), HDL-C < or =40 mg/dL (< or =1.03 mmol/L), and triglyceride < or =300 mg/dL (< or =3.4 mmol/L). The relative risk reduction with pravastatin treatment was 27% for major coronary events (95% CI 8-42%), 27% for coronary heart disease mortality (95% CI 0-47%), 21% for all-cause mortality (95% CI 0-38%), and 51% for stroke (95% CI 24-69%). The number needed to treat to prevent a major coronary event over 6 years was 22. CONCLUSIONS: Treatment with pravastatin in patients with both low LDL-C and low HDL-C significantly reduced major coronary events, stroke, and all-cause mortality. The level of HDL-C is crucial to the risk of recurrent CHD events and, consequently, the benefit of lowering LDL-C.     

HDL-C and triglyceride levels: relationship to coronary heart disease and treatment with statins

The association between low-density lipoprotein cholesterol (LDL-C) levels and risk of coronary heart disease (CHD) is well established and LDL-C-lowering is currently the primary target for the treatment of dyslipidemia. However, low levels of high-density lipoprotein cholesterol (HDL-C), and high levels of triglycerides (TG) are also risk factors for CHD and modifying levels of these lipid subfractions, in addition to LDL-C lowering, may have clinical benefits in many patients.Statins are the first-line drug therapy for the treatment of dyslipidemia because of their efficacy in lowering LDL-C and good tolerability. Statins also have beneficial effects on TG and HDL-C levels although they differ in the degree to which they modify the levels of these lipoproteins. Improvements across the atherogenic components of the lipid profile may be optimized by the co-administration of a statin with a fibrate, niacin or omega-3 fatty acids; however, particular combination therapies have been associated with side effects and may be poorly tolerated. Newer combinations with better tolerability, or new statins with improved efficacy on non-LDL-C lipid subfractions, would be welcome additions to the currently available therapies for the treatment of dyslipidemia.     

Comparison of high-density and low-density lipoprotein cholesterol subclasses and sizes in Asian Indian women with Caucasian women from the Framingham Offspring Study

BACKGROUND: Asian Indian women have a higher rate of coronary artery disease (CAD) than do other ethnic groups, despite similar conventional risk factors and lipid profiles. Smaller high-density lipoprotein cholesterol (HDL-C) particle size is associated with reduced cardiac protection or even an increased risk of CAD. Exceptional longevity correlates better with larger HDL-C particle sizes. HYPOTHESIS: Higher rates of CAD among Asian Indian women may partly be explained by the differenes in the prevalence of atherogenic HDL-C and low-density lipoprotein cholesterol (LDL-C) sizes and their subclass concentrations among Asian Indian women compared with Caucasian women. METHODS: We measured HDL-C concentrations and sizes by nuclear magnetic resonance spectroscopy in 119 relatively healthy Asian Indian women and compared them with those of 1752 Caucasian women from the Framingham Offspring Study (FOS). RESULTS: Asian Indian women were significantly younger (47.9 +/- 11.2 vs. 51.0 +/- 10.1 years, p = 0.0001), leaner (body mass index 24.0 +/- 4.7 vs. 26.0 +/- 5.6, p = < 0.0002), less likely to be postmenopausal (32 vs. 54%, p = < 0.0001), or smoke (< 1 vs. 20%, p = < 0.0001); nevertheless, prevalence of CAD was higher in Asian Indian women (4.2 vs. 1%, p = 0.0006). Asian Indian women had similar HDL-C (53 +/- 13 vs. 53 +/- 13 mg/dl, p = 0.99), smaller HDL-C particle size (8.9 +/- 0.35 vs. 9.4 +/- 0.44 nm, p = < 0.0001), higher total cholesterol (209 +/- 40 vs. 199 +/- 42 mg/dl, p = 0.01), and similar triglyceride (120 +/- 77 vs. 108 +/- 110 mg/d, p = 0.24) levels. Low-density lipoprotein cholesterol, particle concentrations and sizes, as well as prevalence of pattern B were similar. CONCLUSIONS: Compared with the FOS, Asian Indian women have significantly smaller overall HDL particle size and similar levels of HDL-C, which may reflect impaired, reverse cholesterol transport. Total cholesterol was higher, whereas triglyceride and LDL-C levels were similar. This may partly explain the higher CAD rates in Asian Indian women. Further large scale, prospective, long-term studies are warranted.     

