Differences between markers of atherogenic lipoproteins in predicting high cardiovascular risk and subclinical atherosclerosis in asymptomatic men

LDL-C, NON-HDL-C and APO-B for cardiovascular risk assessment: Looking for the ideal marker

The traditional approach to the management of coronary artery disease (CAD) focuses mainly on low density lipoprotein cholesterol (LDL-C) which is often considered a crucial risk factor for the progression of atherosclerosis. Despite its extensive use in predicting CAD risk, it has become a sub-optimal marker owing to several limitations. Recently, non-high density lipoprotein cholesterol (non-HDL-C) and apolipoprotein-B (Apo-B) have been substantiated to be more reliable predictors of CAD risk. On the basis of available evidence, it is fair to say that non-HDL-C is a more realistic primary target of therapy and can be used for initial screening. In the current scenario, India being a developing country, the population would not be burdened with additional cost of Apo-B estimation as non-HDL-C can be estimated in the non-fasting state which makes it both patient and clinician friendly. Considering this fact, the aim of the present review article is to highlight the reliability and efficacy of non-HDL-Cholesterol and hence make recommendations to incorporate non-HDL-C in routine lipid panel for better assessment of CAD.

Relative effect of hypertriglyceridemia on non-HDLC and apolipoprotein B as cardiovascular disease risk markers

BACKGROUND

Non-high density lipoprotein cholesterol (non-HDLC) represents the cholesterol in triglyceride-rich lipoproteins (TRL) and low-density lipoproteins (LDL). Apolipoprotein B (apoB) reflects the number of TRL and LDL particles. In hypertriglyceridemia (HTG), there is triglyceride (TG) enrichment of TRLs, and also a substantial increase of cholesterol in larger TRLs that considerably augments the non-HDLC value. Therefore, in HTG, non-HDLC could increase disproportionately with respect to apoB.

OBJECTIVE

We aimed to compare the relative effect of the full range of mild, moderate, and severe HTG on the status of non-HDLC and apoB as cardiovascular disease (CVD) risk markers.

METHODS

Analysis of lipid profile data from 4347 patients in a Lipid Clinic cohort with baseline fasting lipid profiles documented prior to starting lipid-lowering medications. The correlation between non-HDLC and apoB was assessed in intervals of increasing TG. Non-HDLC and apoB were analyzed at each TG level using comparative CVD risk equivalent categories and assessed for divergence and discordance.

RESULTS

With increasing TG levels: (1) the correlation between non-HDLC and apoB diminished progressively, (2) non-HDLC levels increased continuously, whereas apoB levels plateaued after an initial increase up to TG of ~ 4.0-5.0 mmol/L (~354-443 mg/dL), (3) there was divergence in the stratification of non-HDLC and apoB into CVD risk equivalent categories.

CONCLUSIONS

Non-HDLC and apoB should not be viewed as interchangeable CVD risk markers in the presence of severe HTG. This has never been tested. With increasing HTG severity, discordance between non-HDLC and apoB can cause clinically important divergence in CVD risk categorization.

Apolipoprotein B/apolipoprotein A1 ratio and mortality among incident peritoneal dialysis patients

BACKGROUND

To investigate the association between the ratio of apolipoprotein B (apo B) / apolipoprotein A1 (apo A1) with all-cause mortality and cardiovascular events in peritoneal dialysis (PD) patients.

METHODS

Eight hundred and sixty incident PD patients were enrolled from November 1, 2005, to February 28, 2017, and followed until May 31, 2017. Outcomes were all-cause mortality and cardiovascular events. Associations between the apo B/apo A1 ratio with all-cause mortality and cardiovascular events were evaluated using multivariable-adjusted Cox models.

RESULTS

Of the 860 patients, the mean age was 49.9 ± 14.5 years, 57.6% were men, and 19.3% were diabetic patients. The median apo B/apo A1 ratio was 0.65 (range: 0.22-2.24). During a median follow-up period of 27 months (interquartile range, 13 - 41 months), 202 deaths, and 145 cardiovascular events were recorded. After adjustment for age, sex, body mass index, diabetes, cardiovascular disease, systolic blood pressure, total Kt/V, estimated glomerular filtration rate, hemoglobin level, neutrophil to lymphocyte ratio and albumin, triglyceride, and cholesterol, as well as the use of lipid-lowering agents, the highest apo B/apo A1 ratio tertile was significantly associated with a hazard ratio for all-cause mortality of 1.60 (95% CI: 1.02 to 2.49, P = 0.040) and for cardiovascular events of 2.04 (95% CI: 1.21 to 3.44, P = 0.008).

CONCLUSION

An increased apo B/apo A1 ratio was independently associated with all-cause mortality and cardiovascular events in PD patients.

High triglyceride levels alter the correlation of apolipoprotein B with low- and non-high-density lipoprotein cholesterol mostly in individuals with diabetes or metabolic syndrome

OBJECTIVE

To assess the correlation of Apolipoprotein B (Apo-B) with low-density (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C) in untreated individuals attending a lipid clinic.

METHODS

This was a retrospective study conducted in Greece and including 1000 dyslipidemic subjects. We included individuals not taking lipid-lowering therapy at baseline visit and divided them in 2 groups: subjects diagnosed with diabetes or fulfilling the criteria of metabolic syndrome (MetS) and hyperlipidemic subjects without diabetes or MetS. The correlations (r(2)) of Apo-B with LDL-C and non-HDL-C were assessed in these 2 groups. Further analyses were performed according to the baseline triglyceride (TG) levels (<and ≥200 mg/dL).

