A 45-SNP genetic risk score is increased in early-onset coronary artery disease but independent of familial disease clustering

Risk Factors for Early-Onset Versus Late-Onset Coronary Heart Disease (CHD): Systematic Review and Meta-Analysis

AIM

We aimed to systematically compare literature on prevalence of modifiable and non-modifiable risk factors for early compared to late-onset coronary heart disease (CHD).

METHODS

PubMed, CINAHL, Embase, and Web of Science databases were searched (review protocol registered in PROSPERO CRD42020173216). Study quality was assessed using the National Heart, Lung and Blood Institute tool for observational and case-control studies. Review Manager 5.3 was used for meta-analysis. Effect sizes were expressed as odds ratio (OR) and mean differences (MD)/standardised MD (SMD) with 95% confidence intervals (CI) for categorical and continuous variables.

RESULTS

Individuals presenting with early-onset CHD (age <65 years) compared to late-onset CHD had higher mean body mass index (MD 1.07 kg/m2; 95% CI 0.31-1.83), total cholesterol (SMD 0.43; 95% CI 0.23-0.62), low-density lipoprotein (SMD 0.26; 95% CI 0.15-0.36) and triglycerides (SMD 0.50; 95% CI 0.22-0.68) with lower high-density lipoprotein-cholesterol (SMD 0.26; 95% CI -0.42--0.11). They were more likely to be smokers (OR 1.76, 95% CI 1.39-2.22) and have a positive family history of CHD (OR 2.08, 95% CI 1.74-2.48). They had lower mean systolic blood pressure (MD 4.07 mmHg; 95% CI -7.36--0.78) and were less likely to have hypertension (OR 0.47, 95% CI 0.39-0.57), diabetes mellitus (OR 0.56, 95% CI 0.51-0.61) or stroke (OR 0.31, 95% CI 0.24-0.42).

CONCLUSION

A focus on weight management and smoking cessation and aggressive management of dyslipidaemia in young adults may reduce the risk of early-onset CHD.

Genetic Risk Score for Coronary Heart Disease: Review

The present review deals with the stages of creation, methods of calculation, and the use of a genetic risk score for coronary heart disease in various populations. The concept of risk factors is generally recognized on the basis of the results of epidemiological studies in the 20th century; according to this concept, the high prevalence of diseases of the circulatory system is due to lifestyle characteristics and associated risk factors. An important and relevant task for the healthcare system is to identify the population segments most susceptible to cardiovascular diseases (CVDs). The level of individual risk of an unfavorable cardiovascular prognosis is determined by genetic factors in addition to lifestyle factors.

The ABO Locus is Associated with Increased Fibrin Network Formation in Patients with Stable Coronary Artery Disease

BACKGROUND

 The ABO locus has been associated with increased risk of myocardial infarction (MI) in patients with coronary artery disease (CAD), but the underlying mechanisms are unknown. As altered fibrin clot structure has been demonstrated to predict MI in CAD patients, we examined the association between the ABO risk variant and fibrin clot properties, and investigated the effects of other CAD-associated risk variants.

METHODS

 We included 773 stable CAD patients. Patients were genotyped for 45 genome-wide CAD risk variants, including rs495828 at the ABO locus. We used a genetic risk score (GRS) for CAD calculated as the weighted sum of the number of risk alleles based on all 45 variants. Fibrin clot properties were evaluated using a turbidimetric assay. We studied clot maximum absorbance, a measure of clot density and fiber thickness, together with clot lysis time, an indicator of fibrinolysis potential.

RESULTS

 The rs495828 risk allele was present in 13.2% of patients and associated with higher clot maximum absorbance (adjusted effect size per risk allele: 1.05 [1.01 - 1.09], p = 0.01) but not with clot lysis time (p = 0.97). The rs12936587 (p = 0.04), rs4773144 (p = 0.02), and rs501120 (p = 0.04) were associated with clot lysis time; however, after Bonferroni correction, no significant associations were found between any of the remaining 44 CAD-associated variants and fibrin clot properties. The GRS was not associated with fibrin clot properties (p-values > 0.05).

CONCLUSION

 The ABO risk allele was associated with a more compact fibrin network in stable CAD patients, which may represent a mechanism for increased MI risk in ABO risk variant carriers.

Genetic risk scores based on risk-associated single nucleotide polymorphisms can reveal inherited risk of bladder cancer in Chinese population

Genome-wide association studies have identified single nucleotide polymorphisms (SNPs) associated with bladder cancer (BCa) risk in Caucasian and East Asian population. The objective of this study was to validate these SNPs in Chinese population and evaluate whether these SNPs could differentiate the individual inherited risk for BCa.A case-control study including 581 BCa cases and 1561 healthy controls was performed. Germline DNA samples from all individuals were genotyped for eight SNPs. Genetic risk score (GRS) was calculated for each individual based on the odds ratios and risk allele frequencies of five risk-associated SNPs.Among eight SNPs evaluated in this study, rs798766 at 4p16.3 [OR = 1.39 (1.15-1.67), P < .001], rs9642880 [OR = 1.17 (1.06-1.30), P < .001] and rs4813953 at 20p12.2 [OR = 1.09 (1.02-1.17), P = .016] were found associated with BCa risk in Chinese population. A genetic risk score was established based on five SNPs (including the above three SNPs and two other SNPs which have the consistent direction with previous reported genome-wide association study). The mean GRS was significantly higher in BCa cases than controls (1.22 vs. 1.01, P < .001). When subjects were categorized into low- (<0.8), average- (0.8-1.2), and high-risk (>1.2) groups, the likelihoods of BCa were 25.2%, 33.7% and 55.0%, respectively (P-trend < 2.2 × 10). In subgroup analyses, no significant difference was observed in mean GRS among BCa patients with different stages or grades.In conclusion, two SNPs derived from East Asian and one SNP from Caucasian were associated with BCa risk in Chinese population. These results provided additional information of genetic risks for BCa in Chinese population. Genetic risk score based on these SNPs can reveal inherited risk of BCa, and may have potential for modifying personalized cancer screening strategy.

