Genetic variation in coronary heart disease and myocardial infarction: methodological overview and clinical evidence

Long non-coding RNA in coronary artery disease: the role of PDXDC1-AS1 and SFI1-AS1

This study investigates the interaction between long non-coding RNAs (lncRNAs) and metabolic risk factors that contribute to coronary artery disease (CAD). A total transcriptome high throughput sequencing study was conducted on peripheral blood mononuclear cells from five patients with CAD and five healthy controls. Validation assay by qRT-PCR was conducted among 270 patients and 47 controls. Finally, to evaluate the lncRNAs' diagnostic value for CAD, the Spearman correlation test and receiver operating characteristic curve (ROC) analysis were utilized. Additionally, univariate and multivariate logistic regression along with crossover analyses were conducted to identify the interaction between lncRNA and environmental risk factors. A total of 2149 of 26,027 lncRNAs identified by RNA sequencing were differentially expressed in CAD patients compared to controls. Validation by qRT-PCR showed significantly different relative expression levels for lncRNAs PDXDC1-AS1, SFI1-AS1, RP13-143G15.3, DAPK1-IT1, PPIE-AS1, and RP11-362A1.1 between the two groups (all P<0.05). The area under the ROC values of PDXDC1-AS1 and SFI1-AS1 is 0.645 (sensitivity=0.443 and specificity=0.920) and 0.629 (sensitivity=0.571 and specificity=0.909), especially. Multivariate logistic regression analyses showed that lncRNAs PDXDC1-AS1 (OR=2.285, 95%CI=1.390-3.754, p=0.001) and SFI1-AS1 (OR=1.163, 95%CI=1.163-2.264, p=0.004) were protective factors against CAD. Under the additive model, cross-over analyses demonstrated significant interactions between lncRNAs PDXDC1-AS1 and smoking in relation to CAD risk (S=3.871, 95%CI=1.140-6.599). PDXDC1-AS1 and SFI1-AS1 were sensitive and specific biomarkers for CAD and exhibited synergistic effects with certain environmental factors. These results highlighted their potential use as CAD diagnostic biomarkers for future research.

NFKB1 gene rs28362491 ins/del variation is associated with higher susceptibility to myocardial infarction in a Chinese Han population

Myocardial infarction (MI), the leading cause of mortality and disability worldwide, is a disease in which multiple environmental and genetic factors are involved. Recently, researches suggested that insertion/deletion (ins/del) variation of NFKB1 gene rs28362491 is a functional polymorphism. In the present study, we aimed to explore the relation between variation of NFKB1 gene rs28362491 and MI by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 359 MI patients and 1085 control participants. Gensini score was used to evaluate the degree of coronary artery stenosis in MI patients. The plasma levels of interleukin-6 (IL-6), IL-8, malonaldehyde (MDA) and superoxide dismutase (SOD) were randomly measured by ELISA both in MI patients and control participants. We found that the detected frequencies of D allele (41.2% vs. 36.4%, P = 0.021) and DD genotype (17.5% vs. 12.0%, P = 0.022) were significantly higher in MI patients than in control participants. Compared with II or ID genotype carriers, the Gensini score in MI patients with DD genotype was 32-43% higher (both P < 0.001). Moreover, DD genotype carries had more diseased coronary arteries (P = 0.001 vs. II or ID genotype). Of note, IL-6 levels in MI patients carrying DD genotype were significantly higher than that in control participants and other genotype carriers in MI patients (both P < 0.05). In conclusion, NFKB1 gene rs28362491 DD genotype was associated with a higher risk of MI and more severe coronary artery lesion, which also had a potential influence on the level of inflammatory cytokine IL-6.

A DNA Repair Pathway Polymorphism (rs25487) and Angiographically Proven Coronary Artery Patients in a Population of Southern Iran

BACKGROUND

Coronary Artery Disease (CAD), which is a multifactorial genetic disease, is known as one of the most common causes of death worldwide. In this regard, X-ray Repair Cross-Complementing group 1 (XRCC1), a DNA repair protein involved in Single-Strand Breaks (SSBs), and Base Excision Repair (BER) pathways have been reported to be responsible for the efficient repair of single strand breaks and damaged bases in DNA.

OBJECTIVES

In the current study, we analyzed Arg399Gln (rs25487), which is one of the most common polymorphisms of XRCC1 gene that might be associated with the increased risk for CAD.

METHODS

This case-control study was performed to investigate the relationship between this polymorphism and CAD development. In this study, 290 patients and 216 controls were diagnosed by cardiac angiography and then screened for the above-mentioned polymorphism using Restriction Fragment Length Polymorphisms (RFLP) method.

RESULTS

The frequency of the GA genotype of XRCC1 Arg399Gln (rs25487) was significantly higher in CAD patients compared to the controls (p=0.002, OR: 1.21, 95% CI: 1.06-1.37). Moreover, its dominant mode (AA + GA) genotype had a 1.851-fold increase in the risk of CAD (p = 0.005).

CONCLUSION

Our findings demonstrated that Arg399Gln polymorphism of XRCC1 (rs25487) has a significant relationship with CAD and also plays a probable predisposing role in that. Our results support the role of DNA damages and the malfunctions of DNA repair system in the patients with CAD.

A Case-Control Study of the Association of the Polymorphisms of MTHFR and APOE with Risk Factors and the Severity of Coronary Artery Disease

OBJECTIVES

To explore the association between single-nucleotide polymorphisms (SNPs) in MTHFR and APOE and the risk of CAD and, more importantly, the severity of CAD and the profile of serum lipids, we performed a case-control study in a Chinese Han population.

METHODS

A total of 1,207 cases of consecutive CAD-suspected inpatients were recruited, and 406 CAD cases and 231 non-CAD controls were enrolled for the final analysis after screening for exclusion criteria. All subjects had undergone coronary angiography, and the severity of CAD was evaluated by 2 cardiologists according to the Gensini scores. The genotypes of MTHFR and APOEwere detected using real-time PCR, and then verified by Sanger sequencing. Environmental risk factors, such as age, sex, smoking, alcohol consumption, hypertension, diabetes, dyslipidemia, and BMI were collected. Statistical analyses (the χ2 test, binary logistic regression analysis, and ordinal polytomous logistic regression analysis) were performed with SPSS v16.0.

RESULTS

The genotypes ofall the subjects included in the CAD and non-CAD groups in this study were successfully detected, with an agreement of 100% with Sanger sequencing. The distributions of genotypes CT and TT at MTHFR C667T were higher in CAD cases than in non-CAD controls (OR 1.99, 95% CI 1.34-2.95; OR 1.77, 95% CI 1.18-2.67; p < 0.05), whereas genotype AC at MTHFR A1298Cwas lower in CAD cases (OR 0.71, 95% CI 0.50-1.02; p < 0.05). A significant association was observed in genotypes CT and TT at MTHFR C667T and the risk of CAD (OR 1.44, 95% CI 1.27-3.67; OR 1.56, 95% CI 0.88-2.78; p < 0.05). Both genotypes and alleles of APOE were comparable in the CAD cases and non-CAD controls (p > 0.05). The genotype TT at MTHFR C667T and ε4+ at APOE were more likely to be found in the CAD subgroup with a Gensini score ≥72 (p = 0.040 and p = 0.028, respectively). Meanwhile, in the patients with genotype TT,a higher level of serum Hcy was detected, while genotype ε4+ patients possessed higher levels of serum apolipoprotein E (ApoE) and low-density lipoprotein cholesterol (LDL-C) than other genotypes.