RESULTS

From 821 eligible subjects, 51% were diagnosed with diabetes or MetS. The correlations between Apo-B and LDL-C or non-HDL-C were similar for the individuals with TG < 200 mg/dL. Specifically, Apo-B was significantly correlated with LDL-C (r(2) = 0.755, p < 0.01, for those with diabetes or MetS; r(2) = 0.848, p < 0.01, for non-diabetic and no MetS hyperlipidemic subjects). The corresponding correlations between Apo-B and non-HDL-C for the 2 groups were 0.743 and 0.838, respectively (p < 0.01). Although these correlations remained significant for the individuals with high TG levels (≥200 mg/dL), the correlation factor was markedly decreased mostly in those with diabetes or MetS (r(2) = 0.600, p < 0.01, for the correlation between Apo-B and LDL-C; r(2) = 0.604, p < 0.01, for the correlation between Apo-B and non-HDL-C); in contrast, the corresponding correlations were stronger in the non-diabetic and no MetS hyperlipidemic individuals (r(2) = 0.710 and 0.714, respectively, p < 0.01).

CONCLUSION

Apo-B correlation with both LDL-C and non-HDL-C is reduced in individuals with high TG levels and in particular for those with diabetes or MetS.

Factors associated with major cardiovascular events in patients with systemic necrotizing vasculitides: results of a longterm followup study

OBJECTIVE

Systemic necrotizing vasculitides (SNV) are associated with more frequent subclinical atherosclerosis, suggesting that SNV might be associated with a higher risk of major cardiovascular events (MCVE). We aimed to identify factors predictive of MCVE in patients with SNV.

METHODS

Patients in remission from SNV were assessed for CV risk factors and subclinical atherosclerosis. MCVE was defined as myocardial infarction, stroke, arterial revascularization, hospitalization for unstable angina, and/or death from CV causes. MCVE-free survival curves were compared using the log-rank test.

RESULTS

Forty-two patients were followed for 7.1±2.6 years. Eight patients (18.9%) had MCVE. The respective 5- and 10-year MCVE rates were 9.5% and 26.8%. National Cholesterol Education Program/Adult Treatment Panel III (NCEP/ATP III)-defined high-risk status [hazard ratio (HR) 5.02 (95% CI: 1.17-27.4), p=0.03], BMI>30 kg/m2 [HR 4.84 (95% CI: 1.46-116), p=0.02], and plaque detection in the abdominal aorta (p=0.01) were significantly associated with MCVE. SNV characteristics, corticosteroid maintenance therapy, and C-reactive protein>5 mg/l were not associated with MCVE. Plaque in the aorta was significantly associated with high-risk status (p<0.001), while BMI and high-risk status were independent variables. Thus, a BMI>30 kg/m2 and/or a high-risk status were strongly associated with MCVE (p=0.004). Carotid intima-media thickness (IMT) identified patients with early MCVE and was correlated with the time to MCVE (r2=0.68, p=0.01).

CONCLUSION

These results suggest that factors associated with a higher MCVE risk in patients with SNV are NCEP/ATP III-defined high-risk status and BMI>30 kg/m2. Carotid IMT could help identify patients with SNV at risk of early MCVE.

LDL-cholesterol versus non-HDL-to-HDL-cholesterol ratio and risk for coronary heart disease in type 2 diabetes

AIMS

We assessed the association between different blood lipid measures and risk of fatal/nonfatal coronary heart disease (CHD), which has been less analysed previously in type 2 diabetes.

DESIGN, METHODS

Observational study of 46,786 patients with type 2 diabetes, aged 30-70 years, from the Swedish National Diabetes Register, followed for a mean of 5.8 years until 2009. Baseline and updated mean low-density lipoprotein (LDL)-, high-density lipoprotein (HDL)-, non-HDL-cholesterol, and non-HDL-to-HDL-cholesterol ratio were measured.

RESULTS

Hazard ratios (HR) for CHD with quartiles 2-4 of baseline lipid measures, with lowest quartile 1 as reference: 1.03-1.29-1.63 for LDL; 1.23-1.41-1.95 for non-HDL; 1.29-1.39-1.57 for HDL; and 1.31-1.67-2.01 for non-HDL:HDL, all p < 0.001 except for quartile 2 of LDL, when adjusted for clinical characteristics and nonlipid risk factors. A similar picture was seen with updated mean values. Splines with absolute 6-year CHD rates in a Cox model showed decreasing rates only down to around 3 mmol/l for LDL, with linearly decreasing rates to the lowest level of non-HDL:HDL. Non-HDL and HDL were independent additive risk factors for CHD risk. HRs per 1 SD continuous decrease in baseline or updated mean HDL were 1.14-1.17 when fully adjusted as above, and 1.08-1.13 when also adjusted for non-HDL (p < 0.001). HRs were 1.13-1.16 adjusted for LDL, and 1.22-1.26 adjusted for total cholesterol and triglycerides (p < 0.001). Splines showed progressively increasing 6-year CHD rates with lower HDL down to 0.5 mmol/l.

CONCLUSIONS

This study suggests that lower levels of non-HDL:HDL are a better risk marker for CHD than LDL-cholesterol below 3 mmol/l.

Gender-specific association of coronary artery calcium and lipoprotein parameters: the Heinz Nixdorf Recall Study

BACKGROUND

Coronary atherosclerosis can be detected by computed tomography. The amount of coronary artery calcification (CAC) is related to cardiovascular risk factors, the strength of the gender specific relation between lipoprotein parameters and CAC has not extensively been studied. Especially, the role of routinely determined lipoproteins in contrast to less common and computed lipid parameters (e.g. ratios) remains to be clarified.

METHODS AND RESULTS

The study cohort (n = 3956, 52% women, age 45-75 years) was randomly selected from three cities of a German metropolitan area. Lipoproteins-low-and high density lipoprotein (LDL-C/HDL-C), total cholesterol, apolipoprotein A-1 and B (apoA-1/apoB) as well as lipoprotein (a) (Lp(a)) were measured, while non-HDL-C was calculated. All participants received an electron-beam computed tomography (EBCT) for quantification of CAC. Adjusted for age and cardiovascular risk factors, CAC increased by a factor of 1.97 (1.51-2.57, 95% CI) and 1.94 (1.53-2.45, 95% CI) comparing the fourth to the first quartile of LDL-C for men and women, respectively. This association with LDL-C was also found after dichotomization of CAC at thresholds >0, ≥ 100 and ≥ 400. The best association of CAC was, however, found to be apoB and the second best was non HDL-C, in both men and women. For apoB, the model including all risk factors reached an explained variance for CAC of 20.2% in men and of 21.6% in women. When using LDL-C as a given parameter according to the current practice and advice, HDL-C in men and apoB in women provided an additional but small benefit.