稳定型冠心病患者血清低密度脂蛋白胆固醇和载脂蛋白B浓度与SYNTAX评分的关系

目的探讨稳定型冠状动脉粥样硬化性心脏病(stable coronary artery disease,SCAD)患者血清低密度脂蛋白胆固醇(low-density lipoprotein cholesterol,LDL-C)和载脂蛋白B浓度与SYNTAX评分的关系。方法回顾性选择2016年1月至2017年12月在宝鸡市中心医院接受冠状动脉造影检查确诊的SCAD患者150例作为研究对象,根据SYNTAX评分结果将患者分为0~22分组(低分组,n=80)、23~32分组(中分组,n=40)和33分以上组(高分组,n=30)。SYNTAX评分与不同临床特征间的相关性采用Spearman相关性分析和多元线性回归分析。结果3组患者血小板分布宽度(platelet distribution width,PDW)、红细胞分布宽度(red cell distribution width,RDW)、纤维蛋白原、总胆固醇、高密度脂蛋白胆固醇(high density lipoprotein-cholesterol,HDL-C)、LDL-C、脂蛋白a、载脂蛋白A1、载脂蛋白B、SYNTAX评分比较,差异有统计学意义(P<0.05)。Spearman相关性分析结果显示,SYNTAX评分与HDL-C、载脂蛋白A1呈负相关(P<0.05),与纤维蛋白原、总胆固醇、LDL-C、PDW、RDW、脂蛋白a、载脂蛋白B呈正相关(P<0.05)。多元线性回归分析结果显示,HDL-C、LDL-C、纤维蛋白原、载脂蛋白B均是影响冠状动脉病变的危险因素(P<0.05)。结论随着血清LDL-C、载脂蛋白B浓度的升高,SCAD患者SYNTAX评分升高,冠状动脉病变严重程度加重。血清LDL-C、载脂蛋白B浓度可作为判断SCAD患者冠状动脉病变严重程度的参考指标。     

Influence of triglyceride concentration on the relationship between lipoprotein cholesterol and apolipoprotein B and A-I levels

A sample of 2,103 men aged 47 to 76 years from the Québec Cardiovascular Study cohort was examined to quantify the influence of plasma triglyceride (TG) levels on the relationship between plasma lipoprotein cholesterol and either apolipoprotein A-I (apo A-I) or apo B concentrations. Regression analyses between high-density lipoprotein cholesterol (HDL-C) and apo A-I through TG tertiles showed highly significant correlations (.62 < or = r < or = .75, P < .0001) in all TG tertiles between these 2 variables. The associations for plasma apo B versus low-density lipoprotein cholesterol (LDL-C) and non-HDL-C levels were also studied on the basis of TG concentrations, and correlation coefficients between either LDL-C or non-HDL-C and apo B were essentially similar among TG tertiles (.78 < or = r < or = .85 and .83 < or = r < or = .86 for LDL-C and non-HDL-C, respectively, P < .0001). Regression analyses also showed that lower HDL-C levels were found for any given apo A-I concentration among men in the 2 upper TG tertiles, whereas lower LDL-C concentrations were observed at any given apo B level among subjects in the upper TG tertile. We further investigated whether there were synergistic alterations in the HDL-C/apo A-I and LDL-C/apo B ratios as a function of increasing plasma TG. A significant association was noted between these 2 ratios (r = .37; P < .0001). Mean HDL-C/apo A-I and LDL-C/apo B ratios were then calculated across quintiles of plasma TG concentrations. Increased TG concentrations were first associated with a reduced HDL-C/apo A-I ratio, followed by a decreased LDL-C/apo B ratio. These results suggest that a relatively modest increase in TG may rapidly alter the relative cholesterol content of HDL particles. Finally, the cholesterol content of the non-HDL fraction appears to be influenced less by TG levels than HDL-C and LDL-C fractions. Thus, the plasma apo B-containing lipoprotein cholesterol level may provide a better index of number of atherogenic particles than the LDL-C concentration, particularly in the presence of hypertriglyceridemia (HTG).     

