The Asp298 allele of endothelial nitric oxide synthase is a risk factor for myocardial infarction among patients with type 2 diabetes mellitus

Precision prognostics for cardiovascular disease in Type 2 diabetes: a systematic review and meta-analysis

BACKGROUND

Precision medicine has the potential to improve cardiovascular disease (CVD) risk prediction in individuals with Type 2 diabetes (T2D).

METHODS

We conducted a systematic review and meta-analysis of longitudinal studies to identify potentially novel prognostic factors that may improve CVD risk prediction in T2D. Out of 9380 studies identified, 416 studies met inclusion criteria. Outcomes were reported for 321 biomarker studies, 48 genetic marker studies, and 47 risk score/model studies.

RESULTS

Out of all evaluated biomarkers, only 13 showed improvement in prediction performance. Results of pooled meta-analyses, non-pooled analyses, and assessments of improvement in prediction performance and risk of bias, yielded the highest predictive utility for N-terminal pro b-type natriuretic peptide (NT-proBNP) (high-evidence), troponin-T (TnT) (moderate-evidence), triglyceride-glucose (TyG) index (moderate-evidence), Genetic Risk Score for Coronary Heart Disease (GRS-CHD) (moderate-evidence); moderate predictive utility for coronary computed tomography angiography (low-evidence), single-photon emission computed tomography (low-evidence), pulse wave velocity (moderate-evidence); and low predictive utility for C-reactive protein (moderate-evidence), coronary artery calcium score (low-evidence), galectin-3 (low-evidence), troponin-I (low-evidence), carotid plaque (low-evidence), and growth differentiation factor-15 (low-evidence). Risk scores showed modest discrimination, with lower performance in populations different from the original development cohort.

CONCLUSIONS

Despite high interest in this topic, very few studies conducted rigorous analyses to demonstrate incremental predictive utility beyond established CVD risk factors for T2D. The most promising markers identified were NT-proBNP, TnT, TyG and GRS-CHD, with the highest strength of evidence for NT-proBNP. Further research is needed to determine their clinical utility in risk stratification and management of CVD in T2D.

Glu298Asp variant of the endothelial nitric oxide synthase gene and acute coronary syndrome or premature coronary artery disease: A systematic review and meta-analysis

INTRODUCTION

Several published studies have reported an association between the Glu298Asp polymorphism (rs1799983), residing in the endothelial nitric oxide synthase (NOS3) gene, and lower levels of circulating nitric oxide, as well as an increased risk of coronary artery disease (CAD). However, association status of this genetic variant with acute coronary syndrome (ACS) or premature CAD (PCAD) is still unclear. Against this background, we conducted a systematic review and study level meta-analysis to assess the association of the NOS3 Glu298Asp polymorphism with ACS or PCAD.

MATERIALS AND METHODS

A comprehensive online search to identify relevant studies was performed on several databases including PubMed, EMBASE, MEDLINE, Scopus, Cochrane library and Web of Science. The identified studies were stratified into two ancestral subgroups: 'European ancestry' and 'All other ancestries combined'. Study level odds ratios (ORs) and their 95% confidence intervals (CI) were pooled using random/fixed effects employing a Z test.

RESULTS

Out of a total of 195 distinct records identified through online search, 37 articles with 39 different studies, with a total sample size of 27,441 (11,516 cases/15,925 controls) were included for quantitative synthesis. Pooled results suggested significant associations of the NOS3 Glu298Asp polymorphism with ACS or PCAD through dominant as well as allelic genetic models (p ≤ 0.002), primarily driven by the 'All other ancestries combined' subgroup. The 'All other ancestries combined' subgroup demonstrated an additional risk of 36% for ACS or PCAD, through both dominant and allelic genetic models (OR = 1.36, 95%CI = 1.13, 1.63, p = 0.001 and OR = 1.36, 95%CI = 1.14, 1.61, p = 0.0005 respectively). On the other hand, the 'European ancestry' subgroup did not show any significant associations. Sensitivity analysis and a sub-analysis for the myocardial infarction endpoint further supported these observed associations.