CONCLUSION

ApoB showed the best association with CAC compared to all other tested lipoproteins. Neither the ratio LDL-C/HDL-C nor apoB/apoA-1, or Lp(a) revealed a closer association with CAC. While lipoproteins are related to CAC more closely in women than in men, their association with CAC is, however, not particularly strong. Our results may influence primary and secondary prevention advices in order to improve detection of subclinical atherosclerosis, for which lipoprotein parameters can only play a minor role.

The relationship between subclinical atherosclerosis, non-high-density lipoprotein cholesterol, exercise, and diet among male participants of the PACC Project

BACKGROUND

Non-high-density lipoprotein (HDL) cholesterol is recommended as a secondary lipid goal treated initially with lifestyle modification. However, the relationship between non-HDL and subclinical atherosclerosis is unknown. We examined the independent relationships between coronary artery calcium (CAC), lipids including non-HDL, exercise, and diet among healthy male participants of the Prospective Army Coronary Calcium (PACC) Project.

METHODS

Male participants from the PACC Project (n = 1637, mean age 42.8 years; no history of coronary heart disease) were studied. We used validated surveys to measure dietary quality and habitual physical exercise. Fasting lipid concentrations and other cardiovascular risk variables were measured. Subclinical atherosclerosis was detected with the use of electron beam computed tomography for CAC. Factors independently associated with the presence of any detectable CAC (CAC score > 0), including standard CV risk variables, non-HDL, exercise, and diet, were evaluated with the use of logistic regression.

RESULTS

The mean Framingham risk score was 4.6 ± 2.6%; CAC was present in 22.4%. Fasting lipid concentrations showed mean LDL-C 128 ± 32 mg/dL, HDL-C 50 ± 13 mg/dL, TG-C 130 ± 86 mg/dL, and non-HDL-C 154 ± 37 mg/dL. Men with CAC had significantly greater levels of LDL-C (135 vs 127 mg/dL), TG (148 vs 124 mg/dL), and non-HDL-C (164 vs 151 mg/dL) and less habitual physical activity (P = 0.006). There were nonsignificant trends between prevalent CAC, greater amounts of dietary fat intake, and lower HDL-C. In successive multivariable logistic regression models for the dependent variable CAC, only non-HDL-C (odds ratio [OR] 1.012 per mg/dL; 95% CI 1.002-1.023; P = .019) and age (OR 1.119 per year; 95% CI 1.063-1.178; P < .001) were independently associated with the presence of CAC, and exercise (OR 0.808; 95% CI 0.703-0.928; P = 0.003) was associated with the absence of CAC.

CONCLUSIONS

Non-HDL-C and exercise are independently predictive of the presence of subclinical CAC among healthy lower-risk middle-aged men.

Non-high-density lipoprotein cholesterol versus apolipoprotein B in cardiovascular risk stratification: do the math

With the emergence of new lipid risk markers and a growing cardiometabolic risk burden in the United States, there is a need to better integrate residual risk into cardiovascular disease (CVD) risk stratification. In anticipation of the Adult Treatment Panel IV (ATP IV) guidelines from the National Cholesterol Education Program (NCEP), there exists controversy regarding the comparative performance of the 2 foremost markers, apolipoprotein B (apoB) and non-high-density lipoprotein cholesterol (non-HDL-C), as they relate to the current standard of risk assessment and treatment: low-density lipoprotein cholesterol (LDL-C). Although some emerging markers may demonstrate better performance compared with LDL-C, certain fundamental characteristics intrinsic to a beneficial biomarker must be met prior to routine use. Collectively, studies have found that non-HDL-C and apoB perform better than LDL-C in CVD risk prediction, both on- and off-treatment, as well as in subclinical CVD risk prediction. The performance of non-HDL-C compared with apoB, however, has been a point of ongoing debate. Although both offer the practical benefits of accuracy independent of triglyceride level and prandial state, non-HDL-C proves to be the better marker of choice at this time, given established cutpoints with safe and achievable goals, no additional cost, and quick time to result with an easy mathematical calculation. The purpose of this review is to assess the performance of these parameters in this context and to discuss the considerations of implementation into clinical practice.

ApoB/apoA-I ratio is better than LDL-C in detecting cardiovascular risk

BACKGROUND AND AIMS

Cardiovascular (CV) events occur even when LDL-C are <100mg/dL. To improve the detection of CV risk we investigated the apoB/apoA-I ratio versus LDL-C in subjects considered normal glucose tolerant (NGT) by oral glucose tolerance test (OGTT).

METHODS AND RESULTS

We enrolled 616 NGT (273 men and 343 women), and we measured insulin resistance, lipid profile, apoB/apoA-I and the factors compounding the metabolic syndrome (MetS). An unfavourable apoB/apoA-I (≥0.9 for males and ≥0.8 for females) was present in 13.9% of 108 patients with LDL-C <100mg/dL: compared to subjects with lower apoB/apoA-I (<0.9 for males and <0.8 for females), they had more elements of MetS and their lipid profile strongly correlated with high CV risk. Out of 314 patients with lower apoB/apoA-I, 40.12% had LDL-C ≥130mg/dL: these retained a more favourable lipid profile than corresponding subjects with elevated apoB/apoA-I ratio. Finally, we found a significant correlation between LDL-C and apoB/apoA-I ratio (r=0.48, p<0.0001).

CONCLUSIONS

In NGT with LDL-C <100mg/dL, a higher apoB/apoA-I exhibited an atherogenic lipid profile, indicating that LDL-C alone is insufficient to define CV risk. Independent from LDL-level, when apoB/apoA-I is lower, the lipid profile is, in fact, less atherogenic. This study demonstrates that apoB/apoA-I is at least complementary to LDL-C in identifying the "effective" CV risk profile of asymptomatic NGT subjects.

