Genetic Variants and Haplotypes in OPG Gene Are Associated with Premature Coronary Artery Disease and Traditional Cardiovascular Risk Factors in Mexican Population: The GEA Study

MCP-1 rs1024611 Polymorphism, MCP-1 Concentrations, and Premature Coronary Artery Disease: Results of the Genetics of Atherosclerotic Disease (GEA) Mexican Study

Monocyte chemoattractant protein-1 (MCP-1) participates in the initiation and progression of atherosclerosis. In vitro studies have reported that the MCP-1 rs1024611 polymorphism is associated with increased MCP-1 concentrations. The study aimed to define whether MCP-1 concentrations are associated with premature coronary artery disease (pCAD) and to establish whether variations in the rs1024611 polymorphism increase MCP-1 concentrations. MCP-1 rs1024611 polymorphism was determined in 972 pCAD patients and 1070 control individuals by real-time PCR. MCP-1 concentrations were determined by the Bio-Plex system. In the total population, men had higher MCP-1 concentrations when compared to women (p < 0.001). When stratified by rs1024611 genotypes, higher MCP-1 concentrations were observed in AA individuals compared to GG subjects (p = 0.023). When performing the analysis considering sex, the differences remained significant in women (AA vs. GG, p = 0.028 and GA vs. GG, p = 0.008). MCP-1 concentrations were similar in pCAD patients and controls (p = 0.782). However, the independent analysis of the studied groups showed that in patients with the AA genotype, MCP-1 concentrations were significantly higher when compared to patients with the GG genotype (p = 0.009). Considering that the AA genotype increases MCP-1 concentration, we evaluated whether, in AA genotype carriers, MCP-1 concentrations were associated with pCAD. The results showed that for every ten pg/mL increase in MCP-1 concentration, the risk of presenting pCAD increases by 2.7% in AA genotype individuals. Individuals with the MCP-1 rs1024611 AA genotype present an increase in MCP-1 concentration. In those individuals, increased MCP-1 concentrations increase the risk of presented pCAD.

Interleukin 6 polymorphisms are associated with cardiovascular risk factors in premature coronary artery disease patients and healthy controls of the GEA Mexican study

BACKGROUND AND AIMS

Interleukin-6 (IL-6) is an acute-phase protein that plays an important role in the inflammatory response, vascular inflammation, and atherosclerosis process. The study aimed to establish whether IL-6 gene polymorphisms and IL-6 concentrations are associated with premature coronary artery disease (pCAD) and cardiovascular risk factors.

METHODS

The IL-6 concentrations and the rs2069827, rs1800796, and rs1800795 IL-6 polymorphisms were determined in 1150 pCAD patients and 1083 healthy controls (coronary artery calcium equal to zero determined by tomography).

RESULTS

The IL-6 polymorphisms studied were not associated with pCAD, but they were associated with cardiovascular risk factors in patients and controls. In controls, under the dominant model, the rs1800795 C allele and the rs2069827 T allele were associated with a low risk of central obesity (OR = 0.401, p = 0.017 and OR = 0.577, p = 0.031, respectively), hypoalphalipoproteinemia (OR = 0.581, p = 0.027 and OR = 0.700, p = 0.014, respectively) and hypertriglyceridemia (OR = 0.575, p = 0.030 and OR = 0.728, p = 0.033, respectively). In pCAD, the rs1800795 C allele was associated with an increased risk of hypoalphalipoproteinemia (OR = 1.370, padditive = 0.025) and increased C-reactive protein (CRP) concentrations (OR = 1.491, padditive = 0.007). pCAD patients had significantly higher serum IL-6 concentrations compared to controls (p = 0.002). In the total population, individuals carrying the rs1800795 GC + CC genotypes had higher levels of IL-6 than carriers of the GG genotype (p = 0.025). In control individuals carrying the C allele (CG + CC), an inverse correlation was observed between IL-6 and HDL-cholesterol levels (p = 0.003).