CONCLUSIONS

This meta-analysis indicates towards an association between the NOS3 Glu298Asp polymorphism and ACS or PCAD, predominantly driven by 'All other ancestries combined' subgroup. In contrast, the 'European ancestry' subgroup did not demonstrate any significant association. Further large-scale investigations are required to confirm our derived results.

Precision Prognostics for Cardiovascular Disease in Type 2 Diabetes: A Systematic Review and Meta-analysis

Background Precision medicine has the potential to improve cardiovascular disease (CVD) risk prediction in individuals with type 2 diabetes (T2D). Methods We conducted a systematic review and meta-analysis of longitudinal studies to identify potentially novel prognostic factors that may improve CVD risk prediction in T2D. Out of 9380 studies identified, 416 studies met inclusion criteria. Outcomes were reported for 321 biomarker studies, 48 genetic marker studies, and 47 risk score/model studies. Results Out of all evaluated biomarkers, only 13 showed improvement in prediction performance. Results of pooled meta-analyses, non-pooled analyses, and assessments of improvement in prediction performance and risk of bias, yielded the highest predictive utility for N-terminal pro b-type natriuretic peptide (NT-proBNP) (high-evidence), troponin-T (TnT) (moderate-evidence), triglyceride-glucose (TyG) index (moderate-evidence), Genetic Risk Score for Coronary Heart Disease (GRS-CHD) (moderate-evidence); moderate predictive utility for coronary computed tomography angiography (low-evidence), single-photon emission computed tomography (low-evidence), pulse wave velocity (moderate-evidence); and low predictive utility for C-reactive protein (moderate-evidence), coronary artery calcium score (low-evidence), galectin-3 (low-evidence), troponin-I (low-evidence), carotid plaque (low-evidence), and growth differentiation factor-15 (low-evidence). Risk scores showed modest discrimination, with lower performance in populations different from the original development cohort. Conclusions Despite high interest in this topic, very few studies conducted rigorous analyses to demonstrate incremental predictive utility beyond established CVD risk factors for T2D. The most promising markers identified were NT-proBNP, TnT, TyG and GRS-CHD, with the highest strength of evidence for NT-proBNP. Further research is needed to determine their clinical utility in risk stratification and management of CVD in T2D.

Evaluation of Association Studies and Meta-Analyses of eNOS Polymorphisms in Type 2 Diabetes Mellitus Risk

Background: Numerous studies reported the associations between endothelial nitric oxide synthase (eNOS) polymorphisms (4b/a VNTR (rs869109213), G894T (rs1799983) and T786C (rs2070744)) and type 2 diabetes mellitus (T2DM) risk. However, the conclusions were incongruent. Moreover, since no published meta-analyses were performed, a key issue regarding false-positive results needs to be addressed. Furthermore, four new articles have been published on these issues. Therefore, an updated meta-analysis was conducted to further explore these associations.

Objectives: To investigate the association between eNOS 4b/a, G894T and T786C polymorphisms and T2DM risk.

Methods: Studies were searched by using the PubMed, China National Knowledge Infrastructure (CNKI), Medline, Embase, International Statistical Institute (ISI) and the China Wanfang databases. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the associations using five genetic models. Furthermore, the false-positive report probability (FPRP), Bayesian false discovery probability (BFDP), and the Venice criteria were employed to assess the credibility of statistically significant associations.

Results: Overall, the eNOS 4b/a polymorphism was associated with a significantly decreased T2DM risk in Asians (bb vs. aa: OR = 0.44, 95% CI = 0.23–0.84; ab + bb vs. aa: OR = 0.45, 95% CI = 0.24–0.86; bb vs. aa + ab: OR = 0.73, 95% CI = 0.59–0.91; b vs. a: OR = 0.71, 95% CI = 0.57–0.88); the eNOS G894T polymorphism was associated with a significantly increased T2DM risk in Asians (GT vs. GG: OR = 1.52, 95% CI = 1.15–2.01; GT + TT vs. GG: OR = 1.52, 95% CI = 1.15–2.01; T vs. G: OR = 1.39, 95% CI = 1.09–1.76); the eNOS T786C polymorphism was associated with a significantly increased T2DM risk in Indian (TC vs. TT: OR = 1.93, 95% CI = 1.27–2.94; TC + CC vs. TT: OR = 2.06, 95%CI = 1.26–3.36; C vs. T: OR = 1.90, 95%CI = 1.17–3.08). However, when a sensitivity analysis was performed after excluding low quality and Hardy–Weinberg Disequilibrium (HWD) studies, no significant association was found for the eNOS G894T polymorphism. After credibility assessment, we identified “less-credible positive results” for the statistically significant associations in the current meta-analysis.