Relative atherogenicity and predictive value of non-high-density lipoprotein cholesterol for coronary heart disease

Although low-density lipoprotein cholesterol (LDL-C) is a well-established atherogenic factor for coronary heart disease, it does not completely represent the risk associated with atherogenic lipoproteins in the presence of high triglyceride (TG) levels. Constituent lipoproteins constituting non-high-density lipoprotein cholesterol (non-HDL-C) include atherogenic TG-rich lipoproteins, cholesteryl ester-enriched remnants of TG-rich lipoproteins, and lipoprotein(a). Recent observational and intervention studies suggest that the predictive value of non-HDL-C for cardiovascular risk and mortality is better than low-density lipoprotein cholesterol and that non-HDL-C correlates highly with plasma apolipoprotein B levels. Currently, the National Cholesterol Education Program Adult Treatment Panel III guidelines identify non-HDL-C as a secondary target of therapy in patients with TG elevation (> or =200 mg/dl) after the attainment of LDL-C target goals. In patients with coronary heart disease or coronary heart disease risk equivalents, an optional non-HDL-C goal is <100 mg/dl. To achieve the non-HDL-C goal, statin therapy may be intensified or combined with ezetimibe, niacin, a fibrate, or omega-3 fatty acids. In conclusion, non-HDL-C remains an important target of therapy for patients with elevated TGs, although its widespread adoption has yet to gain a foothold among health care professionals treating patients with dyslipidemia.     

Lipid levels and risk of new-onset atrial fibrillation: A systematic review and dose-response meta-analysis

Lipid levels are closely associated with health, but whether lipid levels are associated with atrial fibrillation (AF) remains controversial. We thought that blood lipid levels may influence new-onset AF. Here, we used a meta-analysis to examine the overall association between lipid levels and new-onset AF. PubMed and EMBASE databases were searched up to 20 December 2019. We conducted a systematic review and quantitative meta-analysis of prospective studies to clarify the association between lipid levels and the risk of new-onset AF. Sixteen articles with data on 4 032 638 participants and 42 825 cases of AF were included in this meta-analysis. The summary relative risk (RR) for a 1 mmol/L increment in total cholesterol (TC) was 0.95 (95% CI 0.93-0.96, I² = 74.6%, n = 13). Subgroup analyses showed that follow-up time is a source of heterogeneity; for low-density lipoprotein cholesterol (LDL-C), RR was 0.95 (95% CI 0.92-0.97, I² = 71.5%, n = 10). Subgroup analyses indicated that adjusting for heart failure explains the source of heterogeneity; for high-density lipoprotein cholesterol (HDL-C), RR was 0.97 (95% CI 0.96-0.99, I² = 26.1%, n = 11); for triglycerides (TGs), RR was 1.00 (95% CI 0.96-1.03, I² = 81.1%, n = 8). Subgroup analysis showed that gender, age, follow-up time, and adjustment for heart failure are sources of heterogeneity. Higher levels of TC, LDL-C, and HDL-C were associated with lower risk of new-onset AF. TG levels were not associated with new-onset AF in all subjects.     