Apolipoprotein B, non-HDL cholesterol and LDL cholesterol for identifying individuals at increased cardiovascular risk

BACKGROUND

To compare apolipoprotein B (apoB), non-high-density lipoprotein-cholesterol (non-HDL-c) and low-density lipoprotein-cholesterol (LDL-c) for identifying individuals with a deteriorated cardiovascular (CV) risk profile, including a panel of subclinical atherosclerosis measurements and prevalent cardiovascular disease (CVD) in a Dutch population-based cohort.

METHODS

Clinical and biochemical measurements and a panel of noninvasive parameters of subclinical atherosclerosis were determined in 1517 individuals, aged 50-70 years.

RESULTS

Both men and women with increasing levels of apoB and non-HDL-c were more obese, had higher blood pressure and fasting glucose levels, and a more atherogenic lipid profile. Furthermore, compared to the reference group (composed of those with apoB, non-HDL-c and LDL-c levels in the bottom quartiles), participants with high apoB and high non-HDL-c levels had a lower ankle-brachial index at rest (-3.5% and -3.1%, respectively) and after exercise (-6.3% and -4.7%, respectively), a thicker near wall (+4.8% and +4.2%, respectively), far wall (both +6.2%), and mean intima-media thickness (+5.7% and +5.3%, respectively) and more plaques (+54.2% and +54.3%, respectively). In addition, they also showed increased stiffness parameters (e.g. pulse wave velocity both +3.6%). Less clear differences in CV risk profile and subclinical atherosclerosis parameters were observed when participants were stratified by LDL-c level. Furthermore, apoB but not LDL-c detected prevalent CVD, and non-HDL-c only detected prevalent CVD in men. The discriminatory power for prevalent CVD expressed as area under the receiver operating characteristic curve was 0.60 (P < 0.001) for apoB, 0.57 (P = 0.001) for non-HDL-c and 0.54 (P = 0.108) for LDL-c.

CONCLUSION

Our data support the use of first apoB and secondly non-HDL-c above LDL-c for identifying individuals from the general population with a compromised CV phenotype.

Apolipoprotein B is related to arterial pulse wave velocity in young adults: the Cardiovascular Risk in Young Finns Study

OBJECTIVE

Limited data are available regarding the relationship of apolipoproteins B (ApoB) and A-1 (ApoA-1) with arterial stiffness. We conducted the present study to determine whether adulthood ApoB and ApoA-1 are related to arterial pulse wave velocity (PWV). Moreover, we examined whether ApoB and ApoA-1 measured in young adulthood are predictive of PWV assessed 6 years later.

METHODS

The study population consisted of 1618 apparently healthy Finnish young adults (aged 30-45 years, 44.9% males) whose apolipoproteins, other cardiovascular risk factors and PWV were measured in 2007. In a sub-sample population, apolipoproteins and other cardiovascular risk factors had also been measured in 2001 (n=1264). PWV measurements were performed using a whole-body impedance cardiography device.

RESULTS

ApoB (p<0.001) and the ApoB/ApoA-1 ratio (p<0.001) were directly associated with PWV. ApoB and the ApoB/ApoA-1 ratio measured in young adulthood were also predictive of PWV measured 6 later (p<0.001 for both). These relations remained significant (p<0.006) in models adjusted for non-lipid risk factors. The areas under the receiver-operating characteristic (ROC) curves (AUC) were similar for ApoB and non-HDL cholesterol (2001: p for AUC comparison=0.15; 2007: p for AUC comparison=0.07) in detecting subjects with increased PWV (PWV≥90th percentile).

CONCLUSION

The present study suggests that elevation of ApoB or non-HDL cholesterol is associated with increased arterial stiffness in young adults.

Dietary interventions that lower lipoproteins containing apolipoprotein C-III are more effective in whites than in blacks: results of the OmniHeart trial

BACKGROUND

Blacks have lower average triglyceride and LDL cholesterol concentrations than do whites but higher rates of coronary heart disease. Apolipoprotein (apo) C-III in VLDL and LDL stimulates atherogenic processes in vascular cells. In blacks, the concentration of lipoproteins with apo C-III is unknown, and the response to dietary strategies that lower triglyceride and apo C-III has not been investigated

OBJECTIVE

We compared the concentration of and dietary effects on apo C-III-containing lipoproteins in blacks and whites.

DESIGN

In a randomized, 3-period feeding study [OmniHeart (Optimal Macronutrient Intake Trial to Prevent Heart Disease)], we measured lipoprotein concentrations in 89 blacks and 73 whites who consumed self-selected diets (baseline) and after 3 healthful diets emphasizing carbohydrate, unsaturated fat, or protein. Participants had prehypertension or hypertension, and 79% were overweight or obese.

RESULTS

While consuming self-selected diets, blacks had lower apo C-III in total plasma, VLDL, and LDL than did whites. Unsaturated fat and protein diets lowered plasma apo C-III (16% and 18%, respectively) and triglyceride (12% and 21%, respectively) in whites but not in blacks, reducing racial differences. Most important, blacks had a lower concentration of atherogenic LDL with apo C-III at baseline and after study diets (34-41% lower, P < 0.02). The molar ratio of apo E to apo B was higher in blacks than in whites in total plasma and LDL at baseline and after the study diets.

CONCLUSIONS

Blacks have lower concentrations of atherogenic lipoproteins that contain apo C-III than do whites when consuming diverse diets and an attenuated dietary response of triglyceride and apo C-III. Dietary efforts to lower triglyceride and apo C-III may be more effective in whites than in blacks. The OmniHeart Trial was registered at www.clinicaltrials.gov as NCT00051350.