The ABO locus is associated with increased platelet aggregation in patients with stable coronary artery disease

BACKGROUND

Genome-wide association studies of patients with coronary artery disease (CAD) suggest that several risk loci increase the risk of CAD and myocardial infarction (MI) equally. In contrast, the ABO locus is stronger associated with MI than with CAD, but the underlying mechanisms are unknown.

PURPOSE

To investigate the association between the ABO risk variant and platelet activation and aggregation. Moreover, to explore the effects of other CAD-associated risk variants.

METHODS

We included 879 stable CAD patients receiving low-dose aspirin. All patients were genotyped for 45 genome-wide significant CAD risk variants, including rs495828 at the ABO locus. A genetic risk score (GRS) was calculated to assess the combined risk of all genetic variants. Serum soluble P-selectin (sP-selectin) and thromboxane B₂ were used as measures of platelet activation, and platelet aggregation was assessed by multiple electrode aggregometry (MEA) using arachidonic acid and collagen as agonists and VerifyNow.

RESULTS

The rs495828 CAD risk allele was associated with higher MEA platelet aggregation; arachidonic acid: 14.9% (6.7-23.7%, p = 0.0002) higher AUC (Area Under aggregation Curve) per risk allele, and collagen: 13.1% (5.8%-20.9%, p = 0.0003). Conversely, sP-selectin levels were 7.5% (3.1%-11.7%, p = 0.001) lower per risk allele. Rs495828 genotypes were not associated with aggregation assessed by VerifyNow (p = 0.30) or S-thromboxane B₂ levels (p = 0.98). None of the remaining variants or the GRS were associated with platelet activation or aggregation.

CONCLUSIONS

The ABO risk allele was associated with increased platelet aggregation as assessed by MEA. This finding may contribute to explain the increased MI risk in ABO risk variant carriers.

The SH2B3 and KCNK5 loci may be implicated in regulation of platelet count, volume, and maturity

INTRODUCTION

In recent genome-wide association studies, coronary artery disease (CAD) and myocardial infarction (MI) have been linked to a number of genetic variants, but their role in thrombopoiesis is largely unknown.

AIM

We investigated the association between CAD and MI-associated genetic variants and five thrombopoiesis-related indices: platelet count (PC), mean platelet volume (MPV), immature platelet count (IPC), immature platelet fraction (IPF), and serum thrombopoietin (TPO).

METHODS

We genotyped 45 genome-wide significant CAD/MI-markers in 879 stable CAD patients. A genetic risk score was calculated to assess the combined risk associated with all the genetic variants. Platelet indices were analysed using the Sysmex XE-2100 haematology analyser. TPO was measured by ELISA.

RESULTS

Two variants were nominally associated with several indices; for rs10947789 (KCNK5), the adjusted geometric mean was 2% higher for MPV (95% confidence interval: 1-2%, p=0.002), 6% for IPC (0-12%, p=0.033), and 9% for IPF (3-16%, p=0.004) per CAD risk allele. Moreover, an 11% lower TPO (3-19%, p=0.010) was observed. Rs3184504 (SH2B3) was associated with a higher adjusted geometric mean of 3% (1-6%, p=0.003) per CAD risk allele for PC, and an 11% (5-17%, p<0.001) lower TPO. Furthermore, the adjusted IPC was 5% (0-9%, p=0.037) lower per CAD risk allele for PC, whereas IPF levels did not vary across genotypes.

CONCLUSION

As a novel finding, our study suggests a role for KCNK5 in the regulation of platelet size and maturity. Furthermore, our findings confirm an association between the SH2B3-locus and platelet count.

Coronary artery disease-associated genetic variants and biomarkers of inflammation

INTRODUCTION

Genetic constitution and inflammation both contribute to development of coronary artery disease (CAD). Several CAD-associated single-nucleotide polymorphisms (SNPs) have recently been identified, but their functions are largely unknown. We investigated the associations between CAD-associated SNPs and five CAD-related inflammatory biomarkers.

METHODS

We genotyped 45 CAD-associated SNPs in 701 stable CAD patients in whom levels of high-sensitivity C-reactive protein (hsRCP), interleukin-6, calprotectin, fibrinogen and complement component 3 levels had previously been measured. A genetic risk score was calculated to assess the combined risk associated with all the genetic variants. A multiple linear regression model was used to assess associations between the genetic risk score, single SNPs, and the five inflammatory biomarkers.

RESULTS

The minor allele (G) (CAD risk allele) of rs2075650 (TOMM40/APOE) was associated with lower levels of high-sensitivity C-reactive protein (effect per risk allele: -0.37 mg/l [95%CI -0.56 to -0.18 mg/l]). The inflammatory markers tested showed no association with the remaining 44 SNPs or with the genetic risk score.

CONCLUSIONS

In stable CAD patients, the risk allele of a common CAD-associated marker at the TOMM40/APOE locus was associated with lower hsCRP levels. No other genetic variants or the combined effect of all variants were associated with the five inflammatory biomarkers.