Comparison of rosuvastatin with atorvastatin, simvastatin and pravastatin in achieving cholesterol goals and improving plasma lipids in hypercholesterolaemic patients with or without the metabolic syndrome in the MERCURY I trial

AIM: The metabolic syndrome (MS) increases the risk of coronary heart disease, yet few data are available on the effects of statin treatment in improving lipid measures in patients with the syndrome. This analysis compares the effects of statin therapy on plasma low-density lipoprotein cholesterol (LDL-C) goal achievement and lipid levels in hypercholesterolaemic patients with or without the MS. METHODS: The Measuring Effective Reductions in Cholesterol Using Rosuvastatin TherapY I (MERCURY I) trial compared rosuvastatin 10 mg with atorvastatin 10 mg and 20 mg, simvastatin 20 mg and pravastatin 40 mg over 8 weeks in patients with coronary or other atherosclerotic diseases or diabetes who had fasting levels of LDL-C of >or=2.99 mmol/l and triglycerides of <4.52 mmol/l. Modified National Cholesterol Education Program Adult Treatment Panel III (ATP III) criteria for the MS were met by 1342 (43%) of 3140 patients. RESULTS: LDL-C goal achievement rates and reductions in LDL-C, total cholesterol and non-high-density lipoprotein cholesterol (HDL-C) were similar in patients with and without the MS within statin treatment groups; triglycerides were reduced more and HDL-C tended to be increased more in patients with the MS, as expected. Treatment with rosuvastatin 10 mg was more effective in allowing patients with and without the MS to reach European and ATP III LDL-C goals, compared to atorvastatin 10 mg, simvastatin 20 mg and pravastatin 40 mg (p < 0.0001 for all comparisons); consistently produced greater reductions in LDL-C, total cholesterol and non-HDL-C, compared to these treatments; and produced similar or greater reductions in triglycerides and increases in HDL-C, compared to the other treatments. CONCLUSIONS: Statin therapy is effective in allowing LDL-C goal achievement and improving the lipid profile in hypercholesterolaemic high-risk patients with the MS. Rosuvastatin 10 mg presents significant advantages in goal achievement and lipid lowering over other statins at commonly used doses in patients both with and without the MS.     

非高密度脂蛋白胆固醇及基质金属蛋白酶3对老年高血压患者急性冠脉综合征发生的影响

目的 研究血清非高密度脂蛋白胆固醇(non-HDL-C)及基质金属蛋白酶3(MMP3)对老年高血压患者急性冠脉综合征(ACS)发病的影响.方法 2016年1月-2017年12月,收集60岁以上高血压患者住院当天生化检测样本,检测MMP3、总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白...     

Therapies to increase high-density lipoprotein cholesterol and their effect on cardiovascular outcomes and regression of atherosclerosis

Epidemiological studies have shown that decreased level of high-density lipoprotein (HDL) cholesterol (C) is an independent inverse predictor of coronary artery disease (CAD) even in patients with normal levels of low-density lipoprotein (LDL)-C. There is an abundance of evidence in favor of statins and aggressive LDL-C lowering therapy for both primary and secondary prevention of CAD. In contrast, the evidence for reduction of CAD risk with HDL-C raising therapy is relatively thin, partly due to the paucity of effective and safe drugs for increasing HDL-C level. However, there are emerging new therapies for raising HDL-C level and growing evidence in favor of pharmacologic therapies to raise HDL-C level. We present in this article a review of pharmacologic therapies that are currently available to increase HDL-C level, their safety and efficacy in relation to cardiovascular endpoints.     

Effect of levo-thyroxine replacement on non-high-density lipoprotein cholesterol in hypothyroid patients

