Fasting cholesteryl ester transfer protein concentration is independently associated with the postprandial decrease in high-density lipoprotein cholesterol concentration after fat-rich meals: the Hoorn prandial study.

The aim of the study was to test whether fasting or postprandial cholesteryl ester transfer protein (CETP) concentrations are associated with postprandial changes in high-density lipoprotein cholesterol (HDL-c) concentrations after fat-rich or carbohydrate-rich meals. Postmenopausal women (76 with normal glucose metabolism [NGM], 41 with type 2 diabetes mellitus [T2DM], and 38 T2DM women with statin therapy [T2DM-ST]) received 2 consecutive fat-rich or carbohydrate-rich meals on separate occasions. Linear regression analysis was performed to assess the associations of fasting CETP and postprandial changes of CETP with postprandial changes in HDL-c. Mean plasma HDL-c concentrations decreased significantly after the fat-rich meals: 0.18 +/- 0.09 mmol/L in NGM, 0.16 +/- 0.09 mmol/L in T2DM, and 0.14 +/- 0.08 mmol/L in T2DM-ST women. This effect was smaller after using carbohydrate-rich meals: 0.12 +/- 0.09 mmol/L in the NGM, 0.12 +/- 0.08 mmol/L in the T2DM, and 0.10 +/- 0.05 mmol/L in the T2DM-ST study group. Higher fasting but not postprandial CETP concentrations were associated with a larger postprandial decrease in HDL-c (beta -0.034; 95% confidence interval, -0.067 to -0.001) after the fat-rich meals. This association was independent of the postprandial increase in triglycerides and similar among the 3 study groups. A high fasting CETP concentration may contribute to the postprandial atherogenic lipoprotein profile in postmenopausal women by decreasing HDL-c after fat-rich meals. This effect is independent from the postprandial increase in triglycerides.

High-density lipoprotein particle size and concentration and coronary risk.

BACKGROUND: High-density lipoprotein (HDL) cholesterol levels are inversely related to risk for coronary artery disease (CAD). Because HDL particles are heterogeneous in size and composition, they may be differentially associated with other cardiovascular risk factors and with cardiovascular risk. OBJECTIVE: To study the independent relationships of HDL size and particle concentration to risk for future CAD. DESIGN: Nested case-control study within the EPIC (European Prospective Investigation into Cancer and Nutrition)-Norfolk cohort; baseline survey between 1993 and 1997, follow-up until November 2003. SETTING: Norfolk, United Kingdom. PARTICIPANTS: Case patients were 822 apparently healthy men and women who developed CAD during follow-up. Control participants were 1401 participants who remained without CAD and were matched to case patients by sex, age, and enrollment time. MEASUREMENTS: First CAD event leading to either hospitalization or death. RESULTS: Nuclear magnetic resonance spectroscopy-measured HDL particle concentration (mean, 33.9 micromol/L [SD, 5] vs. 32.9 micromol/L [SD, 6]; P < 0.001) and HDL size (mean, 8.9 nm [SD, 0.5] vs. 8.8 nm [SD, 0.5]; P < 0.001), as well as gradient gel electrophoresis-measured HDL size (mean, 8.9 nm [SD, 0.4] vs. 8.8 nm [SD, 0.4]; P = 0.005) were lower in case patients than in control participants. High-density lipoprotein size and HDL particle concentration were only weakly correlated (r = 0.08, for those measured with nuclear magnetic resonance spectroscopy; r = 0.10, for those measured with gradient gel electrophoresis). High-density lipoprotein size was strongly associated with risk factors characteristic of the metabolic syndrome, including waist-to-hip ratio, triglyceride level, and apolipoprotein B level, whereas HDL particle concentration was not. Both HDL size and HDL particle concentration were independently associated with CAD risk. The association between HDL size and CAD risk was abolished on adjustment for apolipoprotein B and triglyceride levels (adjusted odds ratio, 1.00 [95% CI, 0.71 to 1.39] for top vs. bottom quartile), whereas HDL particle concentration remained independently associated with CAD risk (adjusted odds ratio, 0.50 [CI, 0.37 to 0.66]). LIMITATION: Measurements were performed in nonfasting blood samples, and residual confounding cannot be excluded. CONCLUSION: Both HDL size and HDL particle concentration were independently associated with other cardiovascular risk factors and with the risk for CAD. The relationship between HDL size and CAD risk was explained by markers associated with the metabolic syndrome, indicating that part of the relationship between HDL cholesterol and CAD risk is merely a reflection of this metabolic risk.

Current and future pharmacologic options for the management of patients unable to achieve low-density lipoprotein-cholesterol goals with statins.

Low-density lipoprotein-cholesterol (LDL-C) lowering is the mainstay of the current treatment guidelines in the management of cardiovascular risk. HMG-CoA reductase inhibitors (statins) are currently the most effective LDL-C-lowering drugs. However, a substantial number of patients do not reach treatment targets with statins. Therefore, an unmet medical need exists for lipid-lowering drugs with novel mechanisms of action to reach the recommended cholesterol target levels, either by monotherapy or combination therapy. Upregulation of the LDL receptor with squalene synthase inhibitors has shown promising results in animal studies but the clinical development of the lead compound lapaquistat (TAK-475) has recently been discontinued. Ezetimibe combined with statins allowed significantly more patients to reach their LDL-C targets. Other inhibitors of intestinal cholesterol absorption such as disodium ascorbyl phytostanol phosphate (FM-VP4) and bile acid transport inhibitors have shown positive results in early development trials, whereas the prospect of acyl coenzyme A: cholesterol acyltransferase inhibition in cardiovascular prevention is dire. Selective inhibition of messenger RNA (mRNA) by antisense oligonucleotides is a new approach to modify cholesterol levels. The inhibition of apolipoprotein B mRNA is in advanced development and mipomersen sodium (ISIS 301012) has shown striking results in phase II studies both as monotherapy as well as in combination with statins.