Coronary artery calcium and cardiovascular risk in diabetes

Measurement of coronary artery calcium score (CACS) by electron beam tomography has been shown to a powerful predictor of coronary heart disease events in asymptomatic non-diabetic subjects. In type 2 diabetes, measurement of CACS was found to be a powerful predictor of cardiovascular events which could enhance prediction provided by established risk models. 23% of type 2 diabetic subjects with low CACS were found to be at low risk for cardiovascular events. Moreover mortality was similar for type 2 diabetic and non-diabetic subjects with undetectable coronary artery calcification. Conversely type 2 diabetic subjects with high CACS were identified who were at high cardiovascular risk. Thus not all those with type 2 diabetes are at similar cardiovascular risk. Measurement of CACS enables cardiovascular risk in type 2 diabetes to be stratified so that the level of preventive therapy could be reduced in some and intensified in others. Although prospective data for the power of CACS to predict CHD events in type 1 diabetes are lacking, measurement of CACS could help in deciding on preventive therapy in type 1 diabetes.

Correlation of non-high-density lipoprotein cholesterol and low-density lipoprotein cholesterol with apolipoprotein B during simvastatin + fenofibrate therapy in patients with combined hyperlipidemia (a subanalysis of the SAFARI trial)

Guidelines have recommended non-high-density lipoprotein (non-HDL) cholesterol as a secondary target for therapy after the low-density lipoprotein (LDL) cholesterol goals have been met in patients with hypertriglyceridemia; non-HDL cholesterol is viewed as a surrogate for apolipoprotein (Apo)B, an alternate end point of treatment. The present analysis of the previously reported Simvastatin plus Fenofibrate for Combined Hyperlipidemia (SAFARI) trial assessed the associations of non-HDL cholesterol and LDL cholesterol with ApoB levels in patients with combined hyperlipidemia treated with combination simvastatin (20 mg) and fenofibrate (160 mg) or simvastatin monotherapy (20 mg). The correlations of these factors were analyzed in the overall modified intent-to-treat population (n = 594) and in patient subgroups stratified by triglyceride (TG) tertiles. Simvastatin plus fenofibrate and simvastatin alone significantly reduced LDL cholesterol, TG, non-HDL cholesterol and ApoB levels and non-HDL cholesterol/ApoB ratio (p < or =0.0004), regardless of the TG level. The greatest reductions occurred with combination treatment. The baseline levels of non-HDL cholesterol and LDL cholesterol correlated highly with ApoB and were stronger in the lower TG tertiles than in the higher TG tertiles. After 12 weeks, the correlations had changed little with simvastatin monotherapy but had increased substantially with combination therapy and were most improved at high TG levels. In conclusion, these results suggest that both non-HDL cholesterol and ApoB provide similar information in relation to treatment response in patients with combined hyperlipidemia and hypertriglyceridemia, and that non-HDL cholesterol is a good indicator of ApoB-containing lipoproteins, supporting its recommended use as a secondary therapeutic target in these patients.

Primary prevention of cardiovascular disease and type 2 diabetes in patients at metabolic risk: an endocrine society clinical practice guideline

OBJECTIVE

The objective was to develop clinical practice guidelines for the primary prevention of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) in patients at metabolic risk.

CONCLUSIONS

Healthcare providers should incorporate into their practice concrete measures to reduce the risk of developing CVD and T2DM. These include the regular screening and identification of patients at metabolic risk (at higher risk for both CVD and T2DM) with measurement of blood pressure, waist circumference, fasting lipid profile, and fasting glucose. All patients identified as having metabolic risk should undergo 10-yr global risk assessment for either CVD or coronary heart disease. This scoring will determine the targets of therapy for reduction of apolipoprotein B-containing lipoproteins. Careful attention should be given to the treatment of elevated blood pressure to the targets outlined in this guideline. The prothrombotic state associated with metabolic risk should be treated with lifestyle modification measures and in appropriate individuals with low-dose aspirin prophylaxis. Patients with prediabetes (impaired glucose tolerance or impaired fasting glucose) should be screened at 1- to 2-yr intervals for the development of diabetes with either measurement of fasting plasma glucose or a 2-h oral glucose tolerance test. For the prevention of CVD and T2DM, we recommend that priority be given to lifestyle management. This includes antiatherogenic dietary modification, a program of increased physical activity, and weight reduction. Efforts to promote lifestyle modification should be considered an important component of the medical management of patients to reduce the risk of both CVD and T2DM.

Glycemic control in adolescents with type 1 diabetes mellitus improves lipid serum levels and oxidative stress

INTRODUCTION

Atherosclerosis begins in childhood, and diabetes is a risk factor for coronary heart disease. Dyslipidemia is prevalent in children with type 1 diabetes mellitus (T1DM), with an association between elevated hemoglobin A1c (HbA1c), serum lipid levels, and oxidative stress. Our aim was to examine the effect of metabolic control on serum lipid levels and oxidative stress in adolescents with T1DM.

METHODS

Twenty-six adolescents (13 boys and 13 girls), aged 15.65 +/- 1.5 yr, with disease duration of 5.9 +/- 2.8 yr and average HbA1c 10.8 +/- 1.9% were assigned to intensive insulin therapy for 3 months. Comparisons for HbA1c, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein cholesterol, total triglycerides (TG), total cholesterol (TC), apolipoprotein AI, apolipoprotein AII, apolipoprotein B (ApoB), and thiobarbituric acid reactive substances (TBARS) were done between patients whose HbA1c improved by 0.5% or more (GR1) and the rest of the cohort (patients whose HbA1c improved by <0.5%, did not change, or increased) (GR2).

RESULTS

ApoB (p = 0.047) and TBARS (p = 0.01) were significantly lower at the end of the study in GR1. In GR2, TC (p = 0.01) and LDL (p = 0.03) were significantly higher at study end. Overall, significant beneficial changes in TC (p = 0.006), TG (p = 0.04), LDL (p = 0.02), ApoB (p = 0.015), and oxidative stress (p = 0.001) were found in GR1 compared with GR2.

CONCLUSIONS

We provide direct evidence for the beneficial effect of tight metabolic control on serum lipids and oxidative stress in adolescents with T1DM, indicating that tight metabolic control may reduce cardiovascular risk in these patients.