Conclusion: In conclusion, this article suggests that all substantial relationships between eNOS 4b/a, G894T, and T786C polymorphisms and T2DM risk are most likely due to false positive results rather than real connections or biological variables.

NOS3 rs1799983 and rs2070744 polymorphisms and their association with advanced chronic kidney disease and coronary heart disease in Canarian population with type 2 diabetes

CONTEXT

Different polymorphisms of the endothelial nitric oxide synthase gene (NOS3) have been related to diabetic kidney disease.

OBJECTIVE

To evaluate the association between advanced diabetic chronic kidney disease (ACKD) and the rs1799983 and rs2070744 poymorphisms of NOS3 in a population from the Gran Canaria island.

DESIGN

Cross-sectional case-control study.

SUBJECTS AND METHODS

Polymorphisms were genotyped in 152 subjects with ACKD secondary to type 2 diabetes [estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m²], 110 subjects with type 2 diabetes for 20 or more years since diagnosis without ACKD (eGFR ≥45 mL/min/1.73m² and albumin/creatinine ratio <300 mg/g and/or 24-h urinary albumin excretion <300 mg) and 292 healthy controls. Association between both polymorphisms and established coronary heart disease (CHD) was also analyzed in both groups with diabetes.

RESULTS

A greater proportion of homozygous individuals for the risk allele C of rs2070744 was found among subjects with ACKD. Association between ACKD and rs2070744 was observed in a recessive genetic model, both for comparison to subjects with diabetes but no ACKD [OR 2.17 (95% CI: 1.17-4.00), p=0.014] and for comparison to healthy controls [OR 1.61 (1.03-2.52), p=0.036]. The frequency of the C allele was significantly higher among subjects with CHD, but only in the group with ACKD. No associations were found for rs1799983.

CONCLUSIONS

NOS3 rs2070744 is associated with ACKD in population with type 2 diabetes from Gran Canaria. A link between this genetic variant and CHD in Canarian subjects with type 2 diabetes could be restricted to cases with ACKD.

T2DiACoD: A Gene Atlas of Type 2 Diabetes Mellitus Associated Complex Disorders

We performed integrative analysis of genes associated with type 2 Diabetes Mellitus (T2DM) associated complications by automated text mining with manual curation and also gene expression analysis from Gene Expression Omnibus. They were analysed for pathogenic or protective role, trends, interaction with risk factors, Gene Ontology enrichment and tissue wise differential expression. The database T2DiACoD houses 650 genes, and 34 microRNAs associated with T2DM complications. Seven genes AGER, TNFRSF11B, CRK, PON1, ADIPOQ, CRP and NOS3 are associated with all 5 complications. Several genes are studied in multiple years in all complications with high proportion in cardiovascular (75.8%) and atherosclerosis (51.3%). T2DM Patients' skeletal muscle tissues showed high fold change in differentially expressed genes. Among the differentially expressed genes, VEGFA is associated with several complications of T2DM. A few genes ACE2, ADCYAP1, HDAC4, NCF1, NFE2L2, OSM, SMAD1, TGFB1, BDNF, SYVN1, TXNIP, CD36, CYP2J2, NLRP3 with details of protective role are catalogued. Obesity is clearly a dominant risk factor interacting with the genes of T2DM complications followed by inflammation, diet and stress to variable extents. This information emerging from the integrative approach used in this work could benefit further therapeutic approaches. The T2DiACoD is available at www.http://t2diacod.igib.res.in/ .