CONCLUSION

This study revealed that the SNP site of MTHFR C667Tis associatedwith the risk of CAD in this Chinese Han population. In addition, the genotypes of TT in MTHFR C667T and ε4+in APOE may increase the severity of CAD, and higher Hcy, LDL-C, and ApoE levels may be involved in this pathogenic process.

The interplay of LncRNA ANRIL and miR-181b on the inflammation-relevant coronary artery disease through mediating NF-κB signalling pathway

This study was designed to investigate whether ANRIL affected the aetiology of coronary artery disease (CAD) by acting on downstream miR-181b and NF-κB signalling. Altogether 327 CAD patients diagnosed by angiography were included, and mice models of CAD were established. Human coronary endothelial cells (HCAECs) and human umbilical vein endothelial cells (HUVECs) were also purchased. In addition, shRNA-ANRIL, shRNA-NC, pcDNA3.1-ANRIL, miR-181b mimic, miR-181b inhibitor and miR-NC were transfected into the cells. The lipopolysaccharides (LPS) and pyrrolidine dithiocarbamate (PDTC) were also added to activate or deactivate NF-κB signalling. Both highly expressed ANRIL and lowly expressed miR-181b were associated with CAD population aged over 60 years old, with smoking history, with hypertension and hyperlipidemia, with CHOL H 4.34 mmol/L, TG ≥ 1.93 mmol/L and Hcy ≥ 16.8 μmol/L (all P < 0.05). Besides, IL-6, IL-8, NF-κB, TNF-α, iNOS, ICAM-1, VCAM-1 and COX-2 expressions observed within AD mice models were all beyond those within NC and sham-operated groups (P < 0.05). Also VEGF and HSP 70 were highly expressed within AD mice models than within NC and sham-operated mice (P < 0.05). Transfection of either pcDNA-ANRIL or miR-181b inhibitor could significantly fortify HCAECs' viability and put on their survival rate. At the meantime, the inflammatory factors and vascular-protective parameters were released to a greater level (P < 0.05). Finally, highly expressed ANRIL also notably bring down miR-181b expression and raise p50/p65 expressions within HCAECs (P < 0.05). The joint role of ANRIL, miR-181b and NF-κB signalling could aid in further treating and diagnosing CAD.

Gene-gene interaction between PPARG and CYP1A1 gene on coronary artery disease in the Chinese Han Population

AIMS

To observe the influence of the peroxisome proliferator-activator receptor-G (PPAR-G) gene and cytochrome P4501A1 (CYP1A1) single-nucleotide polymorphisms (SNPs), and interactions among several SNPs on coronary artery disease (CAD) risk.

METHODS

A total of 1106 participants (including 583 males and 523 females) including 550 CAD patients and 556 control subjects were recruited in this study, and the mean age for these participants was 55.5 ± 11.8 years old. Logistic regression was used to observe association of SNP within PPARG and CYP1A1 with CAD risk and GMDR model was used to screen the best interaction combinations.

RESULTS

CAD susceptibility was higher in those with homozygous mutant of rs10865710, rs1805192 and rs4646903 than those with wild-type homozygotes, OR (95%CI) were 1.47 (1.15-1.92), 1.69 (1.27-2.09) and 1.72 (1.35-2.32), respectively. We also found a significant two-locus model involving rs1805192 and rs4646903 (p = 0.0107), and the cross-validation consistency of this locus model was 10 of 10, the testing accuracy of this model is 62.17%. Logistic regression shown that CAD risk was the highest in those with rs1805192- Pro/Ala or Ala/Ala and rs4646903- AG+GG genotype, and was lowest in those with rs1805192- Pro/ Pro and rs4646903- AA genotype, OR(95%CI) = 3.56 (1.91-5.42).

CONCLUSIONS

Polymorphism in rs10865710, rs1805192 and rs4646903 and interaction between rs1805192 and rs4646903 were related with increased CAD susceptibility.

Sex-specific association of SH2B3 and SMARCA4 polymorphisms with coronary artery disease susceptibility

To determine whether sex differences affect the association between genetic polymorphisms and coronary artery disease (CAD) in the Chinese Han population, we conducted a study comparing the frequency of SH2B3 and SMARCA4 variants in 456 CAD patients (291 men, 165 women) and 685 age-matched controls (385 men, 300 women). Ten single nucleotide polymorphisms (SNPs) in SH2B3 and SMARCA4 were genotyped using MassARRAY technology. Allelic and genotypic models and haplotype frequencies were compared between groups. Logistic regression was used to estimate the CAD risk associated with the genotypes. We found that the “A” alleles in both rs11879293 and rs12232780 of SMARCA4 were associated with CAD risk in men (p = 0.036 and p = 0.001, respectively). The genetic model showed that SH2B3 was associated with CAD susceptibility in both women and men, while SMARCA4 was associated with reduced odds of CAD in men. SH2B3 haplotypes were associated with decreased CAD risk in women (p = 0.007) and increased CAD risk in men (p = 0.047). By providing evidence for the sex-related association between SH2B3 and SMARCA4 gene variants and CAD susceptibility in the Chinese Han population, this study may help define useful diagnostic and preventive markers for these patients.

G-T haplotype established by rs3785889-rs16941382 in GOSR2 gene is associated with coronary artery disease in Chinese Han population

Objectives

The aim of the present study is to assess the association between the human GOSR2 gene and coronary artery disease using a haplotype-based case-control study in Chinese Han population.

Methods

A total of 283 coronary artery disease patients and 280 controls were genotyped for the human GOSR2 gene (rs197932, rs3785889, rs197922, rs17608766, and rs16941382). Data were analyzed for three separate groups: the total subjects, men, and women.

Results

For the total subjects, the frequency of the G-T haplotype established by rs3785889-rs16941382 was significantly higher in the coronary artery disease patients as compared to the control subjects (P=0.009). Multiple logistic regression analysis also confirmed that the subjects with G-T haplotype established by rs3785889-rs16941382 (homozygote) were found having significantly higher chance suffering from coronary artery disease than the ones without this haplotype (OR=1.887, P=0.007).

Conclusions

The G-T haplotype established by rs3785889-rs16941382 may be a risk genetic marker for coronary artery disease patients in Chinese Han population.

Impact of interaction between CYP1A1 genetic polymorphisms and smoking on coronary artery disease in the Han of China

AIMS

To investigate the association of CYP1A1 genotype and additional gene-smoking interaction with coronary artery disease (CAD) risk based on a Chinese case-control study.