Apolipoprotein B is a better marker than non-HDL-cholesterol for the metabolic syndrome in Koreans

Apolipoprotein B (apoB) concentration reflects the number of atherogenic particles and is closely associated with atherosclerosis. Non-HDL-cholesterol (non-HDL-C) has been considered a therapeutic target for patients with hypertriglyceridemia. We compared the predictive values of apoB and non-HDL-C for the metabolic syndrome (MetS) in 3335 Korean adults (mean age, 45.2 years) who participated consecutively in a health examination in a university hospital. Anthropometry, blood pressure, fasting glucose, lipid profiles and apoB were measured. MetS, as defined by a modification of the NCEP-ATP III criteria, was present in 22.1% of men and 16.1% of women. Among the components of the MetS, triglycerides showed the strongest correlation with apoB (r=0.393, P<0.001 in men, and r=0.326, P<0.001 in women) and non-HDL-C (r=0.376, P<0.001 in men, and r=0.349, P<0.001 in women). When apoB and non-HDL-C were mutually adjusted, the ORs for the MetS of non-HDL-C were not significant. As a function of the quartile of apoB levels, the ORs for the MetS were 2.04 (1.26-3.30), 3.54 (2.11-5.93), and 5.38 (3.16-9.17) in men (P for trend <0.001) and 3.75 (1.42-9.87), 5.55 (2.09-14.69), and 13.41 (5.02-35.79) in women (P for trend <0.001), respectively. These findings indicate that apoB is a better marker than non-HDL-C for identifying the MetS among Koreans.

Effect of ezetimibe/simvastatin vs atorvastatin on lowering levels of LDL-C and non-HDL-C, ApoB, and hs-CRP in patients with type 2 diabetes

BACKGROUND

In addition to low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), apolipoprotein B (ApoB), and high-sensitivity C-reactive protein (hs-CRP) are considered predictive for cardiovascular disease in type 2 diabetes mellitus (T2DM) patients.

OBJECTIVE

To assess the proportion of T2DM patients with hypercholesterolemia who attained the optional target level of LDL-C (<70 mg/dL) and additionally non-HDL-C (<100 mg/dL), ApoB (<90 mg/dL), and hs-CRP (<2 mg/L), following treatment with ezetimibe/simvastatin (E/S) vs atorvastatin (A).

METHODS

This post-hoc analysis of a multicenter, randomized, double-blind, 6-week parallel study assessed the proportion of T2DM patients who attained specified LDL-C levels and non-HDL-C, ApoB, and hs-CRP with usual, recommended starting doses of E/S (10/20 mg) vs A (10 or 20 mg) and next highest doses of E/S (10/40 mg) vs A (40 mg) by logistic regression. Baseline triglyceride and hs-CRP effects were also evaluated.

RESULTS

Significantly higher percentages of patients treated with E/S compared to A achieved individual and concurrent target levels of LDL-C (<70 mg/dL), non-HDL-C (<100 mg/dL), and ApoB (<90 mg/dL) at all dose comparisons (P < 0.05 to P < 0.001). Baseline triglyceride levels had no effect on reaching LDL-C levels. Attainment of non-HDL-C (<100 mg/dL), and ApoB (<90 mg/dL) was lower at triglycerides ≥200 mg/dL than <200 mg/dL. Achievement of hs-CRP level (<2 mg/L) was comparable for both treatments. Significantly more patients attained both LDL-C (<70 mg/dL) and hs-CRP (<2 mg/L) at all E/S doses compared to A (P < 0.05 to P < 0.001), regardless of baseline CRP levels.

CONCLUSION

E/S provides a therapeutic option to T2DM patients for lowering not only LDL-C, but also non-HDL-C, ApoB, and hs-CRP. These factors may help guide assessment and treatment of cardiovascular disease risk in these patients.

Apolipoprotein B and non-high density lipoprotein cholesterol and the risk of coronary heart disease in Chinese

The aim of our study was to compare apolipoprotein B (apoB), non-high density lipoprotein cholesterol (nonHDL-C), low density lipoprotein cholesterol (LDL-C), and other lipid markers as predictors of coronary heart disease (CHD) in Chinese. Overall, 122 individuals developed CHD during a median 13.6 years of follow-up in 3,568 adult participants from a community-based cohort. The multivariate relative risk of CHD in the highest quintile compared with the lowest quintile was 2.74 [95% confidence interval (CI), 1.45-5.19] for apoB, 1.98 (95% CI, 1.00-3.92) for nonHDL-C, and 1.86 (95% CI, 1.00-3.49) for LDL-C (all tests for trend, P < 0.05). ApoB also had the highest receiver operator characteristic curve area (0.63; 95% CI, 0.58-0.68) in predicting CHD. When apoB and nonHDL-C were mutually adjusted, only apoB was predictive; the relative risk was 2.80 (95% CI, 1.31-5.96; P = 0.001) compared with 1.09 (95% CI, 0.49-2.40; P = 0.75) for nonHDL-C. Compared with the lowest risk, participants with the highest apoB and total cholesterol/HDL-C had a 3-fold increased risk of developing CHD (relative risk = 3.21; 95% CI, 1.45-7.14). These data provide strong evidence that apoB concentration was a better predictor of CHD than other lipid markers in Chinese.

Significance of Determining Levels of Apolipoproteins A-I and B in the Diagnostics and Assessment of Lipid-Related Atherogenic Risk in Hyperalpha-Lipoproteinemia, Hypocholesterolemia and Hypo-Hdl-Cholesterolemia

The significance of determining apolipoproteins apoB and apoA-I and their correlation with lipid status parameters were tested in hyperalpha-lipoproteinemia (30 women), hypocholesterolemia (10 men) and hypo-HDL-cholesterolemia (15 women and 21 men). Control groups were 20 normolipidemic men and women, each. ApoA-I showed positive correlation with HDL-cholesterol in hyperalpha-lipoproteinemia, with total and HDL-cholesterol in hypocholesterolemia, and with total and LDL-cholesterol in females with hypo-HDL-cholesterolemia, and negative correlation with cholesterol ratios only in hypocholesterolemia. ApoB showed a positive correlation with total and LDL-cholesterol in all groups, and with cholesterol ratios in hyperalpha-lipoproteinemia and hypo-HDL-cholesterolemia. The apoB/apoA-I ratio, correlating with the majority of lipid parameters, and with the highest percentage of pathological values in all tested groups, was singled out as the most sensitive parameter for the evaluation of lipid-related atherogenic risks.