The role of CETP inhibition in dyslipidemia.

Cholesteryl ester transfer protein (CETP) inhibitors are currently being investigated because of their ability to increase high-density lipoprotein cholesterol levels. In various metabolic settings, the relationship between CETP and lipoprotein metabolism is complex and may depend largely on the concentration of triglyceride-rich lipoproteins. Two CETP inhibitors, JTT-705 and torcetrapib, are in an advanced phase of development. Following hopeful intermediate results, a large endpoint study using torcetrapib has just been discontinued due to increased mortality in torcetrapib-treated subjects. In this review we summarize clinical data on the use of CETP inhibitors.

Role of the apolipoprotein B-apolipoprotein A-I ratio in cardiovascular risk assessment: a case-control analysis in EPIC-Norfolk.

BACKGROUND: An elevated apolipoprotein B-apolipoprotein A-I (apo B-apo A-I) ratio is a risk factor for future coronary artery disease (CAD). It is not known whether this ratio is better than traditional lipid values for risk assessment and prediction and whether it adds predictive value to the Framingham risk score. OBJECTIVE: To evaluate whether the apo B-apo A-I ratio is associated with future CAD events independent of traditional lipid measurements and the Framingham risk score and to evaluate the ability of this ratio to predict occurrence of future CAD. DESIGN: Prospective, nested case-control study. SETTING: Norfolk, United Kingdom. PARTICIPANTS: Apparently healthy men and women (45 to 79 years of age) in the European Prospective Investigation into Cancer and Nutrition-Norfolk. Cases (n = 869) were persons who developed fatal or nonfatal CAD. Controls (n = 1511) were persons without CAD who were matched for age, sex, and enrollment period. MEASUREMENTS: Total cholesterol, high-density lipoprotein (HDL) cholesterol, triglyceride, apolipoprotein, and C-reactive protein levels were measured directly. Low-density lipoprotein (LDL) cholesterol values were calculated by using the Friedewald formula. RESULTS: The apo B-apo A-I ratio was associated with future CAD events, independent of traditional lipid values (adjusted odds ratio, 1.85 [95% CI, 1.15 to 2.98]), including the total cholesterol-HDL cholesterol ratio, and independent of the Framingham risk score (adjusted odds ratio, 1.77 [CI, 1.31 to 2.39]). However, it did no better than lipid values at discriminating between CAD cases and controls (area under the receiver-operating characteristic curve, 0.670 for total cholesterol-HDL cholesterol ratio vs. 0.673 for apo B-apo A-I ratio [P = 0.38]) and added little to the predictive value of the Framingham risk score (area under the receiver-operating characteristic curve, 0.594 for Framingham risk score alone vs. 0.613 for Framingham risk score plus apo B-apo A-I ratio [P < 0.001]). In addition, it incorrectly classified 41.1% of cases and 50.4% of controls. LIMITATIONS: No participant was taking lipid-lowering medication, and diabetes was uncommon. CONCLUSIONS: The apo B-apo A-I ratio is independently associated with, but adds little to, existing measures for CAD risk assessment and discrimination in the general population. Other characteristics of the test, such as the ability to perform it on nonfasting samples, may still make it useful in some settings.

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.

Cholesteryl ester transfer protein (CETP) inhibition beyond raising high-density lipoprotein cholesterol levels: pathways by which modulation of CETP activity may alter atherogenesis.

Raising high-density lipoprotein cholesterol (HDL-C) is a promising strategy in the struggle to prevent cardiovascular disease, and cholesteryl ester transfer protein (CETP) inhibitors have been developed to accomplish this. The first results are encouraging, and, in fact, in rabbits, inhibition of CETP reduces atherosclerosis. Because human data regarding the reduction of atheroma burden require more time, the biochemical mechanisms underlying the putative atheroprotection of CETP inhibitors are currently dissected, and several pathways have emerged. First, CETP inhibition increases HDL-C and reduces low-density lipoprotein cholesterol (LDL-C) levels consistent with CETP lipid transfer activity and its role in reverse cholesterol transport (RCT). This coincides with putative beneficial increases in both HDL and LDL size. However, many aspects regarding the impact of CETP inhibition on the RCT pathway remain elusive, in particular whether the first step concerning cholesterol efflux from peripheral tissues to HDL is influenced. Moreover, the relevance of scavenger receptor BI and consequently the central role of HDL in human RCT is still unclear. Second, CETP inhibition was shown recently to increase antioxidant enzymes associated with HDL, in turn associated with decreased oxidation of LDL. Atheroprotection in man is currently anticipated based on the improvement of these biochemical parameters known to influence atherosclerosis, but final confirmation regarding the impact of CETP inhibition on cardiovascular outcome will have to come from trials evaluating clinical end points.