CONTEXT: Recently, non-high-density lipoprotein cholesterol (non-HDL-C), a measure of total cholesterol minus HDL-C, has emerged as a predictor of cardiovascular disease. OBJECTIVE: We evaluated the effect of L-T4 replacement on non-HDL-C levels in patients with primary hypothyroidism. METHODS: Thirteen patients with overt hypothyroidism and 26 patients with subclinical hypothyroidism participated in the study. The lipid profiles, including non-HDL-C, were measured in patients with hypothyroidism before and 3 months after L-T4 replacement was started. RESULTS: After L-T4 replacement, the serum concentrations of all lipoproteins, exclusive of lipoprotein (a) [Lp(a)], were significantly decreased in patients with overt hypothyroidism. In patients with subclinical hypothyroidism, the serum concentrations of total cholesterol, non-HDL-C, remnant-like particle cholesterol, and apolipoprotein B (Apo B) were significantly decreased, whereas no significant changes in the serum concentrations of low-density lipoprotein cholesterol, HDL-C, triglycerides, apolipoprotein A-I, and Lp(a) were observed. In all 39 patients, the reduction in the non-HDL-C levels correlated with the reduction in the low-density lipoprotein cholesterol, remnant-like particle cholesterol, and Apo B levels. However, the reduction in the non-HDL-C levels did not correlate with the reduction in the HDL-C, Lp(a), and apolipoprotein A-I levels. CONCLUSIONS: This study is the first to show that L-T4 replacement may reduce serum concentrations of non-HDL-C in patients with hypothyroidism. The study also suggests that such altered serum concentrations of non-HDL-C in hypothyroidism may be related to the disturbed metabolism of low-density lipoprotein, remnant lipoprotein, and Apo B.     

Relation of cholesterol and lipoprotein parameters with carotid artery plaque characteristics: the Atherosclerosis Risk in Communities (ARIC) carotid MRI study

Objective

There is a paucity of data regarding relations of apolipoproteins (apolipoprotein B [ApoB] and apolipoprotein A-1 [Apo A-1]), lipoprotein particle measures (low-density lipoprotein particle concentration [LDLp] and high-density lipoprotein particle concentration [HDLp]), and lipoprotein cholesterol measures (low-density lipoprotein cholesterol [LDL-C], non-high-density lipoprotein cholesterol [non-HDL-C], and high-density lipoprotein cholesterol [HDL-C]) with atherosclerotic plaque burden, plaque eccentricity, and lipid-rich core presence as a marker of high-risk plaques.

Methods

Carotid artery magnetic resonance imaging was performed in 1670 Atherosclerosis Risk in Communities study participants. Vessel wall and lipid cores were measured; normalized wall index (NWI), standard deviation (SD) of wall thickness (measure of plaque eccentricity) were calculated; and lipid cores were detected in vessels with ≥1.5 mm thickness. Fasting concentrations of cholesterol, ApoB and Apo A-1, and LDLp and HDLp were measured.

Results

Measures of plaque burden (carotid wall volume, wall thickness, and NWI) were positively associated with atherogenic cholesterol and lipoproteins (p < 0.05 for total cholesterol, LDL-C, non-HDL-C, ApoB, and LDLp), but not with HDL-C, Apo A-1, or HDLp. SD of wall thickness was associated with total cholesterol (p 0.01) and non-HDL-C (p 0.02). Although measures of atherogenic or anti-atherogenic cholesterol or lipoprotein were not individually associated with detection of a lipid-rich core, their ratios (total cholesterol/HDL-C, non-HDL-C/HDL-C, and LDLp/HDLp) were associated with lipid-rich core presence (p ≤ 0.05).

Conclusion

Extent of carotid atherosclerosis is associated with atherogenic cholesterol and lipoproteins. Atherogenic/anti-atherogenic cholesterol or particle ratios were associated with presence of a detectable lipid-rich core.     

Association between traditional cholesterol parameters, lipoprotein particle concentration, novel biomarkers and carotid plaques in retired National Football League players