Apolipoprotein A1 and B

This article reviews the evidence showing that apolipoprotein (apo) B and A-1 are superior to the conventional cholesterol indices as analytes in laboratory practice, indices of the lipoprotein-related risk for vascular disease, and measures of the adequacy of low-density lipoprotein-lowering therapy.

Papel de la dislipemia aterogénica en el desarrollo del síndrome metabólico

BACKGROUND AND OBJECTIVE

Our goal was to know if the diagnosis of metabolic syndrome (MS) as defined by International Diabetes Federation (IDF) criteria 2005 identifies more subjects with atherogenic dyslipidemia and high cardiovascular risk than the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP-III) criteria.

PATIENTS AND METHOD

Cross-sectional study in an adult population (20-70 years) of 344 subjects (158 males and 186 females), who visited an out-patient clinic in the metropolitan area of Valencia over a period of one year. Opportunistic search method was used. We studied: anthropometrics parameters, blood pressure, plasma lipids -non-high-density lipoprotein cholesterol (no-HDL-c), and total cholesterol:high-density lipoprotein cholesterol index (TC-HDL-c)-, glucose and insulin, and HOMA (Homeostasis Model Assessment) index.

RESULTS

We have separated the subjects on the basis to the IDF or ATP-III criteria to define the MS. The MS define a group of subjects with important plasma lipids alterations and cardiovascular risk: increase of no-HDL-c, of TC:HDL-c index and of apolipoprotein B. The TC:HDL-c index was > or = 6 in 28.6% of the subjects with MS and only in 9.4% of the subjects without MS (p < 0.0001) by IDF criteria and in 34.6% of the subjects with MS-ATP-III, and in 8.6% without MS-ATP-III (p < 0.0001). The apolipoprotein B > or = 1.2 g/l was observed in 44% of the subjects with MS and only in 26% without MS IDF criteria (p < 0.0001), and only in 47.6% and 28.6%, respectively, by ATP-III criteria (p < 0.0001).

CONCLUSIONS

The MS defined by the IDF or ATP-III criteria equally identifies subjects with atherogenic dyslipidemia, with increase of no-HDL-c, of the TC: HDL-c index and of the apolipoprotein B and, for this reason, with high cardiovascular risk.

Increased prevalence of subclinical atherosclerosis in patients with small-vessel vasculitis

BACKGROUND AND OBJECTIVE

Although changes in smaller vessels is the hallmark of medium-sized and small-vessel vasculitis, it has been suggested that large arteries of such patients may also be affected by the early atherosclerotic process because of coexisting risk factors or systemic inflammation. This study aimed to bring additional arguments supporting this hypothesis.

DESIGN, SETTING AND PATIENTS

50 consecutive patients with primary systemic necrotising vasculitis and 100 controls matched for age and sex underwent ultrasonic detection of plaque in three peripheral vessels (carotid and femoral arteries and abdominal aorta). Cardiovascular risk factors and inflammation (C reactive protein (CRP)) were concomitantly measured in all participants, and diagnosis of high-risk status was defined by the presence of known history of cardiovascular disease, type 2 diabetes or 10-year-Framingham Risk Score > or =20%.

RESULTS

Patients had higher frequency of plaque than controls in the carotid arteries (p<0.05), in the aorta (p<0.01) and in the three vessels examined (p<0.001), and adjustment for high-risk status did not confound such difference in the aorta and in the three vessels. In the overall population of patients and controls, vasculitis was associated with a higher frequency of three-vessel plaques (p<0.05), independently of high-risk status and CRP. In patients, the higher frequency of three-vessel plaques was associated with high-risk status (p<0.05) but not with CRP, or disease and treatment characteristics.

CONCLUSIONS

Small-vessel vasculitis is associated with more frequent subclinical atherosclerosis, especially extended to multiple peripheral vessels, and such association is not entirely explained by cardiovascular risk factors and systemic inflammation.

The apoB/apoA-I ratio: a strong, new risk factor for cardiovascular disease and a target for lipid-lowering therapy--a review of the evidence

During the last several years interest has focused on the importance of the lipid-transporting apolipoproteins--apoB transports all potentially atherogenic very low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL) and LDL particles, and apoA-I transports and acts as the major antiatherogenic protein in the HDL particles. The evidence for the apoB/apoA-I ratio being a strong, new risk factor for cardiovascular (CV) disease and a target for lipid-lowering therapy is reviewed. Results from clinical prospective studies and lipid-lowering trials in healthy subjects and in patients with different clinical manifestations of atherosclerosis are reported. Risk of nonfatal and fatal myocardial infarction and stroke, and manifestations of atherosclerosis documented by angiographic, ultrasound and other techniques has been related to conventional lipids and apolipoproteins (apo). The cholesterol balance determined as the apoB/apoA-I ratio has repeatedly been shown to be a better marker than lipids, lipoproteins and lipid ratios. The results indicate that the apoB/apoA-I ratio is a simple, accurate and new risk factor for CV disease--the lower the apoB/apoA-I ratio, the lower is the risk. Guidelines should be developed in order to recognize the important clinical risk information embedded in the apoB/apoA-I ratio.

