Toll‐like receptor 4 polymorphism is associated with coronary stenosis but not with the occurrence of acute or old myocardial infarctions

Objective. Atherosclerosis is considered to be a chronic inflammatory disease. Toll‐like receptor 4 (TLR‐4), a key mediator in activating inflammatory cascade, has an A‐to‐G functional polymorphism that changes aspartic acid to glycine at position 299. TLR‐4 is activated by, for example, lipopolysaccharides. The purpose of this study was to investigate the role of a common Asp299Gly polymorphism of the TLR‐4 gene in atherosclerosis. Material and methods. The study comprised autopsy material from 657 men (the Helsinki Sudden Death Study; mean age 53, range 33–70 years). Results. Fewer G‐allele carriers had 3‐vessel coronary artery disease compared with AA homozygotes (OR 0.32; 95?% CI, 0.12–0.88, p = 0.027), and they also had a lower mean value for maximal coronary stenosis (p = 0.019). TLR‐4 polymorphism was not significantly associated with the occurrence of acute or old myocardial infarction (MI). Conclusions. The G allele of the TLR‐4 gene, which is associated with a lower inflammation response, was associated with a lower risk of coronary stenosis but not with the occurrence of MI and hence is not a major factor in the development of coronary atherosclerosis.     

Platelet-activating factor-acetylhydrolase A379V (exon 11) gene polymorphism is an independent and functional risk factor for premature myocardial infarction

BACKGROUND: Oxidation of low density lipoproteins is an initial step of atherogenesis that generates pro-inflammatory phospholipids, including platelet-activating factor (PAF). PAF is degraded by PAF-acetylhydrolase (PAF-AH), which has been postulated to be a risk factor for myocardial infarction (MI). The role of PAF-AH for the onset of premature MI is unclear. METHODS: Polymorphisms located in putatively functional regions were investigated in a cohort of patients having premature MI onset prior to 46 years of age (n = 200) and a sex-age-matched control group (n = 200). The activity of PAF-AH and coronary angiograms were evaluated for the severity of coronary atherosclerosis. RESULTS: The V allele of A379V (exon 11) polymorphism on PAF-AH gene was more frequent in patients with premature MI (P = 0.001). This V allele polymorphism was also associated with a lower activity of plasma PAF-AH and a more complex coronary atherosclerosis (p Trends <0.05). Multiple logistic regression analysis showed that this polymorphism was an independent risk factor (Odds Ratio [OR] 1.66, 95% CI 1.14.1 to 5.80, P = 0.008) as well as smoking (OR 3.72, 95% CI 1.77 to 9.28, P = 0.001), diabetes mellitus (OR 2.25, 95% CI 1.40 to 5.32, P = 0.007) and hypertension (OR 1.88, 95% CI 1.25 to 5.36, P = 0.003) for the onset of premature MI. CONCLUSION: We conclude that a functional and significant association between the A379V polymorphism on exon 11 of PAF-AH gene and premature MI exists in this Taiwanese population. This polymorphism is significantly associated with the PAF-AH activity and the severity of coronary atherosclerosis.     

Toll-like receptor-4 Asp299Gly polymorphism does not influence progression of atherosclerosis in patients with familial hypercholesterolaemia

BACKGROUND: Toll-like receptor-4 (TLR4) is a major receptor for inflammatory stimuli potentially involved in the pathogenesis of atherosclerosis, such as lipopolysaccharide (LPS) and heat-shock proteins. The Asp299Gly polymorphism of the TLR4 gene has been associated with a reduced intima-media thickness (IMT) of the common carotid artery in healthy individuals. We have investigated whether the presence of the Asp299Gly polymorphism in patients with familial hypercholesterolaemia (FH) has a similar protective effect, and whether it influences the effects of HMG-CoA reductase treatment. MATERIALS AND METHODS: A cohort of 293 FH patients and 200 healthy volunteers were genotyped for the presence of the Asp299Gly allele using polymerase chain reaction followed by restriction fragment length polymorphism analysis. Intima-media thickness measurements, inflammatory parameters and the effect of HMG-CoA reductase inhibitors were compared between the patients with and without Asp299Gly allele. RESULTS: The Asp299Gly allele was present in 10.6% of the FH patients and 11.0% of the healthy individuals. Whereas the FH patients carrying the Asp299Gly allele displayed a reduced absolute IMT value compared with the FH patients carrying the wild-type allelle, the difference did not reach statistical significance. In addition, the effect of treatment with HMG-CoA reductase inhibitors was not influenced by the presence of Asp299Gly allele. CONCLUSION: The presence of the Asp299Gly allele of the TLR4 gene does not seem to exert a major influence on the progression of atherosclerosis in patients with FH.     