CONCLUSIONS

In summary, the IL-6 polymorphisms were not associated with pCAD, however, they were associated with cardiovascular risk factors in pCAD patients and healthy controls. Individuals carrying the rs1800795 GC + CC genotypes had higher levels of IL-6 than carriers of the GG genotype.

Osteoprotegerin Gene Polymorphisms Are Associated with Subclinical Atherosclerosis in the Mexican Mestizo Population

Subclinical atherosclerosis (SA) is the presence of coronary calcification in the absence of cardiovascular symptoms, and it usually progresses to atherosclerotic disease. Studies have shown an association of osteoprotegerin gene (OPG) variants with calcification process in cardiovascular diseases; however, to this day there are no studies that evaluate individuals in the asymptomatic stage of atherosclerotic disease. Therefore, the purpose of this study was to analyze the association of four genetic variants and haplotypes of the OPG gene with the development of SA, through TaqMan genotyping assays. We also aimed to identify potential response elements for transcription factors in these genetic variants. The study included 1413 asymptomatic participants (1041 were controls and 372 were individuals with SA). The rs3102735 polymorphism appeared as a protective marker (OR = 0.693; 95% CI = 0.493−0.974; pheterozygote = 0.035; OR = 0.699; 95% CI = 0.496−0.985; pcodominant 1 = 0.040) and two haplotypes were associated with SA, one as a decreased risk: GACC (OR = 0.641, 95% CI = 0.414−0.990, p = 0.045) and another as an increased risk: GACT (OR = 1.208, 95% CI = 1.020−1.431, p = 0.029). Our data suggest a lower risk of SA in rs3102735 C carriers in a representative sample of Mexican mestizo population.

Osteoprotegerin and MTHFR gene variations in rheumatoid arthritis: association with disease susceptibility and markers of subclinical atherosclerosis

We aimed to explore whether the rs2073618 variant (G1181C) of the osteoprotegerin (OPG) gene and the methylenetetrahydrofolate reductase (MTHFR) rs1801131 (A1298AC) and rs1801133 (C677T) gene polymorphisms contribute to rheumatoid arthritis (RA) susceptibility and RA related subclinical atherosclerosis. Overall 283 RA patients and 595 healthy controls (HC) were genotyped for common variants of the OPG and MTHFR genes using PCR based assays. Clinical and laboratory parameters were recorded following thorough chart review. Surrogate markers of subclinical atherosclerosis (Carotid/Femoral intima media thickness/plaque formation) along with traditional risk factors for atherosclerosis were assessed in all RA patients and 280HC. Increased prevalence of the CC genotype of the rs2073618 variant was detected in RA patients vs HC (42.4% vs. 33%, p-value: 0.04). RA patients with high serum titers of rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP) antibodies displayed increased prevalence of the CC genotype of the rs2073618 variant of the OPG gene compared to HC (48.6% and 47.5 vs 33.3%, p-values: 0.0029and 0.0077 respectively). Of interest, this genotype turned to be associated with higher carotid IMT scores (0.872 ± 0.264 vs 0.816 ± 0.284, p-value: 0.01) and marginally with higher rates of carotid plaque formation (66% vs 54.1%, p = 0.06). The MTHFR 1298CC genotype was more prevalent only in the anti-CCP positive group compared to HC, with no associations detected with markers of subclinical atherosclerosis, following adjustment for traditional cardiovascular (CVD) risk factors. Reduced rates of carotid/femoral plaque formation were detected among RA patients harboring the MTHFR TT genotype (52.4 vs 72.7, p-value: 0.009, respectively). This association remained significant following adjustment for classical CVD risk factors (OR [95% CI 0.364 [0.173-0.765], p-value: 0.008). Genetic variations of the osteoprotegerin and MTHFR genes seem to increase susceptibility for seropositive RA and potentially contribute to subclinical atherosclerosis linked to RA. Larger studies are needed to confirm these findings.