Measurement and meaning of apolipoprotein AI and apolipoprotein B plasma levels

Apolipoproteins AI and B are structural components of lipoprotein particles, and also determinants of the metabolic fate of the encapsulated lipid, cholesterol and triglyceride. Development of accurate assays for these apolipoproteins has opened the way for their use as predictors of coronary heart disease risk. Interpretation of AI and apo B levels is best undertaken with background knowledge of the metabolic status of an individual, especially the lipolytic capacity as reflected in the triglyceride concentration. Those with raised triglyceride, in general, not only have an elevated apo B/apo AI ratio, but also apo B-containing lipoproteins with a prolonged residence time and hence ample opportunity for modification and damage. Assessment of apolipoprotein levels is an aid to risk prediction and can be useful in tailoring treatment.

Apo B versus cholesterol in estimating cardiovascular risk and in guiding therapy: report of the thirty-person/ten-country panel

There is abundant evidence that the risk of atherosclerotic vascular disease is directly related to plasma cholesterol levels. Accordingly, all of the national and transnational screening and therapeutic guidelines are based on total or LDL cholesterol. This presumes that cholesterol is the most important lipoprotein-related proatherogenic risk variable. On the contrary, risk appears to be more directly related to the number of circulating atherogenic particles that contact and enter the arterial wall than to the measured concentration of cholesterol in these lipoprotein fractions. Each of the atherogenic lipoprotein particles contains a single molecule of apolipoprotein (apo) B and therefore the concentration of apo B provides a direct measure of the number of circulating atherogenic lipoproteins. Evidence from fundamental, epidemiological and clinical trial studies indicates that apo B is superior to any of the cholesterol indices to recognize those at increased risk of vascular disease and to judge the adequacy of lipid-lowering therapy. On the basis of this evidence, we believe that apo B should be included in all guidelines as an indicator of cardiovascular risk. In addition, the present target adopted by the Canadian guideline groups of an apo B <90 mg dL(-1) in high-risk patients should be reassessed in the light of the new clinical trial results and a new ultra-low target of <80 mg dL(-1) be considered. The evidence also indicates that the apo B/apo A-I ratio is superior to any of the conventional cholesterol ratios in patients without symptomatic vascular disease or diabetes to evaluate the lipoprotein-related risk of vascular disease.

Serum Lipid Profile Constituents as Markers of Cardiovascular Morbidity in Patients on Chronic Hemodialysis

We designed the present case-control study in order to examine the validity of apolipoprotein (apo) A-I, B, apoB/apoA-I ratio and Lp(a) as alternative markers of cardiovascular morbidity in end-stage renal disease (ESRD) patients undergoing chronic hemodialysis (HD). Twenty-five HD patients (18 males, mean age 63, range 52–69 years) comprised the group with prevalent cardiovascular disease (CVD) and 50 HD patients (35 males, mean age 62, range 40–77 years) with non evident cardiovascular disease history constituted the second study group. Patients with CVD had significantly higher concentrations of serum apoB, apoB/apoA-I ratio and Lp(a), and lower levels of apoA-I compared to patients without incident CVD. All three parameters studied were correlated with cardiovascular morbidity, i.e. apoA-I negatively and apoB and apoB/apoA-I ratio positively (r = −0.6, P < 0.05; r = 0.659, P < 0.01; and r = 0.614, P < 0.01, respectively). Furthermore, logCRP exhibited as well a significant positive correlation with cardiovascular morbidity (r = 0.704, P < 0.001), not this being the case for Lp(a) which was not found to exhibit such a correlation (r = 0.05, P = NS). Among them, apoB and apoB/apoA-I ratio exhibited the characteristics most coherent to CVD. The age- and sex-adjusted OR for the presence of CVD was 2.3 and 2.0, respectively, which remained independent of any confounding effect of inflammation. In conclusion, serum apoB levels and apoB/apoA-I ratio exhibit characteristics of credible independent markers of in HD patients.

Non–High-Density Lipoprotein Cholesterol and Apolipoprotein B in the Prediction of Coronary Heart Disease in Men

BACKGROUND

Apolipoprotein B (apoB) plasma levels reflect the concentration of proatherogenic lipoproteins very low-density lipoprotein and low-density lipoprotein (LDL), whereas non-high-density lipoprotein cholesterol (non-HDL-C) levels reflect the concentration of cholesterol transported by these particles.

METHODS AND RESULTS

The aim of our study was to compare apoB, non-HDL-C, LDL cholesterol (LDL-C), and other lipid markers as predictors of coronary heart disease (CHD) in a nested case-control study among 18 225 participants in the Health Professionals Follow-up Study. Among men who were free of diagnosed cardiovascular disease at the time of blood collection, 266 had nonfatal myocardial infarction or fatal CHD during 6 years of follow-up. Through the use of risk set sampling, control subjects were selected at a 2:1 ratio and matched with regard to age, date of blood collection, and smoking status. After adjustment for matching factors, the relative risk of CHD in the highest quintile compared with the lowest quintile was 2.76 (95% confidence interval [CI], 1.66 to 4.58) for non-HDL-C, 3.01 (95% CI, 1.81 to 5.00) for apoB, 1.81 (95% CI, 1.12 to 2.93) for LDL-C, 0.31 (95% CI, 0.18 to 0.52) for HDL-C, 2.41 (95% CI, 1.43 to 4.07) for triglycerides (all P trend <0.001), and 1.42 (95% CI, 0.86 to 2.32, P trend =0.19) for lipoprotein(a). When non-HDL-C and LDL-C were mutually adjusted, only non-HDL-C was predictive of CHD. When non-HDL-C and apoB were mutually adjusted, only apoB was predictive; the relative risk was 4.18 (95% CI, 1.30 to 13.49; P trend =0.02) for apoB compared with 0.70 (95% CI, 0.21 to 2.27; P trend =0.72) for non-HDL-C. Triglycerides added significant information to non-HDL-C but not to apoB for CHD risk prediction.

CONCLUSIONS

Although non-HDL-C and apoB were both strong predictors of CHD in this male cohort, more so than LDL-C, the findings support the concept that the plasma concentration of atherogenic lipoprotein particles measured by apoB is more predictive in development of CHD than the cholesterol carried by these particles, measured by non-HDL-C.