Simple genotype analysis of the Asp299Gly polymorphism of the Toll-like receptor-4 gene that is associated with lipopolysaccharide hyporesponsiveness

A nonsynonymous single nucleotide polymorphism (Asp299Gly) in the Toll-like receptor-4 (TLR-4) gene affects the responsiveness to lipopolysaccharide in humans. To analyze this important polymorphism more efficiently, we developed a simple polymerase chain reaction (PCR) restriction length fragment polymorphism (RFLP) assay and examined the Asp299Gly allele frequency in a Japanese population. The PCR primer was designed with 1- or 2-bp mismatches, creating the recognition sequence for restriction enzyme BsaBI or BstXI, allowing RFLP analysis of the digested products. Genotyping was carried out with this assay for 275 DNA specimens from 107 healthy volunteers and 168 patients with various diseases, including ulcerative colitis (n = 86). The Asp299Gly allele of the TLR-4 gene was not detected in any of the specimens, suggesting that it is very rare in Japanese.     

The polymorphism in acetaldehyde dehydrogenase 2 gene, causing a substitution of Glu > Lys(504), is not associated with coronary atherosclerosis severity in Han Chinese

Alcohol consumption has an important effect on coronary atherosclerotic heart disease (CAD). Acetaldehyde dehydrogenase 2 (ALDH2) is a key enzyme in alcohol metabolism. A G-to-A missense mutation of ALDH2 gene, which causes a Glu > Lys(504) substitution, was recently shown to be associated with carotid atherosclerosis; however, its relationship with coronary atherosclerosis has not been well studied. We, therefore, investigated this relationship in Han Chinese. There are two ALDH2 alleles (1 and 2) and their combination: 1/1 (GG, typical homozygote), 1/2 (GA, heterozygote) and 2/2 (AA, atypical homozygote) in the population. Successive Han Chinese, including 89 with myocardial infarction (MI) and 142 with unstable angina, were recruited, and underwent coronary angiography and gene sequencing. Coronary atherosclerosis severity was expressed by the number of lesioned coronary arteries (>or=50% diameter stenosis) and Gensini score, calculated based on the luminal narrowing degree and its geographic importance, as assessed by angiography. Based on their ALDH2 genotypes, the 231 patients were divided into wild-type (1/1, n = 145) and mutation groups (1/2 and 2/2, n = 86). There were no significant differences in basic clinical data between the two groups; however, the mutation group had significantly higher rates of diabetes mellitus and MI, and lower prevalence of alcohol consumption than wild-type group. Yet, the two groups were not significantly different in coronary atherosclerosis severity. Multiple regression analysis has shown that the ALDH2 genotype 1/2 or 2/2 is an independent risk factor for MI, but is not associated with coronary atherosclerosis severity in Han Chinese.     

-374T/A polymorphism of the RAGE gene promoter in relation to severity of coronary atherosclerosis

BACKGROUND: We have recently reported that homozygosity for the minor A-allele of RAGE (receptor for advanced glycation end products) -374T/A polymorphism may exert a protective effect toward the development of angiographic coronary artery disease (CAD). Here we focused on the putative involvement of this functional RAGE polymorphism on the severity of coronary atherosclerosis as assessed by angiography. METHODS: In a total of 234 consecutive Caucasian patients with angiographically proven CAD, the severity of coronary atherosclerosis was assessed by the number of diseased vessels (greater than 50% stenosis). Genotyping for the -374T/A variant was performed by means of PCR-RFLPs. RESULTS: The mean number of diseased vessels was significantly lower in patients with the AA genotype (1.47+/-0.68) than in those with the AT or TT genotype (1.88+/-0.82, p=0.029). After confounding variables were controlled for, the number of diseased vessels remained significantly different in the AA genotype carriers from that in the AT or TT carriers (p=0.041, ANCOVA). CONCLUSIONS: Our data suggest that the RAGE -374T/A polymorphism is one of the likely candidate determinants for the genetic variance of disease phenotype in coronary atherosclerosis.     