Post-operative endothelial dysfunction assessment using laser Doppler perfusion measurement in cardiac surgery patients

BACKGROUND

Coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB) is associated with systemic inflammatory response and endothelial dysfunction. Our hypothesis is that CPB-induced post-operative endothelial dysfunction may be detected using laser Doppler perfusion monitoring (LDPM) in the skin microcirculation.

METHODS

We used LDPM to investigate the subacute effects of the CPB on systemic microvascular reactivity among patients undergoing CABG surgery with CPB. Thirty patients were submitted to the study of skin microcirculation and blood sample collection at baseline (pre-surgery) and at 7 days post-surgical procedure. The skin microcirculation was evaluated by acetylcholine (ACh) and sodium nitroprusside (SNP) iontophoresis, and thermal hyperemia (TH). Plasma levels of nitrite/nitrate were also analyzed, and cytokine profiles were determined using a multiplex system.

RESULTS

On-pump CABG surgery induced a significant reduction of the increased microvascular dermal flux observed after cumulative doses of ACh iontophoresis and after TH. On-pump CABG surgery did not induce any significant changes in the microvascular flux after cumulative doses of SNP. Patients still presented high levels of interleukin (IL)-6, IL-8, and C-reactive protein, and low bioavailability of nitric oxide 7 days after the CABG surgery with CPB.

CONCLUSION

We observed a significant impairment of systemic microvascular endothelial function and well-preserved endothelium-independent vasodilatation in the skin microcirculation of patients 1 week after CABG surgery with CPB. Our results suggest that LDPM is a useful tool for the assessment of on-pump CABG-induced subacute post-operative endothelial dysfunctions.

Endothelial nitric oxide synthase gene G894T polymorphism and myocardial infarction: a meta-analysis of 34 studies involving 21,068 subjects

Background

Researches have revealed that the endothelial nitric oxide synthase (eNOS) gene G894T polymorphism is associated with the risk of Myocardial infarction (MI), but the results remain conflicting.

Objective and Methods

A meta-analysis was conducted to investigate the association between eNOS G894T polymorphism and MI. Published studies from PubMed, Embase, CNKI and CBM databases were retrieved. The pooled odds ratios (ORs) for the association between eNOS G894T polymorphism and MI and their corresponding 95% confidence intervals (CIs) were estimated using the random- or fixed- effect model.

Results

A total of 34 studies including 8229 cases and 12839 controls were identified for the meta-analysis. The eNOS G894T polymorphism was significantly associated with MI under a homozygous genetic model (OR = 1.41, 95% CI = 1.08–1.84; P = 0.012), a recessive genetic model (OR = 1.35, 95% CI = 1.06–1.70; P = 0.014), a dominant genetic model (OR = 1.18, 95% CI = 1.04–1.34; P = 0.009). In the subgroup analysis by ethnicity (non-Asian and Asian), no significant association was observed between eNOS G894T polymorphism and MI risk among non-Asians (P>0.05), but a positive significant association was found among Asians (P<0.05).

Conclusions

The eNOS G894T polymorphism is associated with increased MI risk in Asians. The results indicate that ethnicity plays important roles in the association between eNOS G894T polymorphism and MI.

Glu298Asp polymorphism influences the beneficial effects of fish oil fatty acids on postprandial vascular function

Our objective was to determine whether the endothelial nitric oxide synthase (eNOS) Glu298Asp polymorphism influences vascular response to raised NEFA enriched with saturated fatty acids (SFA) or long-chain (LC) n-3 polyunsaturated fatty acids (PUFA). Subjects were prospectively recruited for genotype (Glu298, n = 30 and Asp298, n = 29; balanced for age and gender) consumed SFA on two occasions, with and without the substitution of 0.07 g fat/kg body weight with LC n-3 PUFA, and with heparin infusion to elevate NEFA. Endothelial function was measured before and after NEFA elevation (240 min), with blood samples taken every 30 min. Flow-mediated dilation (FMD) decreased following SFA alone and increased following SFA+LC n-3 PUFA. There were 2-fold differences in the change in FMD response to the different fat loads between the Asp298 and Glu298 genotypes (P = 0.002) and between genders (P < 0.02). Sodium nitroprusside-induced reactivity, measured by laser Doppler imaging with iontophoresis, was significantly greater with SFA+LC n-3 PUFA in all female subjects (P < 0.001) but not in males. Elevated NEFA influences both endothelial-dependent and endothelial-independent vasodilation during the postprandial phase. Effects of fat composition appear to be genotype and gender dependent, with the greatest difference in vasodilatory response to the two fat loads seen in the Asp298 females.

