Elevated cholesteryl ester transfer protein concentration is associated with an increased risk for cardiovascular disease in women, but not in men, with Type 2 diabetes: the Hoorn Study

The Association between HDL-C and Subclinical Atherosclerosis Depends on CETP Plasma Concentration: Insights from the IMPROVE Study

The impact of cholesteryl ester transfer protein (CETP) on atherosclerosis is highly debated. This study aimed to investigate the associations between plasma CETP or CETP genotypes and carotid intima-media thickness (cIMT) and the influence of high-density lipoprotein cholesterol (HDL-C) on these associations. Plasma CETP and HDL-C concentrations were measured in 552 subjects free of any pharmacological treatment from the IMPROVE cohort, which includes 3711 European subjects at high cardiovascular risk. CETP single-nucleotide polymorphisms (SNPs) and cIMT measures (cIMT_max; cIMT_mean-max of bifurcations, common and internal carotids; plaque-free common carotid [PF CC]-IMT_mean) were available for the full cohort. In drug-free subjects, plasma CETP correlated with HDL-C levels (r = 0.19, p < 0.0001), but not with cIMT variables. When stratified according to HDL-C quartiles, CETP positively correlated with cIMT_max and cIMT_mean-max, but not with PF CC-IMT_mean, in the top HDL-C quartile only. Positive associations between the CETP concentration and cIMT_max or cIMT_mean-max were found in the top HDL-C quartile, whereas HDL-C levels were negatively correlated with cIMT_max and cIMT_mean-max when the CETP concentration was below the median (HDL-C × CETP interaction, p = 0.001 and p = 0.003 for cIMT_max and cIMT_mean-max, respectively). In the full cohort, three CETP SNPs (rs34760410, rs12920974, rs12708968) were positively associated with cIMT_max. rs12444708 exhibited a significant interaction with HDL-C levels in the prediction of cIMT_max. In conclusion, a significant interplay was found between plasma CETP and/or CETP genotype and HDL-C in the prediction of carotid plaque thickness, as indexed by cIMT_max. This suggests that the association of HDL-C with carotid atherosclerosis is CETP-dependent.

CETP activity is not associated with carotid intima-media thickness in patients with poorly controlled type 2 diabetes

AIM

The impact of cholesteryl ester transfer protein (CETP) on atherosclerotic development in humans remains unclear. Plasma cholesteryl ester transfer was shown to be associated with carotid intima-media thickness in type 2 diabetic (T2D) patients with adequate metabolic control. Since glycation of CETP may influence cholesteryl ester transfer processes, it is important to determine if plasma cholesteryl ester transfer is still a determinant of carotid intima-media thickness (IMT) in patients with poorly controlled diabetes. The aim of the present study was to determine whether CETP activity influences carotid IMT in T2D patients with poor metabolic control.

METHODS

In 110 individuals with T2D, we measured CETP mass concentration with ELISA, CETP activity with a radioactivity method and carotid intima-media thickness with high-resolution real-time B-mode ultrasonography.

RESULTS

The mean HbA1C was 8.8 ± 1.7%. Carotid IMT did not correlate with CETP activity in the total population. In T2D patients with HbA1C < 8% (n = 33), mean HbA1C was 6.9% and the correlation between carotid IMT and CETP activity was not significant (p = 0.09). In a multivariable analysis that included the total population, carotid intima-media thickness was positively associated with diabetes duration (p = 0.02) but not with CETP activity or HbA1C.

CONCLUSIONS

We observed no correlation between carotid intima-media thickness, a marker of early atherosclerosis, and CETP activity in T2D patients with poor metabolic control. Disease duration, which reflects accumulated metabolic abnormalities, may have blunted the potential effect of CETP on atherosclerosis. Metabolic control appears essential to determine the pro- or anti-atherogenic influence of CETP in patients with T2D.

In-depth human plasma proteome analysis captures tissue proteins and transfer of protein variants across the placenta

Here, we present a method for in-depth human plasma proteome analysis based on high-resolution isoelectric focusing HiRIEF LC-MS/MS, demonstrating high proteome coverage, reproducibility and the potential for liquid biopsy protein profiling. By integrating genomic sequence information to the MS-based plasma proteome analysis, we enable detection of single amino acid variants and for the first time demonstrate transfer of multiple protein variants between mother and fetus across the placenta. We further show that our method has the ability to detect both low abundance tissue-annotated proteins and phosphorylated proteins in plasma, as well as quantitate differences in plasma proteomes between the mother and the newborn as well as changes related to pregnancy.

Blood cells travel through the blood vessels in a soupy mixture of proteins called plasma. Most of these proteins are plasma-specific, yet small amounts of proteins can leak into the plasma from other body parts and may provide hints about what is going on elsewhere in the body. This could allow doctors to use plasma samples to assess health or detect disease. But so far developing methods to detect these leaked proteins has proved difficult.

Plasma passing through the placenta can transfer proteins between a pregnant woman and her baby. Learning more about these protein exchanges may help scientists understand how the mother and baby adapt to each other and what triggers child birth. But, so far, they have been hard to study. Using DNA to help trace the origins of proteins found in mother or baby could make it easier.