An integrated evaluation of endothelial constitutive nitric oxide synthase polymorphisms and coronary artery disease in men

In the present study, we sought to evaluate the role of three polymorphisms in the ecNOS (endothelial constitutive nitric oxide synthase) gene in relation to the existence, severity and progression of CAD (coronary artery disease), MI (myocardial infarction) and the occurrence of ischaemia in a predominantly Caucasian population. Patients with CAD (n = 760) and age- and sex-matched population-based controls (n = 691) were genotyped for the -786T/C, E/D298 and 4a/b polymorphisms. Patients were randomized to pravastatin (40 mg) or placebo. Progression of atherosclerosis was evaluated by sequential angiography. Functionality was assessed by ST segment analysis of ambulant ECGs. The E298 (P = 0.003) and 4a (P = 0.001) alleles were associated with CAD. Furthermore, E298 (P = 0.009) and -786T (P = 0.022) alleles were associated with previous MI among patients, predominantly smokers. D/D298 homozygotes, but not -786T/C or 4a/4b mutants, had longer-lasting ischaemia than others (P < 0.05). We found no differences in progression of atherosclerosis, irrespective of pravastatin use. We conclude that the E/D298 polymorphism is most consistently associated with CAD, but not with progression of atherosclerosis. The E allele is associated with CAD and MI, whereas the D allele is associated with ischaemia.     

Inducible cardiac ischaemia is related to a decrease in the whole-blood Toll-like receptor 2 and 4 response

TLR (Toll-like receptor) activation-induced inflammatory responses are important in the progression of atherosclerosis. We previously showed that TLR-dependent leucocyte responsiveness is acutely attenuated following percutaneous coronary intervention or vascular surgery. Furthermore, cytokine release following whole-blood TLR-2 and TLR-4 stimulation is negatively correlated with fractional flow reserve, suggesting that chronic ischaemia can elicit an enhanced inflammatory response. In the present study, we assessed the association between leucocyte TLR-2 and TLR-4 responsiveness and pre-existent and inducible ischaemia in patients undergoing SPECT (single-photon emission computed tomography)-MPI (myocardial perfusion imaging). TLR-2, TLR-4 and CD11b expression on monocytes were measured in blood samples that were obtained from 100 patients with suspected coronary artery disease before and after myocardial stress testing for SPECT-MPI. IL-8 (interleukin-8) levels were determined after whole-blood stimulation with Pam3Cys (TLR-2) and LPS (lipopolysaccharide; TLR-4). On the basis of SPECT-MPI, patients were categorized into three groups: reversible defect, irreversible defect and no defect. Myocardial stress induced a reduction in TLR-4 expression (2.46±0.21 compared with 2.17±0.16 arbitrary units, P=0.001) and CD11b expression (83.2±1.73 compared with 76.0±1.89 arbitrary units, P<0.001). TLR-induced IL-8 production before myocardial stress induction was not associated with the results of SPECT-MPI. However, a significant decrease in IL-8 production following TLR stimulation was observed after stress, which was more pronounced in patients with a reversible defect. In conclusion, inducible ischaemia is associated with a decrease in whole-blood TLR-2 and TLR-4 response. These results point to a regulating role of TLRs in order to prevent excessive inflammatory events known to occur during acute ischaemia.     

Endothelial function in patients with and without diabetes mellitus with different degrees of coronary artery stenosis

PURPOSE: To evaluate endothelial function using flow-mediated dilatation (FMD) of the brachial artery in patients with and without diabetes mellitus (DM) with different degrees of coronary artery stenosis. METHOD: We investigated 293 patients, 69 (23.6%) of whom had DM. FMD and coronary arteriography were performed. RESULTS: Patients with DM had a significantly lower FMD (mean +/- SD, 3.7 +/- 3.8%) compared with patients without DM (mean +/- SD, 5.2 +/- 5.3%) (p < 0.05). When the results were broken down by the severity of coronary artery disease (CAD) (no significant coronary artery stenosis, 1-vessel disease, 2-vessel disease, and 3-vessel disease) the only statistically significant difference between diabetics and nondiabetics was found in patients without significant coronary stenosis (mean FMD +/- SD: 5.2 +/- 4.4% in diabetics, 7.6 +/- 5.4% in nondiabetics [p < 0.05]). CONCLUSION: In CAD patients, the presence of DM was associated with endothelial dysfunction. The difference in the FMD was clearly expressed between patients with and without DM in the subgroup without significant coronary stenosis, and was no longer present with advanced coronary atherosclerosis.     