METHODS

A total of 1862 participants (1134 men, 728 women) were selected, including 620 CAD patients and 1242 normal controls. Logistic regression was performed to investigate association of CYP1A1 genotype, gene-gene, and gene-smoking interaction with CAD. Generalized multifactor dimensionality reduction (GMDR) was used to screen the best gene-gene and gene-smoking interaction combination, cross-validation consistency, the testing balanced accuracy, and the sign test, to assess if each selected interaction was calculated.

RESULTS

The carriers of homozygous mutant of rs4886605 polymorphism and heterozygous of rs4646903 are associated with increased CAD risk than those with wild-type homozygotes; OR (95% CI) was 1.98 (1.53-2.61) and 1.58 (1.24-1.96), respectively. The carriers of homozygous mutant of rs1048943 polymorphism is associated with decreased CAD risk than those with wild-type homozygotes, OR (95% CI) = 0.75 (0.60-0.93). GMDR model indicated a potential gene-gene interaction between rs4886605 and rs4646903 and a potential gene-smoking interaction between rs4886605 and smoking. Participants with rs4886605-CT or TT and rs4646903-TC or CC genotype have the highest CAD risk, compared to participants with rs4886605-CC and rs4646903-TT genotype; OR (95% CI) was 2.72 (2.03-3.61). In addition, we also found that smokers with rs4886605-CT or TT genotype have the highest CAD risk, compared to nonsmokers with rs4886605-CC genotype; OR (95% CI) was 3.07 (2.23-3.96).

CONCLUSIONS

rs4886605 and rs4646903 are associated with increased CAD risk, but rs1048943 is associated with decreased CAD risk; we also found gene-gene interaction between rs4886605 and rs4646903 and gene-environment interaction between rs4886605 and smoking.

ApoE gene polymorphism and its relationship with coronary artery disease in ethnic Kashmiri population

Apolipoprotein E is a fundamental component of various lipoproteins and plays substantial role in cholesterol/lipid transport among cells of various tissues. The ApoE gene is polymorphic with three alleles ε2, ε3, and ε4, coding for isoforms E2, E3, and E4 having different binding inclination for corresponding receptors. This work aimed to investigate the association between ApoE gene polymorphism and coronary artery disease (CAD) in Kashmiri population. APOE genotyping was done by polymerase chain reaction-restriction fragment length polymorphism. Our study indicated ApoE ε3/ε3 to be the most common genotype in both CAD and control group. The frequency of ε2, ε3, and ε4 alleles of ApoE gene in cases was observed to be 0.06, 0.72, and 0.20, while in control subjects it was 0.075, 0.82, and 0.11, respectively. A significant difference was found between cases and controls with respect to TC, LDL, and HDL levels. Our data showed that frequency of ε4/ε4, ε4/ε3 genotype and ε4 allele was significantly higher in cases than in controls (p = 0.02, p = 0.004, p < 0.001 respectively). Moreover, the CAD patients carrying ε4 allele had significantly higher TC and LDL levels (p value <0.01). Thus our data showed a significant association of ApoE ε4 allele with the risk of CAD. The data revealed that ApoE ε4 allele is associated with increased risk of CAD and increased levels LDL and TC in Kashmiri population.

The association between CYP1A1 genetic polymorphisms and coronary artery disease in the Uygur and Han of China

Background

The cytochrome P450, family 1, subfamily A, polypeptide 1 (CYP1A1) gene is expressed in the vascular endothelium, which metabolizes arachidonic acid into 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs). 20-HETE mediates cardiovascular homeostasis and growth response in vascular smooth muscle cells (VSMCs) as well as the anti-platelet effect. EETs are potent endogenous vasodilators and inhibitors of vascular inflammation. This study assessed the association between human CYP1A1 gene polymorphisms and coronary artery disease (CAD) in the Uygur and Han in China.

Methods

Two independent case–control studies that recruited Han (389 patients with CAD and 411 controls) and Uygur participants (293 patients with CAD and 408 controls) analyzed the relationship between CYP1A1 single nucleotide polymorphisms (SNPs: rs4886605, rs12441817, rs4646422 and rs1048943) and CAD. All patients with CAD and controls were genotyped for the four SNPs of CYP1A1 using TaqMan SNP genotyping assays.

Results

In the Uygur group, the distribution of the dominant model(CC vs CT + TT) of rs4886605 for the total sample and the males was significantly different between CAD patients and control participants (P = 0.001 and P = 0.012, respectively), The difference remained significant after a multivariate adjustment (P = 0.018, P = 0.015, respectively). The rs12441817 was also associated with CAD in a dominant model for all participants (P = 0.003) and men (P = 0.012), and the difference remained significant after a multivariate adjustment (P = 0.016, P = 0.002, respectively). However, we did not observe differences in the Uygur females and Han group with regard to the allele frequency or genotypic distribution of rs4886605 and rs12441817 between patients with CAD and control participants. Patients with CAD did not significantly differ from the control participants with regard to the distributions of rs4646422 and rs1048943 genotypes, the dominant model, the recessive model, or allele frequency in the Han and Uygur groups.

Conclusion

Both rs4886605 and rs12441817 SNPs of the CYP1A1 gene are associated with CAD in the Uygur population of China.

Interaction between air pollution exposure and genes in relation to levels of inflammatory markers and risk of myocardial infarction

OBJECTIVES

Air pollution exposure induces cardiovascular effects, possibly via systemic inflammation and coagulation misbalance. Genetic variation may determine individual susceptibility. Our aim was to investigate effect modification by inflammation (Interleukin6 (IL6), tumour necrosis factor-α (TNF-α)) and coagulation (fibrinogen Bβ, plasminogen activator inhibitor-1 (PAI-1)) gene variants on the effect of long-term or short-term air pollution exposure on both blood marker levels and non-fatal myocardial infarction (MI) risk.

DESIGN

Population-based case-control study with a nested case-crossover study. Gene-environment interactions for short-term and long-term air pollution on blood marker levels were studied in population controls, for long-term exposure on MI risk using case-control design, and for short-term exposure on MI onset using case-crossover design.

SETTING

The Stockholm Heart Epidemiology Programme (SHEEP) conducted in 1992-1994 in Stockholm, Sweden. Spatial modelling was used to assess long-term (up to 30 years retrospectively) air pollution exposure to traffic-NO2 and heating-SO2 emissions at home addresses. Urban background NO2, SO2, PM10 and O3 measurements were used to estimate short-term (up to 5 days) air pollution exposure.

PARTICIPANTS

1192 MI cases and 1506 population controls aged 45-70 years.

OUTCOMES

The levels of blood markers of inflammation (IL-6, TNF-α) and coagulation (fibrinogen, PAI-1) and MI risk.

RESULTS

We observed gene-environment interaction for several IL6 and TNF SNPs in relation to inflammation blood marker levels. One-year traffic-NO2 exposure was associated with higher IL-6 levels with each additional IL6-174C allele, and 1-year heating-SO2 exposure with higher levels of TNF-α in TNF-308AA homozygotes versus -308G carriers. Short-term air pollution exposure also interacted with IL6 and TNF in relation to marker levels. The risk of MI followed the effect on blood markers in each genotype group.

