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.

Increased carotid intima-media thickness and cardiometabolic risk factors are associated with IL-6 gene polymorphisms in Mexican individuals: The Genetics of Atherosclerotic Disease Mexican study

Interleukin 6 (IL-6) is a cytokine implicated in the development of atherosclerosis. This study aimed to determine the association of three IL-6 gene polymorphisms with increased carotid intima-media thickness (CIMT) and cardiometabolic risk factors. Three IL-6 polymorphisms (rs1800795, rs2069827, and rs1800796) were analyzed in 178 individuals with increased CIMT (CIMT ≥ 75th percentile) and 906 individuals without increased CIMT (CIMT < 75th percentile). Logistic regression, adjusted for confounding variables, was employed to assess the associations. The rs1800796 polymorphism was significantly associated with an elevated risk of increased CIMT (OR = 1.354, Padditive = 0.016; OR = 1.803, Precessive = 0.014; OR = 1.989, Pcodominant2 = 0.008). One haplotype (GCG) correlated with a higher risk of increased CIMT (OR = 1.288; P = 0.008), while another (GGG) demonstrated a reduced risk (OR = 0.773; P = 0.006). In individuals without increased CIMT, the rs2069827 polymorphism was associated with low risks of central obesity, hypoalphalipoproteinemia, and a low risk of presenting with high levels of total cholesterol (TC), non-high-density lipoprotein cholesterol (non-HDL-C), low-density lipoprotein cholesterol (LDL-C) /HDL-C index, apolipoprotein B, and gamma-glutamyl transpeptidase. The rs1800796 polymorphism was associated with a low risk of adipose tissue insulin resistance, and the rs1800795 was associated with a minimal risk of central obesity and hypoalphalipoproteinemia. Among those with increased CIMT, the rs2069827 was associated with low risks of central obesity, hypertriglyceridemia, metabolic syndrome, and a high triglyceride (TG)/HDL-C index, while rs1800796 was associated with a low risk of fatty liver. Similar IL-6 concentrations were observed in both individuals with and without increased CIMT. In conclusion, the rs1800796 polymorphism is associated with increased CIMT, while the rs2069827 and rs1800795 are linked to cardiovascular risk factors.

Impact of Lipids and Vascular Damage on Early Atherosclerosis in Adolescents with Parental Premature Coronary Artery Disease

AIM

To assess the relationship of cardiovascular risk factors (CRFs) with carotid intima media thickness (IMT) in adolescents with a parental history of premature coronary artery disease (PCAD).

METHODS

This cross-sectional study included 50 healthy adolescents, aged 14-18 years, both sexes, with a parental history of PCAD, that were compared to 50 controls without this history. Questionnaires regarding information of CRFs were applied. Blood chemistry analyses, included lipid profile, lipoprotein (a), low density lipoprotein (LDL) susceptibility to oxidation, and inflammatory cytokine levels. The IMT was evaluated by ultrasound.

RESULTS

The mean age of all participants was 15.9 years. Anthropometric measurements, blood pressure, and lipid profile were similar in both groups. However, the parental history of PCAD group exhibited lower high density lipoprotein cholesterol concentrations, shorter LDL particle oxidation time, and higher lipoprotein (a) levels compared to the control group. IMT was significantly higher in adolescents with a parental history of PCAD compared to controls, (0.53 ± 0.04 mm vs 0.47 ± 0.02 mm, p = 0.001). Among adolescents with a parental history of PCAD, those with ≥ 3 CRFs had significantly higher IMT values (0.56 mm) than those with < 3 CRFs (0.52 mm) and controls (0.48 mm). Multivariable analyses identified that systolic blood pressure and parental history of PCAD explained 26.8% and 16.1% of the variation in IMT. Furthermore, body mass index, LDL-C, ApoB-100, triglycerides and lipoprotein (a) interact with blood pressure levels to explain the IMT values.

CONCLUSION

Adolescents with a parental history of PCAD had higher IMT values than the control group, primary explained by systolic blood pressure and the parental inheritance. Adolescents with parental history of PCAD and ≥ 3 CRFs exhibited the highest IMT values. Notably, lipids and systolic blood pressure jointly contribute to explain IMT in these adolescents.