CETP (cholesteryl ester transfer protein) promoter -1337 C>T polymorphism protects against coronary atherosclerosis in Japanese patients with heterozygous familial hypercholesterolaemia

CETP (cholesteryl ester transfer protein) and HL (hepatic lipase) play a role in the metabolism of plasma lipoproteins, but the effects of CETP and LIPC (gene encoding HL) genotypes on coronary atherosclerosis may be dependent on LDL (low-density lipoprotein)-receptor activity. Recently, the -1337 C>T polymorphism in the CETP gene has been reported in REGRESS (Regression Growth Evaluation Statin Study) to be a major determinant of promoter activity and plasma CETP concentration. In the present study, we have investigated the effects of the CETP promoter -1337 C>T and LIPC promoter -514 C>T polymorphisms on serum lipid profiles and risk of coronary atherosclerosis in 206 patients (154 males) with heterozygous FH (familial hypercholesterolaemia). To evaluate coronary atherosclerosis, we used CSI (coronary stenosis index) calculated from coronary angiograms. The CETP -1337 T allele was less frequent in subjects with a CSI > or =14 (mean value) in the group with coronary artery disease (P=0.04, as determined by chi(2) test). ANOVA revealed that HDL-C (high-density lipoprotein-cholesterol) and triacylglycerol (triglyceride) levels were not significantly higher in the presence of the CETP promoter -1337 T allele. Combined with LIPC promoter polymorphisms, HDL-C levels were highest and CSI were lowest with CETP -1337 CT+TT and LIPC -514 CC genotypes, but a significant interaction was not shown. A multiple logistic regression analysis revealed that, in patients with coronary atherosclerosis, the CETP- 1337 CC genotype was a significant genetic risk factor in FH (odds ratio=2.022; P=0.0256). These results indicate that the CETP promoter -1337C>T polymorphism is associated with the progression of coronary atherosclerosis in Japanese patients with FH, independent of HDL-C and triacylglycerol levels.     

Association between the -2518G/A polymorphism in the monocyte chemoattractant protein-1 (MCP-1) gene and myocardial infarction in Tunisian patients

BACKGROUND: Monocyte chemoattractant protein-1 (MCP-1; gene name CCL2) has been suggested to play an important role in the initiation of atherosclerosis by recruiting monocytes to sites of injured endothelium. Recently, single nucleotide polymorphisms (SNPs) in the MCP-1 regulatory region have been identified. Controversial results regarding the association of the -2518G/A polymorphism of the MCP-1 gene with coronary artery disease (CAD) have been reported. In the present study, we examined a possible association between the -2518G/A polymorphism of the MCP-1 gene and myocardial infarction (MI) in a sample of the Tunisian population. METHODS: A total of 319 Tunisian patients with MI and 467 healthy controls were included in the study. The SNP of the MCP-1 gene was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. RESULTS: Patients with MI had significantly higher frequency of the AG+GG genotypes compared to controls [42.9% vs. 35.8%; OR (95%CI), 1.34 (1.00-1.79); p=0.04]. The MI patient group showed a significant higher frequency of the G allele compared to the controls [0.242 vs. 0.195; OR (95%CI), 1.31(1.02-1.68), p=0.03]. The association between the -2518G/A polymorphism of the MCP-1 gene and MI was no longer significant after adjustment for other well-established risk factors. CONCLUSION: The present study showed a significant but not independent association between the -2518G/A polymorphism of the MCP-1 gene (presence of G allele) and MI in the Tunisian population.     

Association of MMP-9 gene polymorphisms with acute coronary syndrome in the Uygur population of China