CONCLUSIONS

Genetic variants in IL6 and TNF may modify effects of long-term and short-term air pollution exposure on inflammatory marker levels and MI risk.

Neutral and weakly nonneutral sequence variants may define individuality

Large-scale computational analyses of the growing wealth of genome-variation data consistently tell two distinct stories. The first is expected: coding variants reported in disease-related databases significantly alter the function of affected proteins. The second is surprising: the genomes of healthy individuals appear to carry many variants that are predicted to have some effect on function. As long as the complete experimental analysis of all human genome variants remains impossible, computational methods, such as PolyPhen, SNAP, and SIFT, might provide important insights. These methods capture the effects of particular variants very well and can highlight trends in populations of variants. Diseases are, arguably, extreme phenotypic variations and are often attributable to one or a few severely functionally disruptive variants. Our findings suggest a genomic basis of the different nondisease phenotypes. Prediction methods indicate that variants in seemingly healthy individuals tend to be neutral or weakly disruptive for protein molecular function. These variant effects are predicted to be largely either experimentally undetectable or are not deemed significant enough to be published. This may suggest that nondisease phenotypes arise through combinations of many variants whose effects are weakly nonneutral (damaging or enhancing) to the molecular protein function but fall within the wild-type range of overall physiological function.

A haplotype of the GOSR2 gene is associated with myocardial infarction in Japanese men

AIMS

The Golgi SNAP Receptor Complex Member 2 (GOSR2) gene is a Golgi-associated soluble factor attachment receptor (SNARE) protein. Some single-nucleotide polymorphisms (SNPs) in the GOSR2 gene have been found to be associated with myocardial infarction (MI). The aim of the present study was to assess the association between the human GOSR2 gene and MI using a haplotype-based case-control study.

METHODS

A total of 238 MI patients and 284 controls were genotyped for the five SNPs used as genetic markers for the human GOSR2 gene (rs197932, rs3785889, rs197922, rs17608766, and rs16941382). Data were analyzed for three separate groups: the total subjects, men, and women.

RESULTS

The overall distribution of the haplotypes in the total subjects and the men was significantly different between the MI patients and the control subjects (p=0.001, p=0.005, respectively). Additionally, the frequency of the T-G-G haplotype (rs197932-rs3785889-rs197922) for men was significantly lower in the MI patients than in the control subjects (p=0.040). Multiple logistic regression analysis also revealed that the frequency of the subjects with the T-G-G haplotype (homozygous and heterozygous diplotypes) was significantly lower compared with subjects without this haplotype in men after adjustment for the major confounding factors (odds ratio=0.455, p=0.041).

CONCLUSIONS

The results of this study indicate that the T-G-G haplotype may be a protective genetic marker for MI in Japanese men.

Haplotype-based case-control study of CYP4A11 gene and myocardial infarction

CYP4A11, which is a member of the cytochrome P450 family, acts mainly as an enzyme that converts arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE), a metabolite involved in the maintenance of cardiovascular health. Recently, it was reported that many subfamilies of CYP genes have an association with myocardial infarction (MI). The aim of the present study was to assess the association between the human CYP4A11 gene and MI, using a haplotype-based case-control study with a separate analysis of the gender groups. A total of 239 MI patients and 285 controls were genotyped for 3 single-nucleotide polymorphisms (SNPs) of the human CYP4A11 gene (rs2269231, rs1126742, rs9333025). The data obtained via haplotype-based case-control studies were assessed for 3 separate groups: total subjects, men, and women. For the total, men and women groups, the distribution of the genotypes and alleles of the 3 SNPs did not show any significant difference between the MI patients and the control subjects. For the total and the men groups, the overall distribution of the haplotypes constructed with the 3 SNPs significantly differed between the MI patients and control subjects (P < 0.001). Also, for the total and for the men, the frequency of the T-T-A haplotype constructed with the 3 SNPs was significantly lower for the MI patients than for the control subjects (both P < 0.001). The T-T-A haplotype constructed with the 3 SNPs appears to be a protective genetic marker for MI in Japanese men.

A novel polymorphism of the CYP4A11 gene is associated with coronary artery disease

BACKGROUND

CYP4A11 (cytochrome P450, family 4, subfamily A, polypeptide 11) converts arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE), which plays a crucial role in the modulation of cardiovascular homeostasis. The aim of the present study was to assess the association between the human CYP4A11 gene and coronary artery disease (CAD).

METHODS

A total of 361 patients with CAD and 315 controls were genotyped for 4 single-nucleotide polymorphisms (SNPs) of the human CYP4A11 gene (rs9332978, rs4660980, rs3890011, and rs1126742). The data were assessed for 3 groups: total participants, men, and women via case-control studies.

RESULTS

For total participants and men, the distribution of SNP3 (rs3890011) genotypes showed a significant difference between CAD and control participants (P = .030 and P = .013, respectively), the distribution of the recessive model of SNP3 (GG vs CC + GC) was significantly higher in CAD patients than in control participants (P = .011 and P = .014, respectively), the significant difference was retained after adjustment for covariates (for total participants, 95% confidence interval [CI]: 1.137-2.423, P = .009; and for males, 95% CI: 1.173-3.013, P = .009).

CONCLUSIONS

rs3890011 maybe a novel polymorphism of the CYP4A11 gene associated with CAD in a Han Chinese population.

Association of anti-oxidized LDL and candidate genes with severity of coronary stenosis in the Women's Ischemia Syndrome Evaluation study

Atherosclerosis is the major cause of coronary artery disease (CAD), and oxidized LDL (oxLDL) is believed to play a key role in the initiation of the atherosclerotic process. Recent studies show that inflammation and autoimmune reactions are also relevant in atherosclerosis. In this study, we examined the association of antibodies against oxLDL (anti-oxLDL) with the severity of CAD in 558 Women's Ischemia Syndrome Evaluation (WISE) study samples (465 whites; 93 blacks) determined by coronary stenosis (< 20%, 20%-49%, > 50% stenosis). We also examined the relationship of anti-oxLDL with serum lipid levels and nine candidate genes including APOE, APOH, APOA5, LPL, LRP1, HL, CETP, PON1, and OLR1. IgM anti-oxLDL levels were significantly higher in the >20% stenosis group than in the ≥ 20% stenosis group in whites (0.69 ± 0.02 vs. 0.64 ± 0.01, respectively; P = 0.02). IgM anti-oxLDL levels correlated significantly with total cholesterol (r² = 0.01; P = 0.03) and LDL cholesterol (r² = 0.017; P = 0.004) in whites. Multiple regression analysis revealed a suggestive association of LPL/S447X single-nucleotide polymorphism (SNP) with both IgG anti-oxLDL (P = 0.02) and IgM anti-oxLDL (P = 0.07), as well as between IgM anti-oxLDL and the OLR1/3'UTR SNP (P = 0.020). Our data suggest that higher IgM anti-oxLDL levels may provide protection against coronary stenosis and that genetic variation in some candidate genes are determinants of anti-oxLDL levels.