ObjectivesWe assessed whether low-density lipoprotein particle concentration (LDL-P) and high-sensitivity C-reactive protein [hs-CRP] can identify subclinical atherosclerosis better than traditional cholesterol parameters in retired National Football League (NFL) players.BackgroundIt is not known whether LDL-P and the biomarker hs-CRP can identify subclinical atherosclerosis better than low-density lipoprotein cholesterol (LDL-C) or non-high-density-lipoprotein cholesterol (non-HDL-C) in retired NFL players, given high prevalence of metabolic syndrome in these players.MethodsCarotid artery plaque screening was performed with traditional lipids, LDL-P, and hs-CRP in 996 retired players. Logistic regression analyses comparing highest with the lowest quartile were performed.ResultsCarotid artery plaques were seen in 41%. LDL-C (odds ratio [OR] 1.66, 95% confidence interval [CI] 1.06–2.59), non-HDL-C (OR 1.67, 95% CI 1.04–2.67), and LDL-P (OR 2.21, 95% CI 1.35–3.62) were associated with plaques in adjusted models. Among 187 retired players with metabolic syndrome, LDL-C (OR 1.40, 95% CI 0.53–3.72) was not associated with carotid plaques, whereas LDL-P (OR 3.71, 95% CI 1.16–11.84) and non-HDL-C (OR 2.63, 95% CI 0.91–7.63, p = 0.07; borderline significant) were associated with carotid plaques. hs-CRP (OR 1.13, 95% CI 0.71–1.79) was not associated with carotid plaques.ConclusionCarotid artery plaques were common in retired NFL players and were strongly associated with LDL-P, especially among those with metabolic syndrome. hs-CRP was not associated with carotid plaques in this cohort.     

Effects of fenofibrate and ezetimibe, both as monotherapy and in coadministration, on cholesterol mass within lipoprotein subfractions and low-density lipoprotein peak particle size in patients with mixed hyperlipidemia

Coadministration of fenofibrate and ezetimibe (FENO + EZE) produced complementary and favorable effects on the major lipids and lipoproteins, low-density lipoprotein cholesterol (LDL-C), triglycerides, high-density lipoprotein cholesterol (HDL-C), and non-HDL-C levels, and was well tolerated in patients with mixed hyperlipidemia. The current analysis evaluates the effects of FENO and EZE, as monotherapies and in coadministration, on lipoprotein subfractions and LDL particle size distributions in these patients. In a 12-week, multicenter, randomized, double-blind, placebo-controlled, parallel-group study, patients with mixed hyperlipidemia were randomized in a 1:3:3:3 ratio to one of 4 treatment groups: placebo, FENO 160 mg/day, EZE 10 mg/day, or FENO 160 mg/day + EZE 10 mg/day. At baseline and study end point, the Vertical Auto Profile II method was used to measure the cholesterol associated with 2 very low-density lipoprotein (VLDL) subfractions (VLDL-C1 + 2 and VLDL-C3), intermediate-density lipoproteins (IDL-C), and 4 LDL subfractions (LDL-C1 through LDL-C4, from most buoyant to most dense), lipoprotein (Lp) (a), and 2 HDL-C subfractions (HDL-C2 and HDL-C3). The LDL particle size was determined using segmented gradient gel electrophoresis. Fenofibrate reduced cholesterol mass within VLDL, IDL, and dense LDL (primarily LDL-C4) subfractions, and increased cholesterol mass within the more buoyant LDL-C2 subfraction, consistent with a shift to a more buoyant LDL peak particle size. Ezetimibe reduced cholesterol mass within all of the apolipoprotein B-containing particles (eg, VLDL-C, IDL-C, and LDL-C) but did not lead to a shift in the LDL particle size distribution profile. Coadministration of FENO and EZE promoted more pronounced reductions in VLDL-C, IDL-C, and LDL-C, and a preferential decrease in dense LDL subfractions. Fenofibrate and FENO + EZE promoted similar increases in HDL-C2 and HDL-C3. Coadministration of FENO + EZE produced complementary and favorable changes in lipoprotein fractions and subfractions, as assessed by the Vertical Auto Profile II method, in patients with mixed hyperlipidemia. These changes reflected the combined effects of FENO in reducing triglycerides-rich lipoproteins and promoting a shift in the LDL particle distribution profile toward larger, more buoyant particles and of EZE in promoting reductions in cholesterol mass across the apolipoprotein B particle spectrum.