BACKGROUND: Matrix metalloproteinase-9 (MMP-9) plays a pivotal role in early atherosclerosis, vascular remodeling and development of atherosclerotic lesion. The potentially functional MMP-9 gene polymorphism may contribute to the susceptibility of acute coronary syndrome (ACS). This study aimed to investigate the association between two single nucleotide polymorphisms (-1562C>T, R279Q) of the MMP-9 gene in patients with ACS in the Uygur population of China.METHODS: This case-control study was composed of 361 ACS patients and 432 control subjects, who had undergone coronary angiography. Among the ACS patients, 162 (44.9%) had single-vessel disease, 145 (40.2%) had two-vessel disease, and 54 (14.9%) had three-vessel disease. The genotypes of the two selected SNPs were determined by the method of polymerase chain reaction and restriction fragment length polymorphism (RFLP-PCR). The relationship between the polymorphism of the MMP-9 gene and the severity of coronary arterial stenosis was analyzed.RESULTS: Analysis of the two SNPs showed that the frequency of CT and TT genotypes in patients with ACS was significantly higher than that in the control group (ACS vs. controls; CT+TT: 25.5% vs. 15.8%, P=0.001). And the -1562 gene allele (C/T) was significantly associated with acute coronary syndrome (ACS vs. controls; C allele: 85.7% vs. 91.5%, T allele: 14.3% vs. 8.5%, P<0.001). But the frequencies of CT+TT and CC genotypes were not statistically different among ACS patients with one, two and three or more significantly diseased vessels (P=0.55). The R279Q polymorphism site with regard to the association with ACS was not significant (P>0.05). The presence of CT or TT genotypes, assuming codominant effect of the T allele, was independently associated with increased risk of coronary artery disease when adjustment was made for age, body mass index, smoking, hypertension and diabetes mellitus [odds ratio=1.737 (95% confidence interval, 1.337-2.257), P=0.018].CONCLUSIONS: MMP-9-1562C>T polymorphism is associated with the susceptibility to ACS in the Uygur population of China. However, this mutation apparently is not related to the severity of coronary arterial stenosis. Another SNP (R279Q) polymorphism of MMP-9 is not significantly associated with the risk of ACS.     

Association of the insertion/deletion gene polymorphism of the apolipoprotein B signal peptide with myocardial infarction in Tunisian patients

BACKGROUND: Numerous polymorphisms of the apolipoprotein B (APOB) gene have been described. Particularly, the insertion/deletion (Ins/Del) polymorphism located in the coding part of the signal peptide of apoB, associated with modification of lipid concentrations and the risk of coronary artery disease and/or myocardial infarction (MI), has been reported in the general population. Moreover, conflicting results emerge from the literature and suggest that the effect is context-dependent. In the present study, the first investigation of the Ins/Del polymorphism of the APOB gene in Tunisian patients with MI, we examined a possible association between this polymorphism and MI in a subgroup of the Tunisian population. METHODS: A total of 318 Tunisian patients with MI and 368 healthy controls were included in the study. Genomic DNA was extracted from white blood cells, and the Ins/Del polymorphism was determined by electrophoresis in polyacrylamide gels after PCR amplification. A binary logistic regression analysis was performed to test how the association between MI and Ins/Del polymorphism is independent from confounding factors. RESULTS: A significant difference in genotype distribution and allele frequency was observed between patients and controls. Patients with MI had a frequency of 7.2% for the Del/Del genotype, 39.6% for the Ins/Del genotype, and 53.1% for the Ins/Ins genotype. Controls had a frequency of 3.0% for the Del/Del, 32.1% for the Ins/Del and 64.9% for the Ins/Ins genotype (chi2=12.93, p=0.002). The MI patient group showed a significantly higher frequency of the Del allele compared to controls (27.1% vs. 19.1%; chi2=12.50, p=0.0004). In comparison to the Ins/Ins homozygotes, the odds ratio (95% confidence interval) for MI was 1.51 (1.09-2.07) for Ins/Del heterozygotes and 2.95 (1.40-6.22) for Del/Del homozygotes. In multivariate analysis, age (p=0.001), smoking (p<0.001), hypertension (p=0.001), diabetes mellitus (p<0.001), and dyslipidemia (p=0.01) were independent correlates of the presence of MI, whereas the Ins/Del polymorphism (p=0.330) was not an independent predictor of MI. CONCLUSIONS: The present study shows a significant but not independent association between the Ins/Del polymorphism of the APOB gene and MI in the Tunisian population.     