Now, Pernemalm et al. have used DNA sequencing in combination with protein analysis to identify proteins passed between two pregnant mothers and their babies. Comparing the genetic sequences of each mother and child made it possible to trace the origin of the proteins. For example, if a mother had a version of the protein that matched genes the child inherited from its father, they knew it passed from the baby to the mother. This approach found 24 proteins in plasma from two pregnant mothers that had likely passed through the placenta during pregnancy. Pernemalm et al. also analyzed the plasma of 30 healthy individuals and confirmed that it contained several proteins that had likely leaked from other organs, including the lungs and pancreas.

Monitoring protein transfer between pregnant mother and baby may help scientists identify what triggers normal or premature deliveries. One advantage of the technique developed Pernemalm et al. is that it can analyze plasma proteins from large numbers of people, which could enable larger studies. More refinement of the technique may also allow scientists to identify leaked proteins in the plasma that provide an early warning of cancer or other diseases.

Mendelian randomization analysis of cholesteryl ester transfer protein and subclinical atherosclerosis: A population-based study

BACKGROUND

Several trials to prevent cardiovascular disease by inhibiting cholesteryl ester transfer protein (CETP) have failed, except Randomized EValuation of the Effects of Anacetrapib through Lipid-modification. Thus far, it is unclear to what extent CETP is causally related to measures of atherosclerosis.

OBJECTIVE

The aim of the article was to study the causal relationship between genetically determined CETP concentration and carotid intima-media thickness (cIMT) in a population-based cohort study.

METHODS

In the Netherlands Epidemiology of Obesity study, participants were genotyped, and cIMT was measured by ultrasonography. We examined the relation between a weighted genetic risk score for CETP concentration, based on 3 single-nucleotide polymorphisms that have previously been shown to largely determine CETP concentration and cIMT using Mendelian randomization in the total population and in strata by sex, Framingham 10-year risk, (pre)diabetes, high-density lipoprotein cholesterol, triglycerides, and statin use.

RESULTS

We analyzed 5655 participants (56% women) with a mean age of 56 (range 44-66) years, body mass index of 26 (range 17-61) kg/m², and serum CETP of 2.47 (range 0.68-5.33) μg/mL. There was no evidence for a causal relation between genetically determined CETP and cIMT in the total population, but associations were differently directed in men (16 μm per μg/mL increase in genetically determined CETP; 95% confidence interval: -8, 39) and women (-8 μm; -25, 9). Genetically determined CETP appeared to be associated with cIMT in normoglycemic men (26 μm; -1, 52) and in (pre)diabetic women (48 μm; -2, 98).

CONCLUSION

In this population-based study, there was no causal relation between genetically determined CETP concentration and cIMT in the total population although we observed directionally differing effects in men and women. Stratified results suggested associations in individuals with different cardiometabolic risk factor profiles, which require replication.

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.

UKPDS-modelling of cardiovascular risk assessment and lifetime simulation of outcomes

Although known principally as a clinical trial, the UK Prospective Diabetes Study (UKPDS) provided longitudinal data which helped define the natural history of cardiovascular complications in Type 2 diabetes. Using clinical, epidemiological, statistical and economics methods, UKPDS investigators developed mathematical models that helped define predictors (risk factors) for cardiovascular disease including angina, myocardial infarction, stroke, peripheral vascular disease and death in Type 2 diabetes. The UKPDS made clearer the contributions to risk of age, hyperglycaemia, elevated blood pressure, adverse blood lipids and smoking. Equations were developed, combined and incorporated into the UKPDS Risk Engine and the UKPDS Outcomes models. For example, the UKPDS risk engine-version 2-estimates that a white 62-year-old man with 11 years of Type 2 diabetes, a glycated haemoglobin of 8.3%, a systolic blood pressure of 145 mmHg and total and high-density lipoprotein cholesterol values of 5.8 and 1.1 mmol/l who did not smoke has a 33% chance of having overt coronary heart disease within 10 years. These models contribute to the estimation of risk and/or health outcomes adjusted for quality of life for use by, amongst others, clinicians, trialists, health planners, guideline developers and health economists.

Effect of hypoalbuminemia on the increased serum cholesteryl ester transfer protein concentration in children with idiopathic nephrotic syndrome

OBJECTIVES

To examine the alteration of cholesteryl ester transfer protein (CETP) mass with the regression of albumin level in childhood nephrotic syndrome (NS) in order to clarify the effect of albumin on CETP in NS.

DESIGN AND METHODS

Serum concentrations of CETP, kidney parameters and lipid traits were determined in 110 children with idiopathic NS and 150 control subjects. Of the NS patients, 69 children with an active phase formed group 1, and 41 in remission formed group 2.

RESULTS

Group 1 presented severe hypoalbuminemia and hyperlipidemia, while group 2 exhibited marked recovery in both serum albumin level and lipid/lipoprotein profile. CETP concentration was significantly higher in group 1 (7.36+/-2.43 mg/L, compared with controls 3.38+/-1.83 mg/L, P<0.0001), and declined to within normal range in group 2 (2.91+/-1.77 mg/L). CETP concentration had a strong inverse correlation with serum albumin level (r=-0.688, P<0.0001) in NS patients. Furthermore, when multiple linear regression analysis was performed, in which albumin, proteinuria, lipid traits, and prednisone dose were treated as independent variables, albumin was the only variable showing a significant correlation with CETP in the NS patients (R(2)=0.587, beta=-0.475, P<0.0001).

CONCLUSIONS

The results demonstrate that the decreased serum albumin level might be a main determinant of the increased CETP concentration in pediatric NS.