Impact of ACE and ApoE polymorphisms on myocardial perfusion: correlation with myocardial single photon emission computed tomographic imaging

Coronary artery disease is associated with multiple genetic and environmental risk factors. In this study, we evaluated the correlation of angiotensin l-converting enzyme (ACE) (I/D) and ApoE gene polymorphisms (E2, E3, E4 and g.-219G/T) with myocardial perfusion. We examined 410 patients using exercise-rest myocardial perfusion single photon emission computed tomography (SPECT), in which the summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS) indexes were calculated. Homozygotes for the ACE D allele had greater mean values of SSS (P<0.001) and SDS (P<0.001). In addition, E3 homozygotes, E4 heterozygotes and E4 homozygotes had significantly higher values of SSS and SDS compared with E3 heterozygotes (P<0.001); E4 homozygotes had significantly higher values of SSS and SDS compared with E3 homozygotes. Furthermore, for the g.-219G>T polymorphic site at the promoter region of ApoE gene, the mean values of SSS and SDS were significantly higher for T heterozygotes/homozygotes than for GG homozygotes. Adjusting for all demographic and clinical data using multiple linear regression analysis it was found that ACE D and both ApoE genotypes were independent predictors with a cumulative contribution for the prediction of SSS and SDS. Furthermore, logistic regression analysis revealed that all three genotypes had an independent predictive ability for abnormal SSS (SSS>2). These data provide the first evidence of an association and significant cumulative contribution of the aforementioned genotypes in myocardial perfusion with E4 allele having the strongest association followed by ACE D and ApoE g.-219T alleles.

Significant impact of chromosomal locus 1p13.3 on serum LDL cholesterol and on angiographically characterized coronary atherosclerosis

OBJECTIVES

Recently, a significant impact of a new locus on chromosome 1p13.3 on serum LDL (low-density lipoprotein) cholesterol and clinical events of coronary artery disease (CAD) was described. Potential associations between variants on this locus and angiographically characterized coronary atherosclerosis are unknown. We therefore aimed at investigating the association of variants of locus 1p13.3 with coronary atherosclerosis.

METHODS

We performed genotyping of variants rs599839, rs646776, and rs4970834 on chromosome 1p13.3 in a large cohort of 1610 consecutive Caucasian patients undergoing coronary angiography, where lesions of 50% or more were classified as significant.

RESULTS

Compared to the homozygous common allele the rare alleles of variants rs599839, rs646776, and rs4970834 were significantly associated with decreased serum LDL cholesterol (132+/-40mg/dl vs. 125+/-36mg/dl, P=0.003, 132+/-40mg/dl vs. 124+/-36mg/dl, P<0.001, and 131+/-40mg/dl vs. 125+/-37mg/dl, P=0.005, respectively). Further, carriers of the rare alleles of variants rs599839 and rs646776 were at a significantly lower risk of significant coronary stenoses than subjects who were homozygous for the frequent alleles, with odds ratios (ORs) of 0.78 [0.63-0.96]; P=0.019 and 0.74 [0.60-0.91]; P=0.004, respectively. After multivariate adjustment including LDL cholesterol, the protective effect of the rare allele of variant rs646776, but not of variant rs599839, on CAD risk remained significant (OR=0.77 [0.61-0.98], P=0.034).

CONCLUSIONS

We conclude that chromosomal locus 1p13.3 is significantly associated with both, serum LDL cholesterol and coronary atherosclerotic lesions.

Cholesteryl ester transfer protein TaqIB, -629C>A and I405V polymorphisms and risk of coronary heart disease in an Indian population

BACKGROUND

Polymorphisms in cholesteryl ester protein gene have been linked to risk of coronary heart disease (CHD) in many world populations through their effect on reverse cholesterol transport.

METHODS

Five hundred four (504) unrelated electrocardiograph confirmed cases of CHD and 338 population based controls, matched by age and gender, belonging to the Tamilian population of south India were genotyped for polymorphisms in CETP gene using PCR RFLP methods.

RESULTS

The multivariate logistic regression analyses demonstrated that CETP B1B1 and CA genotypes of TaqIB and -629C>A were significantly associated with increased risk for CHD (odds ratio (OR) 2.7; 95% confidence intervals (CI) (1.5-3.3); OR 1.5 (1.1-2.4)) respectively. Combined wild genotypes of CETP gene showed an association with CHD (OR-1.7 (1.0-2.9) as well as the combined heterozygous mutants (OR 1.5 (1.0-2.3); p-0.03). Subgroup analysis based on gender revealed that men harboring CETP B1B1 and CA genotypes have a significant risk for CHD B1B1- 2.7 (1.7-4.3), CA-1.8 (1.3-2.6). There was no link between CETP I450V polymorphism and CHD. Analysis based on hypertensive status showed a significant association between these polymorphisms and non hypertensive CHD patients.

CONCLUSIONS

The risk in non hypertensive and male CHD patients is higher in the presence of CETP B1B1 and CA genotypes.

Detection of altered global DNA methylation in coronary artery disease patients

Epigenetic modifications, especially alteration in DNA methylation, are increasingly being recognized as a key factor in the pathogenesis of complex disorders, including atherosclerosis. However, there are limited data on the epigenetic changes in the coronary artery disease (CAD) patients. In the present study we evaluated the methylation status of genomic DNA from peripheral lymphocytes in a cohort of 287 individuals: 137 angiographically confirmed CAD patients and 150 controls. The differential susceptibility of genomic DNA to methylation-sensitive restriction enzymes was utilized to assess the methylation status of the genome. We observed that the genomic DNA methylation in CAD patients is significantly higher than in controls (p < 0.05). Since elevated homocysteine levels are known to be an independent risk factor for CAD and a key modulator of macromolecular methylation, we investigated the probable correlation between plasma homocysteine levels and global DNA methylation. We observed a significant positive correlation of global DNA methylation with plasma homocysteine levels in CAD patients (p = 0.001). Further, within a higher range of serum homocysteine levels (>/=12-50 muM), global DNA methylation was significantly higher in CAD patients than in controls. The alteration in genomic DNA methylation associated with cardiovascular disease per se appears to be further accentuated by higher homocysteine levels.

Failure to replicate an association of SNPs in the oxidized LDL receptor gene (OLR1) with CAD

Background

The lectin-like oxidized LDL receptor LOX-1 (encoded by OLR1) is believed to play a key role in atherogenesis and some reports suggest an association of OLR1 polymorphisms with myocardial infarction (MI). We tested whether single nucleotide polymorphisms (SNPs) in OLR1 are associated with clinically significant CAD in the Atherosclerotic Disease, VAscular FuNction, & Geneti C Epidemiology (ADVANCE) study.

Methods

ADVANCE is a population-based case-control study of subjects receiving care within Kaiser Permanente of Northern California including a subset of participants of the Coronary Artery Risk Development in Young Adults (CARDIA) study. We first resequenced the promoter, exonic, and splice site regions of OLR1 and then genotyped four single nucleotide polymorphisms (SNPs), including a non-synonymous SNP (rs11053646, Lys167Asn) as well as an intronic SNP (rs3736232) previously associated with CAD.

