Association of arterial stiffness with single nucleotide polymorphism rs1333049 and metabolic risk factors

9p21 Locus Polymorphism Is A Strong Predictor of Metabolic Syndrome and Cardiometabolic Risk Phenotypes Regardless of Coronary Heart Disease

The world population is genetically predisposed to metabolic syndrome (MetS) and its components, also known as cardiometabolic risk phenotypes, which can cause severe health complications including coronary heart disease (CHD). Genetic variants in the 9p21 locus have been associated with CHD in a number of populations including Pakistan. However, the role of the 9p21 locus in MetS and cardiometabolic risk phenotypes (such as obesity, hypertension, hyperglycemia, and dyslipidemia) in populations with CHD or no established CHD has not been explored. Therefore, the present study was designed to explore the association of the minor/risk allele (C) of 9p21 locus SNP rs1333049 with MetS or its risk phenotypes regardless of an established CHD, in Pakistani subjects. Genotyping of rs1333049 (G/C) was performed on subjects under a case-control study design; healthy controls and cases, MetS with CHD (MetS-CHD⁺) and MetS with no CHD (MetS-CHD^-), respectively. Genotype and allele frequencies were calculated in all study groups. Anthropometric and clinical variables (Means ± SD) were compared among study groups (i.e., controls, MetS + CHD and MetS-CHD) and minor/risk C allele carriers (GC + CC) vs. non-carriers (Normal GG genotype). Associations of the risk allele of rs1333049 SNP with disease and individual metabolic risk components were explored using adjusted multivariate logistic regression models (OR at 95% CI) with a threshold p-value of ≤0.05. Our results have shown that the minor allele frequency (MAF) was significantly high in the MAF cases (combined = 0.63, MetS-CHD⁺ = 0.57 and MetS-CHD^- = 0.57) compared with controls (MAF = 0.39). The rs1333049 SNP significantly increased the risk of MetS, irrespective of CHD (MetS-CHD⁺ OR = 2.36, p < 0.05 and MetS-CHD^- OR = 4.04, p < 0.05), and cardiometabolic risk phenotypes; general obesity, central obesity, hypertension, and dyslipidemia (OR = 1.56-3.25, p < 0.05) except hyperglycemia, which lacked any significant association (OR = 0.19, p = 0.29) in the present study group. The 9p21 genetic locus/rs1333049 SNP is strongly associated with, and can be a genetic predictor of, MetS and cardiometabolic risks, irrespective of cardiovascular diseases in the Pakistani population.

Elevated ambulatory systolic-diastolic pressure regression index is genetically determined in hypertensive patients with coronary heart disease

OBJECTIVES

Ambulatory systolic-diastolic pressure regression index (ASDPRI) as a composite marker of cardiovascular (CV) properties is related to CV complications. However, genetic determinants of ASDPRI are not known. The aim of this study is to report the relationship between certain single nucleotide polymorphisms (SNP) and ASDPRI in hypertensive patients with CAD confirmed by coronary angiography.

METHODS

A total of 1345 hypertensive subjects with CAD were included. SNPs were selected from genome-wide association studies. SNPs were reported to be associated with coronary artery disease risk. There were significant differences in 24 h and daytime and nighttime ASDPRIs for PHCTR1, LPA and ADAMTS7 polymorphisms. Genetic risk score (GRS18) was constructed to evaluate additive effect of 18 SNPs for ASDPRI.

RESULTS

Analysis of covariance revealed a significant relationship between the PPAB2B (β - 0.85; 95 CI -1.85--0.16, p < 0.02), WDR12 (β - 1.31; 95 CI -2.19--0.43, p < 0.01) polymorphisms and nighttime ASDPRI dipping. Analysis of covariance revealed a significant relationship between GRS 18 and 24-h ASDPRI (β 0.34; 95 CI 0.16-0.31, p < 0.01).

CONCLUSIONS

In conclusion, ADAMTS7 and LPA polymorphisms are related to 24-h ASDPRI but PPAB2B and WDR12 gene polymorphisms are associated with nighttime ASDPRI dipping. A total of 24-h ASDPRI is determined by GRS18.