Vitamin D receptor gene polymorphism BsmI is not associated with the prevalence and severity of CAD in a large-scale angiographic cohort of 3441 patients

BACKGROUND: Recent studies found a relationship between Vitamin D and atherosclerosis. A common genetic polymorphism of the Vitamin D receptor (VDR) has been associated with coronary artery disease (CAD) in small study populations. To assess its influence on the prevalence and severity of CAD we studied a large-scale population. METHODS: A total of 3441 consecutive patients were referred for diagnostic coronary angiography. The BsmI Vitamin D receptor polymorphism was analyzed by polymerase chain reaction. Angiography was used to define phenotypes with clear coronary arteries (n = 775), coronary sclerosis (diameter stenosis < 50%; n = 579), CAD (diameter stenosis > 50% in at least one vessel; n = 1524). Patients with CAD at a young age (females aged less than 65 years, males aged less than 55 years; n = 563) were specially defined as premature CAD. The risk profile of traditional cardiovascular risk factors was obtained for every patient. RESULTS: The genotype frequencies of the VDR BsmI polymorphism did not differ between all four phenotypes (P = 0.756). The allele frequencies for the B allele were 0.43 vs. 0.44 vs. 0.42 vs. 0.45 in the four phenotypic groups (P = 0.827). All traditional cardiovascular risk factors (hypercholesterolaemia, smoking, hypertension, diabetes mellitus, severe obesity, male gender) were significantly (P < 0.001) associated with the angiographic phenotype. CONCLUSIONS: The VDR gene variant BsmI was not associated with prevalence and severity of CAD in a large-scale cohort phenotyped by angiography.     

Genetic risk factors and ischaemic cerebrovascular disease: role of common variation of the genes encoding apolipoproteins and angiotensin-converting enzyme

DNA polymorphisms in genes encoding apolipoproteins (apo) A-I, C-III, B and E and angiotensin-converting enzyme (ACE) have been proposed to be associated with the risk of coronary artery disease (CAD). We studied whether the same genetic markers would also be associated with the occurrence and extent of atherosclerosis in cervical arteries. DNA samples from 234 survivors of stroke or a transient ischaemic attack aged 60 years or less were examined. The presence of atherosclerosis was assessed using aortic arch angiograms. The SstI polymorphism of apoA-I/C-III gene locus, the Xbal polymorphism of apoB gene, common apoE phenotypes and the insertion/deletion polymorphism of the ACE gene were analysed. The allele frequencies of the apoA-I/C-III, apoB, apoE or ACE gene did not differ between the groups with (n = 148) or without (n = 85) cervical atherosclerosis. However, when patients with at least one apoE4 allele and one X2 allele of apoB were combined and compared with those without either of them (E2E3 or E3E3 and X1X1), a significant association with the presence of cervical atherosclerosis was found (P = 0.03). The patients having the E2E3 phenotype had a significantly elevated serum triglyceride level compared with those with the E3E3 phenotype (P = 0.03). Serum high-density lipoprotein (HDL) cholesterol was lower in the patients with the E2E3 phenotype than in those with the E3E3 and E3E4 (P = 0.01 and P = 0.06, respectively). The apoB or ACE genotypes were not significantly associated with serum lipid or lipoprotein levels. There was no association between the ACE gene polymorphism and the occurrence of hypertension. In conclusion, the interaction of common apoB and apoE alleles may increase the risk of atherosclerosis in cervical arteries.     

Intercellular adhesion molecule 1 (ICAM-1) gene variant is associated with coronary artery calcification independent of soluble ICAM-1 levels.

BACKGROUND: Although circulating levels of soluble intercellular adhesion molecule 1 (sICAM-1) predict cardiovascular events, no studies have examined intercellular adhesion molecule 1 (ICAM-1) gene variants, plasma sICAM-1 levels, and atherosclerosis in the same sample. METHODS: We examined the association of the ICAM-1 K469E gene variant and plasma sICAM-1 with coronary artery calcification (CAC) in 632 asymptomatic subjects, recruited on the basis of a family history of premature cardiovascular disease. RESULTS: In age-adjusted ordinal regression, sICAM-1 levels were associated with CAC (odds ratio [OR] [95% confidence interval (CI)] 1.30 [1.04-1.6] per 100 ng/dL sICAM-1; p = .02), but this association was lost after adjusting for traditional risk factors (OR [95% CI] 0.9 [0.69-1.16]). In men, but not women (interaction p = .018), the ICAM-1 K469E GG genotype predicted lower CAC after adjusting for traditional risk factors (OR [95% CI] 0.33 [0.17-0.61]; p = .001) and further controlling for plasma sICAM-1 (OR [95% CI] 0.27 [0.14-0.52]; p < .001). CONCLUSIONS: In a study sample specifically selected for the characteristic of a family history of premature coronary heart disease, ICAM K469E GG was associated with lower CAC scores in men but not women even after controlling for plasma levels of sICAM-1. These studies suggest that ICAM-1 variants may modulate atherosclerosis in humans and provide support for the concept that inflammatory gene polymorphisms may influence atherosclerosis independent of plasma levels of their gene products.     