Results

In 1,809 cases with clinical CAD and 1,734 controls, the minor allele of the coding SNP was nominally associated with a lower odds ratio (OR) of CAD across all ethnic groups studied (minimally adjusted OR 0.8, P = 0.007; fully adjusted OR 0.8, P = 0.01). The intronic SNP was nominally associated with an increased risk of CAD (minimally adjusted OR 1.12, p = 0.03; fully adjusted OR 1.13, P = 0.03). However, these associations were not replicated in over 13,200 individuals (including 1,470 cases) in the Atherosclerosis Risk in Communities (ARIC) study.

Conclusion

Our results do not support the presence of an association between selected common SNPs in OLR1 and the risk of clinical CAD.

The Mediterranean paradox for susceptibility factors in coronary heart disease extends to genetics

The incidence of coronary heart disease (CHD) shows a North to South gradient in Europe. We tested whether that gradient could be accounted for by the distribution of putative susceptibility genotypes. We correlated the published frequencies of susceptibility genotypes for the genes most often associated with CHD (ACE, AGT, APOE, F2, F5, MTHFR, PON1, and SERPINE1) with the incidence of the disease, controlling for the effects of smoking, systolic pressure, total cholesterol, and body-mass index. In three polymorphisms a negative correlation between the incidence of CHD and the frequency of a suceptibility genotype was observed. For ACE this correlation was significantly negative even when discounting classical susceptibility factors. This suggests that some alleles described as susceptibility factors cannot account for disease incidence at the population level. A genetic component must be added to the "Mediterranean paradox": genetic variants deemed to be risk factors for CHD show a geographical pattern uncorrelated with the disease incidence. This pattern can be understood from the history of populations which has shaped the genetic diversity of the European populations in North-South clines, similar to what is observed for CHD incidence, which will tend to create spurious correlations with polymorphisms related, or not related, to the disease.

Genetic susceptibility to peripheral arterial disease: a dark corner in vascular biology

Peripheral arterial disease (PAD) is characterized by reduced blood flow to the limbs, usually as a consequence of atherosclerosis, and affects approximately 12 million Americans. It is a common cause of cardiovascular morbidity and an independent predictor of cardiovascular mortality. Similar to other atherosclerotic diseases, such as coronary artery disease, PAD is the result of the complex interplay between injurious environmental stimuli and genetic predisposing factors of the host. Genetic susceptibility to PAD is likely contributed by sequence variants in multiple genes, each with modest effects. Although many of these variants probably alter susceptibility both to PAD and to coronary artery disease, it is likely that there exists a set of variants specifically to alter susceptibility to PAD. Despite the prevalence of PAD and its high societal burden, relatively little is known about such genetic variants. This review summarizes our limited present knowledge and gives an overview of recent, more powerful approaches to elucidating the genetic basis of PAD. We discuss the advantages and limitations of genetic studies and highlight the need for collaborative networks of PAD investigators for shedding light on this dark corner of vascular biology.

Human pharmacogenomic variations and their implications for antifungal efficacy

Pharmacogenomics is defined as the study of the impacts of heritable traits on pharmacology and toxicology. Candidate genes with potential pharmacogenomic importance include drug transporters involved in absorption and excretion, phase I enzymes (e.g., cytochrome P450-dependent mixed-function oxidases) and phase II enzymes (e.g., glucuronosyltransferases) contributing to metabolism, and those molecules (e.g., albumin, A1-acid glycoprotein, and lipoproteins) involved in the distribution of antifungal compounds. By using the tools of population genetics to define interindividual differences in drug absorption, distribution, metabolism, and excretion, pharmacogenomic models for genetic variations in antifungal pharmacokinetics can be derived. Pharmacogenomic factors may become especially important in the treatment of immunocompromised patients or those with persistent or refractory mycoses that cannot be explained by elevated MICs and where rational dosage optimization of the antifungal agent may be particularly critical. Pharmacogenomics has the potential to shift the paradigm of therapy and to improve the selection of antifungal compounds and adjustment of dosage based upon individual variations in drug absorption, metabolism, and excretion.

On the association of the oxidised LDL receptor 1 (OLR1) gene in patients with acute myocardial infarction or coronary artery disease

The human oxidised low-density lipoprotein receptor 1 (OLR1) gene is a functional candidate for atherosclerosis. An association of the OLR1 gene with acute myocardial infarction (AMI) or coronary artery disease (CAD) has recently been reported. In the present study a total of 677 Italian subjects, 327 CAD-free, 350 CAD, of which 190 with AMI and 160 AMI-free, was genotyped for the following four OLR1 single nucleotide polymorphisms: exon 4 K167N, IVS4 -73C>T, IVS4 -14A>G, and 3'UTR 188 C>T. No statistically significant difference was observed in allele or genotype distribution of the exon 4, intron 4, or 3'UTR SNPs in CAD patients compared to CAD-free subjects, or within CAD, in AMI patients compared to AMI-free patients. A correlation was found between the K167N G/G genotype and the increased number of obstructed vessels. Even if the OLR1 genotype frequency distribution data in CAD or AMI subjects here reported do not fully confirm the positive results of some other association studies, an association with a marker of CAD severity was observed.

The Finnish Cardiovascular Study (FINCAVAS): characterising patients with high risk of cardiovascular morbidity and mortality

Background

The purpose of the Finnish Cardiovascular Study (FINCAVAS) is to construct a risk profile – using genetic, haemodynamic and electrocardiographic (ECG) markers – of individuals at high risk of cardiovascular diseases, events and deaths.

Methods and design

All patients scheduled for an exercise stress test at Tampere University Hospital and willing to participate have been and will be recruited between October 2001 and December 2007. The final number of participants is estimated to reach 5,000. Technically successful data on exercise tests using a bicycle ergometer have been collected of 2,212 patients (1,400 men and 812 women) by the end of 2004. In addition to repeated measurement of heart rate and blood pressure, digital high-resolution ECG at 500 Hz is recorded continuously during the entire exercise test, including the resting and recovery phases. About 20% of the patients are examined with coronary angiography. Genetic variations known or suspected to alter cardiovascular function or pathophysiology are analysed to elucidate the effects and interactions of these candidate genes, exercise and commonly used cardiovascular medications.

Discussion

FINCAVAS compiles an extensive set of data on patient history, genetic variation, cardiovascular parameters, ECG markers as well as follow-up data on clinical events, hospitalisations and deaths. The data enables the development of new diagnostic and prognostic tools as well as assessments of the importance of existing markers.

