Circulating plasma cholesteryl ester transfer protein activity and blood pressure tracking in the community

Association of CETP Gene Polymorphisms and Haplotypes with Acute Heart Rate Response to Exercise

Polymorphisms in the cholesteryl ester transfer protein (CETP) gene are known to be strongly associated with increased cardiovascular risk, primarily through their effects on the lipid profile and consequently on atherosclerotic risk. The acute heart rate response (AHRR) to physical activity is closely related to individual cardiovascular health. This study aimed to investigate the effect of CETP gene polymorphisms on AHRR. Our analysis examines the association of five single nucleotide polymorphisms (SNPs; rs1532624, rs5882, rs708272, rs7499892, and rs9989419) and their haplotypes (H) in the CETP gene with AHRR in 607 people from the Hungarian population. Individual AHRR in the present study was assessed using the YMCA 3-min step test and was estimated as the difference between resting and post-exercise heart rate, i.e., delta heart rate (ΔHR). To exclude the direct confounding effect of the CETP gene on the lipid profile, adjustments for TG and HDL-C levels, next to conventional risk factors, were applied in the statistical analyses. Among the examined five SNPs, two showed a significant association with lower ΔHR (rs1532624-Cdominant: B = -8.41, p < 0.001; rs708272-Gdominant: B = -8.33, p < 0.001) and reduced the risk of adverse AHRR (rs1532624-Cdominant: OR = 0.44, p = 0.004; rs708272-Gdominant: OR = 0.43, p = 0.003). Among the ten haplotypes, two showed significant association with lower ΔHR (H3-CAGCA: B = -6.81, p = 0.003; H9-CGGCG: B = -14.64, p = 0.015) and lower risk of adverse AHRR (H3-CAGCA: OR = 0.58, p = 0.040; H9-CGGCG: OR = 0.05, p = 0.009) compared to the reference haplotype (H1-AGACG). Our study is the first to report a significant association between CETP gene polymorphisms and AHRR. It also confirms that the association of the CETP gene with cardiovascular risk is mediated by changes in heart rate in response to physical activity, in addition to its effect on lipid profile.

Genetics of Cholesterol-Related Genes in Metabolic Syndrome: A Review of Current Evidence

Metabolic syndrome (MetS) refers to a cluster of metabolic dysregulations, which include insulin resistance, obesity, atherogenic dyslipidemia and hypertension. The complex pathogenesis of MetS encompasses the interplay between environmental and genetic factors. Environmental factors such as excessive nutrients and sedentary lifestyle are modifiable and could be improved by lifestyle modification. However, genetic susceptibility to MetS, a non-modifiable factor, has attracted the attention of researchers, which could act as the basis for future diagnosis, prognosis, and therapy for MetS. Several cholesterol-related genes associated with each characteristic of MetS have been identified, such as apolipoprotein, lipoprotein lipase (LPL), cholesteryl ester transfer protein (CETP) and adiponectin. This review aims to summarize the genetic information of cholesterol-related genes in MetS, which may potentially serve as biomarkers for early prevention and management of MetS.

Blood Pressure Lowering Effect of Cuban Policosanol is Accompanied by Improvement of Hepatic Inflammation, Lipoprotein Profile, and HDL Quality in Spontaneously Hypertensive Rats

We investigated the antihypertensive effect of policosanol on spontaneously hypertensive rats (SHR). For this, we analyzed blood pressure, blood lipid, and lipoprotein properties in male SHR after consumption of Cuban policosanol (PCO). The experimental groups were as follows: normotensive Wistar Kyoto (WKY) control, SHR group fed normal diet (ND), SHR group fed 20 mg of PCO, SHR group fed 100 mg of PCO, and SHR group fed 200 mg of PCO per kg of body weight. After eight weeks, the SHR control group showed gradual increases up to 21% in systolic blood pressure (SBP) and diastolic blood pressure (DBP) compared with values at week 0. However, policosanol consumption had a dose-dependent reduction effect on SBP and also reduced DBP up to 17% in a dose-dependent manner. Heart rate (HR) bpm increased by six percent in the SHR control, whereas the 20 mg, 100 mg, and 200 mg of policosanol groups showed a reduction of 36%, 28%, and 34% respectively. Although serum total cholesterol (TC) level of SHR was not affected by policosanol consumption (70⁻80 mg/dL), serum triglyceride (TG) level significantly decreased in the SHR + 200 mg of PCO group. Serum high-density lipoprotein cholesterol (HDL-C) level was also significantly elevated by policosanol consumption. The % HDL-C/TC ratio was elevated in the policosanol group up to 67⁻70%, whereas the SHR control group showed a ratio of 58%. Serum cholesteryl ester transfer protein (CETP) activity was reduced by policosanol in a dose-dependent manner. Although the serum glutamate oxaloacetate transaminase (GOT)/ glutamate pyruvate transaminase (GPT) were similar across all groups, policosanol consumption caused reduction of reactive oxygen species (ROS) levels in hepatic tissue. The SHR control group showed a 2.1-fold higher serum C-reactive protein (CRP) level than the WKY group, whereas the CRP level decreased in the SHR + 200 mg of PCO group (up to 45%) than SHR control group. Aldosterone level was reduced in the policosanol group (up to 34%) in a dose-dependent manner compared to the control. In conclusion, eight weeks of policosanol consumption in SHR resulted in remarkable reduction of blood pressure, serum aldosterone, and serum TG levels along with the elevation of HDL-C and improvement of hepatic inflammation.

Present therapeutic role of cholesteryl ester transfer protein inhibitors

Therapeutic interventions aimed at increasing high-density lipoprotein (HDL) levels in order to reduce the residual cardiovascular (CV) risk of optimally drug treated patients have not provided convincing results, so far. Transfer of cholesterol from extrahepatic tissues to the liver appears to be the major atheroprotective function of HDL, and an elevation of HDL levels could represent an effective strategy. Inhibition of the cholesteryl ester transfer protein (CETP), raising HDL-cholesterol (HDL-C) and apolipoprotein A-I (apoA-I) levels, reduces low-density lipoprotein-cholesterol (LDL-C) and apoB levels, thus offering a promising approach. Despite the beneficial influence on cholesterol metabolism, off-target effects and lack of reduction in CV events and mortality (with torcetrapib, dalcetrapib and evacetrapib) highlighted the complex mechanism of CETP inhibition. After the failure of the above mentioned inhibitors in phase III clinical development, possibly due to the short duration of the trials masking benefit, the secondary prevention REVEAL trial has recently shown that the inhibitor anacetrapib significantly raised HDL-C (+104%), reduced LDL-C (-18%), with a protective effect on major coronary events (RR, 0.91; 95%CI, 0.85-0.97; p = 0.004). Whether LDL-C lowering fully accounts for the CV benefit or if HDL-C-rise is a crucial factor still needs to be determined, although the reduction of non-HDL (-18%) and Lp(a) (-25%), should be also taken into account. In spite of the positive results of the REVEAL Study, Merck decided not to proceed in asking regulatory approval for anacetrapib. Dalcetrapib (Dal-GenE study) and CKD-519 remain the two molecules within this area still in clinical development.