Effect of apolipoprotein E genotypes on incidence and development of coronary stenosis in Iranian patients with coronary artery disease

Background: Apolipoprotein (apo) E polymorphism plays a significant role in the development of coronary disease, but their involvement in coronary artery stenosis (CAS) is controversial. Therefore, the purpose of this study was to investigate the effects of this polymorphism on atherosclerosis, and severity and extent of CAS in unrelated Iranian population. Methods: DNA was isolated from 390 study participants and APOE genotypes were determined utilizing the polymerase chain reaction and restriction fragment length polymorphism. Results: The APOE‐ε4 and ‐ε2 allele frequencies were significantly higher in the CAS patients than in the control group (P<0.05). The association of Apo E polymorphism with the severity of stenosis was evaluated, which is according to the result that apolipoprotein E alleles were not significantly different when compared with the severity of stenosis (χ²=0.84, P>0.05). Conclusion: Our results suggest that APOE‐ε4 is a risk factor for stenosis but does not has any effect on the severity of this disease. J. Clin. Lab. Anal. 25:43–46, 2011. © 2011 Wiley‐Liss, Inc.     

Preproghrelin Leu72Met polymorphism in Chinese subjects with coronary artery disease and controls

BACKGROUND: Ghrelin, a novel endogenous ligand for the growth hormone secretagogue receptor, is considered to exert a protective effect against atherosclerosis. The Leu72Met (+408C>A) polymorphic variant of the preproghrelin, the gene for the ghrelin precursor, has been linked to obesity, diabetes and metabolic syndrome. However, it is unclear whether this polymorphism is associated with coronary artery disease (CAD). METHODS: We conducted a case-control study with 317 CAD patients and 323 controls to investigate the potential association of the Leu72Met polymorphism with the occurrence of CAD and CAD-related phenotypes in Chinese population. RESULTS: No significant difference in the Leu72Met genotype frequency was observed between CAD patients and controls (P=NS). The Leu72Met polymorphism was not associated with hypertension, diabetes, dyslipidemia, the number of diseased vessels, plasma total cholesterol, triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol or fasting glucose levels in CAD patients. However, among CAD patients, those with variant genotypes (Leu72Met and Met72Met) had lower BMI (24.4+/-0.3 kg/m(2)) than Leu72Leu carriers (25.4+/-0.2 kg/m(2), adjusted P=0.033). CONCLUSION: Our data indicate that the preproghrelin Leu72Met polymorphism is not associated with CAD in Chinese population. However, the Leu72Met variant is associated with BMI among CAD patients.     

Protective effect of the G-765C COX-2 polymorphism on subclinical atherosclerosis and inflammatory markers in asymptomatic subjects with cardiovascular risk factors

BACKGROUND: Cyclooxygenase (COX)-2, a key regulatory enzyme in prostanoid synthesis, plays an important role in inflammatory processes. The -765G>C COX-2 polymorphism has been associated with lower promoter activity in vitro and reduced levels of C-reactive protein (CRP) in atherosclerotic carriers of the C allele. However, its pathophysiological relevance in vivo has not been fully elucidated. METHODS AND RESULTS: We assessed the -765G>C polymorphism and COX-2 expression in 220 asymptomatic subjects free of cardiovascular disease, in relation to global vascular risk, carotid intima-media thickness (IMT), and inflammatory markers (fibrinogen, C-reactive protein [CRP], von Willebrand factor [vWF] and interleukin-6 [IL-6]). Genotype frequencies were: CC (7.7%), CG (34.5%), GG (57.7%). Among hypercholesterolemic subjects (n=140), C allele carriers had lower COX-2 expression (p<0.05), reduced carotid IMT (p<0.01) and diminished levels of inflammatory markers CRP, vWF and IL-6 (p<0.05), as compared to GG homozygous subjects. The association between carotid IMT and COX-2 polymorphism remained significant after adjusting for cardiovascular risk factors and inflammatory markers (p=0.008). CONCLUSIONS: In asymptomatic hypercholesterolemic subjects the C allele of -765G>C COX-2 polymorphism was associated with lower COX-2 expression, and reduced subclinical atherosclerosis and systemic inflammation compared with GG homozygous, thus conferring atherosclerosis protection in this cardiovascular risk population.