The -374A allele of the receptor for advanced glycation end products gene is associated with a decreased risk of ischemic heart disease in African-Brazilians with type 2 diabetes

Three functional polymorphisms described in the promoter of receptor for advanced glycation end products (RAGE) gene were shown to have a marked effect on transcriptional activity. The few studies which analyzed the relationship between these three polymorphisms and the diabetic complications have shown conflicting results. In this case-control study, we evaluated the association between the -429T>C, the -374T>A and the 63bp insertion/deletion (I/D) polymorphisms in the RAGE gene, and the presence of diabetic retinopathy, diabetic nephropathy and ischemic heart disease, in 703 Brazilians with type 2 diabetes (520 Caucasian- and 183 African-Brazilians). Patients underwent a clinical and laboratory evaluation consisting of a questionnaire, physical examination, assessment of diabetic complications and blood collection. Genotype analysis was performed using the polymerase chain reaction and allele-specific restriction. Logistic regression analyses were used to examine associations between the clinical and genetic variables and the presence of diabetic complications. No association between the -429C, the -374A and the 63bp D alleles and diabetic retinopathy, diabetic nephropathy or ischemic heart disease was observed in Caucasian-Brazilians with type 2 diabetes. However, the -374A allele was associated with a decreased risk of having ischemic heart disease in African-Brazilian type 2 diabetic patients [odds ratio (OR)=0.35; 95% confidence interval (CI)=0.15-0.81; P=0.014], independently of other risk factors associated with this complication. Thus, our results show that the -374A allele (-374T>A polymorphism) in the RAGE gene is related to the susceptibility of developing ischemic heart disease in African-Brazilians with type 2 diabetes.

Five polymorphisms in gene candidates for cardiovascular disease in Afro-Brazilian individuals

Associations of polymorphisms in the angiotensin I-converting enzyme (ACE), apolipoprotein B (APOB) and apolipoprotein E (APOE) genes with hypertension and variations in lipid serum levels were evaluated in 184 Afro-Brazilians with a familial history of coronary artery disease (CAD). ACE (Ins/Del) and APOB (Ins/Del, XbaI, and EcoRI) and APOE (HhaI) polymorphisms were determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses on agarose, and polyacrylamide gel electrophoresis. Serum lipids were measured by means of routine enzymatic assays. The results showed a high frequency of hypertension (44%) in Afro-Brazilians that was increased in subjects >40 years old and those with a blood mass index (BMI) higher than 25 kg/m(2) (P<0.001). The ACE Del allele was associated with hypertension in men >40 years old (P<0.05). APOE (HhaI) and APOB (XbaI and Ins/Del) polymorphisms were not associated with hypertension or variations in serum concentrations of lipids, while subjects with the APOB E- allele had higher low-density lipoprotein cholesterol (LDL-C) levels than E+ carriers (P<0.05). These results suggest that ACE Ins/Del polymorphism is associated with hypertension, and APOB EcoRI polymorphism is associated with LDL-C variation in Afro-Brazilians.

Fcgamma receptor IIIA polymorphism as a risk-factor for coronary artery disease

BACKGROUND

Inflammation is important in the pathogenesis of atherosclerosis. Polymorphisms of Fc receptors for IgG (FcgammaR) are associated with modifying effects of several infectious and autoimmune diseases. We have assessed the relationship between polymorphisms in three different FcgammaR genes and coronary artery disease (CAD).

METHODS AND RESULTS

We genotyped for the FcgammaRIIA-R/H131, the FcgammaRIIIB-Na1/Na2, and the FcgammaRIIIA-F/V158 polymorphisms in 882 patients undergoing diagnostic coronary angiography. Significant CAD was defined as >/=50% lumen diameter stenosis in at least one coronary artery. In the analysis, no association was found between the FcgammaRIIA and FcgammaRIIIB genotypes and CAD, whereas the FcgammaRIIIA genotype was strongly related. Compared to those being heterozygous, or homozygous for the F allele, patients homozygous for the V allele had significantly reduced risk: OR, 0.53; (CI, 0.32-0.90). Additional adjustment for classical risk factors and sedimentation rate did not affect the results. The V/V genotype was also inversely related to the extent of CAD defined as no CAD, single, double or triple vessel disease (P trend=0.002).

CONCLUSIONS

Our data provide evidence for an association between FcgammaRIIIA allelic variants and coronary atherosclerosis. Genetic variation in this IgG-receptor may influence the clearance of antibodies by monocyte-derived macrophages involved in the pathogenesis of CAD.

Prospective Association Between Low and High Total and Low-Density Lipoprotein Cholesterol and Coronary Heart Disease in Elderly Men

OBJECTIVES

To examine the relationship between total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) and the incidence of coronary heart disease (CHD) in elderly men.

DESIGN

Prospective.

SETTING

Population based.

PARTICIPANTS

A sample of 2,424, Japanese-American men aged 71 to 93 was used.

MEASUREMENTS

Six years of data on incident fatal plus nonfatal CHD were examined.

RESULTS

Analysis revealed a significant U-shaped relationship between age-adjusted CHD rates and both TC and LDL-C. The ranges of TC and LDL-C with the lowest risk of CHD were 200 to 219 mg/dL and 120 to 139 mg/dL, respectively. As cholesterol concentrations declined and increased beyond these ranges, the risk of CHD increased. These U-shaped relationships remained significant after adjusting for age and other risk factors.

CONCLUSION

The U-shaped associations between TC and LDL-C and CHD imply a complex relationship between lipids and CHD in late life. The results indicate that elevated lipid levels should continue to be treated in healthy elderly individuals, as they are in those who are younger, although pharmacologically lowering lipids to excessively low levels in the elderly may warrant further study, as does the contribution of subclinical frailty to the relationship of lipids to CHD risk.

R643G polymorphism in PECAM-1 influences transendothelial migration of monocytes and is associated with progression of CHD and CHD events

The 643R allele of R643G polymorphism (also known as R670G in the premature protein) in PECAM-1 has been associated with risk of myocardial infarction (MI), while the 643G allele has been associated with risk of coronary artery stenosis (CAS). The aim of this study was to investigate this apparently conflicting association. The association of R643G with risk of MI was determined in the second Northwick Park Heart study (2037 men with 138 CHD events; mean age: 56 years). Smokers homozygous for the 643R allele showed increased risk of MI with a hazard ratio of 2.47 (95% CI: 1.23-4.97; P=0.01) compared to smokers homozygous for the 643G allele. Progression of disease was determined in the Lopid Coronary Angiography Trial (279 men; mean age: 58.9 years). The 643G homozygotes showed greater focal (-0.08 +/- 0.02 mm) and diffuse (-0.01 +/- 0.01 mm) progression of CAS compared to 643R homozygotes (-0.02 +/- 0.02 mm and 0.001 +/- 0.01 mm, respectively; P=0.04). While there was no genotype effect on platelet aggregation, PECAM-1 tyrosine phosphorylation in HUVECs of GG genotype was 2.4-fold greater (P <0.01) than cells of RR genotype, and the level of transendothelial migration of monocytes of GG genotype was greater than that of monocytes of RR genotype following stimulation with either IL-1beta (12% higher, P <0.01) or TNF-alpha (10% higher, P=0.05). These data confirm the association of the R643G polymorphism with MI and CAS and suggest that greater influx of monocytes in individuals homozygous for the 643G may explain the association with CAS.