Association of Endothelial Nitric Oxide Synthase Gene Variant (G894T) With Coronary Artery Disease in Western Iran

There are conflicting reports about the association of endothelial nitric oxide synthase (eNOS) gene polymorphism and the risk of coronary artery disease (CAD). To determine the frequency of eNOS G894T variant and to find the possible association between this polymorphism with CAD we studied 207 unrelated patients with total CAD (with and without diabetes) and 92 controls. The eNOS variants were detected by polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP). The presence of GT + TT genotype was associated with 2.1-fold ( P = .006), 2.29-fold ( P = .006), and 1.93-fold ( P = .032) increased risk of CAD in total CAD, CAD with diabetes, and in CAD without diabetes patients, respectively. The presence of T allele of eNOS increased the risk of CAD 2.15-fold ( P = .001). The levels of low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) tended to be higher in patients carrier for T allele compared to those with G allele. The results of present study revealed that eNOS G894T polymorphism is associated with increased risk of CAD in our population.

Interaction of eNOS polymorphism with MTHFR variants increase the risk of diabetic nephropathy and its progression in type 2 diabetes mellitus patients

The present study has investigated the role of endothelial nitric oxide (eNOS) G894T polymorphism and its interaction with methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C variants on the predisposition to diabetic nephropathy and its progression. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method the eNOS G894T and MTHFR polymorphisms were detected in 72 microalbuminuric, 68 macroalbuminuric, and 72 normoalbuinuric type 2 diabetes mellitus (T2DM) patients from Western Iran. The presence of GT and GT + TT genotypes of eNOS were associated with insignificantly 1.86- and 1.68-fold increased risk of macroalbuminuria, respectively and 1.21- and 1.13-fold increased risk of microalbuminuria, respectively. However, the concomitant presence of eNOST and MTHFR 1298C alleles were significantly increased the risk of macroalbuminuria (6.6-fold, P < 0.001) and progression from micro- to macro-albuminuria (3.85 times, P = 0.011). Also, the presence of both alleles of eNOST and MTHFR 677T were significantly associated with increased risk of macroalbuminuria (4.8-fold, P = 0.005). The presence of GT + TT genotypes of eNOS was significantly associated with increased risk of coronary artery disease in micro- and macro-albuminuric patients compared to normoalbuminuric patients. The concomitant presence of three mutant alleles significantly increased the risk of macroalbuminuria and progression from micro- to macro-albuminuria 38.5- and 10.5-fold, respectively. Our study indicated that eNOS T allele interacts with MTHFR variants, especially MTHFR A1298C to increase the risk of macroalbuminuria and progression from micro-to macro-albuminuria. Also, Interaction between three alleles of eNOST, MTHFR 677T, and 1298C highly increased the risk of macroalbuminuria and progression of diabetic nephropathy in T2DM patients.

The genetics of vascular complications in diabetes mellitus

Prospective identification of which individuals with diabetes mellitus (DM) are at greatest risk for developing cardiovascular disease (CVD) complications would have considerable public health importance by allowing the allocation of limited resources to be focused on those individuals who would most benefit from aggressive intervention. Over the past 20 years genetic disease association studies have demonstrated that polymorphisms at specific genetic loci may identify those individuals at greatest risk for developing CVD in the setting of DM. This article reviews the evidence accumulated to date on four polymorphic loci with the aim of explaining how these polymorphisms modify the risk for CVD in DM by modifying the functional activity of a specific gene. Use of the knowledge of these genetic differences among individuals in targeting drug therapy (pharmacogenomics) is also discussed.