Overweightness, obesity and arterial stiffness in healthy subjects: a systematic review and meta-analysis of literature studies

OBJECTIVE

The relationship between overweightness, obesity and arterial stiffness remains unclear. We performed a meta-analysis evaluating the impact of obesity/overweightness on arterial stiffness in healthy subjects.

METHODS

Literature searches were conducted using databases (eg, MEDLINE, EMBASE) and citations cross-referenced. Studies evaluating the relationship between obesity/overweightness and cfPWV, baPWV, and AIx were systematically searched. A total of 10 studies (1,124 obese/overweight subjects, 1,884 controls) were included.

RESULTS

Compared to controls, obese/overweight subjects showed a significantly higher cfPWV (SMD 0.50 m/s; 95%CI 0.15, 0.86; P = 0.005), baPWV (SMD 0.41 m/s; 95% CI 0.08, 0.74; P = 0.014), and AIx (SMD 1.02；95%CI 0.16, 1.87; P < 0.0001). When analyzing 'high quality' studies, the difference in arterial stiffness among obese/overweight subjects and controls remain (SMD 0.73 m/s; 95%CI 0.16, 1.30; P = 0.013).

CONCLUSION

Arterial stiffness, a recognized marker of cardio vascular risk, is increased in obese/overweight subjects without overt cardiovascular diseases.

Forearm vasodilator reactivity in healthy male carriers of the 3q22.3 rs9818870 polymorphism

BACKGROUND

A genome wide association study has identified a robust risk locus for cardiovascular disease on 3q22.3. However, the mechanisms by which the [C]/[T] polymorphism rs9818870 increases cardiovascular risk are unknown. This forearm blood flow (FBF) study addressed the question if the genetic association with cardiovascular disease in patients is preceded by incipient vasodilator impairment in young, healthy carriers of this new risk locus on chromosome 3.

MATERIALS AND METHODS

After a pre-screening of 74 subjects 17 male healthy volunteers homozygous/heterozygous for a single nucleotide polymorphism (SNP) risk allele on 3q22.3 and a control group of 17 healthy volunteers not carrying the allele were included into this case-control study.

RESULTS

Forearm vascular endothelium-dependent and -independent vasodilator responses were in the normal range in both groups, although endothelium-dependent FBF reactivity to acetylcholine was significantly higher in SNP carriers of the risk allele.

CONCLUSION

The augmented endothelium-dependent vasodilation of the forearm resistance vasculature does not support the presence of endothelial dysfunction in young SNP carriers and indicates that other mechanisms are responsible for the strong association between coronary artery diseases and the rs9818870 polymorphism, located on 3q22.3.

Role of 9p21 and 2q36 variants and arterial stiffness in the prediction of coronary artery disease

BACKGROUND

Genetic polymorphisms and arterial stiffness indices have been associated with cardiovascular prognosis and the presence and extent of angiographic coronary artery disease (CAD). We aimed to investigate whether arterial stiffness indices and 9p21 and 2q36 variants may improve prediction of CAD presence and extent when added to classical cardiovascular risk factors in patients at high risk for CAD.

MATERIALS AND METHODS

In this cross-sectional study, we enrolled 183 consecutive patients with suspected stable CAD (age 61 ± 9 years, 134 males) referred for diagnostic coronary angiography. Framingham risk score (FRS) was calculated. Arterial stiffness was assessed by carotid-femoral pulse wave velocity (PWV) and central augmentation index (AIx) using applanation tonometry. Genetic polymorphisms of 9p21 (rs1333049) and 2q36 (rs2943634) loci were also analysed.

RESULTS

Higher FRS and PWV and the presence of rs2943634 risk allele were independent predictors of CAD (Nagelkerke R(2) 0·252, P < 0·001), while higher FRS and the presence of rs1333049 risk allele were independent predictors of multivessel CAD (Nagelkerke R(2) 0·190, P < 0·001). Genetic polymorphisms and vascular indices did not improve the predictive accuracy of FRS-based models (P > 0·1 for all) for CAD presence or extent.

CONCLUSIONS

In these high-risk patients, 9p21 and 2q36 variants and PWV were independently associated with CAD presence and extent, but the addition of both genetic data and arterial stiffness indices to FRS did not improve the prediction of CAD compared with FRS alone. Further studies are needed to clarify the prognostic role of genetic and vascular indices in the prediction of angiographic CAD.