Oxidized LDL receptor gene (OLR1) is associated with the risk of myocardial infarction

Lectin-like oxidized low-density lipoprotein receptor (LOX-1/OLR1) has been suggested to play a role in the progression of atherogenesis. We analyzed the OLR1 gene and found a single nucleotide polymorphism (SNP), G501C, in patients with ischemic heart disease from a single family, which resulted in the missense mutation of K167N in LOX-1 protein. We compared the group of patients with myocardial infarction (MI) (n=102) with a group of clinically healthy subjects (n=102), and found that the MI group had a significantly high frequency of 501G/C+501C/C (38.2%) compared with the healthy group (17.6%; p<0.002). The odds ratio for the risk of MI associated with the 501G/C+501C/C genotype was 2.89 (95% CI, 1.51-5.53). These findings suggest that OLR1 or a neighboring gene linked with G501C SNP is important for the incidence of MI. Manipulating LOX-1 activity might be a useful therapeutic and preventative approach for coronary artery disease, especially for individuals with the G501C genotype of OLR1.

Coronary atherosclerosis and somatic mutations: an overview of the contributive factors for oxidative DNA damage

Coronary artery disease (CAD) is a multifactorial process that appears to be caused by the interaction of environmental risk factors with multiple predisposing genes. Genetic research on CAD has traditionally focused on investigation aimed at identifying disease-susceptibility genes. Recent evidence suggests that somatically acquired DNA mutations may also contribute significantly to the pathogenesis of the disease, underlining the similarity between atherosclerotic and carcinogenic processes. The generation of oxidative stress has been emphasized as an important cause of DNA damage in atherosclerosis. This review highlights some of the major atherogenic risk factors as likely mediators in the oxidative modification of DNA. It also examines the hypothesis that an increase in oxidative stress may derive from "oxidatively" damaged mitochondria. Accordingly, further research in this field should be given high priority, since increased somatic DNA damage could be an important pathogenic factor and an additional prognostic predictor, as well as a potential target for therapeutic strategies in coronary artery disease.

O componente genético da determinação dos lipídeos séricos

Os níveis de lipídeos séricos são características multifatoriais determinadas por um grande número de fatores genéticos e ambientais. A identificação do componente genético dessas características tem sido intensamente investigada nos últimos anos. Esses estudos têm enfocado principalmente polimorfismos nos genes que codificam proteínas estruturais e enzimas relacionadas com o metabolismo de lipídeos. Estudos mais recentes mostraram que o efeito desses polimorfismos depende em parte das interações dos diferentes genótipos com os fatores de risco clássicos tais como tabagismo, sobrepeso ou sedentarismo. A variabilidade encontrada nesses genes parece também influir na resposta a fármacos comumente utilizados no tratamento das hiperlipidemias.

Rationale and design of the LURIC study--a resource for functional genomics, pharmacogenomics and long-term prognosis of cardiovascular disease

BACKGROUND AND AIM

Coronary artery disease (CAD), arterial hypertension and Type 2 diabetes mellitus are common polygenetic disorders which have a major impact on public health. Disease prevalence and progression to cardiovascular complications, such as myocardial infarction (MI), stroke or heart failure, are the product of environment and gene interaction. The LUdwigshafen RIsk and Cardiovascular Health (LURIC) study aims to provide a well-defined resource for the study of environmental and genetic risk factors, and their interactions, and the study of functional relationships between gene variation and biochemical phenotype (functional genomics) or response to medication (pharmacogenomics). Long-term follow-up on clinical events will allow us to study the prognostic importance of common genetic variants (polymorphisms) and plasma biomarkers.

SETTING

Cardiology unit in tertiary care medical centre in south-west Germany.

STUDY DESIGN

Prospective cohort study of individuals with and without cardiovascular disease at baseline.

PATIENTS AND METHODS

LURIC is an ongoing prospective study of currently > 3300 individuals in whom the cardiovascular and metabolic phenotypes CAD, MI, dyslipidaemia, hypertension, metabolic syndrome and diabetes mellitus have been defined or ruled out using standardised methodologies in all study participants. Inclusion criteria for LURIC were: German ancestry (limitation of genetic heterogeneity) clinical stability (except for acute coronary syndromes [ACSs]) availability of a coronary angiogram (this inclusion criterium was waived for family members provided that they met all other inclusion and exclusion criteria) Exclusion criteria were: any acute illness other than ACSs any chronic disease where non-cardiac disease predominated a history of malignancy within the past five years. Exclusion criteria were pre-specified in order to minimise the impact of concomitant non-cardiovascular disease on intermediate biochemical phenotypes or on clinical prognosis (limitation of clinical heterogeneity). A standardised personal and family history questionnaire and an extensive laboratory work-up (including glucose tolerance testing in non-diabetics and objective assessment of smoking exposure by determination of cotinine plasma levels) was obtained from all individuals after informed consent. A total of 115 ml of fasting venous blood was sampled for the determination of a pre-specified wide range of intermediate biochemical phenotypes in serum, plasma or whole blood, for leukocyte DNA extraction and immortalisation of B-lymphocytes. Biochemical phenotypes measured included markers of endothelial dysfunction, inflammation, oxidative status, coagulation, lipid metabolism and flow cytometric surface receptor expression of lympho-, mono- and thrombocytes. In addition, multiple aliquots of blood samples were stored for future analyses.

RESULTS

A total of 3500 LURIC baseline measurements were performed in 3316 individuals between July 1997 and January 2000. The baseline examination was repeated within a median of 35 days in 5% of study participants (n = 166, including a third examination in 18 after a median of 69 days) for pharmacogenomic assessment of lipid-lowering therapy and for quality control purposes. A five-year follow-up on major clinical events (death, any cardiovascular event including MI, stroke and revascularisation, malignancy and any hospitalisation) is ongoing. The clinical phenotypes prevalent at baseline in the cohort of 2309 men (70%) with a mean age of 62 +/- 11 years and 1007 women (30%), mean age 65 +/- 10 years, were angiographically-documented CAD in 2567 (79%), MI in 1368 (41%), dyslipidaemia in 2050 (62%) with hypercholesterolaemia > or = 240 mg/dl (27%), hypertriglyceridaemia > or = 150 mg/dl (44%) and HDL-cholesterol < or = 35 mg/dl (38%) in individuals not treated with lipid-lowering agents, systemic hypertension in 1921 (58%), metabolic syndrome in 1591 (48%), Type 2 diabetes in 1063 (32%) and obesity defined by body mass index > or = 30 kg/m2 in 770 (23%). Control patients in whom CAD had been ruled out angiographically were five years younger than those with CAD (59 +/- 12 and 64 +/- 10 years, respectively; p < 0.001), twice as often females (48% compared to 25% females in the CAD group, p < 0.001) and had significantly less cardiovascular risk factors than individuals with CAD. The prevalence of specific cardiovascular risk subsets in LURIC, such as the elderly (> or = 75 years), was 375 (11%), while 213 (6%) were young adults (< 45 years) and 904 (27%) were postmenopausal women (90% of all females). A low risk status (< or = 1 out of the four traditional risk factors: dyslipidaemia, smoking, hypertension and diabetes mellitus) was identified in 314 (9%) individuals of the entire cohort (5% in CAD and 26% in controls, p < 0.001) and 97 (3%) carried none of the four risk factors (1% in CAD and 9% in controls, p < 0.001). (ABSTRACT TRUNCATED)